PostgreSQL ExecIndexBuildScanKeys函数分解

该函数用在初始化索引搜索键的处理，也就是处理where条件的部分

void
ExecIndexBuildScanKeys(PlanState *planstate, Relation index,
					   List *quals, bool isorderby,
					   ScanKey *scanKeys, int *numScanKeys,
					   IndexRuntimeKeyInfo **runtimeKeys, int *numRuntimeKeys,
					   IndexArrayKeyInfo **arrayKeys, int *numArrayKeys)
{
	ListCell   *qual_cell;
	ScanKey		scan_keys;
	IndexRuntimeKeyInfo *runtime_keys;
	IndexArrayKeyInfo *array_keys;
	int			n_scan_keys;
	int			n_runtime_keys;
	int			max_runtime_keys;
	int			n_array_keys;
	int			j;

	/* Allocate array for ScanKey structs: one per qual */
	n_scan_keys = list_length(quals);
	scan_keys = (ScanKey) palloc(n_scan_keys * sizeof(ScanKeyData));

	/*
	 * runtime_keys array is dynamically resized as needed.  We handle it this
	 * way so that the same runtime keys array can be shared between
	 * indexquals and indexorderbys, which will be processed in separate calls
	 * of this function.  Caller must be sure to pass in NULL/0 for first
	 * call.
	 */
	runtime_keys = *runtimeKeys;
	n_runtime_keys = max_runtime_keys = *numRuntimeKeys;

	/* Allocate array_keys as large as it could possibly need to be */
	array_keys = (IndexArrayKeyInfo *)
		palloc0(n_scan_keys * sizeof(IndexArrayKeyInfo));
	n_array_keys = 0;

	/*
	 * for each opclause in the given qual, convert the opclause into a single
	 * scan key
	 */
	j = 0;
	foreach(qual_cell, quals)
	{
		Expr	   *clause = (Expr *) lfirst(qual_cell);
		ScanKey		this_scan_key = &scan_keys[j++];
		Oid			opno;		/* operator's OID */
		RegProcedure opfuncid;	/* operator proc id used in scan */
		Oid			opfamily;	/* opfamily of index column */
		int			op_strategy;	/* operator's strategy number */
		Oid			op_lefttype;	/* operator's declared input types */
		Oid			op_righttype;
		Expr	   *leftop;		/* expr on lhs of operator */
		Expr	   *rightop;	/* expr on rhs ... */
		AttrNumber	varattno;	/* att number used in scan */
		int			indnkeyatts;

		indnkeyatts = IndexRelationGetNumberOfKeyAttributes(index);
		if (IsA(clause, OpExpr))
		{
            //where objectid=1会进这个分支
			/* indexkey op const or indexkey op expression */
			int			flags = 0;
			Datum		scanvalue;

            //operator oid
            /*
                p *clause
                $5 = {type = T_OpExpr}
               (gdb) p *(OpExpr*)clause
                $6 = {xpr = {type = T_OpExpr}, opno = 96, opfuncid = 65, opresulttype = 16, opretset = false, opcollid = 0, inputcollid = 0, args = 0x25f5ad8, location = 60}

            */

            /*
                p opno
                $11 = 96
                t select 96::regoper;
                regoper
                --------------
                pg_catalog.=  

            */
			opno = ((OpExpr *) clause)->opno;
            
            /*
               p opfuncid
               $14 = 65
               select 65::regprocedure;
               regprocedure
               -------------------------
               int4eq(integer,integer)
            */
            
			opfuncid = ((OpExpr *) clause)->opfuncid;

			/*
			 * leftop should be the index key Var, possibly relabeled
			 */

            /*
             p *(Var*)leftop
$19 = {xpr = {type = T_Var}, varno = -3, varattno = 1, vartype = 23, vartypmod = -1, varcollid = 0, varnullingrels = 0x0, varlevelsup = 0, varnosyn = 1, varattnosyn = 1,
location = 52}
            */
			leftop = (Expr *) get_leftop(clause);

			if (leftop && IsA(leftop, RelabelType))
				leftop = ((RelabelType *) leftop)->arg;

