C++ TupleDescInitEntry函数代码示例

/*
 * Get status of resource groups
 */
Datum
pg_resgroup_get_status(PG_FUNCTION_ARGS)
{
	FuncCallContext *funcctx;
	ResGroupStatCtx *ctx;

	if (SRF_IS_FIRSTCALL())
	{
		MemoryContext oldcontext;
		TupleDesc	tupdesc;
		int			nattr = 8;

		funcctx = SRF_FIRSTCALL_INIT();

		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

		tupdesc = CreateTemplateTupleDesc(nattr, false);
		TupleDescInitEntry(tupdesc, (AttrNumber) 1, "groupid", OIDOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 2, "num_running", INT4OID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 3, "num_queueing", INT4OID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 4, "num_queued", INT4OID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 5, "num_executed", INT4OID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 6, "total_queue_duration", INTERVALOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 7, "cpu_usage", JSONOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 8, "memory_usage", JSONOID, -1, 0);

		funcctx->tuple_desc = BlessTupleDesc(tupdesc);

		if (IsResGroupActivated())
		{
			Relation	pg_resgroup_rel;
			SysScanDesc	sscan;
			HeapTuple	tuple;
			Oid			inGroupId = PG_GETARG_OID(0);

			int ctxsize = sizeof(ResGroupStatCtx) +
				sizeof(ResGroupStat) * (MaxResourceGroups - 1);

			(void) inGroupId;

			funcctx->user_fctx = palloc(ctxsize);
			ctx = (ResGroupStatCtx *) funcctx->user_fctx;

			/*
			 * others may be creating/dropping resource group concurrently,
			 * block until creating/dropping finish to avoid inconsistent
			 * resource group metadata
			 */
			pg_resgroup_rel = heap_open(ResGroupRelationId, ExclusiveLock);

			sscan = systable_beginscan(pg_resgroup_rel, InvalidOid, false,
									   NULL, 0, NULL);
			while (HeapTupleIsValid(tuple = systable_getnext(sscan)))
			{
				Oid oid = ObjectIdGetDatum(HeapTupleGetOid(tuple));

				if (inGroupId == InvalidOid || inGroupId == oid)
				{
					Assert(funcctx->max_calls < MaxResourceGroups);
					ctx->groups[funcctx->max_calls].cpuUsage = makeStringInfo();
					ctx->groups[funcctx->max_calls].memUsage = makeStringInfo();
					ctx->groups[funcctx->max_calls++].groupId = oid;

					if (inGroupId != InvalidOid)
						break;
				}
			}
			systable_endscan(sscan);

			ctx->nGroups = funcctx->max_calls;
			qsort(ctx->groups, ctx->nGroups, sizeof(ctx->groups[0]), compareRow);

			if (ctx->nGroups > 0)
				getResUsage(ctx, inGroupId);

			heap_close(pg_resgroup_rel, ExclusiveLock);
		}

		MemoryContextSwitchTo(oldcontext);
	}

	/* stuff done on every call of the function */
	funcctx = SRF_PERCALL_SETUP();
	ctx = (ResGroupStatCtx *) funcctx->user_fctx;

	if (funcctx->call_cntr < funcctx->max_calls)
	{
		/* for each row */
		Datum		values[8];
		bool		nulls[8];
		HeapTuple	tuple;
		Oid			groupId;
		char		statVal[MAXDATELEN + 1];
		ResGroupStat *row = &ctx->groups[funcctx->call_cntr];

		MemSet(values, 0, sizeof(values));
		MemSet(nulls, 0, sizeof(nulls));
//.........这里部分代码省略.........

/*
 * stat a file
 */
Datum
pg_stat_file(PG_FUNCTION_ARGS)
{
	text	   *filename_t = PG_GETARG_TEXT_P(0);
	char	   *filename;
	struct stat fst;
	Datum		values[6];
	bool		isnull[6];
	HeapTuple	tuple;
	TupleDesc	tupdesc;

	if (!superuser())
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 (errmsg("must be superuser to get file information"))));

	filename = convert_and_check_filename(filename_t);

	if (stat(filename, &fst) < 0)
		ereport(ERROR,
				(errcode_for_file_access(),
				 errmsg("could not stat file \"%s\": %m", filename)));

	/*
	 * This record type had better match the output parameters declared for me
	 * in pg_proc.h.
	 */
	tupdesc = CreateTemplateTupleDesc(6, false);
	TupleDescInitEntry(tupdesc, (AttrNumber) 1,
					   "size", INT8OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 2,
					   "access", TIMESTAMPTZOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 3,
					   "modification", TIMESTAMPTZOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 4,
					   "change", TIMESTAMPTZOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 5,
					   "creation", TIMESTAMPTZOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 6,
					   "isdir", BOOLOID, -1, 0);
	BlessTupleDesc(tupdesc);

	memset(isnull, false, sizeof(isnull));

	values[0] = Int64GetDatum((int64) fst.st_size);
	values[1] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_atime));
	values[2] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_mtime));
	/* Unix has file status change time, while Win32 has creation time */
#if !defined(WIN32) && !defined(__CYGWIN__)
	values[3] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_ctime));
	isnull[4] = true;
#else
	isnull[3] = true;
	values[4] = TimestampTzGetDatum(time_t_to_timestamptz(fst.st_ctime));
#endif
	values[5] = BoolGetDatum(S_ISDIR(fst.st_mode));

	tuple = heap_form_tuple(tupdesc, values, isnull);

	pfree(filename);

