/*
 * intorel_startup --- executor startup
 */
static void
intorel_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
{
	DR_intorel *myState = (DR_intorel *) self;
	IntoClause *into = myState->into;
	bool		is_matview;
	char		relkind;
	CreateStmt *create;
	Oid			intoRelationId;
	Relation	intoRelationDesc;
	RangeTblEntry *rte;
	Datum		toast_options;
	ListCell   *lc;
	int			attnum;
	static char *validnsps[] = HEAP_RELOPT_NAMESPACES;

	Assert(into != NULL);		/* else somebody forgot to set it */

	/* This code supports both CREATE TABLE AS and CREATE MATERIALIZED VIEW */
	is_matview = (into->viewQuery != NULL);
	relkind = is_matview ? RELKIND_MATVIEW : RELKIND_RELATION;

	/*
	 * Create the target relation by faking up a CREATE TABLE parsetree and
	 * passing it to DefineRelation.
	 */
	create = makeNode(CreateStmt);
	create->relation = into->rel;
	create->tableElts = NIL;	/* will fill below */
	create->inhRelations = NIL;
	create->ofTypename = NULL;
	create->constraints = NIL;
	create->options = into->options;
	create->oncommit = into->onCommit;
	create->tablespacename = into->tableSpaceName;
	create->if_not_exists = false;

	/*
	 * Build column definitions using "pre-cooked" type and collation info. If
	 * a column name list was specified in CREATE TABLE AS, override the
	 * column names derived from the query.  (Too few column names are OK, too
	 * many are not.)
	 */
	lc = list_head(into->colNames);
	for (attnum = 0; attnum < typeinfo->natts; attnum++)
	{
		Form_pg_attribute attribute = typeinfo->attrs[attnum];
		ColumnDef  *col = makeNode(ColumnDef);
		TypeName   *coltype = makeNode(TypeName);

		if (lc)
		{
			col->colname = strVal(lfirst(lc));
			lc = lnext(lc);
		}
		else
			col->colname = NameStr(attribute->attname);
		col->typeName = coltype;
		col->inhcount = 0;
		col->is_local = true;
		col->is_not_null = false;
		col->is_from_type = false;
		col->storage = 0;
		col->raw_default = NULL;
		col->cooked_default = NULL;
		col->collClause = NULL;
		col->collOid = attribute->attcollation;
		col->constraints = NIL;
		col->fdwoptions = NIL;

		coltype->names = NIL;
		coltype->typeOid = attribute->atttypid;
		coltype->setof = false;
		coltype->pct_type = false;
		coltype->typmods = NIL;
		coltype->typemod = attribute->atttypmod;
		coltype->arrayBounds = NIL;
		coltype->location = -1;

		/*
		 * It's possible that the column is of a collatable type but the
		 * collation could not be resolved, so double-check.  (We must check
		 * this here because DefineRelation would adopt the type's default
		 * collation rather than complaining.)
		 */
		if (!OidIsValid(col->collOid) &&
			type_is_collatable(coltype->typeOid))
			ereport(ERROR,
					(errcode(ERRCODE_INDETERMINATE_COLLATION),
					 errmsg("no collation was derived for column \"%s\" with collatable type %s",
							col->colname, format_type_be(coltype->typeOid)),
					 errhint("Use the COLLATE clause to set the collation explicitly.")));

		create->tableElts = lappend(create->tableElts, col);
	}

	if (lc != NULL)
//.........这里部分代码省略.........

//.........这里部分代码省略.........
	{
		switch (tupdesc->attrs[i]->atttypid)
		{
			case ANYELEMENTOID:
				have_anyelement_result = true;
				break;
			case ANYARRAYOID:
				have_anyarray_result = true;
				break;
			case ANYNONARRAYOID:
				have_anyelement_result = true;
				have_anynonarray = true;
				break;
			case ANYENUMOID:
				have_anyelement_result = true;
				have_anyenum = true;
				break;
			default:
				break;
		}
	}
	if (!have_anyelement_result && !have_anyarray_result)
		return true;

	/*
	 * Otherwise, extract actual datatype(s) from input arguments.	(We assume
	 * the parser already validated consistency of the arguments.)
	 */
	if (!call_expr)
		return false;			/* no hope */

	for (i = 0; i < nargs; i++)
	{
		switch (declared_args->values[i])
		{
			case ANYELEMENTOID:
			case ANYNONARRAYOID:
			case ANYENUMOID:
				if (!OidIsValid(anyelement_type))
					anyelement_type = get_call_expr_argtype(call_expr, i);
				break;
			case ANYARRAYOID:
				if (!OidIsValid(anyarray_type))
					anyarray_type = get_call_expr_argtype(call_expr, i);
				break;
			default:
				break;
		}
	}

	/* If nothing found, parser messed up */
	if (!OidIsValid(anyelement_type) && !OidIsValid(anyarray_type))
		return false;

	/* If needed, deduce one polymorphic type from the other */
	if (have_anyelement_result && !OidIsValid(anyelement_type))
		anyelement_type = resolve_generic_type(ANYELEMENTOID,
											   anyarray_type,
											   ANYARRAYOID);
	if (have_anyarray_result && !OidIsValid(anyarray_type))
		anyarray_type = resolve_generic_type(ANYARRAYOID,
											 anyelement_type,
											 ANYELEMENTOID);

	/* Enforce ANYNONARRAY if needed */
	if (have_anynonarray && type_is_array(anyelement_type))
		return false;

	/* Enforce ANYENUM if needed */
	if (have_anyenum && !type_is_enum(anyelement_type))
		return false;

