C++ RelationGetDescr函数代码示例

/*
 * Write a tuple to the outputstream, in the most efficient format possible.
 */
static void
logicalrep_write_tuple(StringInfo out, Relation rel, HeapTuple tuple)
{
	TupleDesc	desc;
	Datum		values[MaxTupleAttributeNumber];
	bool		isnull[MaxTupleAttributeNumber];
	int			i;
	uint16		nliveatts = 0;

	desc = RelationGetDescr(rel);

	for (i = 0; i < desc->natts; i++)
	{
		if (TupleDescAttr(desc, i)->attisdropped)
			continue;
		nliveatts++;
	}
	pq_sendint(out, nliveatts, 2);

	/* try to allocate enough memory from the get-go */
	enlargeStringInfo(out, tuple->t_len +
					  nliveatts * (1 + 4));

	heap_deform_tuple(tuple, desc, values, isnull);

	/* Write the values */
	for (i = 0; i < desc->natts; i++)
	{
		HeapTuple	typtup;
		Form_pg_type typclass;
		Form_pg_attribute att = TupleDescAttr(desc, i);
		char	   *outputstr;

		/* skip dropped columns */
		if (att->attisdropped)
			continue;

		if (isnull[i])
		{
			pq_sendbyte(out, 'n');	/* null column */
			continue;
		}
		else if (att->attlen == -1 && VARATT_IS_EXTERNAL_ONDISK(values[i]))
		{
			pq_sendbyte(out, 'u');	/* unchanged toast column */
			continue;
		}

		typtup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(att->atttypid));
		if (!HeapTupleIsValid(typtup))
			elog(ERROR, "cache lookup failed for type %u", att->atttypid);
		typclass = (Form_pg_type) GETSTRUCT(typtup);

		pq_sendbyte(out, 't');	/* 'text' data follows */

		outputstr = OidOutputFunctionCall(typclass->typoutput, values[i]);
		pq_sendcountedtext(out, outputstr, strlen(outputstr), false);
		pfree(outputstr);

		ReleaseSysCache(typtup);
	}
}

/*
 * Read tuples in correct sort order from tuplesort, and load them into
 * btree leaves.
 */
static void
_bt_load(BTWriteState *wstate, BTSpool *btspool, BTSpool *btspool2)
{
	BTPageState *state = NULL;
	bool		merge = (btspool2 != NULL);
	IndexTuple	itup,
				itup2 = NULL;
	bool		should_free,
				should_free2,
				load1;
	TupleDesc	tupdes = RelationGetDescr(wstate->index);
	int			i,
				keysz = RelationGetNumberOfAttributes(wstate->index);
	ScanKey		indexScanKey = NULL;

	if (merge)
	{
		/*
		 * Another BTSpool for dead tuples exists. Now we have to merge
		 * btspool and btspool2.
		 */

		/* the preparation of merge */
		itup = tuplesort_getindextuple(btspool->sortstate,
									   true, &should_free);
		itup2 = tuplesort_getindextuple(btspool2->sortstate,
										true, &should_free2);
		indexScanKey = _bt_mkscankey_nodata(wstate->index);

		for (;;)
		{
			load1 = true;		/* load BTSpool next ? */
			if (itup2 == NULL)
			{
				if (itup == NULL)
					break;
			}
			else if (itup != NULL)
			{
				for (i = 1; i <= keysz; i++)
				{
					ScanKey		entry;
					Datum		attrDatum1,
								attrDatum2;
					bool		isNull1,
								isNull2;
					int32		compare;

					entry = indexScanKey + i - 1;
					attrDatum1 = index_getattr(itup, i, tupdes, &isNull1);
					attrDatum2 = index_getattr(itup2, i, tupdes, &isNull2);
					if (isNull1)
					{
						if (isNull2)
							compare = 0;		/* NULL "=" NULL */
						else if (entry->sk_flags & SK_BT_NULLS_FIRST)
							compare = -1;		/* NULL "<" NOT_NULL */
						else
							compare = 1;		/* NULL ">" NOT_NULL */
					}
					else if (isNull2)
					{
						if (entry->sk_flags & SK_BT_NULLS_FIRST)
							compare = 1;		/* NOT_NULL ">" NULL */
						else
							compare = -1;		/* NOT_NULL "<" NULL */
					}
					else
					{
						compare =
							DatumGetInt32(FunctionCall2Coll(&entry->sk_func,
														 entry->sk_collation,
															attrDatum1,
															attrDatum2));

						if (entry->sk_flags & SK_BT_DESC)
							compare = -compare;
					}
					if (compare > 0)
					{
						load1 = false;
						break;
					}
					else if (compare < 0)
						break;
				}
			}
			else
				load1 = false;

			/* When we see first tuple, create first index page */
			if (state == NULL)
				state = _bt_pagestate(wstate, 0);

			if (load1)
			{
//.........这里部分代码省略.........

/*
 * Look to see if we have template information for the given language name.
 */
static PLTemplate *
find_language_template(const char *languageName)
{
	PLTemplate *result;
	Relation	rel;
	SysScanDesc scan;
	ScanKeyData key;
	HeapTuple	tup;

	rel = heap_open(PLTemplateRelationId, AccessShareLock);

	ScanKeyInit(&key,
				Anum_pg_pltemplate_tmplname,
				BTEqualStrategyNumber, F_NAMEEQ,
				CStringGetDatum(languageName));
	scan = systable_beginscan(rel, PLTemplateNameIndexId, true,
							  NULL, 1, &key);

	tup = systable_getnext(scan);
	if (HeapTupleIsValid(tup))
	{
		Form_pg_pltemplate tmpl = (Form_pg_pltemplate) GETSTRUCT(tup);
		Datum		datum;
		bool		isnull;

		result = (PLTemplate *) palloc0(sizeof(PLTemplate));
		result->tmpltrusted = tmpl->tmpltrusted;
		result->tmpldbacreate = tmpl->tmpldbacreate;