	PG_RETURN_DATUM(HeapTupleGetDatum(tuple));
}

Datum
pg_stat_get_activity(PG_FUNCTION_ARGS)
{
	FuncCallContext *funcctx;

	if (SRF_IS_FIRSTCALL())
	{
		MemoryContext oldcontext;
		TupleDesc	tupdesc;

		funcctx = SRF_FIRSTCALL_INIT();

		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

		tupdesc = CreateTemplateTupleDesc(13, false);
		TupleDescInitEntry(tupdesc, (AttrNumber) 1, "datid", OIDOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 2, "procpid", INT4OID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 3, "usesysid", OIDOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 4, "application_name", TEXTOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 5, "current_query", TEXTOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 6, "waiting", BOOLOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 7, "act_start", TIMESTAMPTZOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 8, "query_start", TIMESTAMPTZOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 9, "backend_start", TIMESTAMPTZOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 10, "client_addr", INETOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 11, "client_port", INT4OID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 12, "sess_id", INT4OID, -1, 0);  /* GPDB */
		TupleDescInitEntry(tupdesc, (AttrNumber) 13, "waiting_resource", BOOLOID, -1, 0);

		funcctx->tuple_desc = BlessTupleDesc(tupdesc);

		funcctx->user_fctx = palloc0(sizeof(int));
		if (PG_ARGISNULL(0))
		{
			/* Get all backends */
			funcctx->max_calls = pgstat_fetch_stat_numbackends();
		}
		else
		{
			/*
			 * Get one backend - locate by pid.
			 *
			 * We lookup the backend early, so we can return zero rows if it
			 * doesn't exist, instead of returning a single row full of NULLs.
			 */
			int			pid = PG_GETARG_INT32(0);
			int			i;
			int			n = pgstat_fetch_stat_numbackends();

			for (i = 1; i <= n; i++)
			{
				PgBackendStatus *be = pgstat_fetch_stat_beentry(i);

				if (be)
				{
					if (be->st_procpid == pid)
					{
						*(int *) (funcctx->user_fctx) = i;
						break;
					}
				}
			}

			if (*(int *) (funcctx->user_fctx) == 0)
				/* Pid not found, return zero rows */
				funcctx->max_calls = 0;
			else
				funcctx->max_calls = 1;
		}

		MemoryContextSwitchTo(oldcontext);
	}

	/* stuff done on every call of the function */
	funcctx = SRF_PERCALL_SETUP();

	if (funcctx->call_cntr < funcctx->max_calls)
	{
		/* for each row */
		Datum		values[13];
		bool		nulls[13];
		HeapTuple	tuple;
		PgBackendStatus *beentry;
		SockAddr	zero_clientaddr;

		MemSet(values, 0, sizeof(values));
		MemSet(nulls, 0, sizeof(nulls));

		if (*(int *) (funcctx->user_fctx) > 0)
		{
			/* Get specific pid slot */
			beentry = pgstat_fetch_stat_beentry(*(int *) (funcctx->user_fctx));
		}
		else
		{
			/* Get the next one in the list */
			beentry = pgstat_fetch_stat_beentry(funcctx->call_cntr + 1);		/* 1-based index */
		}
		if (!beentry)
		{
//.........这里部分代码省略.........

/*
 * BuildDescForRelation
 *
 * Given a relation schema (list of ColumnDef nodes), build a TupleDesc.
 *
 * Note: the default assumption is no OIDs; caller may modify the returned
 * TupleDesc if it wants OIDs.  Also, tdtypeid will need to be filled in
 * later on.
 */
TupleDesc
BuildDescForRelation(List *schema)
{
	int			natts;
	AttrNumber	attnum;
	ListCell   *l;
	TupleDesc	desc;
	bool		has_not_null;
	char	   *attname;
	Oid			atttypid;
	int32		atttypmod;
	Oid			attcollation;
	int			attdim;

	/*
	 * allocate a new tuple descriptor
	 */
	natts = list_length(schema);
	desc = CreateTemplateTupleDesc(natts, false);
	has_not_null = false;

	attnum = 0;

	foreach(l, schema)
	{
		ColumnDef  *entry = lfirst(l);
		AclResult	aclresult;

		/*
		 * for each entry in the list, get the name and type information from
		 * the list and have TupleDescInitEntry fill in the attribute
		 * information we need.
		 */
		attnum++;

		attname = entry->colname;
		typenameTypeIdAndMod(NULL, entry->typeName, &atttypid, &atttypmod);

		aclresult = pg_type_aclcheck(atttypid, GetUserId(), ACL_USAGE);
		if (aclresult != ACLCHECK_OK)
			aclcheck_error_type(aclresult, atttypid);

		attcollation = GetColumnDefCollation(NULL, entry, atttypid);
		attdim = list_length(entry->typeName->arrayBounds);

		if (entry->typeName->setof)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
					 errmsg("column \"%s\" cannot be declared SETOF",
							attname)));

