/*
 *	PROGRAM:	JRD Command Oriented Query Language
 *	MODULE:		meta.epp
 *	DESCRIPTION:	Meta-data interface
 *
 * The contents of this file are subject to the Interbase Public
 * License Version 1.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy
 * of the License at http://www.Inprise.com/IPL.html
 *
 * Software distributed under the License is distributed on an
 * "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
 * or implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code was created by Inprise Corporation
 * and its predecessors. Portions created by Inprise Corporation are
 * Copyright (C) Inprise Corporation.
 *
 * All Rights Reserved.
 * Contributor(s): ______________________________________.
 */

#include "firebird.h"
#include "dyn_consts.h"
#include <stdio.h>
#include <string.h>
#include "../qli/dtr.h"
#include "../qli/compile.h"
#include "../qli/exe.h"
#include "../jrd/flags.h"
#include "ibase.h"
#include "../qli/reqs.h"
#include "../qli/all_proto.h"
#include "../qli/err_proto.h"
#include "../qli/gener_proto.h"
#include "../qli/hsh_proto.h"
#include "../qli/meta_proto.h"
#include "../common/prett_proto.h"
#include "../yvalve/gds_proto.h"
#include "../common/isc_f_proto.h"
#include "../yvalve/utl_proto.h"
#include "../common/utils_proto.h"
#include "../common/classes/ClumpletWriter.h"
#include "../common/classes/UserBlob.h"

using MsgFormat::SafeArg;


#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

DATABASE DB = FILENAME "yachts.lnk";
DATABASE DB1 = FILENAME "yachts.lnk";

static void add_field(qli_rel*, qli_fld*, USHORT);
static void add_sql_field(qli_rel*, qli_fld*, USHORT, qli_rlb*);
static void blob_copy(qli_rlb*, qli_rel*, ISC_QUAD&);
static void change_field(qli_rel*, qli_fld*);
static bool check_global_field(qli_dbb*, qli_fld*, const TEXT*);
static bool check_relation(qli_rel*);
static void clone_fields(qli_rel*, qli_rel*);
static void clone_global_fields(qli_rel*, qli_rel*);
static void define_global_field(qli_dbb*, qli_fld*, qli_symbol*);
static void delete_fields(qli_rel*);
static ISC_STATUS detach(ISC_STATUS *, qli_dbb*);
static void execute_dynamic_ddl(qli_dbb*, qli_rlb*);
static int field_length(USHORT, USHORT);
static void get_database_type(qli_dbb*);
static TEXT* get_query_header(qli_dbb*, ISC_QUAD&);
static void install(qli_dbb*);
static qli_syntax* make_node(nod_t, USHORT);
static TEXT* make_string(TEXT*, SSHORT);
static qli_symbol* make_symbol(TEXT*, SSHORT);
static qli_const* missing_value(ISC_QUAD&, qli_symbol*);
static qli_syntax* parse_blr(UCHAR**, qli_symbol*);
static qli_syntax* parse_blr_blob(ISC_QUAD&, qli_symbol*);
static void purge_relation(qli_rel*);
static void put_dyn_string(qli_rlb*, const TEXT*);
static void release_request(qli_dbb* db, FB_API_HANDLE& request_handle);
static void rollback_update(qli_dbb*);
static void set_capabilities(qli_dbb*);
static qli_dbb* setup_update(qli_dbb*);
static void sql_grant_revoke(qli_syntax*, USHORT);
static void stuff_priv(qli_rlb*, USHORT, const TEXT*, USHORT, const TEXT*, const TEXT*);
static int truncate_string(TEXT*);

static const UCHAR tpb[] = { isc_tpb_version1, isc_tpb_write };
static const UCHAR db_info[] = { isc_info_implementation, isc_info_end };
static UCHAR global_parm_buffer[256];

// static const UCHAR	dpb_trace [] =	{ isc_dpb_version1, isc_dpb_trace, 1, 1 };
// static const UCHAR	dpb_num_buffers [ ] = { isc_dpb_version1, isc_dpb_num_buffers, 1, 1 };


#define STUFF_STRING(str)	put_dyn_string (rlb, str)
#define BLR_BYTE	*blr++

static const USHORT blr_dtypes[] =
{
	0,
	blr_text,
	blr_text,
	blr_varying,
	0,
	0,
	0,
	0,
	blr_short,
	blr_long,
	blr_quad,
	blr_float,
	blr_double,
	blr_double,
	blr_sql_date,
	blr_sql_time,
	blr_timestamp,
	blr_blob,
	0,
	blr_int64
};


// table used to determine capabilities, checking for specific
// fields in system relations

struct rfr_tab_t
{
	const TEXT* relation;
	const TEXT* field;
	int bit_mask;
};

static const rfr_tab_t rfr_table[] =
{
	{ "RDB$INDICES", "RDB$INDEX_INACTIVE", DBB_cap_idx_inactive },
	// OBSOLETE - 1996-Aug-06 David Schnepper
	//{ "RDB$RELATIONS",	"RDB$STORE_TRIGGER",	DBB_cap_triggers },
	{ "RDB$RELATIONS", "RDB$EXTERNAL_FILE", DBB_cap_extern_file },
	{ "RDB$SECURITY_CLASSES", "RDB$SECURITY_CLASS", DBB_cap_security },
	{ "RDB$FILES", "RDB$FILE_NAME", DBB_cap_files },
	{ "RDB$FUNCTIONS", "RDB$FUNCTION_NAME", DBB_cap_functions },
	{ "RDB$TRIGGERS", "RDB$TRIGGER_BLR", DBB_cap_new_triggers },
	{ "RDB$CONSTRAINTS", "RDB$CONSTRAINT_NAME", DBB_cap_single_trans },
	{ "RDB$FILES", "RDB$SHADOW_NUMBER", DBB_cap_shadowing },
	{ "RDB$TYPES", "RDB$TYPE_NAME", DBB_cap_types },
	{ "RDB$FIELDS", "RDB$DIMENSIONS", DBB_cap_dimensions },
//	{ "RDB$FIELDS", "RDB$EXTERNAL_TYPE", DBB_cap_external_type }, Unused
	{ "RDB$RELATION_FIELDS", "RDB$SYSTEM_FLAG", DBB_cap_rfr_sys_flag },
	{ "RDB$FILTERS", "RDB$FUNCTION_NAME", DBB_cap_filters },
	{ "RDB$INDICES", "RDB$INDEX_TYPE", DBB_cap_index_type },
	{ "RDB$PROCEDURES", "RDB$ENGINE_NAME", DBB_cap_nodyn },		// FB3.0
	{ 0, 0, 0 }
};


bool MET_declare( qli_dbb* database, qli_fld* variable, const qli_name* field_name)
{
/**************************************
 *
 *	M E T _ d e c l a r e
 *
 **************************************
 *
 * Functional description
 *	Find a global field referenced in a DECLARE.
 *
 **************************************/

	if (!database)
		database = QLI_databases;

	for (; database; database = database->dbb_next)
	{
		MET_meta_transaction(database, false);
		if (check_global_field(database, variable, field_name->nam_string))
			return true;
	}

	return false;
}


void MET_define_field( qli_dbb* database, qli_fld* field)
{
/**************************************
 *
 *	M E T _ d e f i n e _ f i e l d
 *
 **************************************
 *
 * Functional description
 *	Define a new global field.
 *
 **************************************/

	database = setup_update(database);

	if (check_global_field(database, NULL, field->fld_name->sym_string))
	{
		rollback_update(database);
		ERRQ_print_error(233, field->fld_name->sym_string);
		// Msg233 global field %s already exists
	}

	define_global_field(database, field, field->fld_name);

	MET_meta_commit(database);
}


void MET_define_index( qli_syntax* node)
{
/**************************************
 *
 *	M E T _ d e f i n e _ i n d e x
 *
 **************************************
 *
 * Functional description
 *	Define a new index.
 *
 **************************************/
	qli_symbol* symbol = (qli_symbol*) node->syn_arg[s_dfi_name];
	qli_rel* relation = (qli_rel*) node->syn_arg[s_dfi_relation];
	qli_syntax* fields = node->syn_arg[s_dfi_fields];
	qli_dbb* database = setup_update(relation->rel_database);

	if (relation->rel_flags & REL_view)
		IBERROR(234);			// Msg234 Can't define an index in a view

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_def_index1])
		X IN DB.RDB$INDICES WITH X.RDB$INDEX_NAME EQ symbol->sym_string
			ERRQ_print_error(235, symbol->sym_string);
			// Msg235 Index %s already exists
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	STORE(REQUEST_HANDLE database->dbb_requests[REQ_def_index2])
		X IN DB.RDB$INDICES

		strcpy(X.RDB$RELATION_NAME, relation->rel_symbol->sym_string);
		strcpy(X.RDB$INDEX_NAME, symbol->sym_string);
		X.RDB$UNIQUE_FLAG = (node->syn_flags & s_dfi_flag_unique);
		X.RDB$INDEX_INACTIVE = (node->syn_flags & s_dfi_flag_inactive) ? TRUE : FALSE;
		X.RDB$SEGMENT_COUNT = fields->syn_count;
		X.RDB$INDEX_TYPE = (node->syn_flags & s_dfi_flag_descending) ? TRUE : FALSE;
	END_STORE
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	// at this point force garbage collection of any index segments left over
	// from previous failures.  The system transaction (which might notice them
	// later does NOT recognize rolled back stuff!  Should someone have actually
	// left an orphanned segment around, kill that too.

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_scan_index])
		X IN DB.RDB$INDEX_SEGMENTS WITH X.RDB$INDEX_NAME = symbol->sym_string
			ERASE X
		ON_ERROR
			rollback_update(database);
			ERRQ_database_error(database, gds_status);
		END_ERROR;
	END_FOR
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	qli_name** ptr = (qli_name**) fields->syn_arg;
	for (int position = 0; position < fields->syn_count; ptr++, position++)
	{
		MET_fields(relation);

		bool present = false;
		for (qli_fld* field = relation->rel_fields; field; field = field->fld_next)
		{
			if (!(strcmp((*ptr)->nam_string, field->fld_name->sym_string)))
			{
				present = true;
				break;
			}
		}

		if (!present)
		{
			rollback_update(database);
			ERRQ_print_error(236, SafeArg() << (*ptr)->nam_string <<
								relation->rel_symbol->sym_string);
			// Msg236 Field %s does not occur in relation %s
		}

		setup_update(database);

		STORE(REQUEST_HANDLE database->dbb_requests[REQ_def_index3])
			X IN DB.RDB$INDEX_SEGMENTS

			strcpy(X.RDB$INDEX_NAME, symbol->sym_string);
			strcpy(X.RDB$FIELD_NAME, (*ptr)->nam_string);
			X.RDB$FIELD_POSITION = position;
		END_STORE
		ON_ERROR
			rollback_update(database);
			ERRQ_database_error(database, gds_status);
		END_ERROR;
	}

	MET_meta_commit(database);
}


void MET_define_relation( qli_rel* relation, qli_rel* source)
{
/**************************************
 *
 *	M E T _ d e f i n e _ r e l a t i o n
 *
 **************************************
 *
 * Functional description
 *	Define a new relation.   There may
 *	be field definitions here or we may
 *	copy the field definitions from somebody
 *	else.
 *
 **************************************/
	qli_symbol* symbol = relation->rel_symbol;

	if (source)
	{
		source->rel_database = setup_update(source->rel_database);
		if (!(check_relation(source)))
			ERRQ_print_error(483, source->rel_symbol->sym_string);
			// Msg 483 Relation %s does not exist
	}

	qli_dbb* database = setup_update(relation->rel_database);
	relation->rel_database = database;

	if (check_relation(relation))
		ERRQ_print_error(237, symbol->sym_string);	// Msg237 Relation %s already exists

	STORE(REQUEST_HANDLE database->dbb_requests[REQ_store_relation])
		X IN DB.RDB$RELATIONS
		strcpy(X.RDB$RELATION_NAME, symbol->sym_string);
	END_STORE
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	if (source)
		clone_fields(relation, source);
	else
	{
		USHORT position = 1;
		for (qli_fld* field = relation->rel_fields; field; field = field->fld_next, position++)
		{
			add_field(relation, field, position);
		}
	}

	MET_meta_commit(database);

	relation = (qli_rel*) ALLOCP(type_rel);
	relation->rel_next = database->dbb_relations;
	database->dbb_relations = relation;
	relation->rel_database = database;

	// Go back and pick up relation id

	setup_update(database);

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_relation_id])
		X IN DB.RDB$RELATIONS WITH X.RDB$RELATION_NAME EQ symbol->sym_string
		relation->rel_id = X.RDB$RELATION_ID;
		symbol = make_symbol(X.RDB$RELATION_NAME, sizeof(X.RDB$RELATION_NAME));
		symbol->sym_type = SYM_relation;
		symbol->sym_object = (BLK) relation;
		relation->rel_symbol = symbol;
		HSH_insert(symbol);
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	delete_fields(relation);
	MET_fields(relation);
}


void MET_define_sql_relation( qli_rel* relation)
{
/**************************************
 *
 *	M E T _ d e f i n e _ s q l _ r e l a t i o n
 *
 **************************************
 *
 * Functional description
 *	Define a new SQL relation, using dynamic ddl.
 *
 **************************************/
	qli_symbol* symbol = relation->rel_symbol;
	qli_dbb* database = setup_update(relation->rel_database);
	relation->rel_database = database;

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_relation_def])
		X IN DB.RDB$RELATIONS WITH X.RDB$RELATION_NAME EQ symbol->sym_string
			ERRQ_print_error(237, symbol->sym_string);
			// Msg237 Relation %s already exists
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	qli_rlb* rlb = NULL;
	CHECK_RLB(rlb);