		/* Remaining fields are variable-width so we need heap_getattr */
		datum = heap_getattr(tup, Anum_pg_pltemplate_tmplhandler,
							 RelationGetDescr(rel), &isnull);
		if (!isnull)
			result->tmplhandler = TextDatumGetCString(datum);

		datum = heap_getattr(tup, Anum_pg_pltemplate_tmplinline,
							 RelationGetDescr(rel), &isnull);
		if (!isnull)
			result->tmplinline = TextDatumGetCString(datum);

		datum = heap_getattr(tup, Anum_pg_pltemplate_tmplvalidator,
							 RelationGetDescr(rel), &isnull);
		if (!isnull)
			result->tmplvalidator = TextDatumGetCString(datum);

		datum = heap_getattr(tup, Anum_pg_pltemplate_tmpllibrary,
							 RelationGetDescr(rel), &isnull);
		if (!isnull)
			result->tmpllibrary = TextDatumGetCString(datum);

		/* Ignore template if handler or library info is missing */
		if (!result->tmplhandler || !result->tmpllibrary)
			result = NULL;
	}
	else
		result = NULL;

	systable_endscan(scan);

	heap_close(rel, AccessShareLock);

	return result;
}

//.........这里部分代码省略.........
	 * NOTE: updating will not work correctly in bootstrap mode; but we don't
	 * expect to be overwriting any shell types in bootstrap mode.
	 */
	pg_type_desc = heap_open(TypeRelationId, RowExclusiveLock);

	tup = SearchSysCacheCopy2(TYPENAMENSP,
							  CStringGetDatum(typeName),
							  ObjectIdGetDatum(typeNamespace));
	if (HeapTupleIsValid(tup))
	{
		/*
		 * check that the type is not already defined.	It may exist as a
		 * shell type, however.
		 */
		if (((Form_pg_type) GETSTRUCT(tup))->typisdefined)
			ereport(ERROR,
					(errcode(ERRCODE_DUPLICATE_OBJECT),
					 errmsg("type \"%s\" already exists", typeName)));

		/*
		 * shell type must have been created by same owner
		 */
		if (((Form_pg_type) GETSTRUCT(tup))->typowner != ownerId)
			aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_TYPE, typeName);

		/* trouble if caller wanted to force the OID */
		if (OidIsValid(newTypeOid))
			elog(ERROR, "cannot assign new OID to existing shell type");

		/*
		 * Okay to update existing shell type tuple
		 */
		tup = heap_modify_tuple(tup,
								RelationGetDescr(pg_type_desc),
								values,
								nulls,
								replaces);

		simple_heap_update(pg_type_desc, &tup->t_self, tup);

		typeObjectId = HeapTupleGetOid(tup);

		rebuildDeps = true;		/* get rid of shell type's dependencies */
	}
	else
	{
		tup = heap_form_tuple(RelationGetDescr(pg_type_desc),
							  values,
							  nulls);

		/* Force the OID if requested by caller */
		if (OidIsValid(newTypeOid))
			HeapTupleSetOid(tup, newTypeOid);
		else if (OidIsValid(binary_upgrade_next_pg_type_oid))
		{
			HeapTupleSetOid(tup, binary_upgrade_next_pg_type_oid);
			binary_upgrade_next_pg_type_oid = InvalidOid;
		}
		/* else allow system to assign oid */

		typeObjectId = simple_heap_insert(pg_type_desc, tup);
	}

	/* Update indexes */
	CatalogUpdateIndexes(pg_type_desc, tup);

/*
 * Alter table space options
 */
void
AlterTableSpaceOptions(AlterTableSpaceOptionsStmt *stmt)
{
	Relation	rel;
	ScanKeyData entry[1];
	HeapScanDesc scandesc;
	HeapTuple	tup;
	Datum		datum;
	Datum		newOptions;
	Datum		repl_val[Natts_pg_tablespace];
	bool		isnull;
	bool		repl_null[Natts_pg_tablespace];
	bool		repl_repl[Natts_pg_tablespace];
	HeapTuple	newtuple;

	/* Search pg_tablespace */
	rel = heap_open(TableSpaceRelationId, RowExclusiveLock);

	ScanKeyInit(&entry[0],
				Anum_pg_tablespace_spcname,
				BTEqualStrategyNumber, F_NAMEEQ,
				CStringGetDatum(stmt->tablespacename));
	scandesc = heap_beginscan(rel, SnapshotNow, 1, entry);
	tup = heap_getnext(scandesc, ForwardScanDirection);
	if (!HeapTupleIsValid(tup))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("tablespace \"%s\" does not exist",
						stmt->tablespacename)));

	/* Must be owner of the existing object */
	if (!pg_tablespace_ownercheck(HeapTupleGetOid(tup), GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_TABLESPACE,
					   stmt->tablespacename);

	/* Generate new proposed spcoptions (text array) */
	datum = heap_getattr(tup, Anum_pg_tablespace_spcoptions,
						 RelationGetDescr(rel), &isnull);
	newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
									 stmt->options, NULL, NULL, false,
									 stmt->isReset);
	(void) tablespace_reloptions(newOptions, true);

	/* Build new tuple. */
	memset(repl_null, false, sizeof(repl_null));
	memset(repl_repl, false, sizeof(repl_repl));
	if (newOptions != (Datum) 0)
		repl_val[Anum_pg_tablespace_spcoptions - 1] = newOptions;
	else
		repl_null[Anum_pg_tablespace_spcoptions - 1] = true;
	repl_repl[Anum_pg_tablespace_spcoptions - 1] = true;
	newtuple = heap_modify_tuple(tup, RelationGetDescr(rel), repl_val,
								 repl_null, repl_repl);

	/* Update system catalog. */
	simple_heap_update(rel, &newtuple->t_self, newtuple);
	CatalogUpdateIndexes(rel, newtuple);
	heap_freetuple(newtuple);