		TupleDescInitEntry(desc, attnum, attname,
						   atttypid, atttypmod, attdim);

		/* Override TupleDescInitEntry's settings as requested */
		TupleDescInitEntryCollation(desc, attnum, attcollation);
		if (entry->storage)
			desc->attrs[attnum - 1]->attstorage = entry->storage;

		/* Fill in additional stuff not handled by TupleDescInitEntry */
		desc->attrs[attnum - 1]->attnotnull = entry->is_not_null;
		has_not_null |= entry->is_not_null;
		desc->attrs[attnum - 1]->attislocal = entry->is_local;
		desc->attrs[attnum - 1]->attinhcount = entry->inhcount;
	}

Datum
gistrescan(PG_FUNCTION_ARGS)
{
	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
	ScanKey		key = (ScanKey) PG_GETARG_POINTER(1);
	ScanKey		orderbys = (ScanKey) PG_GETARG_POINTER(3);

	/* nkeys and norderbys arguments are ignored */
	GISTScanOpaque so = (GISTScanOpaque) scan->opaque;
	bool		first_time;
	int			i;
	MemoryContext oldCxt;

	/* rescan an existing indexscan --- reset state */

	/*
	 * The first time through, we create the search queue in the scanCxt.
	 * Subsequent times through, we create the queue in a separate queueCxt,
	 * which is created on the second call and reset on later calls.  Thus, in
	 * the common case where a scan is only rescan'd once, we just put the
	 * queue in scanCxt and don't pay the overhead of making a second memory
	 * context.  If we do rescan more than once, the first RBTree is just left
	 * for dead until end of scan; this small wastage seems worth the savings
	 * in the common case.
	 */
	if (so->queue == NULL)
	{
		/* first time through */
		Assert(so->queueCxt == so->giststate->scanCxt);
		first_time = true;
	}
	else if (so->queueCxt == so->giststate->scanCxt)
	{
		/* second time through */
		so->queueCxt = AllocSetContextCreate(so->giststate->scanCxt,
											 "GiST queue context",
											 ALLOCSET_DEFAULT_MINSIZE,
											 ALLOCSET_DEFAULT_INITSIZE,
											 ALLOCSET_DEFAULT_MAXSIZE);
		first_time = false;
	}
	else
	{
		/* third or later time through */
		MemoryContextReset(so->queueCxt);
		first_time = false;
	}

	/*
	 * If we're doing an index-only scan, on the first call, also initialize
	 * a tuple descriptor to represent the returned index tuples and create a
	 * memory context to hold them during the scan.
	 */
	if (scan->xs_want_itup && !scan->xs_itupdesc)
	{
		int			natts;
		int			attno;

		/*
		 * The storage type of the index can be different from the original
		 * datatype being indexed, so we cannot just grab the index's tuple
		 * descriptor. Instead, construct a descriptor with the original data
		 * types.
		 */
		natts =  RelationGetNumberOfAttributes(scan->indexRelation);
		so->giststate->fetchTupdesc = CreateTemplateTupleDesc(natts, false);
		for (attno = 1; attno <= natts; attno++)
		{
			TupleDescInitEntry(so->giststate->fetchTupdesc, attno, NULL,
							   scan->indexRelation->rd_opcintype[attno - 1],
							   -1, 0);
		}
		scan->xs_itupdesc = so->giststate->fetchTupdesc;

		so->pageDataCxt = AllocSetContextCreate(so->giststate->scanCxt,
												"GiST page data context",
												ALLOCSET_DEFAULT_MINSIZE,
												ALLOCSET_DEFAULT_INITSIZE,
												ALLOCSET_DEFAULT_MAXSIZE);
	}

	/* create new, empty RBTree for search queue */
	oldCxt = MemoryContextSwitchTo(so->queueCxt);
	so->queue = pairingheap_allocate(pairingheap_GISTSearchItem_cmp, scan);
	MemoryContextSwitchTo(oldCxt);

	so->firstCall = true;

	/* Update scan key, if a new one is given */
	if (key && scan->numberOfKeys > 0)
	{
		void	  **fn_extras = NULL;

		/*
		 * If this isn't the first time through, preserve the fn_extra
		 * pointers, so that if the consistentFns are using them to cache
		 * data, that data is not leaked across a rescan.
		 */
		if (!first_time)
		{
//.........这里部分代码省略.........