	STUFF(isc_dyn_version_1);
	STUFF(isc_dyn_begin);
	STUFF(isc_dyn_def_rel);
	STUFF_STRING(symbol->sym_string);
	STUFF(isc_dyn_rel_sql_protection);
	STUFF_WORD(2);
	STUFF_WORD(1);

    USHORT position = 1;
	for (qli_fld* field = relation->rel_fields; field; field = field->fld_next, position++)
	{
		add_sql_field(relation, field, position, rlb);
	}

	STUFF(isc_dyn_end);
	STUFF(isc_dyn_end);
	STUFF(isc_dyn_eoc);

	execute_dynamic_ddl(database, rlb);
	MET_meta_commit(database);

	relation = (qli_rel*) ALLOCP(type_rel);
	relation->rel_next = database->dbb_relations;
	database->dbb_relations = relation;
	relation->rel_database = database;

	// Go back and pick up relation id

	setup_update(database);

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_relation_id])
		X IN DB.RDB$RELATIONS WITH X.RDB$RELATION_NAME EQ symbol->sym_string
		relation->rel_id = X.RDB$RELATION_ID;
		symbol = make_symbol(X.RDB$RELATION_NAME, sizeof(X.RDB$RELATION_NAME));
		symbol->sym_type = SYM_relation;
		symbol->sym_object = (BLK) relation;
		relation->rel_symbol = symbol;
		HSH_insert(symbol);
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	delete_fields(relation);
	MET_fields(relation);
}


void MET_delete_database( qli_dbb* dbb)
{
/**************************************
 *
 *	M E T _ d e l e t e _ d a t a b a s e
 *
 **************************************
 *
 * Functional description
 *	Drop an existing database, and all its files,
 *	and finish any copies we have active.
 *
 **************************************/

	// generate a database parameter block to include the user/password, if necessary

	const TEXT* user;
	USHORT user_length;
	if (dbb->dbb_user)
	{
		user = (TEXT*) dbb->dbb_user->con_data;
		user_length = dbb->dbb_user->con_desc.dsc_length;
	}
	else
	{
		user = QLI_default_user;
		user_length = static_cast<USHORT>(strlen(QLI_default_user));
	}

	const TEXT* password;
	USHORT password_length;
	if (dbb->dbb_password)
	{
		password = (TEXT*) dbb->dbb_password->con_data;
		password_length = dbb->dbb_user->con_desc.dsc_length;
	}
	else
	{
		password = QLI_default_password;
		password_length = static_cast<USHORT>(strlen(QLI_default_password));
	}

	Firebird::ClumpletWriter dpb(Firebird::ClumpletReader::dpbList, MAX_DPB_SIZE);
	if (user_length)
	{
		dpb.insertString(isc_dpb_user_name, user, user_length);
	}
	if (password_length)
	{
		dpb.insertString(isc_dpb_password, password, password_length);
	}

	ISC_STATUS_ARRAY status_vector;
	if (isc_attach_database(status_vector, 0, dbb->dbb_filename,
							&dbb->dbb_handle, dpb.getBufferLength(),
							reinterpret_cast<const char*>(dpb.getBuffer())))
	{
		ERRQ_database_error(dbb, status_vector);
	}

	qli_lls* stack = NULL;

	gds_trans = MET_transaction(nod_start_trans, dbb);
	DB = dbb->dbb_handle;

	FOR F IN DB.RDB$FILES SORTED BY F.RDB$FILE_START
		qli_str* astring = (qli_str*) ALLOCDV(type_str, static_cast<int>(strlen(F.RDB$FILE_NAME)));
		strcpy(astring->str_data, F.RDB$FILE_NAME);
		ALLQ_push((blk*) astring, &stack);
	END_FOR
	ON_ERROR
		ERRQ_database_error(dbb, gds_status);
	END_ERROR;

	MET_transaction(nod_commit, dbb);

	if (isc_detach_database(gds_status, &dbb->dbb_handle))
		isc_print_status(gds_status);

	qli_dbb* next = NULL;
	for (qli_dbb* database = QLI_databases; database; database = next)
	{
		next = database->dbb_next;
		if (!strcmp(database->dbb_filename, dbb->dbb_filename))
			MET_finish(database);
	}

	while (stack)
	{
		qli_str* sstring = (qli_str*) ALLQ_pop(&stack);
		if (unlink(sstring->str_data))
			ERRQ_print_error(431, sstring->str_data);
			// Msg431 Could not drop database file "%s"
	}

	if (unlink(dbb->dbb_filename))
		ERRQ_print_error(431, dbb->dbb_filename);
		// Msg431 Could not drop database file "%s"
}


void MET_delete_field( qli_dbb* database, qli_name* name)
{
/**************************************
 *
 *	M E T _ d e l e t e _ f i e l d
 *
 **************************************
 *
 * Functional description
 *	Delete a global field.
 *
 **************************************/
	database = setup_update(database);
	USHORT count = 0;

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_check_fld])
		RFR IN DB.RDB$RELATION_FIELDS
		WITH RFR.RDB$FIELD_SOURCE EQ name->nam_string
		REDUCED TO RFR.RDB$RELATION_NAME
		if (!count)
			ERRQ_msg_put(238, name->nam_string);	// Msg238 Field %s is in use in the following relations:
		printf("\t%s\n", RFR.RDB$RELATION_NAME);
		count++;
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	if (count)
		ERRQ_print_error(239, SafeArg() << name->nam_string << database->dbb_filename);
		// Msg239 Field %s is in use in database %s

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_erase_fld])
		FLD IN DB.RDB$FIELDS WITH FLD.RDB$FIELD_NAME EQ name->nam_string

		qli_rlb* rlb = NULL;
		CHECK_RLB(rlb);
		STUFF(isc_dyn_version_1);
		STUFF(isc_dyn_delete_dimensions);
		STUFF_STRING(FLD.RDB$FIELD_NAME);
		STUFF(isc_dyn_end);
		STUFF(isc_dyn_eoc);
		execute_dynamic_ddl(database, rlb);
		ERASE FLD
		ON_ERROR
			rollback_update(database);
			ERRQ_database_error(database, gds_status);
		END_ERROR;
		count++;
	END_FOR
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	if (!count)
		ERRQ_print_error(240, SafeArg() << name->nam_string << database->dbb_filename);
		// Msg240 Field %s is not defined in database %s

	MET_meta_commit(database);
}


void MET_delete_index( qli_dbb* database, qli_name* name)
{
/**************************************
 *
 *	M E T _ d e l e t e _ i n d e x
 *
 **************************************
 *
 * Functional description
 *	Delete an index.
 *
 **************************************/
	database = setup_update(database);
	USHORT count = 0;

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_erase_index])
		IDX IN DB.RDB$INDICES WITH IDX.RDB$INDEX_NAME EQ name->nam_string
			count++;
		ERASE IDX
		ON_ERROR
			rollback_update(database);
			ERRQ_database_error(database, gds_status);
		END_ERROR;
	END_FOR
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	if (!count)
		ERRQ_print_error(241, SafeArg() << name->nam_string << database->dbb_filename);
		// Msg241 Index %s is not defined in database %s

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_erase_segments])
		SEG IN DB.RDB$INDEX_SEGMENTS WITH SEG.RDB$INDEX_NAME EQ name->nam_string
		ERASE SEG
		ON_ERROR
			rollback_update(database);
			ERRQ_database_error(database, gds_status);
		END_ERROR;
	END_FOR
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	MET_meta_commit(database);
}


void MET_delete_relation( qli_rel* relation)
{
/**************************************
 *
 *	M E T _ d e l e t e _ r e l a t i o n
 *
 **************************************
 *
 * Functional description
 *	Delete a relation.
 *
 **************************************/
	// Pass the mess off to dynamic DDL and let it worry

	qli_symbol* symbol = relation->rel_symbol;
	qli_rlb* rlb = NULL;
	CHECK_RLB(rlb);
	STUFF(isc_dyn_version_1);
	STUFF(isc_dyn_delete_rel);
	STUFF_STRING(symbol->sym_string);
	STUFF(isc_dyn_end);
	STUFF(isc_dyn_eoc);
	setup_update(relation->rel_database);

	execute_dynamic_ddl(relation->rel_database, rlb);
	MET_meta_commit(relation->rel_database);

	// Unlink and release various blocks

	purge_relation(relation);
}


int MET_dimensions( qli_dbb* database, const TEXT* field_name)
{
/**************************************
 *
 *	M E T _ d i m e n s i o n s
 *
 **************************************
 *
 * Functional description
 *	Determine if the field has any dimensions.
 *
 **************************************/
	if (!(database->dbb_capabilities & DBB_cap_dimensions))
		return 0;

	USHORT dimensions = 0;

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_fld_dimensions])
		F IN DB.RDB$FIELDS WITH F.RDB$FIELD_NAME = field_name
			dimensions = F.RDB$DIMENSIONS;
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	return dimensions;
}


void MET_fields( qli_rel* relation)
{
/**************************************
 *
 *	M E T _ f i e l d s
 *
 **************************************
 *
 * Functional description
 *	Get all fields for a relation.
 *
 **************************************/

	// If we already have fetched the fields for the relation, don't do it again.

	if (relation->rel_flags & REL_fields)
		return;

	qli_dbb* database = relation->rel_database;
	MET_meta_transaction(database, false);
	relation->rel_flags |= REL_fields;
	qli_fld** ptr = &relation->rel_fields;

	FOR(REQUEST_HANDLE database->dbb_field_request)
		RFR IN DB.RDB$RELATION_FIELDS CROSS
			RFL IN DB.RDB$FIELDS WITH
			RFR.RDB$FIELD_SOURCE EQ RFL.RDB$FIELD_NAME AND
			RFR.RDB$RELATION_NAME EQ relation->rel_symbol->sym_string
			SORTED BY RFR.RDB$FIELD_POSITION, RFR.RDB$FIELD_NAME;

		if (RFR.RDB$FIELD_POSITION > relation->rel_max_field_pos)
			relation->rel_max_field_pos = RFR.RDB$FIELD_POSITION;
		qli_fld* field = (qli_fld*) ALLOCPV(type_fld, 0);
		*ptr = field;
		ptr = &field->fld_next;
		field->fld_relation = relation;
		qli_symbol* symbol = make_symbol(RFR.RDB$FIELD_NAME, sizeof(RFR.RDB$FIELD_NAME));
		if (symbol)
		{
			symbol->sym_object = (BLK) field;
			symbol->sym_type = SYM_field;
			field->fld_name = symbol;
		}
		if ((symbol = make_symbol(RFR.RDB$QUERY_NAME, sizeof(RFR.RDB$QUERY_NAME))) ||
			(symbol = make_symbol(RFL.RDB$QUERY_NAME, sizeof(RFL.RDB$QUERY_NAME))))
		{
			symbol->sym_object = (BLK) field;
			symbol->sym_type = SYM_field;
			field->fld_query_name = symbol;
		}
		field->fld_scale = RFL.RDB$FIELD_SCALE;
		field->fld_id = RFR.RDB$FIELD_ID;

		if (RFL.RDB$SEGMENT_LENGTH.NULL)
			field->fld_segment_length = 80;
		else
		{
			field->fld_segment_length =
				((RFL.RDB$SEGMENT_LENGTH) < 256 && (RFL.RDB$SEGMENT_LENGTH > 0)) ?
					RFL.RDB$SEGMENT_LENGTH : 255;
		}

		ISC_QUAD* blob = & RFR.RDB$QUERY_HEADER;
		if (UserBlob::blobIsNull(*blob))
			blob = & RFL.RDB$QUERY_HEADER;
		if (!UserBlob::blobIsNull(*blob))
			field->fld_query_header = get_query_header(database, *blob);

		blob = & RFL.RDB$COMPUTED_BLR;
		if (!UserBlob::blobIsNull(*blob))
			field->fld_flags |= FLD_computed;

		field->fld_dtype = MET_get_datatype(RFL.RDB$FIELD_TYPE);
		field->fld_length = field_length(field->fld_dtype, RFL.RDB$FIELD_LENGTH);
		if (field->fld_dtype == dtype_varying)
			field->fld_length += sizeof(SSHORT);
		field->fld_sub_type = RFL.RDB$FIELD_SUB_TYPE;
		field->fld_sub_type_missing = RFL.RDB$FIELD_SUB_TYPE.NULL;

		if (!RFL.RDB$MISSING_VALUE.NULL)
			field->fld_missing = missing_value(RFL.RDB$MISSING_VALUE, field->fld_name);

		if (!(field->fld_edit_string =
			make_string(RFR.RDB$EDIT_STRING, sizeof(RFR.RDB$EDIT_STRING))))
		{
			field->fld_edit_string = make_string(RFL.RDB$EDIT_STRING, sizeof(RFL.RDB$EDIT_STRING));
		}
		field->fld_validation = parse_blr_blob(RFL.RDB$VALIDATION_BLR, field->fld_name);
		if (MET_dimensions(database, RFL.RDB$FIELD_NAME) > 0)
			field->fld_flags |= FLD_array;
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;
}


void MET_finish( qli_dbb* dbb)
{
/**************************************
 *
 *	M E T _ f i n i s h
 *
 **************************************
 *
 * Functional description
 *	Finish a database and release all associated blocks.
 *
 **************************************/
	// Get rid of relation and field blocks.

	qli_rel* relation;
	while (relation = dbb->dbb_relations)
	{
		purge_relation(relation);
	}

	// Get rid of any functions

	qli_fun* function;
	while (function = dbb->dbb_functions)
	{
		dbb->dbb_functions = function->fun_next;
		HSH_remove(function->fun_symbol);
		ALLQ_release((qli_frb*) function->fun_symbol);
		ALLQ_release((qli_frb*) function);
	}

	// Finally, actually close down database connection.