			Assert(leftop != NULL);

			if (!(IsA(leftop, Var) &&
				  ((Var *) leftop)->varno == INDEX_VAR))
				elog(ERROR, "indexqual doesn't have key on left side");

            
			varattno = ((Var *) leftop)->varattno;
			if (varattno < 1 || varattno > indnkeyatts)
				elog(ERROR, "bogus index qualification");

			/*
			 * We have to look up the operator's strategy number.  This
			 * provides a cross-check that the operator does match the index.
			 */
            /*opfamily=1976
   
            */
			opfamily = index->rd_opfamily[varattno - 1];

            /*
             select amoplefttype::regtype,amoprighttype::regtype,amopstrategy from pg_amop where amopfamily=1976 and amoppurpose='s' and amopopr=96;
 amoplefttype | amoprighttype | amopstrategy
--------------+---------------+--------------
 integer      | integer       |            3
            */
			get_op_opfamily_properties(opno, opfamily, isorderby,
									   &op_strategy,
									   &op_lefttype,
									   &op_righttype);

			if (isorderby)
				flags |= SK_ORDER_BY;

			/*
			 * rightop is the constant or variable comparison value
			 */
			rightop = (Expr *) get_rightop(clause);

			if (rightop && IsA(rightop, RelabelType))
				rightop = ((RelabelType *) rightop)->arg;

			Assert(rightop != NULL);
         
            //常量
			if (IsA(rightop, Const))
			{
				/* OK, simple constant comparison value */
                //scanvalue=100
				scanvalue = ((Const *) rightop)->constvalue;
				if (((Const *) rightop)->constisnull)
					flags |= SK_ISNULL;
			}
			else
			{
                
				/* Need to treat this one as a runtime key */
				if (n_runtime_keys >= max_runtime_keys)
				{
					if (max_runtime_keys == 0)
					{
						max_runtime_keys = 8;
						runtime_keys = (IndexRuntimeKeyInfo *)
							palloc(max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
					}
					else
					{
						max_runtime_keys *= 2;
						runtime_keys = (IndexRuntimeKeyInfo *)
							repalloc(runtime_keys, max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
					}
				}
				runtime_keys[n_runtime_keys].scan_key = this_scan_key;
				runtime_keys[n_runtime_keys].key_expr =
					ExecInitExpr(rightop, planstate);
				runtime_keys[n_runtime_keys].key_toastable =
					TypeIsToastable(op_righttype);
				n_runtime_keys++;
				scanvalue = (Datum) 0;
			}

			/*
			 * initialize the scan key's fields appropriately
			 */
			ScanKeyEntryInitialize(this_scan_key,
								   flags,
								   varattno,	/* attribute number to scan */
								   op_strategy, /* op's strategy */
								   op_righttype,	/* strategy subtype */
								   ((OpExpr *) clause)->inputcollid,	/* collation */
								   opfuncid,	/* reg proc to use */
								   scanvalue);	/* constant */
		}
		else if (IsA(clause, RowCompareExpr))
		{
			/* (indexkey, indexkey, ...) op (expression, expression, ...) */
			RowCompareExpr *rc = (RowCompareExpr *) clause;
			ScanKey		first_sub_key;
			int			n_sub_key;
			ListCell   *largs_cell;
			ListCell   *rargs_cell;
			ListCell   *opnos_cell;
			ListCell   *collids_cell;

			Assert(!isorderby);

			first_sub_key = (ScanKey)
				palloc(list_length(rc->opnos) * sizeof(ScanKeyData));
			n_sub_key = 0;