	/* And finally replace the tuple column types as needed */
	for (i = 0; i < natts; i++)
	{
		switch (tupdesc->attrs[i]->atttypid)
		{
			case ANYELEMENTOID:
			case ANYNONARRAYOID:
			case ANYENUMOID:
				TupleDescInitEntry(tupdesc, i + 1,
								   NameStr(tupdesc->attrs[i]->attname),
								   anyelement_type,
								   -1,
								   0);
				break;
			case ANYARRAYOID:
				TupleDescInitEntry(tupdesc, i + 1,
								   NameStr(tupdesc->attrs[i]->attname),
								   anyarray_type,
								   -1,
								   0);
				break;
			default:
				break;
		}
	}

	return true;
}

//.........这里部分代码省略.........
	}
	else if (in_dbname != NULL)
	{
		HeapTuple	tuple;
		Form_pg_database dbform;

		tuple = GetDatabaseTuple(in_dbname);
		if (!HeapTupleIsValid(tuple))
			ereport(FATAL,
					(errcode(ERRCODE_UNDEFINED_DATABASE),
					 errmsg("database \"%s\" does not exist", in_dbname)));
		dbform = (Form_pg_database) GETSTRUCT(tuple);
		MyDatabaseId = HeapTupleGetOid(tuple);
		MyDatabaseTableSpace = dbform->dattablespace;
		/* take database name from the caller, just for paranoia */
		strlcpy(dbname, in_dbname, sizeof(dbname));
		pfree(tuple);
	}
	else
	{
		/* caller specified database by OID */
		HeapTuple	tuple;
		Form_pg_database dbform;

		tuple = GetDatabaseTupleByOid(dboid);
		if (!HeapTupleIsValid(tuple))
			ereport(FATAL,
					(errcode(ERRCODE_UNDEFINED_DATABASE),
					 errmsg("database %u does not exist", dboid)));
		dbform = (Form_pg_database) GETSTRUCT(tuple);
		MyDatabaseId = HeapTupleGetOid(tuple);
		MyDatabaseTableSpace = dbform->dattablespace;
		Assert(MyDatabaseId == dboid);
		strlcpy(dbname, NameStr(dbform->datname), sizeof(dbname));
		/* pass the database name back to the caller */
		if (out_dbname)
			strcpy(out_dbname, dbname);
		pfree(tuple);
	}

	/* Now we can mark our PGPROC entry with the database ID */
	/* (We assume this is an atomic store so no lock is needed) */
	MyProc->databaseId = MyDatabaseId;

	/*
	 * Now, take a writer's lock on the database we are trying to connect to.
	 * If there is a concurrently running DROP DATABASE on that database, this
	 * will block us until it finishes (and has committed its update of
	 * pg_database).
	 *
	 * Note that the lock is not held long, only until the end of this startup
	 * transaction.  This is OK since we are already advertising our use of
	 * the database in the PGPROC array; anyone trying a DROP DATABASE after
	 * this point will see us there.
	 *
	 * Note: use of RowExclusiveLock here is reasonable because we envision
	 * our session as being a concurrent writer of the database.  If we had a
	 * way of declaring a session as being guaranteed-read-only, we could use
	 * AccessShareLock for such sessions and thereby not conflict against
	 * CREATE DATABASE.
	 */
	if (!bootstrap)
		LockSharedObject(DatabaseRelationId, MyDatabaseId, 0,
						 RowExclusiveLock);

	/*

//.........这里部分代码省略.........
	 */
	resetStringInfo(&querybuf);
	appendStringInfo(&querybuf,
					 "SELECT newdata FROM %s newdata "
					 "WHERE newdata IS NOT NULL AND EXISTS "
					 "(SELECT * FROM %s newdata2 WHERE newdata2 IS NOT NULL "
					 "AND newdata2 OPERATOR(pg_catalog.*=) newdata "
					 "AND newdata2.ctid OPERATOR(pg_catalog.<>) "
					 "newdata.ctid) LIMIT 1",
					 tempname, tempname);
	if (SPI_execute(querybuf.data, false, 1) != SPI_OK_SELECT)
		elog(ERROR, "SPI_exec failed: %s", querybuf.data);
	if (SPI_processed > 0)
	{
		ereport(ERROR,
				(errcode(ERRCODE_CARDINALITY_VIOLATION),
				 errmsg("new data for \"%s\" contains duplicate rows without any null columns",
						RelationGetRelationName(matviewRel)),
				 errdetail("Row: %s",
			SPI_getvalue(SPI_tuptable->vals[0], SPI_tuptable->tupdesc, 1))));
	}

	SetUserIdAndSecContext(relowner,
						   save_sec_context | SECURITY_LOCAL_USERID_CHANGE);

	/* Start building the query for creating the diff table. */
	resetStringInfo(&querybuf);
	appendStringInfo(&querybuf,
					 "CREATE TEMP TABLE %s AS "
					 "SELECT mv.ctid AS tid, newdata "
					 "FROM %s mv FULL JOIN %s newdata ON (",
					 diffname, matviewname, tempname);

	/*
	 * Get the list of index OIDs for the table from the relcache, and look up
	 * each one in the pg_index syscache.  We will test for equality on all
	 * columns present in all unique indexes which only reference columns and
	 * include all rows.
	 */
	tupdesc = matviewRel->rd_att;
	foundUniqueIndex = false;
	indexoidlist = RelationGetIndexList(matviewRel);

	foreach(indexoidscan, indexoidlist)
	{
		Oid			indexoid = lfirst_oid(indexoidscan);
		Relation	indexRel;
		Form_pg_index indexStruct;

		indexRel = index_open(indexoid, RowExclusiveLock);
		indexStruct = indexRel->rd_index;