	ISC_STATUS_ARRAY status_vector;
	detach(status_vector, dbb);

	if (dbb->dbb_symbol)
	{
		HSH_remove(dbb->dbb_symbol);
		ALLQ_release((qli_frb*) dbb->dbb_symbol);
	}

	int count = 0;
	for (qli_dbb** ptr = &QLI_databases; *ptr; ptr = &(*ptr)->dbb_next)
	{
		if (*ptr == dbb)
		{
			*ptr = dbb->dbb_next;
			ALLQ_release((qli_frb*) dbb);
			count++;
			if (!*ptr) {
				break;
			}
		}
	}

	if (!count)
		ERRQ_bugcheck(231);			// Msg231 database block not found for removal

	if (status_vector[1])
		ERRQ_database_error(NULL, status_vector);
}


int MET_get_datatype( USHORT blr_datatype)
{
/**************************************
 *
 *	M E T _ g e t _ d a t a t y p e
 *
 **************************************
 *
 * Functional description
 *	Convert a blr datatype to a QLI dtype.
 *
 **************************************/
	USHORT retvalue;

	switch (blr_datatype)
	{
	case blr_text:
		retvalue = dtype_text;
		break;
	case blr_varying:
		retvalue = dtype_varying;
		break;
	case blr_cstring:
		retvalue = dtype_cstring;
		break;
	case blr_short:
		retvalue = dtype_short;
		break;
	case blr_long:
		retvalue = dtype_long;
		break;
	case blr_quad:
		retvalue = dtype_quad;
		break;
	case blr_float:
		retvalue = dtype_real;
		break;
	case blr_double:
		retvalue = dtype_double;
		break;
	case blr_timestamp:
		retvalue = dtype_timestamp;
		break;
	case blr_sql_date:
		retvalue = dtype_sql_date;
		break;
	case blr_sql_time:
		retvalue = dtype_sql_time;
		break;
	case blr_blob:
		retvalue = dtype_blob;
		break;
	case blr_int64:
		retvalue = dtype_int64;
		break;
	default:
		retvalue = dtype_unknown;
		break;
	}

	return retvalue;
}



#ifdef DEV_BUILD
void MET_index_info(qli_dbb* db,
					const SCHAR* relation_name,
					const SCHAR* index_name,
					SCHAR* const buffer,
					size_t bufsize)
{
/**************************************
 *
 *	M E T _ i n d e x _ i n f o
 *
 **************************************
 *
 * Functional description
 *	Get info about a particular index.
 *
 **************************************/
	FB_API_HANDLE request_handle = 0;

	SCHAR* b = buffer;
	FOR(REQUEST_HANDLE request_handle)
		IDX IN DB.RDB$INDICES CROSS
			SEG IN DB.RDB$INDEX_SEGMENTS OVER
			RDB$INDEX_NAME WITH
			IDX.RDB$INDEX_NAME EQ index_name AND
			IDX.RDB$RELATION_NAME EQ relation_name
			SORTED BY SEG.RDB$FIELD_POSITION

		const SCHAR* p;
		if (b == buffer)
		{
			for (p = fb_utils::exact_name(IDX.RDB$INDEX_NAME); *p;) {
				*b++ = *p++;
			}
			*b++ = ' ';
			*b++ = '(';
		}

		p = fb_utils::exact_name(SEG.RDB$FIELD_NAME);
		if (p + strlen(p) + 2 > buffer + bufsize)
			break;

		while (*p) {
			*b++ = *p++;
		}

		*b++ = ' ';

	END_FOR
	ON_ERROR
		ERRQ_database_error(NULL, gds_status);
	END_ERROR;

	release_request(db, request_handle);

	// back up over the last space and finish off

	b--;
	*b++ = ')';
	*b++ = 0;
}
#endif


void MET_meta_commit( qli_dbb* database)
{
/**************************************
 *
 *	M E T _ m e t a _ c o m m i t
 *
 **************************************
 *
 * Functional description
 *	Commit the meta data lookup & update
 *	transaction.
 *
 **************************************/
	if (database->dbb_capabilities & DBB_cap_multi_trans)
	{
		ISC_STATUS_ARRAY status_vector;
		if (isc_commit_transaction(status_vector, &database->dbb_meta_trans))
		{
			rollback_update(database);
			ERRQ_database_error(database, status_vector);
		}
	}
}


void MET_meta_rollback( qli_dbb* database)
{
/**************************************
 *
 *	M E T _ m e t a _ r o l l b a c k
 *
 **************************************
 *
 * Functional description
 *	Rollback the metadata transaction,
 *	if there is one.
 *
 **************************************/

	if (database->dbb_capabilities & DBB_cap_multi_trans)
		rollback_update(database);
}


FB_API_HANDLE MET_meta_transaction(qli_dbb* database, bool update_flag)
{
/**************************************
 *
 *	M E T _ m e t a _ t r a n s a c t i o n
 *
 **************************************
 *
 * Functional description
 *	Setup transaction for meta-data operation.  Set up
 *	DB and gds_trans, and return meta-data transaction
 *	handle for yucks.  If we're doing metadata updates,
 *	and lookups we'll use the metadat date transaction,
 *	unless this is an rdb database or gateway in which
 *	case, we'll use the only transacti.
 *
 *	In any event, we will set up the met_transaction because
 *	it's widely used and somebody is going to forget to test
 *	that the database is multi_transaction before using it.
 *	This means that we have to be very careful about committing
 *	or rolling back, because this could affect user data.
 *
 **************************************/
	ISC_STATUS_ARRAY status_vector;

	if (!database)
		IBERROR(243);			// Msg243 no active database for operation

	FB_API_HANDLE transaction = (database->dbb_capabilities & DBB_cap_multi_trans) ?
		database->dbb_meta_trans : 0;

	DB = database->dbb_handle;

	// If we don't know whether or not the database can handle
	// multiple transactions, find out now

	if (!transaction &&
		((database->dbb_capabilities & DBB_cap_multi_trans) ||
		!(database->dbb_capabilities & DBB_cap_single_trans)))
	{
		if (isc_start_transaction(status_vector, &transaction, 1,
								   &database->dbb_handle, sizeof(tpb), tpb))
		{
			database->dbb_capabilities |= DBB_cap_single_trans;
		}
		else
		{
			database->dbb_capabilities |= DBB_cap_multi_trans;
		}
	}

	// If we already have a meta-data transaction, there's more nothing to do

	gds_trans = transaction;

	// If we only support a single transaction, use the data transaction

	if (!gds_trans && (database->dbb_capabilities & DBB_cap_single_trans))
	{
		if (update_flag)
			IBERROR(244);		// Msg244 Interactive metadata updates are not available on Rdb
		if (!(gds_trans = database->dbb_transaction))
			gds_trans = MET_transaction(nod_start_trans, database);
	}
	else if (!gds_trans)
	{
		// otherwise make one more effort to start the transaction
		START_TRANSACTION
		ON_ERROR
			ERRQ_database_error(database, status_vector);
		END_ERROR;
	}

	database->dbb_meta_trans = gds_trans;
	return gds_trans;
}


void MET_modify_field( qli_dbb* database, qli_fld* field)
{
/**************************************
 *
 *	M E T _ m o d i f y _ f i e l d
 *
 **************************************
 *
 * Functional description
 *	Modify an existing global field.
 *
 **************************************/
	database = setup_update(database);
	qli_symbol* field_name = field->fld_name;
	SSHORT flag = 0;

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_modify_fld])
		X IN DB.RDB$FIELDS WITH X.RDB$FIELD_NAME EQ field_name->sym_string
		if (field->fld_dtype &&
			(X.RDB$FIELD_TYPE == blr_blob || blr_dtypes[field->fld_dtype] == blr_blob) &&
			 X.RDB$FIELD_TYPE != blr_dtypes[field->fld_dtype])
		{
			flag = -1;
		}
		else
		{
			flag = 1;
			MODIFY X USING
				if (field->fld_dtype)
				{
					X.RDB$FIELD_TYPE = blr_dtypes[field->fld_dtype];
					X.RDB$FIELD_SCALE = field->fld_scale;
					X.RDB$FIELD_LENGTH = (field->fld_dtype == dtype_varying) ?
						field->fld_length - sizeof(SSHORT) : field->fld_length;
				}
				if (!field->fld_sub_type_missing)
				{
					X.RDB$FIELD_SUB_TYPE.NULL = FALSE;
					X.RDB$FIELD_SUB_TYPE = field->fld_sub_type;
				}
				qli_symbol* asymbol = field->fld_query_name;
				if (asymbol)
				{
					X.RDB$QUERY_NAME.NULL = FALSE;
					strcpy(X.RDB$QUERY_NAME, asymbol->sym_string);
				}
				if (field->fld_edit_string)
				{
					X.RDB$EDIT_STRING.NULL = FALSE;
					strcpy(X.RDB$EDIT_STRING, field->fld_edit_string);
				}
			END_MODIFY
			ON_ERROR
				rollback_update(database);
				ERRQ_database_error(database, gds_status);
			END_ERROR;
		}
	END_FOR
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	if (flag <= 0)
	{
		rollback_update(database);
		// Msg245 global field %s is not defined
		// Msg468 Datatype of field %s may not be changed to or from blob
		const USHORT nErr = flag ? 468 : 245;
		ERRQ_print_error(nErr, field_name->sym_string);
	}

	MET_meta_commit(database);

	// Now go back and re-fetch fields for affected databases

	setup_update(database);

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_update_fld])
		X IN DB.RDB$RELATION_FIELDS WITH X.RDB$FIELD_SOURCE EQ
			field_name->sym_string REDUCED TO X.RDB$RELATION_NAME

		const TEXT* p = X.RDB$RELATION_NAME;
		while (*p && *p != ' ') {
			p++;
		}

		qli_symbol* symbol = HSH_lookup(X.RDB$RELATION_NAME, p - X.RDB$RELATION_NAME);
		for (; symbol; symbol = symbol->sym_homonym)
		{
			qli_rel* relation;
			if (symbol->sym_type == SYM_relation &&
				(relation = (qli_rel*) symbol->sym_object) && relation->rel_database == database)
			{
				delete_fields(relation);
				MET_fields(relation);
			}
		}
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;
}


void MET_modify_index( qli_syntax* node)
{
/**************************************
 *
 *	M E T _ m o d i f y _ i n d e x
 *
 **************************************
 *
 * Functional description
 *	Change the changeable options
 *	of an index.
 *
 **************************************/
	qli_name* name = (qli_name*) node->syn_arg[s_mfi_name];
	qli_dbb* database = (qli_dbb*) node->syn_arg[s_mfi_database];
	database = setup_update(database);

	USHORT count = 0;

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_mdf_index])
		X IN DB.RDB$INDICES WITH X.RDB$INDEX_NAME = name->nam_string
		MODIFY X USING
			if (node->syn_flags & s_dfi_flag_selectivity)
				X.RDB$UNIQUE_FLAG = (node->syn_flags & s_dfi_flag_unique);
			if (node->syn_flags & s_dfi_flag_activity)
				X.RDB$INDEX_INACTIVE = (node->syn_flags & s_dfi_flag_inactive) ? TRUE : FALSE;
			if (node->syn_flags & s_dfi_flag_order)
				X.RDB$INDEX_TYPE = (node->syn_flags & s_dfi_flag_descending) ? TRUE : FALSE;
			if (node->syn_flags & s_dfi_flag_statistics)
				X.RDB$STATISTICS = -1.0;
		END_MODIFY
		ON_ERROR
			rollback_update(database);
			ERRQ_database_error(database, gds_status);
		END_ERROR;
		count++;
	END_FOR
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	if (!count)
		ERRQ_print_error(246, SafeArg() << name->nam_string << database->dbb_filename);
		// Msg246 Index %s does not exist

	MET_meta_commit(database);
}


void MET_modify_relation( qli_rel* relation, qli_fld* fields)
{
/**************************************
 *
 *	M E T _ m o d i f y _ r e l a t i o n
 *
 **************************************
 *
 * Functional description
 *	Modify an existing relation.
 *
 **************************************/
	qli_dbb* database = setup_update(relation->rel_database);
	relation->rel_database = database;
	qli_symbol* relation_name = relation->rel_symbol;

	for (qli_fld* field = fields; field; field = field->fld_next)
	{
		if (field->fld_flags & FLD_drop)
		{
			USHORT count = 0;
			qli_symbol* field_name = field->fld_name;
			FOR(REQUEST_HANDLE database->dbb_requests[REQ_modify_rel])
				X IN DB.RDB$RELATION_FIELDS WITH
					X.RDB$FIELD_NAME EQ field_name->sym_string AND
					X.RDB$RELATION_NAME EQ relation_name->sym_string
				count++;
				ERASE X
				ON_ERROR
					rollback_update(database);
					ERRQ_database_error(database, gds_status);
				END_ERROR;
			END_FOR
			ON_ERROR
				rollback_update(database);
				ERRQ_database_error(database, gds_status);
			END_ERROR;
			if (!count)
			{
				rollback_update(database);
				ERRQ_print_error(247, field_name->sym_string);	// Msg247 field %s doesn't exist
			}
		}
		else if (field->fld_flags & FLD_modify)
			change_field(relation, field);
		else
			add_field(relation, field, 0);
	}

	MET_meta_commit(database);
	setup_update(database);
	delete_fields(relation);
	MET_fields(relation);
}


void MET_ready( qli_syntax* node, const bool create_flag)
{
/**************************************
 *
 *	M E T _ r e a d y
 *
 **************************************
 *
 * Functional description
 *	Create or Ready one or more databases.  If any
 *	fail, all fail.  Fair enough?
 *
 **************************************/
	Firebird::ClumpletWriter dpb(Firebird::ClumpletReader::dpbList, MAX_DPB_SIZE);

	qli_dbb* temp = (qli_dbb*) node->syn_arg[0];

	// Only a SQL CREATE DATABASE will have a pagesize parameter,
	// so only looking at the first pointer is justified.