			/* Scan RowCompare columns and generate subsidiary ScanKey items */
			forfour(largs_cell, rc->largs, rargs_cell, rc->rargs,
					opnos_cell, rc->opnos, collids_cell, rc->inputcollids)
			{
				ScanKey		this_sub_key = &first_sub_key[n_sub_key];
				int			flags = SK_ROW_MEMBER;
				Datum		scanvalue;
				Oid			inputcollation;

				leftop = (Expr *) lfirst(largs_cell);
				rightop = (Expr *) lfirst(rargs_cell);
				opno = lfirst_oid(opnos_cell);
				inputcollation = lfirst_oid(collids_cell);

				/*
				 * leftop should be the index key Var, possibly relabeled
				 */
				if (leftop && IsA(leftop, RelabelType))
					leftop = ((RelabelType *) leftop)->arg;

				Assert(leftop != NULL);

				if (!(IsA(leftop, Var) &&
					  ((Var *) leftop)->varno == INDEX_VAR))
					elog(ERROR, "indexqual doesn't have key on left side");

				varattno = ((Var *) leftop)->varattno;

				/*
				 * We have to look up the operator's associated btree support
				 * function
				 */
				if (index->rd_rel->relam != BTREE_AM_OID ||
					varattno < 1 || varattno > indnkeyatts)
					elog(ERROR, "bogus RowCompare index qualification");
				opfamily = index->rd_opfamily[varattno - 1];

				get_op_opfamily_properties(opno, opfamily, isorderby,
										   &op_strategy,
										   &op_lefttype,
										   &op_righttype);

				if (op_strategy != rc->rctype)
					elog(ERROR, "RowCompare index qualification contains wrong operator");

				opfuncid = get_opfamily_proc(opfamily,
											 op_lefttype,
											 op_righttype,
											 BTORDER_PROC);
				if (!RegProcedureIsValid(opfuncid))
					elog(ERROR, "missing support function %d(%u,%u) in opfamily %u",
						 BTORDER_PROC, op_lefttype, op_righttype, opfamily);

				/*
				 * rightop is the constant or variable comparison value
				 */
				if (rightop && IsA(rightop, RelabelType))
					rightop = ((RelabelType *) rightop)->arg;

				Assert(rightop != NULL);

				if (IsA(rightop, Const))
				{
					/* OK, simple constant comparison value */
					scanvalue = ((Const *) rightop)->constvalue;
					if (((Const *) rightop)->constisnull)
						flags |= SK_ISNULL;
				}
				else
				{
					/* Need to treat this one as a runtime key */
					if (n_runtime_keys >= max_runtime_keys)
					{
						if (max_runtime_keys == 0)
						{
							max_runtime_keys = 8;
							runtime_keys = (IndexRuntimeKeyInfo *)
								palloc(max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
						}
						else
						{
							max_runtime_keys *= 2;
							runtime_keys = (IndexRuntimeKeyInfo *)
								repalloc(runtime_keys, max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
						}
					}
					runtime_keys[n_runtime_keys].scan_key = this_sub_key;
					runtime_keys[n_runtime_keys].key_expr =
						ExecInitExpr(rightop, planstate);
					runtime_keys[n_runtime_keys].key_toastable =
						TypeIsToastable(op_righttype);
					n_runtime_keys++;
					scanvalue = (Datum) 0;
				}

				/*
				 * initialize the subsidiary scan key's fields appropriately
				 */
				ScanKeyEntryInitialize(this_sub_key,
									   flags,
									   varattno,	/* attribute number */
									   op_strategy, /* op's strategy */
									   op_righttype,	/* strategy subtype */
									   inputcollation,	/* collation */
									   opfuncid,	/* reg proc to use */
									   scanvalue);	/* constant */
				n_sub_key++;
			}

			/* Mark the last subsidiary scankey correctly */
			first_sub_key[n_sub_key - 1].sk_flags |= SK_ROW_END;