		/*
		 * We're only interested if it is unique, valid, contains no
		 * expressions, and is not partial.
		 */
		if (indexStruct->indisunique &&
			IndexIsValid(indexStruct) &&
			RelationGetIndexExpressions(indexRel) == NIL &&
			RelationGetIndexPredicate(indexRel) == NIL)
		{
			int			numatts = indexStruct->indnatts;
			int			i;

			/* Add quals for all columns from this index. */
			for (i = 0; i < numatts; i++)
			{
				int			attnum = indexStruct->indkey.values[i];
				Oid			type;
				Oid			op;
				const char *colname;

				/*
				 * Only include the column once regardless of how many times
				 * it shows up in how many indexes.
				 */
				if (usedForQual[attnum - 1])
					continue;
				usedForQual[attnum - 1] = true;

				/*
				 * Actually add the qual, ANDed with any others.
				 */
				if (foundUniqueIndex)
					appendStringInfoString(&querybuf, " AND ");

				colname = quote_identifier(NameStr((tupdesc->attrs[attnum - 1])->attname));
				appendStringInfo(&querybuf, "newdata.%s ", colname);
				type = attnumTypeId(matviewRel, attnum);
				op = lookup_type_cache(type, TYPECACHE_EQ_OPR)->eq_opr;
				mv_GenerateOper(&querybuf, op);
				appendStringInfo(&querybuf, " mv.%s", colname);

				foundUniqueIndex = true;
			}
		}

		/* Keep the locks, since we're about to run DML which needs them. */
		index_close(indexRel, NoLock);
	}

//.........这里部分代码省略.........
		case INT2OID:
			buf = pstrdup("smallint");
			break;

		case INT4OID:
			buf = pstrdup("integer");
			break;

		case INT8OID:
			buf = pstrdup("bigint");
			break;

		case NUMERICOID:
			if (with_typemod)
				buf = printTypmod("numeric", typemod, typeform->typmodout);
			else
				buf = pstrdup("numeric");
			break;

		case INTERVALOID:
			if (with_typemod)
				buf = printTypmod("interval", typemod, typeform->typmodout);
			else
				buf = pstrdup("interval");
			break;

		case TIMEOID:
			if (with_typemod)
				buf = printTypmod("time", typemod, typeform->typmodout);
			else
				buf = pstrdup("time without time zone");
			break;

		case TIMETZOID:
			if (with_typemod)
				buf = printTypmod("time", typemod, typeform->typmodout);
			else
				buf = pstrdup("time with time zone");
			break;

		case TIMESTAMPOID:
			if (with_typemod)
				buf = printTypmod("timestamp", typemod, typeform->typmodout);
			else
				buf = pstrdup("timestamp without time zone");
			break;

		case TIMESTAMPTZOID:
			if (with_typemod)
				buf = printTypmod("timestamp", typemod, typeform->typmodout);
			else
				buf = pstrdup("timestamp with time zone");
			break;

		case VARBITOID:
			if (with_typemod)
				buf = printTypmod("bit varying", typemod, typeform->typmodout);
			else
				buf = pstrdup("bit varying");
			break;

		case VARCHAROID:
			if (with_typemod)
				buf = printTypmod("character varying", typemod, typeform->typmodout);
			else
				buf = pstrdup("character varying");
			break;
	}

	if (buf == NULL)
	{
		/*
		 * Default handling: report the name as it appears in the catalog.
		 * Here, we must qualify the name if it is not visible in the search
		 * path, and we must double-quote it if it's not a standard identifier
		 * or if it matches any keyword.
		 */
		char	   *nspname;
		char	   *typname;

		if (TypeIsVisible(type_oid))
			nspname = NULL;
		else
			nspname = get_namespace_name(typeform->typnamespace);

		typname = NameStr(typeform->typname);

		buf = quote_qualified_identifier(nspname, typname);

		if (with_typemod)
			buf = printTypmod(buf, typemod, typeform->typmodout);
	}

	if (is_array)
		buf = psnprintf(strlen(buf) + 3, "%s[]", buf);

	ReleaseSysCache(tuple);

	return buf;
}

/*
 * format_operator		- converts operator OID to "opr_name(args)"
 *
 * This exports the useful functionality of regoperatorout for use
 * in other backend modules.  The result is a palloc'd string.
 */
char *
format_operator(Oid operator_oid)
{
	char	   *result;
	HeapTuple	opertup;

	opertup = SearchSysCache(OPEROID,
							 ObjectIdGetDatum(operator_oid),
							 0, 0, 0);

	if (HeapTupleIsValid(opertup))
	{
		Form_pg_operator operform = (Form_pg_operator) GETSTRUCT(opertup);
		char	   *oprname = NameStr(operform->oprname);
		char	   *nspname;
		StringInfoData buf;

		/* XXX no support here for bootstrap mode */

		initStringInfo(&buf);

		/*
		 * Would this oper be found (given the right args) by regoperatorin?
		 * If not, we need to qualify it.
		 */
		if (!OperatorIsVisible(operator_oid))
		{
			nspname = get_namespace_name(operform->oprnamespace);
			appendStringInfo(&buf, "%s.",
							 quote_identifier(nspname));
		}

		appendStringInfo(&buf, "%s(", oprname);

		if (operform->oprleft)
			appendStringInfo(&buf, "%s,",
							 format_type_be(operform->oprleft));
		else
			appendStringInfo(&buf, "NONE,");

		if (operform->oprright)
			appendStringInfo(&buf, "%s)",
							 format_type_be(operform->oprright));
		else
			appendStringInfo(&buf, "NONE)");

		result = buf.data;