	SSHORT length;
	const TEXT* lc_ctype = QLI_charset;
	if (lc_ctype && (length = static_cast<SSHORT>(strlen(lc_ctype)))) {
		dpb.insertString(isc_dpb_lc_ctype, lc_ctype, length);
	}

	// It does absolutely nothing inside the engine these days: ignored.
	if (QLI_trace) {
		dpb.insertByte(isc_dpb_trace, 1);
	}

	if (sw_buffers) {
		dpb.insertInt(isc_dpb_num_buffers, ULONG(sw_buffers));
	}

	if (temp->dbb_pagesize) {
		dpb.insertInt(isc_dpb_page_size, ULONG(temp->dbb_pagesize));
	}

	// get a username, if specified globally or on the command line

	const TEXT* q;
	if (temp->dbb_user)
	{
		q = (TEXT*) temp->dbb_user->con_data;
		length = temp->dbb_user->con_desc.dsc_length;
	}
	else
	{
		q = QLI_default_user;
		length = static_cast<SSHORT>(strlen(QLI_default_user));
	}
	if (length) {
		dpb.insertString(isc_dpb_user_name, q, length);
	}

	// get a password, if specified

	if (temp->dbb_password)
	{
		q = (TEXT*) temp->dbb_password->con_data;
		length = temp->dbb_password->con_desc.dsc_length;
	}
	else
	{
		q = QLI_default_password;
		length = static_cast<SSHORT>(strlen(QLI_default_password));
	}
	if (length) {
		dpb.insertString(isc_dpb_password, q, length);
	}

#ifdef TRUSTED_AUTH
	if (QLI_trusted) {
		dpb.insertTag(isc_dpb_trusted_auth);
	}
#endif

	if (QLI_nodb_triggers)
		dpb.insertInt(isc_dpb_no_db_triggers, 1);

	const qli_syntax* const* const end = node->syn_arg + node->syn_count;

	// Start by attaching all databases
	ISC_STATUS_ARRAY status_vector;
	qli_syntax** ptr;
	qli_dbb* dbb = NULL;

	for (ptr = node->syn_arg; ptr < end; ptr++)
	{
		dbb = (qli_dbb*) *ptr;
		if (create_flag)
			isc_create_database(status_vector, 0, dbb->dbb_filename,
								&dbb->dbb_handle, dpb.getBufferLength(),
								reinterpret_cast<const char*>(dpb.getBuffer()), 0);
		else
			isc_attach_database(status_vector, 0, dbb->dbb_filename,
								&dbb->dbb_handle, dpb.getBufferLength(),
								reinterpret_cast<const char*>(dpb.getBuffer()));
		if (status_vector[1])
			break;
	}

	// If any attach failed, cleanup and give up

	if (ptr < end)
	{
		for (qli_syntax** ptr2 = node->syn_arg; ptr2 < ptr; ptr2++)
			detach(gds_status, (qli_dbb*) *ptr2);
		ERRQ_database_error(dbb, status_vector);
	}


	// Databases are up and running.  Install each.

	for (ptr = node->syn_arg; ptr < end; ptr++)
		install((qli_dbb*) *ptr);
}


void MET_shutdown()
{
/**************************************
 *
 *	M E T _ s h u t d o w n
 *
 **************************************
 *
 * Functional description
 *	Shut down all attached databases.
 *
 **************************************/
	ISC_STATUS_ARRAY status_vector;

	for (qli_dbb* dbb = QLI_databases; dbb; dbb = dbb->dbb_next)
	{
		if (detach(status_vector, dbb))
			isc_print_status(status_vector);
	}
}


void MET_sql_alter_table( qli_rel* relation, qli_fld* fields)
{
/**************************************
 *
 *	M E T _ s q l _ a l t e r _ t a b l e
 *
 **************************************
 *
 * Functional description
 *	Alter table data based on a SQL metadata request
 *
 **************************************/
	qli_symbol* symbol = relation->rel_symbol;
	qli_dbb* database = setup_update(relation->rel_database);
	relation->rel_database = database;
	USHORT count = 0;

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_relation_def])
		X IN DB.RDB$RELATIONS WITH X.RDB$RELATION_NAME EQ symbol->sym_string
			count++;
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;
	if (!count)
		ERRQ_print_error(414, symbol->sym_string);	// Msg237 Relation %s is lost

	qli_rlb* rlb = NULL;
	CHECK_RLB(rlb);

	STUFF(isc_dyn_version_1);
	STUFF(isc_dyn_begin);
	STUFF(isc_dyn_mod_rel);
	STUFF_STRING(symbol->sym_string);

	for (qli_fld* field = fields; field; field = field->fld_next)
	{
		if (field->fld_flags & FLD_add)
			add_sql_field(relation, field, 0, rlb);
		else if (field->fld_flags & FLD_drop)
		{
			STUFF(isc_dyn_delete_local_fld);
			STUFF_STRING(field->fld_name->sym_string);
			STUFF(isc_dyn_end);
		}
	}

	STUFF(isc_dyn_end);
	STUFF(isc_dyn_end);
	STUFF(isc_dyn_eoc);

	execute_dynamic_ddl(database, rlb);
	MET_meta_commit(database);

	setup_update(database);
	delete_fields(relation);
	MET_fields(relation);
}


void MET_sql_cr_view( qli_syntax* node)
{
/**************************************
 *
 *	M E T _ s q l _ c r _ v i e w
 *
 **************************************
 *
 * Functional description
 *	Create a view from a SQL metadata request
 *
 **************************************/
	qli_rel* relation = (qli_rel*) node->syn_arg[s_crv_name];
	qli_dbb* database = setup_update(relation->rel_database);
	relation->rel_database = database;
	qli_symbol* symbol = relation->rel_symbol;

	qli_rlb* rlb = NULL;
	CHECK_RLB(rlb);
	STUFF(isc_dyn_version_1);
	STUFF(isc_dyn_begin);

	STUFF(isc_dyn_def_view);
	STUFF_STRING(symbol->sym_string);

	// The meat of the blr generation will go here

	STUFF(isc_dyn_end);
	STUFF(isc_dyn_eoc);

	execute_dynamic_ddl(database, rlb);
	MET_meta_commit(database);
}


void MET_sql_grant( qli_syntax* node)
{
/**************************************
 *
 *	M E T _ s q l _ g r a n t
 *
 **************************************
 *
 * Functional description
 *	Grant access privilege(s) on a SQL table
 *
 **************************************/

	sql_grant_revoke(node, isc_dyn_grant);
}


void MET_sql_revoke( qli_syntax* node)
{
/**************************************
 *
 *	M E T _ s q l _ r e v o k e
 *
 **************************************
 *
 * Functional description
 *	Revoke access privilege(s) on a SQL table
 *
 **************************************/

	sql_grant_revoke(node, isc_dyn_revoke);
}


FB_API_HANDLE MET_transaction( nod_t node_type, qli_dbb* database)
{
/**************************************
 *
 *	M E T _ t r a n s a c t i o n
 *
 **************************************
 *
 * Functional description
 *	Finish off a transaction with a commit, prepare, or rollback.
 *	For commit and rollback, start a new transaction.
 *
 *	Multiple transaction coordination is handled
 *	by the caller.  This is a singleminded routine.
 *
 **************************************/
	ISC_STATUS_ARRAY status_vector;


	switch (node_type)
	{
	case nod_commit:
		isc_commit_transaction(status_vector, &database->dbb_transaction);
		break;

	case nod_rollback:
		isc_rollback_transaction(status_vector, &database->dbb_transaction);
		break;

	case nod_prepare:
		isc_prepare_transaction(status_vector, &database->dbb_transaction);
		break;

	case nod_start_trans:
		isc_start_transaction(status_vector, &database->dbb_transaction, 1,
							   &database->dbb_handle, sizeof(tpb), tpb);
		database->dbb_flags &= ~DBB_updates & ~DBB_prepared;
		break;
	}

	if (status_vector[1])
		ERRQ_database_error(database, status_vector);

	return database->dbb_transaction;
}


static void add_field( qli_rel* relation, qli_fld* field, USHORT position)
{
/**************************************
 *
 *	a d d _ f i e l d
 *
 **************************************
 *
 * Functional description
 *	Add a field to a relation.  Do all sorts of sanity checks.
 *
 **************************************/
	qli_dbb* database = relation->rel_database;
	qli_symbol* relation_name = relation->rel_symbol;
	qli_symbol* field_name = field->fld_name;
	qli_symbol* global_field = field->fld_based;
	if (!global_field)
		global_field = field_name;

	// Check to see if it already exits in relation

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_rfr_def])
		X IN DB.RDB$RELATION_FIELDS WITH
			X.RDB$RELATION_NAME EQ relation_name->sym_string AND
			X.RDB$FIELD_NAME EQ field_name->sym_string
		rollback_update(relation->rel_database);
		ERRQ_print_error(251, SafeArg() << field_name->sym_string << relation_name->sym_string);
		// Msg251 Field %s already exists in relation %s
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	// Check global field.  Define it if it doesn't exist.

	bool global_flag = false;
	if (!check_global_field(database, field, global_field->sym_string))
	{
		global_flag = true;
		define_global_field(database, field, global_field);
	}

	// Finally, store into RFR.  If we defined a global field, assume that
	// the query name and edit string will be inherited from there, otherwise
	// include them here

	STORE(REQUEST_HANDLE database->dbb_requests[REQ_store_rfr])
		X IN DB.RDB$RELATION_FIELDS

		strcpy(X.RDB$RELATION_NAME, relation_name->sym_string);
		strcpy(X.RDB$FIELD_NAME, field_name->sym_string);
		strcpy(X.RDB$FIELD_SOURCE, global_field->sym_string);
		if (position)
		{
			X.RDB$FIELD_POSITION.NULL = FALSE;
			X.RDB$FIELD_POSITION = position;
		}
		else
			X.RDB$FIELD_POSITION.NULL = TRUE;
		const qli_symbol* symbol;
		if (!global_flag && (symbol = field->fld_query_name))
		{
			X.RDB$QUERY_NAME.NULL = FALSE;
			strcpy(X.RDB$QUERY_NAME, symbol->sym_string);
		}
		else
			X.RDB$QUERY_NAME.NULL = TRUE;
		if (!global_flag && (field->fld_edit_string))
		{
			X.RDB$EDIT_STRING.NULL = FALSE;
			strcpy(X.RDB$EDIT_STRING, field->fld_edit_string);
		}
		else
			X.RDB$EDIT_STRING.NULL = TRUE;

	END_STORE
	ON_ERROR
		rollback_update(relation->rel_database);
		ERRQ_database_error(relation->rel_database, gds_status);
	END_ERROR;
}


static void add_sql_field( qli_rel* relation, qli_fld* field, USHORT position, qli_rlb* rlb)
{
/**************************************
 *
 *	a d d _ s q l _ f i e l d
 *
 **************************************
 *
 * Functional description
 *	Add a SQL field to a relation via dyn.
 *
 **************************************/
	CHECK_RLB(rlb);
	qli_dbb* database = relation->rel_database;
	const qli_symbol* relation_name = relation->rel_symbol;
	const qli_symbol* field_name = field->fld_name;

	// Check to see if it already exists in relation

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_rfr_def])
		X IN DB.RDB$RELATION_FIELDS WITH
			X.RDB$RELATION_NAME EQ relation_name->sym_string AND
			X.RDB$FIELD_NAME EQ field_name->sym_string
		rollback_update(relation->rel_database);
		ERRQ_print_error(251, SafeArg() << field_name->sym_string << relation_name->sym_string);
		// Msg251 Field %s already exists in relation %s
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;


	STUFF(isc_dyn_def_sql_fld);
	STUFF_STRING(field->fld_name->sym_string);

	STUFF(isc_dyn_fld_type);
	STUFF_WORD(2);
	STUFF_WORD(blr_dtypes[field->fld_dtype]);

	STUFF(isc_dyn_fld_length);
	STUFF_WORD(2);
	const USHORT l = (field->fld_dtype == dtype_varying) ?
						field->fld_length - sizeof(SSHORT) : field->fld_length;
	STUFF_WORD(l);

	STUFF(isc_dyn_fld_scale);
	STUFF_WORD(2);
	STUFF_WORD(field->fld_scale);

	if (DTYPE_IS_EXACT(field->fld_dtype))
	{
		STUFF(isc_dyn_fld_precision);
		STUFF_WORD(2);
		STUFF_WORD(field->fld_precision);
		STUFF(isc_dyn_fld_sub_type);
		STUFF_WORD(2);
		STUFF_WORD(field->fld_sub_type);
	}

	if (position)
	{
		STUFF(isc_dyn_fld_position);
		STUFF_WORD(2);
		STUFF_WORD(position);
	}

	CHECK_RLB(rlb);

	if (field->fld_flags & FLD_not_null)
	{
		STUFF(isc_dyn_fld_validation_blr);
		STUFF_WORD(8);
		STUFF(blr_version4);
		STUFF(blr_not);
		STUFF(blr_missing);
		STUFF(blr_fid);
		STUFF(0);
		STUFF(0);
		STUFF(0);
		STUFF(blr_eoc);
	}