	/* Conclude heap scan. */
	heap_endscan(scandesc);
	heap_close(rel, NoLock);
}

/*----------
 *	_bt_compare() -- Compare scankey to a particular tuple on the page.
 *
 * The passed scankey must be an insertion-type scankey (see nbtree/README),
 * but it can omit the rightmost column(s) of the index.
 *
 *	keysz: number of key conditions to be checked (might be less than the
 *		number of index columns!)
 *	page/offnum: location of btree item to be compared to.
 *
 *		This routine returns:
 *			<0 if scankey < tuple at offnum;
 *			 0 if scankey == tuple at offnum;
 *			>0 if scankey > tuple at offnum.
 *		NULLs in the keys are treated as sortable values.  Therefore
 *		"equality" does not necessarily mean that the item should be
 *		returned to the caller as a matching key!
 *
 * CRUCIAL NOTE: on a non-leaf page, the first data key is assumed to be
 * "minus infinity": this routine will always claim it is less than the
 * scankey.  The actual key value stored (if any, which there probably isn't)
 * does not matter.  This convention allows us to implement the Lehman and
 * Yao convention that the first down-link pointer is before the first key.
 * See backend/access/nbtree/README for details.
 *----------
 */
int32
_bt_compare(Relation rel,
			int keysz,
			ScanKey scankey,
			Page page,
			OffsetNumber offnum)
{
	TupleDesc	itupdesc = RelationGetDescr(rel);
	BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);
	IndexTuple	itup;
	int			i;

	/*
	 * Force result ">" if target item is first data item on an internal page
	 * --- see NOTE above.
	 */
	if (!P_ISLEAF(opaque) && offnum == P_FIRSTDATAKEY(opaque))
		return 1;

	itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, offnum));

	/*
	 * The scan key is set up with the attribute number associated with each
	 * term in the key.  It is important that, if the index is multi-key, the
	 * scan contain the first k key attributes, and that they be in order.	If
	 * you think about how multi-key ordering works, you'll understand why
	 * this is.
	 *
	 * We don't test for violation of this condition here, however.  The
	 * initial setup for the index scan had better have gotten it right (see
	 * _bt_first).
	 */

	for (i = 1; i <= keysz; i++)
	{
		Datum		datum;
		bool		isNull;
		int32		result;

		datum = index_getattr(itup, scankey->sk_attno, itupdesc, &isNull);

		/* see comments about NULLs handling in btbuild */
		if (scankey->sk_flags & SK_ISNULL)		/* key is NULL */
		{
			if (isNull)
				result = 0;		/* NULL "=" NULL */
			else if (scankey->sk_flags & SK_BT_NULLS_FIRST)
				result = -1;	/* NULL "<" NOT_NULL */
			else
				result = 1;		/* NULL ">" NOT_NULL */
		}
		else if (isNull)		/* key is NOT_NULL and item is NULL */
		{
			if (scankey->sk_flags & SK_BT_NULLS_FIRST)
				result = 1;		/* NOT_NULL ">" NULL */
			else
				result = -1;	/* NOT_NULL "<" NULL */
		}
		else
		{
			/*
			 * The sk_func needs to be passed the index value as left arg and
			 * the sk_argument as right arg (they might be of different
			 * types).	Since it is convenient for callers to think of
			 * _bt_compare as comparing the scankey to the index item, we have
			 * to flip the sign of the comparison result.  (Unless it's a DESC
			 * column, in which case we *don't* flip the sign.)
			 */
			result = DatumGetInt32(FunctionCall2(&scankey->sk_func,
												 datum,
												 scankey->sk_argument));

			if (!(scankey->sk_flags & SK_BT_DESC))
				result = -result;
//.........这里部分代码省略.........

/*
 * pg_get_tableschemadef_string returns the definition of a given table. This
 * definition includes table's schema, default column values, not null and check
 * constraints. The definition does not include constraints that trigger index
 * creations; specifically, unique and primary key constraints are excluded.
 */
static char *
pg_shard_get_tableschemadef_string(Oid tableRelationId)
{
	Relation relation = NULL;
	char *relationName = NULL;
	char relationKind = 0;
	TupleDesc tupleDescriptor = NULL;
	TupleConstr *tupleConstraints = NULL;
	int attributeIndex = 0;
	bool firstAttributePrinted = false;
	AttrNumber defaultValueIndex = 0;
	AttrNumber constraintIndex = 0;
	AttrNumber constraintCount = 0;
	StringInfoData buffer = { NULL, 0, 0, 0 };

	/*
	 * Instead of retrieving values from system catalogs as other functions in
	 * ruleutils.c do, we follow an unusual approach here: we open the relation,
	 * and fetch the relation's tuple descriptor. We do this because the tuple
	 * descriptor already contains information harnessed from pg_attrdef,
	 * pg_attribute, pg_constraint, and pg_class; and therefore using the
	 * descriptor saves us from a lot of additional work.
	 */
	relation = relation_open(tableRelationId, AccessShareLock);
	relationName = generate_relation_name(tableRelationId);

	relationKind = relation->rd_rel->relkind;
	if (relationKind != RELKIND_RELATION && relationKind != RELKIND_FOREIGN_TABLE)
	{
		ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE),
						errmsg("%s is not a regular or foreign table", relationName)));
	}

	initStringInfo(&buffer);
	if (relationKind == RELKIND_RELATION)
	{
		appendStringInfo(&buffer, "CREATE TABLE %s (", relationName);
	}
	else
	{
		appendStringInfo(&buffer, "CREATE FOREIGN TABLE %s (", relationName);
	}