		ReleaseSysCache(opertup);
	}
	else
	{
		/*
		 * If OID doesn't match any pg_operator entry, return it numerically
		 */
		result = (char *) palloc(NAMEDATALEN);
		snprintf(result, NAMEDATALEN, "%u", operator_oid);
	}

	return result;
}

/*
 * Compare two TupleDesc structures for logical equality
 *
 * Note: we deliberately do not check the attrelid and tdtypmod fields.
 * This allows typcache.c to use this routine to see if a cached record type
 * matches a requested type, and is harmless for relcache.c's uses.
 * We don't compare tdrefcount, either.
 */
bool
equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2, bool strict)
{
    int			i,
                j,
                n;

    if (tupdesc1->natts != tupdesc2->natts)
        return false;
    if (strict && tupdesc1->tdtypeid != tupdesc2->tdtypeid)
        return false;
    if (tupdesc1->tdhasoid != tupdesc2->tdhasoid)
        return false;

    for (i = 0; i < tupdesc1->natts; i++)
    {
        Form_pg_attribute attr1 = tupdesc1->attrs[i];
        Form_pg_attribute attr2 = tupdesc2->attrs[i];

        /*
         * We do not need to check every single field here: we can disregard
         * attrelid and attnum (which were used to place the row in the attrs
         * array in the first place).  It might look like we could dispense
         * with checking attlen/attbyval/attalign, since these are derived
         * from atttypid; but in the case of dropped columns we must check
         * them (since atttypid will be zero for all dropped columns) and in
         * general it seems safer to check them always.
         *
         * attcacheoff must NOT be checked since it's possibly not set in both
         * copies.
         */
        if (strcmp(NameStr(attr1->attname), NameStr(attr2->attname)) != 0)
            return false;
        if (attr1->atttypid != attr2->atttypid)
            return false;
        if (attr1->attstattarget != attr2->attstattarget)
            return false;
        if (attr1->attlen != attr2->attlen)
            return false;
        if (attr1->attndims != attr2->attndims)
            return false;
        if (attr1->atttypmod != attr2->atttypmod)
            return false;
        if (attr1->attbyval != attr2->attbyval)
            return false;
        if (attr1->attstorage != attr2->attstorage)
            return false;
        if (attr1->attalign != attr2->attalign)
            return false;

        if (strict)
        {
            if (attr1->attnotnull != attr2->attnotnull)
                return false;
            if (attr1->atthasdef != attr2->atthasdef)
                return false;
            if (attr1->attisdropped != attr2->attisdropped)
                return false;
            if (attr1->attislocal != attr2->attislocal)
                return false;
            if (attr1->attinhcount != attr2->attinhcount)
                return false;
        }
    }

    if (!strict)
        return true;

    if (tupdesc1->constr != NULL)
    {
        TupleConstr *constr1 = tupdesc1->constr;
        TupleConstr *constr2 = tupdesc2->constr;

        if (constr2 == NULL)
            return false;
        if (constr1->has_not_null != constr2->has_not_null)
            return false;
        n = constr1->num_defval;
        if (n != (int) constr2->num_defval)
            return false;
        for (i = 0; i < n; i++)
        {
            AttrDefault *defval1 = constr1->defval + i;
            AttrDefault *defval2 = constr2->defval;

            /*
             * We can't assume that the items are always read from the system
             * catalogs in the same order; so use the adnum field to identify
             * the matching item to compare.
             */
            for (j = 0; j < n; defval2++, j++)
            {
//.........这里部分代码省略.........

/*
 * sepgsql_attribute_post_create
 *
 * This routine assigns a default security label on a newly defined
 * column, using ALTER TABLE ... ADD COLUMN.
 * Note that this routine is not invoked in the case of CREATE TABLE,
 * although it also defines columns in addition to table.
 */
void
sepgsql_attribute_post_create(Oid relOid, AttrNumber attnum)
{
	Relation	rel;
	ScanKeyData skey[2];
	SysScanDesc sscan;
	HeapTuple	tuple;
	char	   *scontext;
	char	   *tcontext;
	char	   *ncontext;
	ObjectAddress object;
	Form_pg_attribute attForm;
	StringInfoData audit_name;

	/*
	 * Only attributes within regular relation have individual security
	 * labels.
	 */
	if (get_rel_relkind(relOid) != RELKIND_RELATION)
		return;

	/*
	 * Compute a default security label of the new column underlying the
	 * specified relation, and check permission to create it.
	 */
	rel = heap_open(AttributeRelationId, AccessShareLock);

	ScanKeyInit(&skey[0],
				Anum_pg_attribute_attrelid,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(relOid));
	ScanKeyInit(&skey[1],
				Anum_pg_attribute_attnum,
				BTEqualStrategyNumber, F_INT2EQ,
				Int16GetDatum(attnum));

	sscan = systable_beginscan(rel, AttributeRelidNumIndexId, true,
							   SnapshotSelf, 2, &skey[0]);

	tuple = systable_getnext(sscan);
	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "catalog lookup failed for column %d of relation %u",
			 attnum, relOid);

	attForm = (Form_pg_attribute) GETSTRUCT(tuple);

	scontext = sepgsql_get_client_label();
	tcontext = sepgsql_get_label(RelationRelationId, relOid, 0);
	ncontext = sepgsql_compute_create(scontext, tcontext,
									  SEPG_CLASS_DB_COLUMN,
									  NameStr(attForm->attname));