	STUFF(isc_dyn_end);
}


static void blob_copy( qli_rlb* rlb, qli_rel* source, ISC_QUAD& source_blob_id)
{
/**************************************
 *
 *	b l o b _ c o p y
 *
 **************************************
 *
 * Functional description
 *	Copy information from one blob to a request
 *	language block to stick it into a new definition.
 *
 **************************************/
	ISC_STATUS_ARRAY status_vector;

	qli_dbb* source_dbb = source->rel_database ? source->rel_database : QLI_databases;
	DB = source_dbb->dbb_handle;
	UserBlob source_blob(status_vector);

	if (!source_blob.open(DB, source_dbb->dbb_meta_trans, source_blob_id))
	{
		rollback_update(source_dbb);
		ERRQ_database_error(source_dbb, status_vector);
	}

	SLONG size, segment_count, max_segment;
	if (!getBlobSize(source_blob, &size, &segment_count, &max_segment))
	{
		rollback_update(source_dbb);
		ERRQ_database_error(source_dbb, status_vector);
	}

    TEXT fixed_buffer[4096];
	TEXT* buffer;
    USHORT buffer_length;
	if (max_segment < static_cast<SLONG>(sizeof(fixed_buffer)))
	{
		buffer_length = sizeof(fixed_buffer);
		buffer = fixed_buffer;
	}
	else
	{
		buffer_length = max_segment;
		buffer = (TEXT*) gds__alloc((SLONG) buffer_length);
	}

	STUFF_WORD((USHORT) size);

	FB_SIZE_T length;
	while (source_blob.getSegment(buffer_length, buffer, length) && !source_blob.getCode())
	{
		while (rlb->rlb_data + length > rlb->rlb_limit)
			rlb = GEN_rlb_extend(rlb);
		const TEXT* p = buffer;
		while (length--)
			STUFF(*p++);
	}

	if (status_vector[1] != isc_segstr_eof)
	{
		rollback_update(source_dbb);
		if (buffer != fixed_buffer)
			gds__free(buffer);
		ERRQ_database_error(source_dbb, status_vector);
	}

	if (buffer != fixed_buffer)
		gds__free(buffer);

	if (!source_blob.close())
	{
		rollback_update(source_dbb);
		ERRQ_database_error(source_dbb, status_vector);
	}

	//return TRUE;
}


static void change_field( qli_rel* relation, qli_fld* field)
{
/**************************************
 *
 *	c h a n g e  _ f i e l d
 *
 **************************************
 *
 * Functional description
 *	Change optional attributes of a field.
 *
 **************************************/
	qli_dbb* database = relation->rel_database;
	const qli_symbol* relation_name = relation->rel_symbol;
	const qli_symbol* field_name = field->fld_name;
	const qli_symbol* global_field = field->fld_based;

	if (field->fld_dtype)
	{
		rollback_update(database);
		ERRQ_print_error(252);
		// Msg252 datatype can not be changed locally
	}

	if (global_field && !(check_global_field(database, NULL, global_field->sym_string)))
	{
		rollback_update(database);
		ERRQ_print_error(253, global_field->sym_string);
		// Msg253 global field %s does not exist
	}

	// Modify  RFR
	USHORT count = 0;

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_mdf_rfr])
		X IN DB.RDB$RELATION_FIELDS WITH
			X.RDB$RELATION_NAME = relation_name->sym_string AND
			X.RDB$FIELD_NAME = field_name->sym_string
		count++;
		MODIFY X USING
			if (global_field)
				strcpy(X.RDB$FIELD_SOURCE, global_field->sym_string);
			const qli_symbol* symbol = field->fld_query_name;
			if (symbol)
				strcpy(X.RDB$QUERY_NAME, symbol->sym_string);
			if (field->fld_edit_string)
				strcpy(X.RDB$EDIT_STRING, field->fld_edit_string);
		END_MODIFY
		ON_ERROR
			rollback_update(relation->rel_database);
			ERRQ_database_error(relation->rel_database, gds_status);
		END_ERROR;
	END_FOR
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	if (!count)
	{
		rollback_update(database);
		ERRQ_print_error(254, SafeArg() << field_name->sym_string << relation_name->sym_string);
		// Msg254 field %s not found in relation %s
	}
}


static bool check_global_field(qli_dbb* database, qli_fld* field, const TEXT* name)
{
/**************************************
 *
 *	c h e c k _ g l o b a l _ f i e l d
 *
 **************************************
 *
 * Functional description
 *	Given a name, check for the existence of a global field
 *	by that name.  If a qli_fld block is supplied,
 *		check its characteristics against the global.
 *	If it is not fully defined, flesh it out from the global.
 *
 **************************************/
	bool previously_defined = false;

	FOR(REQUEST_HANDLE database->dbb_requests[REQ_field_def])
		X IN DB.RDB$FIELDS WITH X.RDB$FIELD_NAME EQ name

		if (field)
		{
			if (field->fld_dtype &&
				(X.RDB$FIELD_TYPE != blr_dtypes[field->fld_dtype] ||
				 X.RDB$FIELD_LENGTH != static_cast<SLONG>(
					((field->fld_dtype == dtype_varying) ?
						field->fld_length - sizeof(SSHORT) : field->fld_length)) ||
				 X.RDB$FIELD_SCALE != field->fld_scale))
			{
				rollback_update(database);
				ERRQ_print_error(255, name);
				// Msg255 Datatype conflict with existing global field %s
			}
			field->fld_dtype = MET_get_datatype(X.RDB$FIELD_TYPE);
			field->fld_length = field_length(field->fld_dtype, X.RDB$FIELD_LENGTH);
			if (field->fld_dtype == dtype_varying) {
				field->fld_length += sizeof(SSHORT);
			}
			field->fld_scale = X.RDB$FIELD_SCALE;
			field->fld_sub_type = X.RDB$FIELD_SUB_TYPE;
			field->fld_sub_type_missing = X.RDB$FIELD_SUB_TYPE.NULL;
			if (!field->fld_edit_string)
			{
				field->fld_edit_string = make_string(X.RDB$EDIT_STRING, sizeof(X.RDB$EDIT_STRING));
			}
			if (!field->fld_query_name)
			{
				field->fld_query_name = make_symbol(X.RDB$QUERY_NAME, sizeof(X.RDB$QUERY_NAME));
			}
			if (!field->fld_query_header)
			{
				ISC_QUAD& blob = X.RDB$QUERY_HEADER;
				if (!UserBlob::blobIsNull(blob))
				{
					field->fld_query_header = get_query_header(database, blob);
				}
			}
		}
		previously_defined = true;
	END_FOR
	ON_ERROR
		ERRQ_database_error(database, gds_status);
	END_ERROR;

	return previously_defined;
}


static bool check_relation( qli_rel* relation)
{
/**************************************
 *
 *	c h e c k _ r e l a t i o n
 *
 **************************************
 *
 * Functional description
 *	Check the existence of the named relation.
 *
 **************************************/
	bool previously_defined = false;
	FB_API_HANDLE spare = DB;
	DB = relation->rel_database->dbb_handle;

	FOR(REQUEST_HANDLE relation->rel_database->dbb_requests[REQ_relation_def]
		TRANSACTION_HANDLE relation->rel_database->dbb_meta_trans)
			X IN DB.RDB$RELATIONS
			WITH X.RDB$RELATION_NAME EQ relation->rel_symbol->sym_string
		previously_defined = true;
	END_FOR
	ON_ERROR
		ERRQ_database_error(relation->rel_database, gds_status);
	END_ERROR;

	DB = spare;
	return previously_defined;
}


static void clone_fields( qli_rel* target, qli_rel* source)
{
/**************************************
 *
 *	c l o n e _ f i e l d s
 *
 **************************************
 *
 * Functional description
 *	Copy the RFR records for one relation
 *	into another.  The target database is already
 *	setup for updates.  If there is a different source
 *	database, get it ready too.  Then make sure that
 *	the source relation actually exists.
 *
 *	If it's two different databases, create the global
 *	fields that are missing in the target (except those
 *	that support computed fields), then create the local
 *	fields and during that pass create the computed
 *	fields and the SQL fields.
 *
 **************************************/
	FB_API_HANDLE req1, req2;

	req1 = req2 = 0;
	FB_API_HANDLE s_trans = gds_trans;
	DB = DB1 = target->rel_database->dbb_handle;

	if (target->rel_database != source->rel_database)
	{
		MET_meta_transaction(source->rel_database, false);
		s_trans = gds_trans;
	}

	if (target->rel_database != source->rel_database)
		clone_global_fields(target, source);

	qli_rlb* rlb = NULL;
	CHECK_RLB(rlb);

	STUFF(isc_dyn_version_1);
	STUFF(isc_dyn_begin);

	FOR(REQUEST_HANDLE req1 TRANSACTION_HANDLE s_trans)
		Y IN DB.RDB$RELATION_FIELDS
			CROSS F IN DB.RDB$FIELDS
			WITH Y.RDB$RELATION_NAME = source->rel_symbol->sym_string
			AND Y.RDB$FIELD_SOURCE = F.RDB$FIELD_NAME
			// If SQL made this field, create a new global field for it
		if (F.RDB$COMPUTED_BLR.NULL &&
			!fb_utils::implicit_domain(Y.RDB$FIELD_NAME) &&
			fb_utils::implicit_domain(F.RDB$FIELD_NAME))
		{
			STUFF(isc_dyn_def_sql_fld);
			STUFF_STRING(Y.RDB$FIELD_NAME);
			STUFF(isc_dyn_fld_type);
			STUFF_WORD(2);
			STUFF_WORD(F.RDB$FIELD_TYPE);

			STUFF(isc_dyn_fld_length);
			STUFF_WORD(2);
			STUFF_WORD(F.RDB$FIELD_LENGTH);

			STUFF(isc_dyn_fld_scale);
			STUFF_WORD(2);
			STUFF_WORD(F.RDB$FIELD_SCALE);

			if (!F.RDB$VALIDATION_BLR.NULL)
			{
				STUFF(isc_dyn_fld_validation_blr);
				blob_copy(rlb, source, F.RDB$VALIDATION_BLR);
			}
		}
		else
		{
			STUFF(isc_dyn_def_local_fld);
			STUFF_STRING(Y.RDB$FIELD_NAME);
			STUFF(isc_dyn_fld_source);
			STUFF_STRING(Y.RDB$FIELD_SOURCE);
		}

		STUFF(isc_dyn_rel_name);
		STUFF_STRING(target->rel_symbol->sym_string);

		if (!Y.RDB$FIELD_POSITION.NULL)
		{
			STUFF(isc_dyn_fld_position);
			STUFF_WORD(2);
			STUFF_WORD(Y.RDB$FIELD_POSITION);
		}

		if (!Y.RDB$QUERY_NAME.NULL)
		{
			STUFF(isc_dyn_fld_query_name);
			STUFF_STRING(Y.RDB$QUERY_NAME);
		}

		if (!Y.RDB$EDIT_STRING.NULL)
		{

			STUFF(isc_dyn_fld_edit_string);
			STUFF_STRING(Y.RDB$EDIT_STRING);
		}
		if (!Y.RDB$UPDATE_FLAG.NULL)
		{
			STUFF(isc_dyn_update_flag);
			STUFF_WORD(2);
			STUFF_WORD(Y.RDB$UPDATE_FLAG);
		}

		if (!Y.RDB$QUERY_HEADER.NULL)
		{
			STUFF(isc_dyn_fld_query_header);
			blob_copy(rlb, source, Y.RDB$QUERY_HEADER);
		}

		if (!Y.RDB$DESCRIPTION.NULL)
		{
			STUFF(isc_dyn_description);
			blob_copy(rlb, source, Y.RDB$DESCRIPTION);
		}

		if (!Y.RDB$DEFAULT_VALUE.NULL)
		{
			STUFF(isc_dyn_fld_default_value);
			blob_copy(rlb, source, Y.RDB$DEFAULT_VALUE);
		}

		if ((source->rel_database->dbb_capabilities & DBB_cap_rfr_sys_flag) &&
			(target->rel_database->dbb_capabilities & DBB_cap_rfr_sys_flag))
		{
			FOR(REQUEST_HANDLE req2 TRANSACTION_HANDLE s_trans)
				S_RFR IN DB.RDB$RELATION_FIELDS WITH
				S_RFR.RDB$FIELD_NAME = Y.RDB$FIELD_NAME AND
				S_RFR.RDB$RELATION_NAME = Y.RDB$RELATION_NAME
	            if (!S_RFR.RDB$SYSTEM_FLAG.NULL)
	            {
	                STUFF(isc_dyn_system_flag);
	                STUFF_WORD(2);
	                STUFF_WORD(S_RFR.RDB$SYSTEM_FLAG);
	            }
			END_FOR
			ON_ERROR
				rollback_update(target->rel_database);
				ERRQ_database_error(source->rel_database, gds_status);
			END_ERROR;
		}

		if (!F.RDB$COMPUTED_BLR.NULL)
		{
			STUFF(isc_dyn_fld_computed_blr);
			blob_copy(rlb, source, F.RDB$COMPUTED_BLR);
			STUFF(isc_dyn_fld_computed_source);
			blob_copy(rlb, source, F.RDB$COMPUTED_SOURCE);

			STUFF(isc_dyn_fld_type);
			STUFF_WORD(2);
			STUFF_WORD(F.RDB$FIELD_TYPE);