	/*
	 * Iterate over the table's columns. If a particular column is not dropped
	 * and is not inherited from another table, print the column's name and its
	 * formatted type.
	 */
	tupleDescriptor = RelationGetDescr(relation);
	tupleConstraints = tupleDescriptor->constr;

	for (attributeIndex = 0; attributeIndex < tupleDescriptor->natts; attributeIndex++)
	{
		Form_pg_attribute attributeForm = tupleDescriptor->attrs[attributeIndex];

		if (!attributeForm->attisdropped && attributeForm->attinhcount == 0)
		{
			const char *attributeName = NULL;
			const char *attributeTypeName = NULL;

			if (firstAttributePrinted)
			{
				appendStringInfoString(&buffer, ", ");
			}
			firstAttributePrinted = true;

			attributeName = NameStr(attributeForm->attname);
			appendStringInfo(&buffer, "%s ", quote_identifier(attributeName));

			attributeTypeName = format_type_with_typemod(attributeForm->atttypid,
														 attributeForm->atttypmod);
			appendStringInfoString(&buffer, attributeTypeName);

			/* if this column has a default value, append the default value */
			if (attributeForm->atthasdef)
			{
				AttrDefault *defaultValueList = NULL;
				AttrDefault *defaultValue = NULL;

				Node *defaultNode = NULL;
				List *defaultContext = NULL;
				char *defaultString = NULL;

				Assert(tupleConstraints != NULL);

				defaultValueList = tupleConstraints->defval;
				Assert(defaultValueList != NULL);

				defaultValue = &(defaultValueList[defaultValueIndex]);
				defaultValueIndex++;

				Assert(defaultValue->adnum == (attributeIndex + 1));
				Assert(defaultValueIndex <= tupleConstraints->num_defval);

//.........这里部分代码省略.........

/*
 * _bitmap_init_buildstate() -- initialize the build state before building
 *	a bitmap index.
 */
void
_bitmap_init_buildstate(Relation index, BMBuildState *bmstate)
{
	MIRROREDLOCK_BUFMGR_DECLARE;

	BMMetaPage	mp;
	HASHCTL		hash_ctl;
	int			hash_flags;
	int			i;
	Buffer		metabuf;


	/* initialize the build state */
	bmstate->bm_tupDesc = RelationGetDescr(index);
	bmstate->bm_tidLocsBuffer = (BMTidBuildBuf *)
		palloc(sizeof(BMTidBuildBuf));
	bmstate->bm_tidLocsBuffer->byte_size = 0;
	bmstate->bm_tidLocsBuffer->lov_blocks = NIL;
	bmstate->bm_tidLocsBuffer->max_lov_block = InvalidBlockNumber;
	
	// -------- MirroredLock ----------
	MIRROREDLOCK_BUFMGR_LOCK;
	
	metabuf = _bitmap_getbuf(index, BM_METAPAGE, BM_READ);
	mp = _bitmap_get_metapage_data(index, metabuf);
	_bitmap_open_lov_heapandindex(index, mp, &(bmstate->bm_lov_heap),
								  &(bmstate->bm_lov_index), 
								  RowExclusiveLock);

	_bitmap_relbuf(metabuf);
	
	MIRROREDLOCK_BUFMGR_UNLOCK;
	// -------- MirroredLock ----------
	
	cur_bmbuild = (BMBuildHashData *)palloc(sizeof(BMBuildHashData));
	cur_bmbuild->hash_funcs = (FmgrInfo *)
						palloc(sizeof(FmgrInfo) * bmstate->bm_tupDesc->natts);
	cur_bmbuild->eq_funcs = (FmgrInfo *)
                        palloc(sizeof(FmgrInfo) * bmstate->bm_tupDesc->natts);
    cur_bmbuild->hash_func_is_strict = (bool *)
                        palloc(sizeof(bool) * bmstate->bm_tupDesc->natts);

	for (i = 0; i < bmstate->bm_tupDesc->natts; i++)
	{
		Oid			typid = bmstate->bm_tupDesc->attrs[i]->atttypid;
		Operator	optup;
		Oid			eq_opr;
		Oid			eq_function;
		Oid			left_hash_function;
		Oid			right_hash_function;

		optup = equality_oper(typid, false);
		eq_opr = oprid(optup);
		eq_function = oprfuncid(optup);
		ReleaseOperator(optup);

		if (!get_op_hash_functions(eq_opr,
								   &left_hash_function,
								   &right_hash_function))
		{
			pfree(cur_bmbuild);
			cur_bmbuild = NULL;
			break;
		}

		Assert(left_hash_function == right_hash_function);
		fmgr_info(eq_function, &cur_bmbuild->eq_funcs[i]);
		fmgr_info(right_hash_function, &cur_bmbuild->hash_funcs[i]);
        cur_bmbuild->hash_func_is_strict[i] = func_strict(right_hash_function);
	}

	if (cur_bmbuild)
	{
		cur_bmbuild->natts = bmstate->bm_tupDesc->natts;
		cur_bmbuild->tmpcxt = AllocSetContextCreate(CurrentMemoryContext,
        	                      "Bitmap build temp space",
            	                  ALLOCSET_DEFAULT_MINSIZE,
                	              ALLOCSET_DEFAULT_INITSIZE,
                    	          ALLOCSET_DEFAULT_MAXSIZE);

		/* setup the hash table */
	    MemSet(&hash_ctl, 0, sizeof(hash_ctl));

	    /**
	     * Reserve enough space for the hash key header and then the data segments (values followed by nulls)
	     */
    	hash_ctl.keysize = MAXALIGN(sizeof(BMBuildHashKey)) +
                           MAXALIGN(sizeof(Datum) * cur_bmbuild->natts) +
                           MAXALIGN(sizeof(bool) * cur_bmbuild->natts);

		hash_ctl.entrysize = hash_ctl.keysize + sizeof(BMBuildLovData) + 200; 
    	hash_ctl.hash = build_hash_key;
	    hash_ctl.match = build_match_key;
	    hash_ctl.keycopy = build_keycopy;
    	hash_ctl.hcxt = AllocSetContextCreate(CurrentMemoryContext,
        	                      "Bitmap build hash table",
//.........这里部分代码省略.........