/*
 * TypeGetTupleDesc
 *
 * Given a type Oid, build a TupleDesc.  (In most cases you should be
 * using get_call_result_type or one of its siblings instead of this
 * routine, so that you can handle OUT parameters, RECORD result type,
 * and polymorphic results.)
 *
 * If the type is composite, *and* a colaliases List is provided, *and*
 * the List is of natts length, use the aliases instead of the relation
 * attnames.  (NB: this usage is deprecated since it may result in
 * creation of unnecessary transient record types.)
 *
 * If the type is a base type, a single item alias List is required.
 */
TupleDesc
TypeGetTupleDesc(Oid typeoid, List *colaliases)
{
	TypeFuncClass functypclass = get_type_func_class(typeoid);
	TupleDesc	tupdesc = NULL;

	/*
	 * Build a suitable tupledesc representing the output rows
	 */
	if (functypclass == TYPEFUNC_COMPOSITE)
	{
		/* Composite data type, e.g. a table's row type */
		tupdesc = lookup_rowtype_tupdesc_copy(typeoid, -1);

		if (colaliases != NIL)
		{
			int			natts = tupdesc->natts;
			int			varattno;

			/* does the list length match the number of attributes? */
			if (list_length(colaliases) != natts)
				ereport(ERROR,
						(errcode(ERRCODE_DATATYPE_MISMATCH),
						 errmsg("number of aliases does not match number of columns")));

			/* OK, use the aliases instead */
			for (varattno = 0; varattno < natts; varattno++)
			{
				char	   *label = strVal(list_nth(colaliases, varattno));

				if (label != NULL)
					namestrcpy(&(tupdesc->attrs[varattno]->attname), label);
			}

			/* The tuple type is now an anonymous record type */
			tupdesc->tdtypeid = RECORDOID;
			tupdesc->tdtypmod = -1;
		}
	}
	else if (functypclass == TYPEFUNC_SCALAR)
	{
		/* Base data type, i.e. scalar */
		char	   *attname;

		/* the alias list is required for base types */
		if (colaliases == NIL)
			ereport(ERROR,
					(errcode(ERRCODE_DATATYPE_MISMATCH),
					 errmsg("no column alias was provided")));

		/* the alias list length must be 1 */
		if (list_length(colaliases) != 1)
			ereport(ERROR,
					(errcode(ERRCODE_DATATYPE_MISMATCH),
			  errmsg("number of aliases does not match number of columns")));

		/* OK, get the column alias */
		attname = strVal(linitial(colaliases));

		tupdesc = CreateTemplateTupleDesc(1, false);
		TupleDescInitEntry(tupdesc,
						   (AttrNumber) 1,
						   attname,
						   typeoid,
						   -1,
						   0);
	}
	else if (functypclass == TYPEFUNC_RECORD)
	{
		/* XXX can't support this because typmod wasn't passed in ... */
		ereport(ERROR,
				(errcode(ERRCODE_DATATYPE_MISMATCH),
				 errmsg("could not determine row description for function returning record")));
	}
	else
	{
		/* crummy error message, but parser should have caught this */
		elog(ERROR, "function in FROM has unsupported return type");
	}

	return tupdesc;
}

/* ----------------------------------------------------------------
 *		ExecInitFunctionScan
 * ----------------------------------------------------------------
 */
FunctionScanState *
ExecInitFunctionScan(FunctionScan *node, EState *estate, int eflags)
{
	FunctionScanState *scanstate;
	RangeTblEntry *rte;
	Oid			funcrettype;
	TypeFuncClass functypclass;
	TupleDesc	tupdesc = NULL;

	/*
	 * FunctionScan should not have any children.
	 */
	Assert(outerPlan(node) == NULL);
	Assert(innerPlan(node) == NULL);

	/*
	 * create new ScanState for node
	 */
	scanstate = makeNode(FunctionScanState);
	scanstate->ss.ps.plan = (Plan *) node;
	scanstate->ss.ps.state = estate;

	/*
	 * Miscellaneous initialization
	 *
	 * create expression context for node
	 */
	ExecAssignExprContext(estate, &scanstate->ss.ps);

#define FUNCTIONSCAN_NSLOTS 2

	/*
	 * tuple table initialization
	 */
	ExecInitResultTupleSlot(estate, &scanstate->ss.ps);
	ExecInitScanTupleSlot(estate, &scanstate->ss);

	/*
	 * initialize child expressions
	 */
	scanstate->ss.ps.targetlist = (List *)
		ExecInitExpr((Expr *) node->scan.plan.targetlist,
					 (PlanState *) scanstate);
	scanstate->ss.ps.qual = (List *)
		ExecInitExpr((Expr *) node->scan.plan.qual,
					 (PlanState *) scanstate);

	/* Check if targetlist or qual contains a var node referencing the ctid column */
	scanstate->cdb_want_ctid = contain_ctid_var_reference(&node->scan);

    ItemPointerSet(&scanstate->cdb_fake_ctid, 0, 0);
    ItemPointerSet(&scanstate->cdb_mark_ctid, 0, 0);

	/*
	 * get info about function
	 */
	rte = rt_fetch(node->scan.scanrelid, estate->es_range_table);
	Assert(rte->rtekind == RTE_FUNCTION);