			STUFF(isc_dyn_fld_length);
			STUFF_WORD(2);
			STUFF_WORD(F.RDB$FIELD_LENGTH);

			if (!F.RDB$FIELD_SCALE.NULL)
			{
				STUFF(isc_dyn_fld_scale);
				STUFF_WORD(2);
				STUFF_WORD(F.RDB$FIELD_SCALE);
			}

			if (!F.RDB$FIELD_SUB_TYPE.NULL)
			{
				STUFF(isc_dyn_fld_sub_type);
				STUFF_WORD(2);
				STUFF_WORD(F.RDB$FIELD_SUB_TYPE);
			}
		}
		STUFF(isc_dyn_end);
	END_FOR
	ON_ERROR
		rollback_update(source->rel_database);
		ERRQ_database_error(source->rel_database, gds_status);
	END_ERROR;

	STUFF(isc_dyn_end);
	STUFF(isc_dyn_eoc);

	execute_dynamic_ddl(target->rel_database, rlb);

	release_request(source->rel_database, req1);
	release_request(source->rel_database, req2);
}


static void clone_global_fields( qli_rel* target, qli_rel* source)
{
/**************************************
 *
 *	c l o n e _ g l o b a l _ f i e l d s
 *
 **************************************
 *
 * Functional description
 *	Copy the global field definitions required by a relation
 *      from one database into another.  Both databases are
 *	setup correctly.  (Set up the handles again just because
 *	we're compulsive.)
 *
 *	In this routine, as in clone fields, be careful to probe
 *	for our extensions rather than just using them so we
 *	can copy relations from V2 and from Rdb.
 *
 *	Don't clone fields that already exist and have the
 *	correct datatype and length.
 *
 *	Don't clone computed fields since they will be cloned
 *	later with the local field definitions.   Don't clone
 *	SQL defined fields for the same reason.
 *
 **************************************/
	FB_API_HANDLE req1, req2, req3;
	req1 = req2 = req3 = 0;

	FB_API_HANDLE s_trans = source->rel_database->dbb_meta_trans;
	FB_API_HANDLE t_trans = target->rel_database->dbb_meta_trans;
	DB = source->rel_database->dbb_handle;
	DB1 = target->rel_database->dbb_handle;

	qli_rlb* rlb = NULL;
	bool first_field = true;

	FOR(REQUEST_HANDLE req1 TRANSACTION_HANDLE s_trans)
		RFR IN DB.RDB$RELATION_FIELDS CROSS
		Y IN DB.RDB$FIELDS
		WITH RFR.RDB$RELATION_NAME = source->rel_symbol->sym_string AND
		Y.RDB$FIELD_NAME = RFR.RDB$FIELD_SOURCE REDUCED TO Y.RDB$FIELD_NAME
		if (!Y.RDB$COMPUTED_BLR.NULL ||
			(!fb_utils::implicit_domain(RFR.RDB$FIELD_NAME) &&
			fb_utils::implicit_domain(Y.RDB$FIELD_NAME)))
		{
			continue;
		}

		bool predefined = false;

		FOR(REQUEST_HANDLE req2 TRANSACTION_HANDLE t_trans)
			A IN DB1.RDB$FIELDS WITH A.RDB$FIELD_NAME = Y.RDB$FIELD_NAME
			if ((A.RDB$FIELD_TYPE != Y.RDB$FIELD_TYPE) ||
				(A.RDB$FIELD_LENGTH != Y.RDB$FIELD_LENGTH) ||
				(A.RDB$FIELD_SCALE.NULL != Y.RDB$FIELD_SCALE.NULL) ||
				((!Y.RDB$FIELD_SCALE.NULL) && (A.RDB$FIELD_SCALE != Y.RDB$FIELD_SCALE)) ||
				(A.RDB$FIELD_SUB_TYPE.NULL != Y.RDB$FIELD_SUB_TYPE.NULL) ||
				((!Y.RDB$FIELD_SUB_TYPE.NULL) && (A.RDB$FIELD_SUB_TYPE != Y.RDB$FIELD_SUB_TYPE)))
			{
				TEXT* name = ALLQ_malloc((SLONG) sizeof(Y.RDB$FIELD_NAME));
				strcpy(name, Y.RDB$FIELD_NAME);
				rollback_update(target->rel_database);
				// CVC: When is this memory deallocated?
				ERRQ_error(413, name);
				// conflicting previous definition
			}
			else
				predefined = true;
		END_FOR
		ON_ERROR
			ERRQ_database_error(target->rel_database, gds_status);
		END_ERROR;

		if (predefined)
			continue;

		if (first_field)
		{
			CHECK_RLB(rlb);
			STUFF(isc_dyn_version_1);
			STUFF(isc_dyn_begin);
			first_field = false;
		}
		STUFF(isc_dyn_def_global_fld);
		STUFF_STRING(Y.RDB$FIELD_NAME);

		STUFF(isc_dyn_fld_type);
		STUFF_WORD(2);
		STUFF_WORD(Y.RDB$FIELD_TYPE);

		STUFF(isc_dyn_fld_length);
		STUFF_WORD(2);
		STUFF_WORD(Y.RDB$FIELD_LENGTH);

		if (!Y.RDB$FIELD_SCALE.NULL)
		{
			STUFF(isc_dyn_fld_scale);
			STUFF_WORD(2);
			STUFF_WORD(Y.RDB$FIELD_SCALE);
		}

		if (!Y.RDB$FIELD_SUB_TYPE.NULL)
		{
			STUFF(isc_dyn_fld_sub_type);
			STUFF_WORD(2);
			STUFF_WORD(Y.RDB$FIELD_SUB_TYPE);
		}

		if (!Y.RDB$SEGMENT_LENGTH.NULL)
		{
			STUFF(isc_dyn_fld_segment_length);
			STUFF_WORD(2);
			STUFF_WORD(Y.RDB$SEGMENT_LENGTH);
		}

		if (!Y.RDB$SYSTEM_FLAG.NULL)
		{
			STUFF(isc_dyn_system_flag);
			STUFF_WORD(2);
			STUFF_WORD(Y.RDB$SYSTEM_FLAG);
		}

		if (!Y.RDB$QUERY_NAME.NULL)
		{
			STUFF(isc_dyn_fld_query_name);
			STUFF_STRING(Y.RDB$QUERY_NAME);
		}

		if (!Y.RDB$EDIT_STRING.NULL)
		{
			STUFF(isc_dyn_fld_edit_string);
			STUFF_STRING(Y.RDB$EDIT_STRING);
		}

		if (!Y.RDB$MISSING_VALUE.NULL)
		{
			STUFF(isc_dyn_fld_missing_value);
			blob_copy(rlb, source, Y.RDB$MISSING_VALUE);
		}

		if (!Y.RDB$DEFAULT_VALUE.NULL)
		{
			STUFF(isc_dyn_fld_default_value);
			blob_copy(rlb, source, Y.RDB$DEFAULT_VALUE);
		}

		if (!Y.RDB$QUERY_HEADER.NULL)
		{
			STUFF(isc_dyn_fld_query_header);
			blob_copy(rlb, source, Y.RDB$QUERY_HEADER);
		}

		if (!Y.RDB$DESCRIPTION.NULL)
		{
			STUFF(isc_dyn_description);
			blob_copy(rlb, source, Y.RDB$DESCRIPTION);
		}

		if (!Y.RDB$VALIDATION_BLR.NULL)
		{
			STUFF(isc_dyn_fld_validation_blr);
			blob_copy(rlb, source, Y.RDB$VALIDATION_BLR);
		}

		if (!Y.RDB$VALIDATION_SOURCE.NULL)
		{
			STUFF(isc_dyn_fld_validation_source);
			blob_copy(rlb, source, Y.RDB$VALIDATION_SOURCE);
		}

		if ((target->rel_database->dbb_capabilities & DBB_cap_dimensions) &&
			(source->rel_database->dbb_capabilities & DBB_cap_dimensions))
		{
			bool first_dimension = true;
			FOR(REQUEST_HANDLE req3 TRANSACTION_HANDLE s_trans)
				F IN DB.RDB$FIELDS CROSS
					D IN DB.RDB$FIELD_DIMENSIONS
					WITH F.RDB$FIELD_NAME = D.RDB$FIELD_NAME AND
					F.RDB$FIELD_NAME = Y.RDB$FIELD_NAME

				if (first_dimension)
				{
					first_dimension = false;
					STUFF(isc_dyn_fld_dimensions);
					STUFF_WORD(2);
					STUFF_WORD(F.RDB$DIMENSIONS);
				}

				STUFF(isc_dyn_def_dimension);
				STUFF_WORD(2);
				STUFF_WORD(D.RDB$DIMENSION);

				if (!D.RDB$LOWER_BOUND.NULL)
				{
					STUFF(isc_dyn_dim_lower);
					STUFF_WORD(2);
					STUFF_WORD(D.RDB$LOWER_BOUND);
				}

				if (!D.RDB$UPPER_BOUND.NULL)
				{
					STUFF(isc_dyn_dim_upper);
					STUFF_WORD(2);
					STUFF_WORD(D.RDB$UPPER_BOUND);
				}
				STUFF(isc_dyn_end);
			END_FOR
			ON_ERROR
				if (target->rel_database->dbb_meta_trans)
					rollback_update(target->rel_database);
				rollback_update(source->rel_database);
				ERRQ_database_error(source->rel_database, gds_status);
			END_ERROR;
		}
		STUFF(isc_dyn_end);
	END_FOR
	ON_ERROR
		rollback_update(source->rel_database);
		if (target->rel_database->dbb_meta_trans)
			rollback_update(target->rel_database);
		ERRQ_database_error(source->rel_database, gds_status);
	END_ERROR;

	if (rlb)
	{
		STUFF(isc_dyn_end);
		STUFF(isc_dyn_eoc);
		execute_dynamic_ddl(target->rel_database, rlb);
	}

	release_request(source->rel_database, req1);
	release_request(target->rel_database, req2);
	release_request(source->rel_database, req3);
}


static void define_global_field( qli_dbb* database, qli_fld* field, qli_symbol* name)
{
/**************************************
 *
 *	d e f i n e _ g l o b a l _ f i e l d
 *
 **************************************
 *
 * Functional description
 *
 *	Define a global field if we've got enough
 *	information.
 *
 **************************************/
	if (!field->fld_dtype)
	{
		rollback_update(database);
		ERRQ_print_error(256, name->sym_string);	// Msg256 No datatype specified for field %s
	}

	STORE(REQUEST_HANDLE database->dbb_requests[REQ_store_field])
		X IN DB.RDB$FIELDS
        strcpy(X.RDB$FIELD_NAME, name->sym_string);
		X.RDB$FIELD_TYPE = blr_dtypes[field->fld_dtype];
		X.RDB$FIELD_SCALE = field->fld_scale;
		X.RDB$FIELD_LENGTH = (field->fld_dtype == dtype_varying) ?
			field->fld_length - sizeof(SSHORT) : field->fld_length;
		if (!field->fld_sub_type_missing)
		{
			X.RDB$FIELD_SUB_TYPE.NULL = FALSE;
			X.RDB$FIELD_SUB_TYPE = field->fld_sub_type;
		}
		else
			X.RDB$FIELD_SUB_TYPE.NULL = TRUE;
		const qli_symbol* symbol = field->fld_query_name;
		if (symbol)
		{
			X.RDB$QUERY_NAME.NULL = FALSE;
			strcpy(X.RDB$QUERY_NAME, symbol->sym_string);
		}
		else
			X.RDB$QUERY_NAME.NULL = TRUE;
		if (field->fld_edit_string)
		{
			X.RDB$EDIT_STRING.NULL = FALSE;
			strcpy(X.RDB$EDIT_STRING, field->fld_edit_string);
		}
		else
			X.RDB$EDIT_STRING.NULL = TRUE;
	END_STORE
	ON_ERROR
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	END_ERROR;
}


static void delete_fields( qli_rel* relation)
{
/**************************************
 *
 *	d e l e t e _ f i e l d s
 *
 **************************************
 *
 * Functional description
 *	Delete field definitions.
 *
 **************************************/
	while (qli_fld* field = relation->rel_fields)
	{
		relation->rel_fields = field->fld_next;
		ALLQ_release((qli_frb*) field->fld_name);
		if (field->fld_query_name)
			ALLQ_release((qli_frb*) field->fld_query_name);
		ALLQ_release((qli_frb*) field);
	}

	relation->rel_flags &= ~REL_fields;
}


static ISC_STATUS detach(ISC_STATUS* status_vector, qli_dbb* dbb)
{
/**************************************
 *
 *	d e t a c h
 *
 **************************************
 *
 * Functional description
 *	Shut down a database.  Return the status of the
 *	first failing call, if any.
 *
 **************************************/
	if (!dbb->dbb_handle)
		return FB_SUCCESS;

	ISC_STATUS_ARRAY alt_vector;
	ISC_STATUS* status = status_vector;

	if (dbb->dbb_transaction)
		if (isc_commit_transaction(status, &dbb->dbb_transaction))
			status = alt_vector;

	if (dbb->dbb_proc_trans && (dbb->dbb_capabilities & DBB_cap_multi_trans))
		if (isc_commit_transaction(status, &dbb->dbb_proc_trans))
			status = alt_vector;

	if (dbb->dbb_meta_trans && (dbb->dbb_capabilities & DBB_cap_multi_trans))
		if (isc_commit_transaction(status, &dbb->dbb_meta_trans))
			status = alt_vector;

	isc_detach_database(status, &dbb->dbb_handle);

	return status_vector[1];
}


static void execute_dynamic_ddl( qli_dbb* database, qli_rlb* rlb)
{
/**************************************
 *
 *	e x e c u t e _ d y n a m i c _ d d l
 *
 **************************************
 *
 * Functional description
 *	Execute a ddl command, for better or for worse.
 *
 **************************************/
	const USHORT length = rlb->rlb_data - rlb->rlb_base;

	if (QLI_blr)
		PRETTY_print_dyn(rlb->rlb_base, NULL, NULL, 0);

	if (isc_ddl(gds_status, &database->dbb_handle, &database->dbb_meta_trans,
				 length, (const char*) rlb->rlb_base))
	{
		rollback_update(database);
		ERRQ_database_error(database, gds_status);
	}