			/*
			 * We don't use ScanKeyEntryInitialize for the header because it
			 * isn't going to contain a valid sk_func pointer.
			 */
			MemSet(this_scan_key, 0, sizeof(ScanKeyData));
			this_scan_key->sk_flags = SK_ROW_HEADER;
			this_scan_key->sk_attno = first_sub_key->sk_attno;
			this_scan_key->sk_strategy = rc->rctype;
			/* sk_subtype, sk_collation, sk_func not used in a header */
			this_scan_key->sk_argument = PointerGetDatum(first_sub_key);
		}
		else if (IsA(clause, ScalarArrayOpExpr))
		{
			/* indexkey op ANY (array-expression) */


            /*
explain select length(st_asewkt(shape)) from poly100w where globalid in ('{04C70C50-5FBD-4EC9-AFC7-8A405CD0548B}','{8D5FB77F-2EB0-4806-B584-84ACD9166EDC}','{DD792D3C-372C-45E6-B28E-264E5F79D8EB}');
                                                                                   QUERY PLAN
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Index Scan using uuid_13 on poly100w  (cost=0.43..27.22 rows=3 width=4)
   Index Cond: ((globalid)::text = ANY ('{"{04C70C50-5FBD-4EC9-AFC7-8A405CD0548B}","{8D5FB77F-2EB0-4806-B584-84ACD9166EDC}","{DD792D3C-372C-45E6-B28E-264E5F79D8EB}"}'::text[]))

            优化器把in 操作子优化成 ANY test[]操作符了，在PG中用ScalarArrayOpExpr表示

            */

            /*
               saop={xpr = {type = T_ScalarArrayOpExpr}, opno = 98, opfuncid = 67, hashfuncid = 0, negfuncid = 0, useOr = true, inputcollid = 100, args = 0x25e5850, location = 61}
               
               
            */
			ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
			int			flags = 0;
			Datum		scanvalue;

			Assert(!isorderby);

			Assert(saop->useOr);
            /*98::regoper=pg_catalog.=*/
			opno = saop->opno;
            //67::regprocedure=texteq(text,text)
			opfuncid = saop->opfuncid;

			/*
			 * leftop should be the index key Var, possibly relabeled
			 */

            /*leftop={xpr = {type = T_Var}, varno = -3, varattno = 1, vartype = 1043, vartypmod = 42, varcollid = 100, varnullingrels = 0x0, varlevelsup = 0, varnosyn = 1, varattnosyn = 2,
  location = 52}*/
			leftop = (Expr *) linitial(saop->args);

			if (leftop && IsA(leftop, RelabelType))
				leftop = ((RelabelType *) leftop)->arg;

			Assert(leftop != NULL);

			if (!(IsA(leftop, Var) &&
				  ((Var *) leftop)->varno == INDEX_VAR))
				elog(ERROR, "indexqual doesn't have key on left side");

			varattno = ((Var *) leftop)->varattno;
			if (varattno < 1 || varattno > indnkeyatts)
				elog(ERROR, "bogus index qualification");

			/*
			 * We have to look up the operator's strategy number.  This
			 * provides a cross-check that the operator does match the index.
			 */
            //opfamily=1994
			opfamily = index->rd_opfamily[varattno - 1];

            //op_strategy=3 lefttype=25 righttype=25
			get_op_opfamily_properties(opno, opfamily, isorderby,
									   &op_strategy,
									   &op_lefttype,
									   &op_righttype);

			/*
			 * rightop is the constant or variable array value
			 */
            /*
rightop={xpr = {type = T_Const}, consttype = 1009, consttypmod = -1, constcollid = 100, constlen = -1, constvalue = 38965072, constisnull = false, constbyval = false,
  location = -1}
            */
			rightop = (Expr *) lsecond(saop->args);

			if (rightop && IsA(rightop, RelabelType))
				rightop = ((RelabelType *) rightop)->arg;

			Assert(rightop != NULL);