//.........这里部分代码省略.........
	HeapTuple	oldtup = NULL;
	HeapTuple	scantup;
	ScanKeyData key[4];
	SysScanDesc scan;

	/*
	 * Make sure the new referenced object doesn't go away while we record the
	 * dependency.
	 */
	shdepLockAndCheckObject(refclassid, refobjid);

	/*
	 * Look for a previous entry
	 */
	ScanKeyInit(&key[0],
				Anum_pg_shdepend_dbid,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(dbid));
	ScanKeyInit(&key[1],
				Anum_pg_shdepend_classid,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(classid));
	ScanKeyInit(&key[2],
				Anum_pg_shdepend_objid,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(objid));
	ScanKeyInit(&key[3],
				Anum_pg_shdepend_objsubid,
				BTEqualStrategyNumber, F_INT4EQ,
				Int32GetDatum(objsubid));

	scan = systable_beginscan(sdepRel, SharedDependDependerIndexId, true,
							  NULL, 4, key);

	while ((scantup = systable_getnext(scan)) != NULL)
	{
		/* Ignore if not of the target dependency type */
		if (((Form_pg_shdepend) GETSTRUCT(scantup))->deptype != deptype)
			continue;
		/* Caller screwed up if multiple matches */
		if (oldtup)
			elog(ERROR,
			   "multiple pg_shdepend entries for object %u/%u/%d deptype %c",
				 classid, objid, objsubid, deptype);
		oldtup = heap_copytuple(scantup);
	}

	systable_endscan(scan);

	if (isSharedObjectPinned(refclassid, refobjid, sdepRel))
	{
		/* No new entry needed, so just delete existing entry if any */
		if (oldtup)
			simple_heap_delete(sdepRel, &oldtup->t_self);
	}
	else if (oldtup)
	{
		/* Need to update existing entry */
		Form_pg_shdepend shForm = (Form_pg_shdepend) GETSTRUCT(oldtup);

		/* Since oldtup is a copy, we can just modify it in-memory */
		shForm->refclassid = refclassid;
		shForm->refobjid = refobjid;

		simple_heap_update(sdepRel, &oldtup->t_self, oldtup);

		/* keep indexes current */
		CatalogUpdateIndexes(sdepRel, oldtup);
	}
	else
	{
		/* Need to insert new entry */
		Datum		values[Natts_pg_shdepend];
		bool		nulls[Natts_pg_shdepend];

		memset(nulls, false, sizeof(nulls));

		values[Anum_pg_shdepend_dbid - 1] = ObjectIdGetDatum(dbid);
		values[Anum_pg_shdepend_classid - 1] = ObjectIdGetDatum(classid);
		values[Anum_pg_shdepend_objid - 1] = ObjectIdGetDatum(objid);
		values[Anum_pg_shdepend_objsubid - 1] = Int32GetDatum(objsubid);

		values[Anum_pg_shdepend_refclassid - 1] = ObjectIdGetDatum(refclassid);
		values[Anum_pg_shdepend_refobjid - 1] = ObjectIdGetDatum(refobjid);
		values[Anum_pg_shdepend_deptype - 1] = CharGetDatum(deptype);

		/*
		 * we are reusing oldtup just to avoid declaring a new variable, but
		 * it's certainly a new tuple
		 */
		oldtup = heap_form_tuple(RelationGetDescr(sdepRel), values, nulls);
		simple_heap_insert(sdepRel, oldtup);

		/* keep indexes current */
		CatalogUpdateIndexes(sdepRel, oldtup);
	}

	if (oldtup)
		heap_freetuple(oldtup);
}

//.........这里部分代码省略.........
	 * we still need to make the check --- effectively, we're applying the
	 * check against the live child row, although we can use the values from
	 * this row since by definition all columns of interest to us are the
	 * same.
	 *
	 * This might look like just an optimization, because the index AM will
	 * make this identical test before throwing an error.  But it's actually
	 * needed for correctness, because the index AM will also throw an error
	 * if it doesn't find the index entry for the row.  If the row's dead then
	 * it's possible the index entry has also been marked dead, and even
	 * removed.
	 */
	tmptid = new_row->t_self;
	if (!heap_hot_search(&tmptid, trigdata->tg_relation, SnapshotSelf, NULL))
	{
		/*
		 * All rows in the HOT chain are dead, so skip the check.
		 */
		return PointerGetDatum(NULL);
	}

	/*
	 * Open the index, acquiring a RowExclusiveLock, just as if we were going
	 * to update it.  (This protects against possible changes of the index
	 * schema, not against concurrent updates.)
	 */
	indexRel = index_open(trigdata->tg_trigger->tgconstrindid,
						  RowExclusiveLock);
	indexInfo = BuildIndexInfo(indexRel);

	/*
	 * The heap tuple must be put into a slot for FormIndexDatum.
	 */
	slot = MakeSingleTupleTableSlot(RelationGetDescr(trigdata->tg_relation));

	ExecStoreHeapTuple(new_row, slot, InvalidBuffer, false);

	/*
	 * Typically the index won't have expressions, but if it does we need an
	 * EState to evaluate them.  We need it for exclusion constraints too,
	 * even if they are just on simple columns.
	 */
	if (indexInfo->ii_Expressions != NIL ||
		indexInfo->ii_ExclusionOps != NULL)
	{
		estate = CreateExecutorState();
		econtext = GetPerTupleExprContext(estate);
		econtext->ecxt_scantuple = slot;
	}
	else
		estate = NULL;

	/*
	 * Form the index values and isnull flags for the index entry that we need
	 * to check.
	 *
	 * Note: if the index uses functions that are not as immutable as they are
	 * supposed to be, this could produce an index tuple different from the
	 * original.  The index AM can catch such errors by verifying that it
	 * finds a matching index entry with the tuple's TID.  For exclusion
	 * constraints we check this in check_exclusion_constraint().
	 */
	FormIndexDatum(indexInfo, slot, estate, values, isnull);

	/*
	 * Now do the appropriate check.