	GEN_rlb_release (rlb);

}


static int field_length( USHORT dtype, USHORT length)
{
/**************************************
 *
 *	f i e l d _ l e n g t h
 *
 **************************************
 *
 * Functional description
 *	Return implementation specific length for field.
 *
 **************************************/

	switch (dtype)
	{
	case dtype_short:
		return sizeof(SSHORT);
	case dtype_long:
		return sizeof(SLONG);
	case dtype_real:
		return sizeof(float);
	case dtype_double:
		return sizeof(double);
	case dtype_int64:
		return sizeof(SINT64);

	case dtype_sql_time:
	case dtype_sql_date:
		return sizeof(SLONG);

	case dtype_timestamp:
	case dtype_blob:
	case dtype_quad:
		return sizeof(ISC_QUAD);
	}

	return length;
}


static void get_database_type( qli_dbb* new_dbb)
{
/**************************************
 *
 *	g e t _ d a t a b a s e _ t y p e
 *
 **************************************
 *
 * Functional description
 *	Ask what type of database this is.
 *
 **************************************/
	ISC_STATUS_ARRAY status_vector;
	UCHAR buffer[1024];

	isc_database_info(status_vector, &new_dbb->dbb_handle, sizeof(db_info),
					   reinterpret_cast<const char*>(db_info),
					   sizeof(buffer), (char*) buffer);

	if (status_vector[1])
		ERRQ_database_error(new_dbb, gds_status);

	const UCHAR* p = buffer;

	while (*p != isc_info_end && p < buffer + sizeof(buffer))
	{
		UCHAR item = *p++;
		const USHORT l = gds__vax_integer(p, 2);
		p += 2;
		switch (item)
		{
		case isc_info_implementation:
			{
				const UCHAR* q = p;
				int count = *q++;
				while (count--)
				{
					//new_dbb->dbb_type = *q; // Not used
					++q;
					if (*q++ == isc_info_db_class_access)
						break;
				}
			}
			break;

		default:
			ERRQ_error(257);
			// Msg257 database info call failed
		}
		p += l;
	}
}


static TEXT* get_query_header( qli_dbb* database, ISC_QUAD& blob_id)
{
/**************************************
 *
 *	g e t _ q u e r y _ h e a d e r
 *
 **************************************
 *
 * Functional description
 *	Pick up a query header for a field.
 *
 **************************************/
	ISC_STATUS_ARRAY status_vector;
	TEXT header[1024], buffer[1024];
	UserBlob blob(status_vector);

	if (!blob.open(database->dbb_handle, gds_trans, blob_id))
	{
		ERRQ_database_error(database, status_vector);
	}

	TEXT* p = header;
	const char* const end = header + sizeof(header) - 3;

	// CVC: No bounds check here: it's assumed that 1024 is enough, but "p"
	// might overflow "header" eventually.
	for (;;)
	{
		if (p >= end)
			break;
		FB_SIZE_T length;
		if (!blob.getSegment(sizeof(buffer), buffer, length))
			break;
		if (length && buffer[length - 1] == '\n')
			--length;
		buffer[length] = 0;
		const TEXT* q = buffer;
		if (*q == '"')
			do {
				*p++ = *q++;
			} while (*q && p < end);
		else
		{
			*p++ = '"';
			while (*q && p < end)
				*p++ = *q++;
			*p++ = '"';
		}
	}

	if (!blob.close())
		ERRQ_database_error(database, gds_status);

	*p = 0;
	if (!strcmp(header, "\" \""))
	{
		header[0] = '-';
		header[1] = 0;
		p = header + 1;
	}

	const USHORT len = p - header;
	if (len)
		return make_string(header, len);

	return NULL;
}


static void install( qli_dbb* old_dbb)
{
/**************************************
 *
 *	i n s t a l l
 *
 **************************************
 *
 * Functional description
 *	Install a database.  Scan relations, etc., make up relation
 *	blocks, etc, and copy the database block to someplace more
 *	permanent.
 *
 **************************************/

	// Copy the database block to one out of the permanent pool

	const SSHORT l = old_dbb->dbb_filename_length;
	qli_dbb* new_dbb = (qli_dbb*) ALLOCPV(type_dbb, l);
	new_dbb->dbb_filename_length = l;
	memcpy(new_dbb->dbb_filename, old_dbb->dbb_filename, l);
	DB = new_dbb->dbb_handle = old_dbb->dbb_handle;
	new_dbb->dbb_capabilities = old_dbb->dbb_capabilities;

	new_dbb->dbb_next = QLI_databases;
	QLI_databases = new_dbb;

	// If a name was given, make up a symbol for the database.

	qli_name* name = (qli_name*) old_dbb->dbb_symbol;
	if (name)
	{
		qli_symbol* asymbol = make_symbol(name->nam_string, name->nam_length);
		new_dbb->dbb_symbol = asymbol;
		asymbol->sym_type = SYM_database;
		asymbol->sym_object = (BLK) new_dbb;
		HSH_insert(asymbol, true);
	}

	gds_trans = MET_transaction(nod_start_trans, new_dbb);

	// Find out whose database this is so later we don't ask Rdb/VMS
	// or its pals to do any unnatural acts.  While we're at it get
	// general capabilities

	get_database_type(new_dbb);
	set_capabilities(new_dbb);

	if (new_dbb->dbb_capabilities & DBB_cap_nodyn)
	{
		const char* str = new_dbb->dbb_filename;
		if (name && strncmp(name->nam_string, "QLI_", 4))
			str = name->nam_string;
		ERRQ_msg_put(530, str);
	}

	// Get all relations in database.  For each relation make up a
	// relation block, make up a symbol block, and insert the symbol
	// into the hash table.

	FB_API_HANDLE request = 0;

	FOR(REQUEST_HANDLE request) X IN DB.RDB$RELATIONS
		SORTED BY DESCENDING X.RDB$RELATION_NAME

		qli_rel* relation = (qli_rel*) ALLOCP(type_rel);
		relation->rel_next = new_dbb->dbb_relations;
		new_dbb->dbb_relations = relation;
		relation->rel_database = new_dbb;
		relation->rel_id = X.RDB$RELATION_ID;
		qli_symbol* rsymbol = make_symbol(X.RDB$RELATION_NAME, sizeof(X.RDB$RELATION_NAME));
		rsymbol->sym_type = SYM_relation;
		rsymbol->sym_object = (BLK) relation;
		relation->rel_symbol = rsymbol;
		HSH_insert(rsymbol);
		if (strcmp(rsymbol->sym_string, "QLI$PROCEDURES") == 0)
			new_dbb->dbb_flags |= DBB_procedures;
		if (relation->rel_system_flag = X.RDB$SYSTEM_FLAG)
			relation->rel_flags |= REL_system;
		if (!X.RDB$VIEW_BLR.NULL)
			relation->rel_flags |= REL_view;
	END_FOR
	ON_ERROR
		ERRQ_database_error(new_dbb, gds_status);
	END_ERROR;

	release_request(new_dbb, request);

	// Pick up functions, if appropriate

	if (new_dbb->dbb_capabilities & DBB_cap_functions)
	{
		FB_API_HANDLE request2 = 0;
		FOR(REQUEST_HANDLE request) X IN DB.RDB$FUNCTIONS
		    qli_symbol* fsymbol = make_symbol(X.RDB$FUNCTION_NAME, sizeof(X.RDB$FUNCTION_NAME));
			if (!fsymbol)
                continue;
			//qli_fun* function = (qli_fun*) ALLOCPV(type_fun, 0);
			qli_fun* function = (qli_fun*) ALLOCP(type_fun);
			function->fun_next = new_dbb->dbb_functions;
			new_dbb->dbb_functions = function;
			function->fun_symbol = fsymbol;
			function->fun_database = new_dbb;
			FOR(REQUEST_HANDLE request2) Y IN DB.RDB$FUNCTION_ARGUMENTS WITH
				Y.RDB$FUNCTION_NAME EQ X.RDB$FUNCTION_NAME AND
					Y.RDB$ARGUMENT_POSITION EQ X.RDB$RETURN_ARGUMENT
				function->fun_return.dsc_dtype = MET_get_datatype(Y.RDB$FIELD_TYPE);
				function->fun_return.dsc_length =
					field_length(function->fun_return.dsc_dtype, Y.RDB$FIELD_LENGTH);
				function->fun_return.dsc_scale = Y.RDB$FIELD_SCALE;
			END_FOR
			ON_ERROR
				ERRQ_database_error(new_dbb, gds_status);
			END_ERROR;
			if (!function->fun_return.dsc_dtype)
			{
				function->fun_return.dsc_dtype = dtype_text;
				function->fun_return.dsc_length = 20;
			}
			fsymbol->sym_type = SYM_function;
			fsymbol->sym_object = (BLK) function;
			HSH_insert(fsymbol);

			// Insert another symbol if there is a function query name

            qli_symbol* symbol2 = make_symbol(X.RDB$QUERY_NAME, sizeof(X.RDB$QUERY_NAME));
			if (symbol2)
			{
				function->fun_query_name = symbol2;
				symbol2->sym_type = SYM_function;
				symbol2->sym_object = (BLK) function;
				HSH_insert(symbol2, true);
			}
		END_FOR
		ON_ERROR
			ERRQ_database_error(new_dbb, gds_status);
		END_ERROR;
		release_request(new_dbb, request);
		release_request(new_dbb, request2);
	}
}


static qli_syntax* make_node( nod_t type, USHORT count)
{
/**************************************
 *
 *	m a k e _ n o d e
 *
 **************************************
 *
 * Functional description
 *	Generate a syntax node.
 *
 **************************************/
	qli_syntax* node = (qli_syntax*) ALLOCPV(type_syn, count);
	node->syn_count = count;
	node->syn_type = type;

	return node;
}


static TEXT* make_string( TEXT* string, SSHORT length)
{
/**************************************
 *
 *	m a k e _ s t r i n g
 *
 **************************************
 *
 * Functional description
 *	Make up a permanent string from a large string.  Chop off
 *	trailing blanks.  If there's nothing left, return NULL.
 *
 **************************************/
	fb_assert(length > 0);

	string[length] = 0;

	if (!(length = truncate_string(string)))
		return NULL;

	qli_str* str = (qli_str*) ALLOCPV(type_str, length + 1);
	TEXT* p = str->str_data;
	do {
		*p++ = *string++;
	} while (--length);
	*p = 0;

	return str->str_data;
}


static qli_symbol* make_symbol( TEXT* string, SSHORT length)
{
/**************************************
 *
 *	m a k e _ s y m b o l
 *
 **************************************
 *
 * Functional description
 *	Make up a symbol from a string.  If the string is all blanks,
 *	don't make up a symbol.  Phooey.
 *
 **************************************/
	if (!(length = truncate_string(string)))
		return NULL;

	qli_symbol* symbol = (qli_symbol*) ALLOCPV(type_sym, length);
	symbol->sym_type = SYM_relation;
	symbol->sym_length = length;
	TEXT* p = symbol->sym_name;
	symbol->sym_string = p;
	memcpy(p, string, length);
	return symbol;
}


static qli_const* missing_value( ISC_QUAD& blob_id, qli_symbol* symbol)
{
/**************************************
 *
 *	m i s s i n g _ v a l u e
 *
 **************************************
 *
 * Functional description
 *	Get a missing value into a constant
 *	block for later reference.
 *
 **************************************/
	qli_syntax* element = parse_blr_blob(blob_id, symbol);
	if (element)
		return ((qli_const*) element->syn_arg[0]);

	return NULL;
}


static qli_syntax* parse_blr( UCHAR** ptr, qli_symbol* symbol)
{
/**************************************
 *
 *	p a r s e _ b l r
 *
 **************************************
 *
 * Functional description
 *	Parse a BLR expression.
 *
 **************************************/
	qli_syntax** arg;
	qli_const* constant;
	nod_t operatr;
	qli_name* name;
	UCHAR* p;
	SSHORT dtype, scale, length, l, op;