            //查看索引是否支持多值查询
			if (index->rd_indam->amsearcharray)
			{
				/* Index AM will handle this like a simple operator */
                /*后续执行过程要用到这个falgs，以确定rightop-->constvalue为text[]数组类型，并在_bt_first-->_bt_preprocess_keys会被展开
                会
                */
				flags |= SK_SEARCHARRAY;
				if (IsA(rightop, Const))
				{
					/* OK, simple constant comparison value */
					scanvalue = ((Const *) rightop)->constvalue;
					if (((Const *) rightop)->constisnull)
						flags |= SK_ISNULL;
				}
				else
				{
					/* Need to treat this one as a runtime key */
					if (n_runtime_keys >= max_runtime_keys)
					{
						if (max_runtime_keys == 0)
						{
							max_runtime_keys = 8;
							runtime_keys = (IndexRuntimeKeyInfo *)
								palloc(max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
						}
						else
						{
							max_runtime_keys *= 2;
							runtime_keys = (IndexRuntimeKeyInfo *)
								repalloc(runtime_keys, max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
						}
					}
					runtime_keys[n_runtime_keys].scan_key = this_scan_key;
					runtime_keys[n_runtime_keys].key_expr =
						ExecInitExpr(rightop, planstate);

					/*
					 * Careful here: the runtime expression is not of
					 * op_righttype, but rather is an array of same; so
					 * TypeIsToastable() isn't helpful.  However, we can
					 * assume that all array types are toastable.
					 */
					runtime_keys[n_runtime_keys].key_toastable = true;
					n_runtime_keys++;
					scanvalue = (Datum) 0;
				}
			}
			else
			{
				/* Executor has to expand the array value */
				array_keys[n_array_keys].scan_key = this_scan_key;
				array_keys[n_array_keys].array_expr =
					ExecInitExpr(rightop, planstate);
				/* the remaining fields were zeroed by palloc0 */
				n_array_keys++;
				scanvalue = (Datum) 0;
			}

			/*
			 * initialize the scan key's fields appropriately
			 */

            /*具体看到代码2*/
			ScanKeyEntryInitialize(this_scan_key,
								   flags,
								   varattno,	/* attribute number to scan */
								   op_strategy, /* op's strategy */
								   op_righttype,	/* strategy subtype */
								   saop->inputcollid,	/* collation */
								   opfuncid,	/* reg proc to use */
								   scanvalue);	/* constant */
		}
		else if (IsA(clause, NullTest))
		{
			/* indexkey IS NULL or indexkey IS NOT NULL */
			NullTest   *ntest = (NullTest *) clause;
			int			flags;

			Assert(!isorderby);

			/*
			 * argument should be the index key Var, possibly relabeled
			 */
			leftop = ntest->arg;

			if (leftop && IsA(leftop, RelabelType))
				leftop = ((RelabelType *) leftop)->arg;

			Assert(leftop != NULL);

			if (!(IsA(leftop, Var) &&
				  ((Var *) leftop)->varno == INDEX_VAR))
				elog(ERROR, "NullTest indexqual has wrong key");

			varattno = ((Var *) leftop)->varattno;

			/*
			 * initialize the scan key's fields appropriately
			 */
			switch (ntest->nulltesttype)
			{
				case IS_NULL:
					flags = SK_ISNULL | SK_SEARCHNULL;
					break;
				case IS_NOT_NULL:
					flags = SK_ISNULL | SK_SEARCHNOTNULL;
					break;
				default:
					elog(ERROR, "unrecognized nulltesttype: %d",
						 (int) ntest->nulltesttype);
					flags = 0;	/* keep compiler quiet */
					break;
			}

			ScanKeyEntryInitialize(this_scan_key,
								   flags,
								   varattno,	/* attribute number to scan */
								   InvalidStrategy, /* no strategy */
								   InvalidOid,	/* no strategy subtype */
								   InvalidOid,	/* no collation */
								   InvalidOid,	/* no reg proc for this */
								   (Datum) 0);	/* constant */
		}
		else
			elog(ERROR, "unsupported indexqual type: %d",
				 (int) nodeTag(clause));
	}