	/*
	 * Now determine if the function returns a simple or composite type, and
	 * build an appropriate tupdesc.
	 */
	functypclass = get_expr_result_type(rte->funcexpr,
										&funcrettype,
										&tupdesc);

	if (functypclass == TYPEFUNC_COMPOSITE)
	{
		/* Composite data type, e.g. a table's row type */
		Assert(tupdesc);
		/* Must copy it out of typcache for safety */
		tupdesc = CreateTupleDescCopy(tupdesc);
	}
	else if (functypclass == TYPEFUNC_SCALAR)
	{
		/* Base data type, i.e. scalar */
		char	   *attname = strVal(linitial(rte->eref->colnames));

		tupdesc = CreateTemplateTupleDesc(1, false);
		TupleDescInitEntry(tupdesc,
						   (AttrNumber) 1,
						   attname,
						   funcrettype,
						   -1,
						   0);
	}
	else if (functypclass == TYPEFUNC_RECORD)
	{
		tupdesc = BuildDescFromLists(rte->eref->colnames,
									 rte->funccoltypes,
									 rte->funccoltypmods);
	}
	else
	{
		/* crummy error message, but parser should have caught this */
//.........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;
}

/*
 * create_toast_table --- internal workhorse
 *
 * rel is already opened and exclusive-locked
 * toastOid and toastIndexOid are normally InvalidOid, but during
 * bootstrap they can be nonzero to specify hand-assigned OIDs
 */
static bool
create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
				   bool is_part_child)
{
	Oid			relOid = RelationGetRelid(rel);
	HeapTuple	reltup;
	TupleDesc	tupdesc;
	bool		shared_relation;
	Relation	class_rel;
	Oid			toast_relid;
	Oid			toast_idxid;
	Oid			namespaceid;
	char		toast_relname[NAMEDATALEN];
	char		toast_idxname[NAMEDATALEN];
	IndexInfo  *indexInfo;
	Oid			classObjectId[2];
	int16		coloptions[2];
	ObjectAddress baseobject,
				toastobject;

	/*
	 * Is it already toasted?
	 */
	if (rel->rd_rel->reltoastrelid != InvalidOid)
		return false;

	/*
	 * Check to see whether the table actually needs a TOAST table.
	 */
	if (!RelationNeedsToastTable(rel))
		return false;

	/*
	 * Toast table is shared if and only if its parent is.
	 *
	 * We cannot allow toasting a shared relation after initdb (because
	 * there's no way to mark it toasted in other databases' pg_class).
	 */
	shared_relation = rel->rd_rel->relisshared;
	if (shared_relation && !IsBootstrapProcessingMode())
		ereport(ERROR,
				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
				 errmsg("shared tables cannot be toasted after initdb")));

	/*
	 * Create the toast table and its index
	 */
	snprintf(toast_relname, sizeof(toast_relname),
			 "pg_toast_%u", relOid);
	snprintf(toast_idxname, sizeof(toast_idxname),
			 "pg_toast_%u_index", relOid);

	/* this is pretty painful...  need a tuple descriptor */
	tupdesc = CreateTemplateTupleDesc(3, false);
	TupleDescInitEntry(tupdesc, (AttrNumber) 1,
					   "chunk_id",
					   OIDOID,
					   -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 2,
					   "chunk_seq",
					   INT4OID,
					   -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 3,
					   "chunk_data",
					   BYTEAOID,
					   -1, 0);

	/*
	 * Ensure that the toast table doesn't itself get toasted, or we'll be
	 * toast :-(.  This is essential for chunk_data because type bytea is
	 * toastable; hit the other two just to be sure.
	 */
	tupdesc->attrs[0]->attstorage = 'p';
	tupdesc->attrs[1]->attstorage = 'p';
	tupdesc->attrs[2]->attstorage = 'p';

	/*
	 * Toast tables for regular relations go in pg_toast; those for temp
	 * relations go into the per-backend temp-toast-table namespace.
	 */
	if (rel->rd_istemp)
		namespaceid = GetTempToastNamespace();
	else
		namespaceid = PG_TOAST_NAMESPACE;

	/*
	 * XXX would it make sense to apply the master's reloptions to the toast
	 * table?  Or maybe some toast-specific reloptions?
	 */
	toast_relid = heap_create_with_catalog(toast_relname,
										   namespaceid,
										   rel->rd_rel->reltablespace,
										   toastOid,
//.........这里部分代码省略.........

Datum
pg_control_init(PG_FUNCTION_ARGS)
{
	Datum		values[12];
	bool		nulls[12];
	TupleDesc	tupdesc;
	HeapTuple	htup;
	ControlFileData *ControlFile;
	bool		crc_ok;

	/*
	 * Construct a tuple descriptor for the result row.  This must match this
	 * function's pg_proc entry!
	 */
	tupdesc = CreateTemplateTupleDesc(12);
	TupleDescInitEntry(tupdesc, (AttrNumber) 1, "max_data_alignment",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 2, "database_block_size",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 3, "blocks_per_segment",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 4, "wal_block_size",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 5, "bytes_per_wal_segment",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 6, "max_identifier_length",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 7, "max_index_columns",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 8, "max_toast_chunk_size",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 9, "large_object_chunk_size",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 10, "float4_pass_by_value",
					   BOOLOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 11, "float8_pass_by_value",
					   BOOLOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 12, "data_page_checksum_version",
					   INT4OID, -1, 0);
	tupdesc = BlessTupleDesc(tupdesc);