	/*
	 * check db_column:{create} permission
	 */
	object.classId = RelationRelationId;
	object.objectId = relOid;
	object.objectSubId = 0;

	initStringInfo(&audit_name);
	appendStringInfo(&audit_name, "%s.%s",
					 getObjectIdentity(&object),
					 quote_identifier(NameStr(attForm->attname)));
	sepgsql_avc_check_perms_label(ncontext,
								  SEPG_CLASS_DB_COLUMN,
								  SEPG_DB_COLUMN__CREATE,
								  audit_name.data,
								  true);

	/*
	 * Assign the default security label on a new procedure
	 */
	object.classId = RelationRelationId;
	object.objectId = relOid;
	object.objectSubId = attnum;
	SetSecurityLabel(&object, SEPGSQL_LABEL_TAG, ncontext);

	systable_endscan(sscan);
	heap_close(rel, AccessShareLock);

	pfree(tcontext);
	pfree(ncontext);
}

/*
 * sepgsql_relation_setattr
 *
 * It checks privileges to set attribute of the supplied relation
 */
void
sepgsql_relation_setattr(Oid relOid)
{
	Relation	rel;
	ScanKeyData skey;
	SysScanDesc sscan;
	HeapTuple	oldtup;
	HeapTuple	newtup;
	Form_pg_class oldform;
	Form_pg_class newform;
	ObjectAddress object;
	char	   *audit_name;
	uint16_t	tclass;

	switch (get_rel_relkind(relOid))
	{
		case RELKIND_RELATION:
			tclass = SEPG_CLASS_DB_TABLE;
			break;
		case RELKIND_SEQUENCE:
			tclass = SEPG_CLASS_DB_SEQUENCE;
			break;
		case RELKIND_VIEW:
			tclass = SEPG_CLASS_DB_VIEW;
			break;
		case RELKIND_INDEX:
			/* deal with indexes specially */
			sepgsql_index_modify(relOid);
			return;
		default:
			/* other relkinds don't need additional work */
			return;
	}

	/*
	 * Fetch newer catalog
	 */
	rel = heap_open(RelationRelationId, AccessShareLock);

	ScanKeyInit(&skey,
				ObjectIdAttributeNumber,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(relOid));

	sscan = systable_beginscan(rel, ClassOidIndexId, true,
							   SnapshotSelf, 1, &skey);

	newtup = systable_getnext(sscan);
	if (!HeapTupleIsValid(newtup))
		elog(ERROR, "catalog lookup failed for relation %u", relOid);
	newform = (Form_pg_class) GETSTRUCT(newtup);

	/*
	 * Fetch older catalog
	 */
	oldtup = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid));
	if (!HeapTupleIsValid(oldtup))
		elog(ERROR, "cache lookup failed for relation %u", relOid);
	oldform = (Form_pg_class) GETSTRUCT(oldtup);

	/*
	 * Does this ALTER command takes operation to namespace?
	 */
	if (newform->relnamespace != oldform->relnamespace)
	{
		sepgsql_schema_remove_name(oldform->relnamespace);
		sepgsql_schema_add_name(newform->relnamespace);
	}
	if (strcmp(NameStr(newform->relname), NameStr(oldform->relname)) != 0)
		sepgsql_schema_rename(oldform->relnamespace);

	/*
	 * XXX - In the future version, db_tuple:{use} of system catalog entry
	 * shall be checked, if tablespace configuration is changed.
	 */

	/*
	 * check db_xxx:{setattr} permission
	 */
	object.classId = RelationRelationId;
	object.objectId = relOid;
	object.objectSubId = 0;
	audit_name = getObjectIdentity(&object);

	sepgsql_avc_check_perms(&object,
							tclass,
							SEPG_DB_TABLE__SETATTR,
							audit_name,
							true);
	pfree(audit_name);

	ReleaseSysCache(oldtup);
	systable_endscan(sscan);
	heap_close(rel, AccessShareLock);
}

/*
 * Create a locale_t from a collation OID.  Results are cached for the
 * lifetime of the backend.  Thus, do not free the result with freelocale().
 *
 * As a special optimization, the default/database collation returns 0.
 * Callers should then revert to the non-locale_t-enabled code path.
 * In fact, they shouldn't call this function at all when they are dealing
 * with the default locale.  That can save quite a bit in hotspots.
 * Also, callers should avoid calling this before going down a C/POSIX
 * fastpath, because such a fastpath should work even on platforms without
 * locale_t support in the C library.
 *
 * For simplicity, we always generate COLLATE + CTYPE even though we
 * might only need one of them.  Since this is called only once per session,
 * it shouldn't cost much.
 */
pg_locale_t
pg_newlocale_from_collation(Oid collid)
{
	collation_cache_entry *cache_entry;

	/* Callers must pass a valid OID */
	Assert(OidIsValid(collid));