	Assert(n_runtime_keys <= max_runtime_keys);

	/* Get rid of any unused arrays */
	if (n_array_keys == 0)
	{
		pfree(array_keys);
		array_keys = NULL;
	}

	/*
	 * Return info to our caller.
	 */
	*scanKeys = scan_keys;
	*numScanKeys = n_scan_keys;
	*runtimeKeys = runtime_keys;
	*numRuntimeKeys = n_runtime_keys;
	if (arrayKeys)
	{
		*arrayKeys = array_keys;
		*numArrayKeys = n_array_keys;
	}
	else if (n_array_keys != 0)
		elog(ERROR, "ScalarArrayOpExpr index qual found where not allowed");
}

代码2

/*
 * ScanKeyEntryInitialize
 *		Initializes a scan key entry given all the field values.
 *		The target procedure is specified by OID (but can be invalid
 *		if SK_SEARCHNULL or SK_SEARCHNOTNULL is set).
 *
 * Note: CurrentMemoryContext at call should be as long-lived as the ScanKey
 * itself, because that's what will be used for any subsidiary info attached
 * to the ScanKey's FmgrInfo record.
 */
void
ScanKeyEntryInitialize(ScanKey entry,
					   int flags,
					   AttrNumber attributeNumber,
					   StrategyNumber strategy,
					   Oid subtype,
					   Oid collation,
					   RegProcedure procedure,
					   Datum argument)
{
	entry->sk_flags = flags;
	entry->sk_attno = attributeNumber;
	entry->sk_strategy = strategy;
    //过滤字段类型
	entry->sk_subtype = subtype;
	entry->sk_collation = collation;
    //Const参数，可以是数组
	entry->sk_argument = argument;
   
	if (RegProcedureIsValid(procedure))
	{
        //初始化函数
        //根据函数的oid，填充函数结构体，具体看代码3
		fmgr_info(procedure, &entry->sk_func);
	}
	else
	{
		Assert(flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
		MemSet(&entry->sk_func, 0, sizeof(entry->sk_func));
	}
}

代码3

/*
 * This routine fills a FmgrInfo struct, given the OID
 * of the function to be called.
 *
 * The caller's CurrentMemoryContext is used as the fn_mcxt of the info
 * struct; this means that any subsidiary data attached to the info struct
 * (either by fmgr_info itself, or later on by a function call handler)
 * will be allocated in that context.  The caller must ensure that this
 * context is at least as long-lived as the info struct itself.  This is
 * not a problem in typical cases where the info struct is on the stack or
 * in freshly-palloc'd space.  However, if one intends to store an info
 * struct in a long-lived table, it's better to use fmgr_info_cxt.
 */
void
fmgr_info(Oid functionId, FmgrInfo *finfo)
{
	fmgr_info_cxt_security(functionId, finfo, CurrentMemoryContext, false);
}


/*
 * This one does the actual work.  ignore_security is ordinarily false
 * but is set to true when we need to avoid recursion.
 */
static void
fmgr_info_cxt_security(Oid functionId, FmgrInfo *finfo, MemoryContext mcxt,
					   bool ignore_security)
{
	const FmgrBuiltin *fbp;
	HeapTuple	procedureTuple;
	Form_pg_proc procedureStruct;
	Datum		prosrcdatum;
	char	   *prosrc;

	/*
	 * fn_oid *must* be filled in last.  Some code assumes that if fn_oid is
	 * valid, the whole struct is valid.  Some FmgrInfo struct's do survive
	 * elogs.
	 */
	finfo->fn_oid = InvalidOid;
	finfo->fn_extra = NULL;
	finfo->fn_mcxt = mcxt;
	finfo->fn_expr = NULL;		/* caller may set this later */