	/* read the control file */
	ControlFile = get_controlfile(DataDir, NULL, &crc_ok);
	if (!crc_ok)
		ereport(ERROR,
				(errmsg("calculated CRC checksum does not match value stored in file")));

	values[0] = Int32GetDatum(ControlFile->maxAlign);
	nulls[0] = false;

	values[1] = Int32GetDatum(ControlFile->blcksz);
	nulls[1] = false;

	values[2] = Int32GetDatum(ControlFile->relseg_size);
	nulls[2] = false;

	values[3] = Int32GetDatum(ControlFile->xlog_blcksz);
	nulls[3] = false;

	values[4] = Int32GetDatum(ControlFile->xlog_seg_size);
	nulls[4] = false;

	values[5] = Int32GetDatum(ControlFile->nameDataLen);
	nulls[5] = false;

	values[6] = Int32GetDatum(ControlFile->indexMaxKeys);
	nulls[6] = false;

	values[7] = Int32GetDatum(ControlFile->toast_max_chunk_size);
	nulls[7] = false;

	values[8] = Int32GetDatum(ControlFile->loblksize);
	nulls[8] = false;

	values[9] = BoolGetDatum(ControlFile->float4ByVal);
	nulls[9] = false;

	values[10] = BoolGetDatum(ControlFile->float8ByVal);
	nulls[10] = false;

	values[11] = Int32GetDatum(ControlFile->data_checksum_version);
	nulls[11] = false;

	htup = heap_form_tuple(tupdesc, values, nulls);

	PG_RETURN_DATUM(HeapTupleGetDatum(htup));
}

Datum
pg_control_checkpoint(PG_FUNCTION_ARGS)
{
	Datum		values[19];
	bool		nulls[19];
	TupleDesc	tupdesc;
	HeapTuple	htup;
	ControlFileData *ControlFile;
	XLogSegNo	segno;
	char		xlogfilename[MAXFNAMELEN];
	bool		crc_ok;

	/*
	 * Construct a tuple descriptor for the result row.  This must match this
	 * function's pg_proc entry!
	 */
	tupdesc = CreateTemplateTupleDesc(18);
	TupleDescInitEntry(tupdesc, (AttrNumber) 1, "checkpoint_lsn",
					   LSNOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 2, "redo_lsn",
					   LSNOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 3, "redo_wal_file",
					   TEXTOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 4, "timeline_id",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 5, "prev_timeline_id",
					   INT4OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 6, "full_page_writes",
					   BOOLOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 7, "next_xid",
					   TEXTOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 8, "next_oid",
					   OIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 9, "next_multixact_id",
					   XIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 10, "next_multi_offset",
					   XIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 11, "oldest_xid",
					   XIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 12, "oldest_xid_dbid",
					   OIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 13, "oldest_active_xid",
					   XIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 14, "oldest_multi_xid",
					   XIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 15, "oldest_multi_dbid",
					   OIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 16, "oldest_commit_ts_xid",
					   XIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 17, "newest_commit_ts_xid",
					   XIDOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 18, "checkpoint_time",
					   TIMESTAMPTZOID, -1, 0);
	tupdesc = BlessTupleDesc(tupdesc);

	/* Read the control file. */
	ControlFile = get_controlfile(DataDir, NULL, &crc_ok);
	if (!crc_ok)
		ereport(ERROR,
				(errmsg("calculated CRC checksum does not match value stored in file")));

	/*
	 * Calculate name of the WAL file containing the latest checkpoint's REDO
	 * start point.
	 */
	XLByteToSeg(ControlFile->checkPointCopy.redo, segno, wal_segment_size);
	XLogFileName(xlogfilename, ControlFile->checkPointCopy.ThisTimeLineID,
				 segno, wal_segment_size);

	/* Populate the values and null arrays */
	values[0] = LSNGetDatum(ControlFile->checkPoint);
	nulls[0] = false;

	values[1] = LSNGetDatum(ControlFile->checkPointCopy.redo);
	nulls[1] = false;

	values[2] = CStringGetTextDatum(xlogfilename);
	nulls[2] = false;

	values[3] = Int32GetDatum(ControlFile->checkPointCopy.ThisTimeLineID);
	nulls[3] = false;

	values[4] = Int32GetDatum(ControlFile->checkPointCopy.PrevTimeLineID);
	nulls[4] = false;

	values[5] = BoolGetDatum(ControlFile->checkPointCopy.fullPageWrites);
	nulls[5] = false;

	values[6] = CStringGetTextDatum(psprintf("%u:%u",
											 ControlFile->checkPointCopy.nextXidEpoch,
											 ControlFile->checkPointCopy.nextXid));
	nulls[6] = false;

	values[7] = ObjectIdGetDatum(ControlFile->checkPointCopy.nextOid);
	nulls[7] = false;

	values[8] = TransactionIdGetDatum(ControlFile->checkPointCopy.nextMulti);
	nulls[8] = false;

	values[9] = TransactionIdGetDatum(ControlFile->checkPointCopy.nextMultiOffset);
//.........这里部分代码省略.........