	UCHAR* blr = *ptr;
	SSHORT args = 2;
	qli_syntax* node = NULL;

	switch (op = BLR_BYTE)
	{
	case blr_any:
	case blr_unique:
	case blr_eoc:
		return NULL;

	case blr_eql:
		operatr = nod_eql;
		break;
	case blr_neq:
		operatr = nod_neq;
		break;
	case blr_gtr:
		operatr = nod_gtr;
		break;
	case blr_geq:
		operatr = nod_geq;
		break;
	case blr_lss:
		operatr = nod_lss;
		break;
	case blr_leq:
		operatr = nod_leq;
		break;
	case blr_containing:
		operatr = nod_containing;
		break;
	case blr_starting:
		operatr = nod_starts;
		break;
	case blr_matching:
		operatr = nod_matches;
		break;
	case blr_matching2:
		operatr = nod_sleuth;
		break;
	case blr_like:
		operatr = nod_like;
		break;
	case blr_and:
		operatr = nod_and;
		break;
	case blr_or:
		operatr = nod_or;
		break;
	case blr_add:
		operatr = nod_add;
		break;
	case blr_subtract:
		operatr = nod_subtract;
		break;
	case blr_multiply:
		operatr = nod_multiply;
		break;
	case blr_divide:
		operatr = nod_divide;
		break;
	case blr_upcase:
		operatr = nod_upcase;
		break;
	case blr_lowcase:
		operatr = nod_lowcase;
		break;
	case blr_null:
		operatr = nod_null;
		break;

	case blr_between:
		operatr = nod_between;
		args = 3;
		break;

	case blr_not:
		operatr = nod_not;
		args = 1;
		break;

	case blr_negate:
		operatr = nod_negate;
		args = 1;
		break;

	case blr_missing:
		operatr = nod_missing;
		args = 1;
		break;

	case blr_fid:
		(void) BLR_BYTE;
		blr += 2;
		node = make_node(nod_field, 1);
		name = (qli_name*) ALLOCPV(type_nam, symbol->sym_length);
		node->syn_arg[0] = (qli_syntax*) name;
		name->nam_length = symbol->sym_length;
		strcpy(name->nam_string, symbol->sym_string);
		break;

	case blr_field:
		(void) BLR_BYTE;
		length = BLR_BYTE;
		node = make_node(nod_field, 1);
		name = (qli_name*) ALLOCPV(type_nam, length);
		node->syn_arg[0] = (qli_syntax*) name;
		name->nam_length = length;
		p = (UCHAR*) name->nam_string;
		do {
			*p++ = BLR_BYTE;
		} while (--length);
		break;

	case blr_function:
		length = BLR_BYTE;
		node = make_node(nod_function, s_fun_count);
		node->syn_arg[s_fun_function] = (qli_syntax*) HSH_lookup((SCHAR*) blr, length);
		blr += length;
		args = BLR_BYTE;
		node->syn_arg[s_fun_args] = make_node(nod_list, args);
		arg = node->syn_arg[s_fun_args]->syn_arg;
		while (--args >= 0)
		{
			if (!(*arg++ = parse_blr(&blr, symbol)))
				return NULL;
		}
		break;

	case blr_literal:
		scale = 0;
		switch (BLR_BYTE)
		{
		case blr_text:
			dtype = dtype_text;
			length = l = gds__vax_integer(blr, 2);
			blr += 2;
			break;

		case blr_text2:
			dtype = dtype_text;
			scale = gds__vax_integer(blr, 2);
			blr += 2;
			length = l = gds__vax_integer(blr, 2);
			blr += 2;
			break;

		case blr_varying:
			dtype = dtype_varying;
			length = l = static_cast<SSHORT>(gds__vax_integer(blr, 2) + sizeof(USHORT));
			blr += 2;
			break;

		case blr_varying2:
			dtype = dtype_varying;
			scale = gds__vax_integer(blr, 2);
			blr += 2;
			length = l = static_cast<SSHORT>(gds__vax_integer(blr, 2) + sizeof(USHORT));
			blr += 2;
			break;

		case blr_short:
			dtype = dtype_short;
			l = 2;
			length = sizeof(SSHORT);
			scale = (int) BLR_BYTE;
			break;

		case blr_long:
			dtype = dtype_long;
			length = sizeof(SLONG);
			l = 4;
			scale = (int) BLR_BYTE;
			break;

		case blr_quad:
			dtype = dtype_quad;
			l = 8;
			length = sizeof(ISC_QUAD);
			scale = (int) BLR_BYTE;
			break;

		case blr_int64:
			dtype = dtype_int64;
			l = 8;
			length = sizeof(SINT64);
			scale = (int) BLR_BYTE;
			break;

		case blr_timestamp:
			dtype = dtype_timestamp;
			l = 8;
			length = sizeof(ISC_QUAD);
			break;

		case blr_sql_date:
			dtype = dtype_sql_date;
			l = 4;
			length = sizeof(SLONG);
			break;

		case blr_sql_time:
			dtype = dtype_sql_time;
			l = 4;
			length = sizeof(ULONG);
			break;
		}
		constant = (qli_const*) ALLOCPV(type_con, length);
		constant->con_desc.dsc_dtype = dtype;
		constant->con_desc.dsc_scale = scale;
		constant->con_desc.dsc_length = length;
		constant->con_desc.dsc_address = p = constant->con_data;
		QLI_validate_desc(constant->con_desc);
		switch (dtype)
		{
		case dtype_text:
			while (l--)
				*p++ = BLR_BYTE;
			break;
		case dtype_short:
			*(SSHORT*) p = gds__vax_integer(blr, l);
			blr += l;
			break;
		case dtype_long:
			*(SLONG*) p = gds__vax_integer(blr, l);
			blr += l;
			break;
		}
		node = make_node(nod_constant, 1);
		node->syn_count = 0;
		node->syn_arg[0] = (qli_syntax*) constant;
		break;

	default:
		ERRQ_print_error(258, SafeArg() << op);	// Msg258 don't understand BLR operatr %d
	}

	if (!node)
	{
		node = make_node(operatr, args);
		arg = node->syn_arg;
		while (--args >= 0)
		{
			if (!(*arg++ = parse_blr(&blr, symbol)))
				return NULL;
		}
	}

	*ptr = blr;

	return node;
}


static qli_syntax* parse_blr_blob(ISC_QUAD& blob_id, qli_symbol* symbol)
{
/**************************************
 *
 *	p a r s e _ b l r _ b l o b
 *
 **************************************
 *
 * Functional description
 *	Gobble up a BLR blob, if possible.
 *
 **************************************/
	ISC_STATUS_ARRAY status_vector;

	if (UserBlob::blobIsNull(blob_id))
		return NULL;

	UserBlob handle(status_vector);

	if (!handle.open(DB, gds_trans, blob_id))
		return NULL;

	UCHAR buffer[1024];
	UCHAR* ptr = buffer;

	for (;;)
	{
		FB_SIZE_T length = buffer + sizeof(buffer) - ptr;
		if (!length)
			break;
		// The old code considered getting a portion of a segment a bug.
		// Anyway, 1024 is not much to contain the BLR stream, even for validation.
		if (!handle.getSegment(length, ptr, length) || handle.getCode())
			break;
		ptr += length;
	}

	if (!handle.close())
		return NULL;

	if (ptr == buffer)
		return NULL;

	ptr = buffer;

	if (*ptr++ != blr_version4)
		return NULL;

	qli_syntax* node = parse_blr(&ptr, symbol);

	if (*ptr != blr_eoc)
		return NULL;

	return node;
}


static void purge_relation(qli_rel* relation)
{
/**************************************
 *
 *	p u r g e _ r e l a t i o n
 *
 **************************************
 *
 * Functional description
 *	Purge a relation out of internal data structures.
 *
 **************************************/
	qli_symbol* symbol = relation->rel_symbol;
	qli_dbb* database = relation->rel_database;
	HSH_remove(symbol);

	for (qli_rel** ptr = &database->dbb_relations; *ptr; ptr = &(*ptr)->rel_next)
	{
		if (*ptr == relation)
		{
			*ptr = relation->rel_next;
			break;
		}
	}

	qli_fld* field;
	while (field = relation->rel_fields)
	{
		relation->rel_fields = field->fld_next;
		ALLQ_release((qli_frb*) field->fld_name);
		if (symbol = field->fld_query_name) {
			ALLQ_release((qli_frb*) symbol);
		}
		ALLQ_release((qli_frb*) field);
	}

	ALLQ_release((qli_frb*) relation);
}


static void put_dyn_string( qli_rlb* rlb, const TEXT* string)
{
/**************************************
 *
 *	p u t _ d y n _ s t r i n g
 *
 **************************************
 *
 * Functional description
 *	Move a string to a dynamic DDL command block.
 *
 **************************************/

	const SSHORT l = static_cast<SSHORT>(strlen(string));

	while ((SSHORT) (rlb->rlb_limit - rlb->rlb_data) < l) {
		rlb = GEN_rlb_extend(rlb);
	}

	STUFF_WORD(l);

	while (*string) {
		STUFF(*string++);
	}
	CHECK_RLB(rlb);
}


static void release_request(qli_dbb* db, FB_API_HANDLE& request_handle)
{
	if (request_handle)
	{
		if (isc_release_request(gds_status, &request_handle))
			ERRQ_database_error(db, gds_status);
	}
}


static void rollback_update( qli_dbb* database)
{
/**************************************
 *
 *	 r o l l b a c k _ u p d a t e
 *
 **************************************
 *
 * Functional description
 *	Roll back  a meta-data update.
 *
 **************************************/
	if (gds_trans == database->dbb_meta_trans &&
		(database->dbb_capabilities & DBB_cap_multi_trans))
	{
	    ISC_STATUS_ARRAY alt_vector;
		isc_rollback_transaction(alt_vector, &database->dbb_meta_trans);
		// Note: No message given if rollback fails
	}

	gds_trans = 0;
}


static void set_capabilities( qli_dbb* database)
{
/**************************************
 *
 *	s e t _ c a p a b i l i t i e s
 *
 **************************************
 *
 * Functional description
 *	Probe the database to determine
 *	what metadata capabilities it has.
 *	The table, rfr_table, in the static
 *	data declarations has the relation
 *	and field names, together with the
 *	capabilities bits.
 *
 **************************************/
	FB_API_HANDLE req = 0;

	// Look for desireable fields in system relations

	for (const rfr_tab_t* rel_field_table = rfr_table; rel_field_table->relation; rel_field_table++)
	{
		FOR(REQUEST_HANDLE req) x IN DB.RDB$RELATION_FIELDS
			WITH x.RDB$RELATION_NAME = rel_field_table->relation
				AND x.RDB$FIELD_NAME = rel_field_table->field

            database->dbb_capabilities |= rel_field_table->bit_mask;
		END_FOR
		ON_ERROR
			ERRQ_database_error(database, gds_status);
		END_ERROR;
	}

	release_request(database, req);
}


static qli_dbb* setup_update( qli_dbb* database)
{
/**************************************
 *
 *	s e t u p _ u p d a t e
 *
 **************************************
 *
 * Functional description
 *	Get ready to do a meta data update.
 *	If no database was specified, use the
 *	most recently readied one.
 *
 **************************************/

	if (!database)
		database = QLI_databases;

	MET_meta_transaction(database, true);

	return database;
}


static void sql_grant_revoke( qli_syntax* node, USHORT type)
{
/*****************************************************
 *
 *	s q l _ g r a n t _ r e v o k e
 *
 *****************************************************
 *
 *	Build a DYN string for a SQL GRANT or REVOKE statement
 *
 *****************************************************/
	const USHORT privileges = (IPTR) node->syn_arg[s_grant_privileges];
	qli_rel* relation = (qli_rel*) node->syn_arg[s_grant_relation];
	qli_dbb* database = setup_update(relation->rel_database);
	relation->rel_database = database;
	const TEXT* relation_name = relation->rel_symbol->sym_string;

	qli_rlb* rlb = NULL;
	CHECK_RLB(rlb);

	STUFF(isc_dyn_version_1);
	STUFF(isc_dyn_begin);

	// For each user create a separate grant string
	//      For each specified field create a separate grant string

	qli_syntax* names = node->syn_arg[s_grant_users];
	qli_syntax* fields = node->syn_arg[s_grant_fields];

	qli_name** name = (qli_name**) names->syn_arg;
	for (qli_name** const end = name + names->syn_count; name < end; name++)
	{
		if (fields->syn_count)
		{
		    qli_name** field = (qli_name**) fields->syn_arg;
		    qli_name** const end_field = field + fields->syn_count;
			for (; field < end_field; field++)
			{
				stuff_priv(rlb, type, relation_name, privileges,
						   (*name)->nam_string, (*field)->nam_string);
			}
		}
		else
			stuff_priv(rlb, type, relation_name, privileges, (*name)->nam_string, NULL);
	}

	STUFF(isc_dyn_end);
	STUFF(isc_dyn_eoc);

	execute_dynamic_ddl(database, rlb);
	MET_meta_commit(database);
}


static int truncate_string( TEXT* string)
{
/**************************************
 *
 *	t r u n c a t e _ s t r i n g
 *
 **************************************
 *
 * Functional description
 *	Convert a blank filled string to
 *	a null terminated string without
 *	trailing blanks.  Because some
 *	strings contain embedded blanks
 *	(e.g. query headers & edit strings)
 *	truncate from the back forward.
 *	Return the number of characters found,
 *	not including the terminating null.
 *
 **************************************/
	const int len = fb_utils::name_length(string);
	string[len] = 0;
	return len;
}


static void stuff_priv(qli_rlb* rlb, USHORT type,
					   const TEXT* relation, USHORT privileges, const TEXT* user, const TEXT* field)
{
/**************************************
 *
 *	s t u f f _ p r i v
 *
 **************************************
 *
 * Functional description
 *	Stuff a privilege for grant/revoke.
 *
 **************************************/
	CHECK_RLB(rlb);
	STUFF(type);

	// Stuff privileges first

	USHORT priv_count = 0;
	if (privileges & PRV_select)
		priv_count++;
	if (privileges & PRV_insert)
		priv_count++;
	if (privileges & PRV_delete)
		priv_count++;
	if (privileges & PRV_update)
		priv_count++;

	STUFF_WORD(priv_count);

	if (privileges & PRV_select)
		STUFF('S');

	if (privileges & PRV_insert)
		STUFF('I');

	if (privileges & PRV_delete)
		STUFF('D');

	if (privileges & PRV_update)
		STUFF('U');

	STUFF(isc_dyn_rel_name);
	STUFF_STRING(relation);

	STUFF(isc_dyn_grant_user);
	STUFF_STRING(user);

	if (field)
	{
		STUFF(isc_dyn_fld_name);
		STUFF_STRING(field);
	}

	if (privileges & PRV_grant_option)
	{
		STUFF(isc_dyn_grant_options);
		STUFF_WORD(2);
		STUFF_WORD(TRUE);
	}

	STUFF(isc_dyn_end);
}