    //是否内置函数
	if ((fbp = fmgr_isbuiltin(functionId)) != NULL)
	{
		/*
		 * Fast path for builtin functions: don't bother consulting pg_proc
		 */
		finfo->fn_nargs = fbp->nargs;
		finfo->fn_strict = fbp->strict;
		finfo->fn_retset = fbp->retset;
		finfo->fn_stats = TRACK_FUNC_ALL;	/* ie, never track */
		finfo->fn_addr = fbp->func;
		finfo->fn_oid = functionId;
		return;
	}

	/* Otherwise we need the pg_proc entry */
    /*不是内置，从pg_proc中查询*/
	procedureTuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(functionId));
	if (!HeapTupleIsValid(procedureTuple))
		elog(ERROR, "cache lookup failed for function %u", functionId);
	procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);

	finfo->fn_nargs = procedureStruct->pronargs;
	finfo->fn_strict = procedureStruct->proisstrict;
	finfo->fn_retset = procedureStruct->proretset;

	/*
	 * If it has prosecdef set, non-null proconfig, or if a plugin wants to
	 * hook function entry/exit, use fmgr_security_definer call handler ---
	 * unless we are being called again by fmgr_security_definer or
	 * fmgr_info_other_lang.
	 *
	 * When using fmgr_security_definer, function stats tracking is always
	 * disabled at the outer level, and instead we set the flag properly in
	 * fmgr_security_definer's private flinfo and implement the tracking
	 * inside fmgr_security_definer.  This loses the ability to charge the
	 * overhead of fmgr_security_definer to the function, but gains the
	 * ability to set the track_functions GUC as a local GUC parameter of an
	 * interesting function and have the right things happen.
	 */
	if (!ignore_security &&
		(procedureStruct->prosecdef ||
		 !heap_attisnull(procedureTuple, Anum_pg_proc_proconfig, NULL) ||
		 FmgrHookIsNeeded(functionId)))
	{
		finfo->fn_addr = fmgr_security_definer;
		finfo->fn_stats = TRACK_FUNC_ALL;	/* ie, never track */
		finfo->fn_oid = functionId;
		ReleaseSysCache(procedureTuple);
		return;
	}

	switch (procedureStruct->prolang)
	{
		case INTERNALlanguageId:

			/*
			 * For an ordinary builtin function, we should never get here
			 * because the fmgr_isbuiltin() search above will have succeeded.
			 * However, if the user has done a CREATE FUNCTION to create an
			 * alias for a builtin function, we can end up here.  In that case
			 * we have to look up the function by name.  The name of the
			 * internal function is stored in prosrc (it doesn't have to be
			 * the same as the name of the alias!)
			 */
			prosrcdatum = SysCacheGetAttrNotNull(PROCOID, procedureTuple,
												 Anum_pg_proc_prosrc);
			prosrc = TextDatumGetCString(prosrcdatum);
			fbp = fmgr_lookupByName(prosrc);
			if (fbp == NULL)
				ereport(ERROR,
						(errcode(ERRCODE_UNDEFINED_FUNCTION),
						 errmsg("internal function \"%s\" is not in internal lookup table",
								prosrc)));
			pfree(prosrc);
			/* Should we check that nargs, strict, retset match the table? */
			finfo->fn_addr = fbp->func;
			/* note this policy is also assumed in fast path above */
			finfo->fn_stats = TRACK_FUNC_ALL;	/* ie, never track */
			break;

        /*自定义c函数*/
		case ClanguageId:
			fmgr_info_C_lang(functionId, finfo, procedureTuple);
			finfo->fn_stats = TRACK_FUNC_PL;	/* ie, track if ALL */
			break;

		case SQLlanguageId:
			finfo->fn_addr = fmgr_sql;
			finfo->fn_stats = TRACK_FUNC_PL;	/* ie, track if ALL */
			break;
        /*其它语言*/
		default:
			fmgr_info_other_lang(functionId, finfo, procedureTuple);
			finfo->fn_stats = TRACK_FUNC_OFF;	/* ie, track if not OFF */
			break;
	}

	finfo->fn_oid = functionId;
	ReleaseSysCache(procedureTuple);
}