Datum
pg_stat_get_archiver(PG_FUNCTION_ARGS)
{
	TupleDesc	tupdesc;
	Datum		values[7];
	bool		nulls[7];
	PgStat_ArchiverStats *archiver_stats;

	/* Initialise values and NULL flags arrays */
	MemSet(values, 0, sizeof(values));
	MemSet(nulls, 0, sizeof(nulls));

	/* Initialise attributes information in the tuple descriptor */
	tupdesc = CreateTemplateTupleDesc(7, false);
	TupleDescInitEntry(tupdesc, (AttrNumber) 1, "archived_count",
					   INT8OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 2, "last_archived_wal",
					   TEXTOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 3, "last_archived_time",
					   TIMESTAMPTZOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 4, "failed_count",
					   INT8OID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 5, "last_failed_wal",
					   TEXTOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 6, "last_failed_time",
					   TIMESTAMPTZOID, -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 7, "stats_reset",
					   TIMESTAMPTZOID, -1, 0);

	BlessTupleDesc(tupdesc);

	/* Get statistics about the archiver process */
	archiver_stats = pgstat_fetch_stat_archiver();

	/* Fill values and NULLs */
	values[0] = Int64GetDatum(archiver_stats->archived_count);
	if (*(archiver_stats->last_archived_wal) == '\0')
		nulls[1] = true;
	else
		values[1] = CStringGetTextDatum(archiver_stats->last_archived_wal);

	if (archiver_stats->last_archived_timestamp == 0)
		nulls[2] = true;
	else
		values[2] = TimestampTzGetDatum(archiver_stats->last_archived_timestamp);

	values[3] = Int64GetDatum(archiver_stats->failed_count);
	if (*(archiver_stats->last_failed_wal) == '\0')
		nulls[4] = true;
	else
		values[4] = CStringGetTextDatum(archiver_stats->last_failed_wal);

	if (archiver_stats->last_failed_timestamp == 0)
		nulls[5] = true;
	else
		values[5] = TimestampTzGetDatum(archiver_stats->last_failed_timestamp);

	if (archiver_stats->stat_reset_timestamp == 0)
		nulls[6] = true;
	else
		values[6] = TimestampTzGetDatum(archiver_stats->stat_reset_timestamp);

	/* Returns the record as Datum */
	PG_RETURN_DATUM(HeapTupleGetDatum(
								   heap_form_tuple(tupdesc, values, nulls)));
}

void
AlterTableCreateAoVisimapTable(Oid relOid, bool is_part_child)
{
	Relation	rel;
	IndexInfo  *indexInfo;
	TupleDesc	tupdesc;
	Oid			classObjectId[2];
	int16		coloptions[2];

	elogif(Debug_appendonly_print_visimap, LOG,
		   "Create visimap for relation %d",
		   relOid);

	/*
	 * Grab an exclusive lock on the target table, which we will NOT release
	 * until end of transaction.  (This is probably redundant in all present
	 * uses...)
	 */
	if (is_part_child)
		rel = heap_open(relOid, NoLock);
	else
		rel = heap_open(relOid, AccessExclusiveLock);

	if (!RelationIsAoRows(rel) && !RelationIsAoCols(rel))
	{
		heap_close(rel, NoLock);
		return;
	}

	/* Create a tuple descriptor */
	tupdesc = CreateTemplateTupleDesc(Natts_pg_aovisimap, false);
	TupleDescInitEntry(tupdesc, (AttrNumber) 1,
					   "segno",
					   INT4OID,
					   -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 2,
					   "first_row_no",
					   INT8OID,
					   -1, 0);
	TupleDescInitEntry(tupdesc, (AttrNumber) 3,
					   "visimap",
					   BYTEAOID,
					   -1, 0);

	/*
	 * We don't want any toast columns here.
	 */
	tupdesc->attrs[0]->attstorage = 'p';
	tupdesc->attrs[1]->attstorage = 'p';
	tupdesc->attrs[2]->attstorage = 'p';

	/*
	 * Create index on segno, first_row_no.
	 */
	indexInfo = makeNode(IndexInfo);
	indexInfo->ii_NumIndexAttrs = 2;
	indexInfo->ii_KeyAttrNumbers[0] = 1;
	indexInfo->ii_KeyAttrNumbers[1] = 2;
	indexInfo->ii_Expressions = NIL;
	indexInfo->ii_ExpressionsState = NIL;
	indexInfo->ii_Predicate = NIL;
	indexInfo->ii_PredicateState = NIL;
	indexInfo->ii_Unique = true;
	indexInfo->ii_Concurrent = false;

	classObjectId[0] = INT4_BTREE_OPS_OID;
	classObjectId[1] = INT8_BTREE_OPS_OID;

	coloptions[0] = 0;
	coloptions[1] = 0;