	/* Return 0 for "default" collation, just in case caller forgets */
	if (collid == DEFAULT_COLLATION_OID)
		return (pg_locale_t) 0;

	cache_entry = lookup_collation_cache(collid, false);

	if (cache_entry->locale == 0)
	{
		/* We haven't computed this yet in this session, so do it */
#ifdef HAVE_LOCALE_T
		HeapTuple	tp;
		Form_pg_collation collform;
		const char *collcollate;
		const char *collctype;
		locale_t	result;

		tp = SearchSysCache1(COLLOID, ObjectIdGetDatum(collid));
		if (!HeapTupleIsValid(tp))
			elog(ERROR, "cache lookup failed for collation %u", collid);
		collform = (Form_pg_collation) GETSTRUCT(tp);

		collcollate = NameStr(collform->collcollate);
		collctype = NameStr(collform->collctype);

		if (strcmp(collcollate, collctype) == 0)
		{
			/* Normal case where they're the same */
#ifndef WIN32
			result = newlocale(LC_COLLATE_MASK | LC_CTYPE_MASK, collcollate,
							   NULL);
#else
			result = _create_locale(LC_ALL, collcollate);
#endif
			if (!result)
				report_newlocale_failure(collcollate);
		}
		else
		{
#ifndef WIN32
			/* We need two newlocale() steps */
			locale_t	loc1;

			loc1 = newlocale(LC_COLLATE_MASK, collcollate, NULL);
			if (!loc1)
				report_newlocale_failure(collcollate);
			result = newlocale(LC_CTYPE_MASK, collctype, loc1);
			if (!result)
				report_newlocale_failure(collctype);
#else

			/*
			 * XXX The _create_locale() API doesn't appear to support this.
			 * Could perhaps be worked around by changing pg_locale_t to
			 * contain two separate fields.
			 */
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("collations with different collate and ctype values are not supported on this platform")));
#endif
		}

		cache_entry->locale = result;

		ReleaseSysCache(tp);
#else							/* not HAVE_LOCALE_T */

		/*
		 * For platforms that don't support locale_t, we can't do anything
		 * with non-default collations.
		 */
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
		errmsg("nondefault collations are not supported on this platform")));
#endif   /* not HAVE_LOCALE_T */
	}

//.........这里部分代码省略.........

/*
 * sepgsql_relation_post_create
 *
 * The post creation hook of relation/attribute
 */
void
sepgsql_relation_post_create(Oid relOid)
{
	Relation	rel;
	ScanKeyData skey;
	SysScanDesc sscan;
	HeapTuple	tuple;
	Form_pg_class classForm;
	ObjectAddress object;
	uint16		tclass;
	char	   *scontext;		/* subject */
	char	   *tcontext;		/* schema */
	char	   *rcontext;		/* relation */
	char	   *ccontext;		/* column */
	char	   *nsp_name;
	StringInfoData audit_name;

	/*
	 * Fetch catalog record of the new relation. Because pg_class entry is not
	 * visible right now, we need to scan the catalog using SnapshotSelf.
	 */
	rel = heap_open(RelationRelationId, AccessShareLock);

	ScanKeyInit(&skey,
				ObjectIdAttributeNumber,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(relOid));

	sscan = systable_beginscan(rel, ClassOidIndexId, true,
							   SnapshotSelf, 1, &skey);

	tuple = systable_getnext(sscan);
	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "catalog lookup failed for relation %u", relOid);

	classForm = (Form_pg_class) GETSTRUCT(tuple);

	/* ignore indexes on toast tables */
	if (classForm->relkind == RELKIND_INDEX &&
		classForm->relnamespace == PG_TOAST_NAMESPACE)
		goto out;

	/*
	 * check db_schema:{add_name} permission of the namespace
	 */
	object.classId = NamespaceRelationId;
	object.objectId = classForm->relnamespace;
	object.objectSubId = 0;
	sepgsql_avc_check_perms(&object,
							SEPG_CLASS_DB_SCHEMA,
							SEPG_DB_SCHEMA__ADD_NAME,
							getObjectIdentity(&object),
							true);

	switch (classForm->relkind)
	{
		case RELKIND_RELATION:
			tclass = SEPG_CLASS_DB_TABLE;
			break;
		case RELKIND_SEQUENCE:
			tclass = SEPG_CLASS_DB_SEQUENCE;
			break;
		case RELKIND_VIEW:
			tclass = SEPG_CLASS_DB_VIEW;
			break;
		case RELKIND_INDEX:
			/* deal with indexes specially; no need for tclass */
			sepgsql_index_modify(relOid);
			goto out;
		default:
			/* ignore other relkinds */
			goto out;
	}

	/*
	 * Compute a default security label when we create a new relation object
	 * under the specified namespace.
	 */
	scontext = sepgsql_get_client_label();
	tcontext = sepgsql_get_label(NamespaceRelationId,
								 classForm->relnamespace, 0);
	rcontext = sepgsql_compute_create(scontext, tcontext, tclass,
									  NameStr(classForm->relname));

	/*
	 * check db_xxx:{create} permission
	 */
	nsp_name = get_namespace_name(classForm->relnamespace);
	initStringInfo(&audit_name);
	appendStringInfo(&audit_name, "%s.%s",
					 quote_identifier(nsp_name),
					 quote_identifier(NameStr(classForm->relname)));
	sepgsql_avc_check_perms_label(rcontext,
								  tclass,
								  SEPG_DB_DATABASE__CREATE,
//.........这里部分代码省略.........