//.........这里部分代码省略.........
	values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
	values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
	values[Anum_pg_proc_pronargdefaults - 1] = UInt16GetDatum(list_length(parameterDefaults));
	values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
	values[Anum_pg_proc_proargtypes - 1] = PointerGetDatum(parameterTypes);
	if (allParameterTypes != PointerGetDatum(NULL))
		values[Anum_pg_proc_proallargtypes - 1] = allParameterTypes;
	else
		nulls[Anum_pg_proc_proallargtypes - 1] = true;
	if (parameterModes != PointerGetDatum(NULL))
		values[Anum_pg_proc_proargmodes - 1] = parameterModes;
	else
		nulls[Anum_pg_proc_proargmodes - 1] = true;
	if (parameterNames != PointerGetDatum(NULL))
		values[Anum_pg_proc_proargnames - 1] = parameterNames;
	else
		nulls[Anum_pg_proc_proargnames - 1] = true;
	if (parameterDefaults != NIL)
		values[Anum_pg_proc_proargdefaults - 1] = CStringGetTextDatum(nodeToString(parameterDefaults));
	else
		nulls[Anum_pg_proc_proargdefaults - 1] = true;
	values[Anum_pg_proc_prosrc - 1] = CStringGetTextDatum(prosrc);
	if (probin)
		values[Anum_pg_proc_probin - 1] = CStringGetTextDatum(probin);
	else
		nulls[Anum_pg_proc_probin - 1] = true;
	if (proconfig != PointerGetDatum(NULL))
		values[Anum_pg_proc_proconfig - 1] = proconfig;
	else
		nulls[Anum_pg_proc_proconfig - 1] = true;
	/* proacl will be determined later */

	rel = heap_open(ProcedureRelationId, RowExclusiveLock);
	tupDesc = RelationGetDescr(rel);

	/* Check for pre-existing definition */
	oldtup = SearchSysCache3(PROCNAMEARGSNSP,
							 PointerGetDatum(procedureName),
							 PointerGetDatum(parameterTypes),
							 ObjectIdGetDatum(procNamespace));

	if (HeapTupleIsValid(oldtup))
	{
		/* There is one; okay to replace it? */
		Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);
		Datum		proargnames;
		bool		isnull;

		if (!replace)
			ereport(ERROR,
					(errcode(ERRCODE_DUPLICATE_FUNCTION),
			errmsg("function \"%s\" already exists with same argument types",
				   procedureName)));
		if (!pg_proc_ownercheck(HeapTupleGetOid(oldtup), proowner))
			aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
						   procedureName);

		/*
		 * Not okay to change the return type of the existing proc, since
		 * existing rules, views, etc may depend on the return type.
		 */
		if (returnType != oldproc->prorettype ||
			returnsSet != oldproc->proretset)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
					 errmsg("cannot change return type of existing function"),

/**
 *begin scanning of a parquet relation
 */
ParquetScanDesc
parquet_beginscan(
		Relation relation,
		Snapshot parquetMetaDataSnapshot,
		TupleDesc relationTupleDesc,
		bool *proj)
{
	ParquetScanDesc 			scan;
	AppendOnlyEntry				*aoEntry;

	AppendOnlyStorageAttributes	*attr;

	/*
	 * increment relation ref count while scanning relation
	 *
	 * This is just to make really sure the relcache entry won't go away while
	 * the scan has a pointer to it.  Caller should be holding the rel open
	 * anyway, so this is redundant in all normal scenarios...
	 */
	RelationIncrementReferenceCount(relation);

	/* allocate scan descriptor */
	scan = (ParquetScanDescData *)palloc0(sizeof(ParquetScanDescData));

	/*
	 * Get the pg_appendonly information for this table
	 */
	aoEntry = GetAppendOnlyEntry(RelationGetRelid(relation), parquetMetaDataSnapshot);
	scan->aoEntry = aoEntry;
	Assert(aoEntry->majorversion == 1 && aoEntry->minorversion == 0);

#ifdef FAULT_INJECTOR
				FaultInjector_InjectFaultIfSet(
											   FailQeWhenBeginParquetScan,
											   DDLNotSpecified,
											   "",	// databaseName
											   ""); // tableName
#endif

	/*
	 * initialize the scan descriptor
	 */
	scan->pqs_filenamepath_maxlen = AOSegmentFilePathNameLen(relation) + 1;
	scan->pqs_filenamepath = (char*)palloc0(scan->pqs_filenamepath_maxlen);
	scan->pqs_rd = relation;
	scan->parquetScanInitContext = CurrentMemoryContext;

	/*
	 * Fill in Parquet Storage layer attributes.
	 */
	attr = &scan->storageAttributes;

	/*
	 * These attributes describe the AppendOnly format to be scanned.
	 */
	if (aoEntry->compresstype == NULL || pg_strcasecmp(aoEntry->compresstype, "none") == 0)
		attr->compress = false;
	else
		attr->compress = true;
	if (aoEntry->compresstype != NULL)
		attr->compressType = aoEntry->compresstype;
	else
		attr->compressType = "none";
	attr->compressLevel     = aoEntry->compresslevel;
	attr->checksum			= aoEntry->checksum;
	attr->safeFSWriteSize	= aoEntry->safefswritesize;
	attr->splitsize = aoEntry->splitsize;
	attr->version			= aoEntry->version;