	(void) CreateAOAuxiliaryTable(rel,
								  "pg_aovisimap",
								  RELKIND_AOVISIMAP,
								  tupdesc, indexInfo, classObjectId, coloptions);

	heap_close(rel, NoLock);
}

/*
 * Get status of resource groups in key-value style
 */
Datum
pg_resgroup_get_status_kv(PG_FUNCTION_ARGS)
{
	FuncCallContext *funcctx;
	StringInfoData   str;
	bool             do_dump;

	do_dump = (strncmp(text_to_cstring(PG_GETARG_TEXT_P(0)), "dump", 4) == 0);
	
	if (do_dump)
	{
		/* Only super user can call this function with para=dump. */
		if (!superuser())
		{
			ereport(ERROR,
					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
					 errmsg("only superusers can call this function")));
		}
		
		initStringInfo(&str);
		/* dump info in QD and collect info from QEs to form str.*/
		dumpResGroupInfo(&str);
	}

	if (SRF_IS_FIRSTCALL())
	{
		MemoryContext oldcontext;
		TupleDesc	tupdesc;
		int			nattr = 3;

		funcctx = SRF_FIRSTCALL_INIT();

		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

		tupdesc = CreateTemplateTupleDesc(nattr, false);
		TupleDescInitEntry(tupdesc, (AttrNumber) 1, "groupid", OIDOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 2, "prop", TEXTOID, -1, 0);
		TupleDescInitEntry(tupdesc, (AttrNumber) 3, "value", TEXTOID, -1, 0);

		funcctx->tuple_desc = BlessTupleDesc(tupdesc);
		funcctx->max_calls = do_dump ? 1 : 0;

		MemoryContextSwitchTo(oldcontext);
	}

	/* stuff done on every call of the function */
	funcctx = SRF_PERCALL_SETUP();

	if (funcctx->call_cntr < funcctx->max_calls)
	{
		if (do_dump)
		{
			Datum		values[3];
			bool		nulls[3];
			HeapTuple	tuple;

			MemSet(values, 0, sizeof(values));
			MemSet(nulls, 0, sizeof(nulls));

			nulls[0] = nulls[1] = true;
			values[2] = CStringGetTextDatum(str.data);
			
			tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls);
		
			SRF_RETURN_NEXT(funcctx, HeapTupleGetDatum(tuple));
		}
		else
		{
			SRF_RETURN_DONE(funcctx);
		}
	}
	else
	{
		/* nothing left */
		SRF_RETURN_DONE(funcctx);
	}
}

/* ----------------------------------------------------------------
 *		ExecInitFunctionScan
 * ----------------------------------------------------------------
 */
FunctionScanState *
ExecInitFunctionScan(FunctionScan *node, EState *estate, int eflags)
{
	FunctionScanState *scanstate;
	Oid			funcrettype;
	TypeFuncClass functypclass;
	TupleDesc	tupdesc = NULL;

	/* check for unsupported flags */
	Assert(!(eflags & EXEC_FLAG_MARK));

	/*
	 * FunctionScan should not have any children.
	 */
	Assert(outerPlan(node) == NULL);
	Assert(innerPlan(node) == NULL);

	/*
	 * create new ScanState for node
	 */
	scanstate = makeNode(FunctionScanState);
	scanstate->ss.ps.plan = (Plan *) node;
	scanstate->ss.ps.state = estate;
	scanstate->eflags = eflags;

	/*
	 * Miscellaneous initialization
	 *
	 * create expression context for node
	 */
	ExecAssignExprContext(estate, &scanstate->ss.ps);

	/*
	 * tuple table initialization
	 */
	ExecInitResultTupleSlot(estate, &scanstate->ss.ps);
	ExecInitScanTupleSlot(estate, &scanstate->ss);

	/*
	 * initialize child expressions
	 */
	scanstate->ss.ps.targetlist = (List *)
		ExecInitExpr((Expr *) node->scan.plan.targetlist,
					 (PlanState *) scanstate);
	scanstate->ss.ps.qual = (List *)
		ExecInitExpr((Expr *) node->scan.plan.qual,
					 (PlanState *) scanstate);

	/*
	 * Now determine if the function returns a simple or composite type, and
	 * build an appropriate tupdesc.
	 */
	functypclass = get_expr_result_type(node->funcexpr,
										&funcrettype,
										&tupdesc);

	if (functypclass == TYPEFUNC_COMPOSITE)
	{
		/* Composite data type, e.g. a table's row type */
		Assert(tupdesc);
		/* Must copy it out of typcache for safety */
		tupdesc = CreateTupleDescCopy(tupdesc);
	}
	else if (functypclass == TYPEFUNC_SCALAR)
	{
		/* Base data type, i.e. scalar */
		char	   *attname = strVal(linitial(node->funccolnames));

		tupdesc = CreateTemplateTupleDesc(1, false);
		TupleDescInitEntry(tupdesc,
						   (AttrNumber) 1,
						   attname,
						   funcrettype,
						   -1,
						   0);
	}
	else if (functypclass == TYPEFUNC_RECORD)
	{
		tupdesc = BuildDescFromLists(node->funccolnames,
									 node->funccoltypes,
									 node->funccoltypmods);
	}
	else
	{
		/* crummy error message, but parser should have caught this */
		elog(ERROR, "function in FROM has unsupported return type");
	}

	/*
	 * For RECORD results, make sure a typmod has been assigned.  (The
	 * function should do this for itself, but let's cover things in case it
	 * doesn't.)
	 */
	BlessTupleDesc(tupdesc);

	scanstate->tupdesc = tupdesc;
//.........这里部分代码省略.........