//.........这里部分代码省略.........

	pg_proc_entry = (Form_pg_proc) GETSTRUCT(proctuple);

	if (CALLED_AS_TRIGGER(fcinfo))
	{
		TriggerData *trigdata = (TriggerData *) fcinfo->context;
		Trigger *trigger = trigdata->tg_trigger;
		TupleDesc tupdesc = trigdata->tg_relation->rd_att;
		HeapTuple oldtuple = trigdata->tg_trigtuple;

		/* first the CREATE TRIGGER fixed arguments */
		for (i = 0; i < trigger->tgnargs; i++)
		{
			arguments[argc++] = trigger->tgargs[i];
		}

		if (TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
			for (i = 0; i < tupdesc->natts; i++)
			{
				char * s;
				bool isnull;
				Datum attr;

				attr = heap_getattr(oldtuple, i + 1, tupdesc, &isnull);
				if (isnull)
					s = "";
				else
					s = type_to_cstring(attr, tupdesc->attrs[i]->atttypid);

				elog(DEBUG2, "arg %d is \"%s\" (type %u)", i, s,
					 tupdesc->attrs[i]->atttypid);

				arguments[argc++] = s;
			}

		/* since we can't alter the tuple anyway, set up a return
           tuple right now */
		if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
			returntuple = trigdata->tg_trigtuple;
		else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
			returntuple = trigdata->tg_trigtuple;
		else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
			returntuple = trigdata->tg_newtuple;
#ifdef TRIGGER_FIRED_BY_TRUNCATE
		else if (TRIGGER_FIRED_BY_TRUNCATE(trigdata->tg_event))
			returntuple = trigdata->tg_trigtuple;
#endif
		else
			elog(ERROR, "unrecognized trigger action: not INSERT, DELETE, UPDATE, or TRUNCATE");
	}
	else if (CALLED_AS_EVENT_TRIGGER(fcinfo))
	{
		/* nothing */
	}
	else /* not trigger */
	{
		for (i = 0; i < pg_proc_entry->pronargs; i++)
		{
			char * s;

			if (PG_ARGISNULL(i))
				s = "";
			else
				s = type_to_cstring(PG_GETARG_DATUM(i),
									pg_proc_entry->proargtypes.values[i]);

			elog(DEBUG2, "arg %d is \"%s\"", i, s);

			arguments[argc++] = s;
		}
	}

	/* terminate list */
	arguments[argc] = NULL;

	ret = handler_internal2(tempfile,
							arguments,
							NameStr(pg_proc_entry->proname),
							CALLED_AS_TRIGGER(fcinfo) ? (TriggerData *) fcinfo->context : NULL,
							CALLED_AS_EVENT_TRIGGER(fcinfo) ? (EventTriggerData *) fcinfo->context : NULL);


	ReleaseSysCache(proctuple);

	if (CALLED_AS_TRIGGER(fcinfo))
	{
		PG_RETURN_DATUM(PointerGetDatum(returntuple));
	}
	else if (CALLED_AS_EVENT_TRIGGER(fcinfo))
	{
		PG_RETURN_NULL();
	}
	else
	{
		if (ret)
			PG_RETURN_DATUM(cstring_to_type(ret, pg_proc_entry->prorettype));
		else
			PG_RETURN_NULL();
	}
}

//.........这里部分代码省略.........
             */
            if (num != DatumGetPointer(datum)) 
                tofree = num;

			break;
		
		/*
		 * ====== CHARACTER TYPES =======
		 */
		case CHAROID:			/* char(1), single character */
			char_buf = DatumGetChar(datum);
			buf = &char_buf;
			len = 1;
			break;

		case BPCHAROID: /* char(n), blank-padded string, fixed storage */
		case TEXTOID:   /* text */
		case VARCHAROID: /* varchar */ 
		case BYTEAOID:   /* bytea */
			{
				int tmplen;
				varattrib_untoast_ptr_len(datum, (char **) &buf, &tmplen, &tofree);
				/* adjust length to not include trailing blanks */
				if (type != BYTEAOID && tmplen > 1)
					tmplen = ignoreblanks((char *) buf, tmplen);

				len = tmplen;
				break;
			}

		case NAMEOID:
			namebuf = DatumGetName(datum);
			len = NAMEDATALEN;
			buf = NameStr(*namebuf);

			/* adjust length to not include trailing blanks */
			if (len > 1)
				len = ignoreblanks((char *) buf, len);
			break;
		
		/*
		 * ====== OBJECT IDENTIFIER TYPES ======
		 */
		case OIDOID:				/* object identifier(oid), maximum 4 billion */
		case REGPROCOID:			/* function name */
		case REGPROCEDUREOID:		/* function name with argument types */
		case REGOPEROID:			/* operator name */
		case REGOPERATOROID:		/* operator with argument types */
		case REGCLASSOID:			/* relation name */
		case REGTYPEOID:			/* data type name */
			intbuf = (int64) DatumGetUInt32(datum);	/* cast to 8 byte before hashing */
			buf = &intbuf;
			len = sizeof(intbuf);
			break;

        case TIDOID:                /* tuple id (6 bytes) */
            buf = DatumGetPointer(datum);
            len = SizeOfIptrData;
            break;
			
		/*
		 * ====== DATE/TIME TYPES ======
		 */
		case TIMESTAMPOID:		/* date and time */
			tsbuf = DatumGetTimestamp(datum);
			buf = &tsbuf;

/*
 * Validator for a bloom opclass.
 */
bool
blvalidate(Oid opclassoid)
{
	bool		result = true;
	HeapTuple	classtup;
	Form_pg_opclass classform;
	Oid			opfamilyoid;
	Oid			opcintype;
	Oid			opckeytype;
	char	   *opclassname;
	HeapTuple	familytup;
	Form_pg_opfamily familyform;
	char	   *opfamilyname;
	CatCList   *proclist,
			   *oprlist;
	List	   *grouplist;
	OpFamilyOpFuncGroup *opclassgroup;
	int			i;
	ListCell   *lc;