	AORelationVersion_CheckValid(attr->version);

	scan->proj = proj;

	scan->pqs_tupDesc = (relationTupleDesc == NULL) ? RelationGetDescr(relation) : relationTupleDesc;

	scan->hawqAttrToParquetColChunks = (int*)palloc0(scan->pqs_tupDesc->natts * sizeof(int));

	initscan(scan);

	return scan ;
}

/*
 * This function initializes a part and returns true if a new index has been prepared for scanning.
 */
static bool
initNextIndexToScan(DynamicIndexScanState *node)
{
	IndexScanState *indexState = &(node->indexScanState);
	DynamicIndexScan *dynamicIndexScan = (DynamicIndexScan *)node->indexScanState.ss.ps.plan;
	EState *estate = indexState->ss.ps.state;

	/* Load new index when the scanning of the previous index is done. */
	if (indexState->ss.scan_state == SCAN_INIT ||
		indexState->ss.scan_state == SCAN_DONE)
	{
		/* This is the oid of a partition of the table (*not* index) */
		Oid *pid = hash_seq_search(&node->pidxStatus);
		if (pid == NULL)
		{
			/* Return if all parts have been scanned. */
			node->shouldCallHashSeqTerm = false;
			return false;
		}

		/* Collect number of partitions scanned in EXPLAIN ANALYZE */
		if(NULL != indexState->ss.ps.instrument)
		{
			Instrumentation *instr = indexState->ss.ps.instrument;
			instr->numPartScanned ++;
		}

		DynamicIndexScan_ReMapColumns(node, *pid);

		/*
		 * The is the oid of the partition of an *index*. Note: a partitioned table
		 * has a root and a set of partitions (may be multi-level). An index
		 * on a partitioned table also has a root and a set of index partitions.
		 * We started at table level, and now we are fetching the oid of an index
		 * partition.
		 */
		Relation currentRelation = OpenScanRelationByOid(*pid);
		indexState->ss.ss_currentRelation = currentRelation;

		indexState->ss.ss_ScanTupleSlot->tts_tableOid = *pid;

		ExecAssignScanType(&indexState->ss, RelationGetDescr(currentRelation));

		/*
		 * Initialize result tuple type and projection info.
		 */
		ExecAssignResultTypeFromTL(&indexState->ss.ps);
		ExecAssignScanProjectionInfo(&indexState->ss);

		MemoryContextReset(node->partitionMemoryContext);
		MemoryContext oldCxt = MemoryContextSwitchTo(node->partitionMemoryContext);

		/* Initialize child expressions */
		indexState->ss.ps.qual = (List *) ExecInitExpr((Expr *) indexState->ss.ps.plan->qual, (PlanState *) indexState);
		indexState->ss.ps.targetlist = (List *) ExecInitExpr((Expr *) indexState->ss.ps.plan->targetlist, (PlanState *) indexState);

		Oid pindex = getPhysicalIndexRelid(currentRelation, dynamicIndexScan->logicalIndexInfo);

		Assert(OidIsValid(pindex));

		indexState->iss_RelationDesc =
			OpenIndexRelation(estate, pindex, *pid);

		/*
		 * build the index scan keys from the index qualification
		 */
		ExecIndexBuildScanKeys((PlanState *) indexState,
						   indexState->iss_RelationDesc,
						   dynamicIndexScan->indexqual,
						   dynamicIndexScan->indexstrategy,
						   dynamicIndexScan->indexsubtype,
						   &indexState->iss_ScanKeys,
						   &indexState->iss_NumScanKeys,
						   &indexState->iss_RuntimeKeys,
						   &indexState->iss_NumRuntimeKeys,
						   NULL,
						   NULL);

		MemoryContextSwitchTo(oldCxt);

		if (indexState->iss_NumRuntimeKeys != 0)
		{
			ExecIndexEvalRuntimeKeys(indexState->iss_RuntimeContext,
									 indexState->iss_RuntimeKeys,
									 indexState->iss_NumRuntimeKeys);
		}
		indexState->iss_RuntimeKeysReady = true;

		indexState->iss_ScanDesc = index_beginscan(currentRelation,
				indexState->iss_RelationDesc,
				estate->es_snapshot,
				indexState->iss_NumScanKeys,
				indexState->iss_ScanKeys);

		indexState->ss.scan_state = SCAN_SCAN;
	}

//.........这里部分代码省略.........

//.........这里部分代码省略.........
			!pg_oper_ownercheck(negatorId, GetUserId()))
			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_OPERATOR,
						   NameListToString(negatorName));
	}
	else
		negatorId = InvalidOid;

	/*
	 * set up values in the operator tuple
	 */

	for (i = 0; i < Natts_pg_operator; ++i)
	{
		values[i] = (Datum) NULL;
		replaces[i] = true;
		nulls[i] = false;
	}

	namestrcpy(&oname, operatorName);
	values[Anum_pg_operator_oprname - 1] = NameGetDatum(&oname);
	values[Anum_pg_operator_oprnamespace - 1] = ObjectIdGetDatum(operatorNamespace);
	values[Anum_pg_operator_oprowner - 1] = ObjectIdGetDatum(GetUserId());
	values[Anum_pg_operator_oprkind - 1] = CharGetDatum(leftTypeId ? (rightTypeId ? 'b' : 'r') : 'l');
	values[Anum_pg_operator_oprcanmerge - 1] = BoolGetDatum(canMerge);
	values[Anum_pg_operator_oprcanhash - 1] = BoolGetDatum(canHash);
	values[Anum_pg_operator_oprleft - 1] = ObjectIdGetDatum(leftTypeId);
	values[Anum_pg_operator_oprright - 1] = ObjectIdGetDatum(rightTypeId);
	values[Anum_pg_operator_oprresult - 1] = ObjectIdGetDatum(operResultType);
	values[Anum_pg_operator_oprcom - 1] = ObjectIdGetDatum(commutatorId);
	values[Anum_pg_operator_oprnegate - 1] = ObjectIdGetDatum(negatorId);
	values[Anum_pg_operator_oprcode - 1] = ObjectIdGetDatum(procedureId);
	values[Anum_pg_operator_oprrest - 1] = ObjectIdGetDatum(restrictionId);
	values[Anum_pg_operator_oprjoin - 1] = ObjectIdGetDatum(joinId);

	pg_operator_desc = heap_open(OperatorRelationId, RowExclusiveLock);