	/* Fetch opclass information */
	classtup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclassoid));
	if (!HeapTupleIsValid(classtup))
		elog(ERROR, "cache lookup failed for operator class %u", opclassoid);
	classform = (Form_pg_opclass) GETSTRUCT(classtup);

	opfamilyoid = classform->opcfamily;
	opcintype = classform->opcintype;
	opckeytype = classform->opckeytype;
	if (!OidIsValid(opckeytype))
		opckeytype = opcintype;
	opclassname = NameStr(classform->opcname);

	/* Fetch opfamily information */
	familytup = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfamilyoid));
	if (!HeapTupleIsValid(familytup))
		elog(ERROR, "cache lookup failed for operator family %u", opfamilyoid);
	familyform = (Form_pg_opfamily) GETSTRUCT(familytup);

	opfamilyname = NameStr(familyform->opfname);

	/* Fetch all operators and support functions of the opfamily */
	oprlist = SearchSysCacheList1(AMOPSTRATEGY, ObjectIdGetDatum(opfamilyoid));
	proclist = SearchSysCacheList1(AMPROCNUM, ObjectIdGetDatum(opfamilyoid));

	/* Check individual support functions */
	for (i = 0; i < proclist->n_members; i++)
	{
		HeapTuple	proctup = &proclist->members[i]->tuple;
		Form_pg_amproc procform = (Form_pg_amproc) GETSTRUCT(proctup);
		bool		ok;

		/*
		 * All bloom support functions should be registered with matching
		 * left/right types
		 */
		if (procform->amproclefttype != procform->amprocrighttype)
		{
			ereport(INFO,
					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
					 errmsg("bloom opfamily %s contains support procedure %s with cross-type registration",
							opfamilyname,
							format_procedure(procform->amproc))));
			result = false;
		}

		/*
		 * We can't check signatures except within the specific opclass, since
		 * we need to know the associated opckeytype in many cases.
		 */
		if (procform->amproclefttype != opcintype)
			continue;

		/* Check procedure numbers and function signatures */
		switch (procform->amprocnum)
		{
			case BLOOM_HASH_PROC:
				ok = check_amproc_signature(procform->amproc, INT4OID, false,
											1, 1, opckeytype);
				break;
			default:
				ereport(INFO,
						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
						 errmsg("bloom opfamily %s contains function %s with invalid support number %d",
								opfamilyname,
								format_procedure(procform->amproc),
								procform->amprocnum)));
				result = false;
				continue;		/* don't want additional message */
		}

		if (!ok)
		{
			ereport(INFO,
					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
					 errmsg("gist opfamily %s contains function %s with wrong signature for support number %d",
							opfamilyname,
//.........这里部分代码省略.........

int
namecmp(Name n1, Name n2)
{
    return strncmp(NameStr(*n1), NameStr(*n2), NAMEDATALEN);
}

/*
 * TupleDescInitEntry
 *		This function initializes a single attribute structure in
 *		a previously allocated tuple descriptor.
 *
 * If attributeName is NULL, the attname field is set to an empty string
 * (this is for cases where we don't know or need a name for the field).
 * Also, some callers use this function to change the datatype-related fields
 * in an existing tupdesc; they pass attributeName = NameStr(att->attname)
 * to indicate that the attname field shouldn't be modified.
 *
 * Note that attcollation is set to the default for the specified datatype.
 * If a nondefault collation is needed, insert it afterwards using
 * TupleDescInitEntryCollation.
 */
void
TupleDescInitEntry(TupleDesc desc,
				   AttrNumber attributeNumber,
				   const char *attributeName,
				   Oid oidtypeid,
				   int32 typmod,
				   int attdim)
{
	HeapTuple	tuple;
	Form_pg_type typeForm;
	Form_pg_attribute att;

	/*
	 * sanity checks
	 */
	AssertArg(PointerIsValid(desc));
	AssertArg(attributeNumber >= 1);
	AssertArg(attributeNumber <= desc->natts);

	/*
	 * initialize the attribute fields
	 */
	att = desc->attrs[attributeNumber - 1];

	att->attrelid = 0;			/* dummy value */

	/*
	 * Note: attributeName can be NULL, because the planner doesn't always
	 * fill in valid resname values in targetlists, particularly for resjunk
	 * attributes. Also, do nothing if caller wants to re-use the old attname.
	 */
	if (attributeName == NULL)
		MemSet(NameStr(att->attname), 0, NAMEDATALEN);
	else if (attributeName != NameStr(att->attname))
		namestrcpy(&(att->attname), attributeName);

	att->attstattarget = -1;
	att->attcacheoff = -1;
	att->atttypmod = typmod;

	att->attnum = attributeNumber;
	att->attndims = attdim;

	att->attnotnull = false;
	att->atthasdef = false;
	att->attisdropped = false;
	att->attislocal = true;
	att->attinhcount = 0;
	/* attacl, attoptions and attfdwoptions are not present in tupledescs */

	tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(oidtypeid));
	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "cache lookup failed for type %u", oidtypeid);
	typeForm = (Form_pg_type) GETSTRUCT(tuple);

	att->atttypid = oidtypeid;
	att->attlen = typeForm->typlen;
	att->attbyval = typeForm->typbyval;
	att->attalign = typeForm->typalign;
	att->attstorage = typeForm->typstorage;
	att->attcollation = typeForm->typcollation;

	ReleaseSysCache(tuple);
}

/*
 * regoperout		- converts operator OID to "opr_name"
 */
Datum
regoperout(PG_FUNCTION_ARGS)
{
	Oid			oprid = PG_GETARG_OID(0);
	char	   *result;
	HeapTuple	opertup;

	if (oprid == Inval