	/*
	 * If we are replacing an operator shell, update; else insert
	 */
	if (operatorObjectId)
	{
		isUpdate = true;

		tup = SearchSysCacheCopy1(OPEROID,
								  ObjectIdGetDatum(operatorObjectId));
		if (!HeapTupleIsValid(tup))
			elog(ERROR, "cache lookup failed for operator %u",
				 operatorObjectId);

		replaces[Anum_pg_operator_oid - 1] = false;
		tup = heap_modify_tuple(tup,
								RelationGetDescr(pg_operator_desc),
								values,
								nulls,
								replaces);

		CatalogTupleUpdate(pg_operator_desc, &tup->t_self, tup);
	}
	else
	{
		isUpdate = false;

		operatorObjectId = GetNewOidWithIndex(pg_operator_desc,
											  OperatorOidIndexId,
											  Anum_pg_operator_oid);
		values[Anum_pg_operator_oid - 1] = ObjectIdGetDatum(operatorObjectId);

		tup = heap_form_tuple(RelationGetDescr(pg_operator_desc),
							  values, nulls);

		CatalogTupleInsert(pg_operator_desc, tup);
	}

	/* Add dependencies for the entry */
	address = makeOperatorDependencies(tup, isUpdate);

	/* Post creation hook for new operator */
	InvokeObjectPostCreateHook(OperatorRelationId, operatorObjectId, 0);

	heap_close(pg_operator_desc, RowExclusiveLock);

	/*
	 * If a commutator and/or negator link is provided, update the other
	 * operator(s) to point at this one, if they don't already have a link.
	 * This supports an alternative style of operator definition wherein the
	 * user first defines one operator without giving negator or commutator,
	 * then defines the other operator of the pair with the proper commutator
	 * or negator attribute.  That style doesn't require creation of a shell,
	 * and it's the only style that worked right before Postgres version 6.5.
	 * This code also takes care of the situation where the new operator is
	 * its own commutator.
	 */
	if (selfCommutator)
		commutatorId = operatorObjectId;

	if (OidIsValid(commutatorId) || OidIsValid(negatorId))
		OperatorUpd(operatorObjectId, commutatorId, negatorId, false);

	return address;
}

/*
 * Change tablespace owner
 */
void
AlterTableSpaceOwner(const char *name, Oid newOwnerId)
{
	Relation	rel;
	ScanKeyData entry[1];
	HeapScanDesc scandesc;
	Form_pg_tablespace spcForm;
	HeapTuple	tup;

	/* Search pg_tablespace */
	rel = heap_open(TableSpaceRelationId, RowExclusiveLock);

	ScanKeyInit(&entry[0],
				Anum_pg_tablespace_spcname,
				BTEqualStrategyNumber, F_NAMEEQ,
				CStringGetDatum(name));
	scandesc = heap_beginscan(rel, SnapshotNow, 1, entry);
	tup = heap_getnext(scandesc, ForwardScanDirection);
	if (!HeapTupleIsValid(tup))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("tablespace \"%s\" does not exist", name)));

	spcForm = (Form_pg_tablespace) GETSTRUCT(tup);

	/*
	 * If the new owner is the same as the existing owner, consider the
	 * command to have succeeded.  This is for dump restoration purposes.
	 */
	if (spcForm->spcowner != newOwnerId)
	{
		Datum		repl_val[Natts_pg_tablespace];
		bool		repl_null[Natts_pg_tablespace];
		bool		repl_repl[Natts_pg_tablespace];
		Acl		   *newAcl;
		Datum		aclDatum;
		bool		isNull;
		HeapTuple	newtuple;

		/* Otherwise, must be owner of the existing object */
		if (!pg_tablespace_ownercheck(HeapTupleGetOid(tup), GetUserId()))
			aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_TABLESPACE,
						   name);

		/* Must be able to become new owner */
		check_is_member_of_role(GetUserId(), newOwnerId);

		/*
		 * Normally we would also check for create permissions here, but there
		 * are none for tablespaces so we follow what rename tablespace does
		 * and omit the create permissions check.
		 *
		 * NOTE: Only superusers may create tablespaces to begin with and so
		 * initially only a superuser would be able to change its ownership
		 * anyway.
		 */

		memset(repl_null, false, sizeof(repl_null));
		memset(repl_repl, false, sizeof(repl_repl));

		repl_repl[Anum_pg_tablespace_spcowner - 1] = true;
		repl_val[Anum_pg_tablespace_spcowner - 1] = ObjectIdGetDatum(newOwnerId);

		/*
		 * Determine the modified ACL for the new owner.  This is only
		 * necessary when the ACL is non-null.
		 */
		aclDatum = heap_getattr(tup,
								Anum_pg_tablespace_spcacl,
								RelationGetDescr(rel),
								&isNull);
		if (!isNull)
		{
			newAcl = aclnewowner(DatumGetAclP(aclDatum),
								 spcForm->spcowner, newOwnerId);
			repl_repl[Anum_pg_tablespace_spcacl - 1] = true;
			repl_val[Anum_pg_tablespace_spcacl - 1] = PointerGetDatum(newAcl);
		}

		newtuple = heap_modify_tuple(tup, RelationGetDescr(rel), repl_val, repl_null, repl_repl);

		simple_heap_update(rel, &newtuple->t_self, newtuple);
		CatalogUpdateIndexes(rel, newtuple);

		heap_freetuple(newtuple);

		/* Update owner dependency reference */
		changeDependencyOnOwner(TableSpaceRelationId, HeapTupleGetOid(tup),
								newOwnerId);
	}

	heap_endscan(scandesc);
	heap_close(rel, NoLock);
}