Adapt for SRF(Set Returning Function).

contrib/pgstattuple/README.pgstattuple

-pgstattuple README			2001/10/01 Tatsuo Ishii
+pgstattuple README			2002/08/22 Tatsuo Ishii
 
 1. What is pgstattuple?
 
-   pgstattuple returns the percentage of the "dead" tuples of a
-   table. This will help users to judge if vacuum is needed.
-
-   In addition, pgstattuple prints more detailed information using
-   NOTICE.
-
-test=# select pgstattuple('tellers');
-NOTICE:  physical length: 0.08MB live tuples: 20 (0.00MB, 1.17%) dead tuples: 320 (0.01MB, 18.75%) free/reusable space: 0.01MB (18.06%) overhead: 62.02%
- pgstattuple 
--------------
-       18.75
-(1 row)
-
-   Above example shows tellers table includes 18.75% dead tuples.
-
-   physical length	physical size of the table in MB
-   live tuples		information on the live tuples
-   dead tuples		information on the dead tuples
-   free/reusable space	available space
-   overhead		overhead space
+   pgstattuple returns the table length, percentage of the "dead"
+   tuples of a table and other info. This may help users to determine
+   whether vacuum is necessary or not. Here is an example session:
+
+test=# \x
+Expanded display is on.
+test=# select * from pgstattuple('pg_proc');
+-[ RECORD 1 ]------+-------
+table_len          | 458752
+tuple_count        | 1470
+tuple_len          | 438896
+tuple_percent      | 95.67
+dead_tuple_count   | 11
+dead_tuple_len     | 3157
+dead_tuple_percent | 0.69
+free_space         | 8932
+free_percent       | 1.95
+
+
+Here are explanations for each column:
+
+table_len		-- physical table length in bytes
+tuple_count		-- number of live tuples
+tuple_len		-- total tuples length in bytes
+tuple_percent		-- live tuples in %
+dead_tuple_len		-- total dead tuples length in bytes
+dead_tuple_percent	-- dead tuples in %
+free_space		-- free space in bytes
+free_percent		-- free space in %
 
 2. Installing pgstattuple
 
@@ -31,12 +40,15 @@ NOTICE:  physical length: 0.08MB live tuples: 20 (0.00MB, 1.17%) dead tuples: 32
 
 3. Using pgstattuple
 
-   pgstattuple can be called as a function:
+   pgstattuple may be called as a SRF (set returning function) and is
+   defined as follows:
 
-   pgstattuple(TEXT) RETURNS FLOAT8
+   CREATE OR REPLACE FUNCTION pgstattuple(text) RETURNS SETOF pgstattuple_view
+     AS 'MODULE_PATHNAME', 'pgstattuple'
+     LANGUAGE 'c' WITH (isstrict);
 
-   The argument is the table name.  pgstattuple returns the percentage
-   of the "dead" tuples of a table.
+   The argument is the table name.  Note that pgstattuple never
+   returns more than 1 tuple.
 
 4. Notes
 

contrib/pgstattuple/README.pgstattuple.euc_jp

-$Id: README.pgstattuple.euc_jp,v 1.2 2001/12/20 01:56:08 ishii Exp $
+$Id: README.pgstattuple.euc_jp,v 1.3 2002/08/23 08:19:49 ishii Exp $
 
-pgstattuple README		2001/10/01 石井達夫
+pgstattuple README		2002/08/22 石井達夫
 
 1. pgstattupleとは
 
    pgstattupleは，UPDATEやDELETEで作られたテーブルのゴミ領域の大きさを，
    テーブル自体の物理的な大きさに対するパーセンテージで返却します．つ
    まり，返却値が大きければ，それだけゴミも多いので，vacuumをかける必
-   要があるという判断の助けになるわけです．
-
-   これだけでは情報量が少ないので，NOTICEメッセージでいろんな情報をつ
-   いでに出力します．
-
-test=# select pgstattuple('tellers');
-NOTICE:  physical length: 0.08MB live tuples: 20 (0.00MB, 1.17%) dead tuples: 320 (0.01MB, 18.75%) free/reusable space: 0.01MB (18.06%) overhead: 62.02%
- pgstattuple 
--------------
-       18.75
-(1 row)
-
-   この実行例では，19%ほどがゴミになっていることが伺えます．NOTICEメッ
-   セージの見方も書いておきます．
-
-   physical length	テーブルの物理的なサイズをMB単位で表示
-   live tuples		ゴミではないタプルに関する情報．タプル数，各
-			タプルが占める領域の合計，テーブル全体に対する
-			比率を表示します．
-   dead tuples		ゴミになったタプルに関する情報．
-   free/reusable space	利用可能な未使用領域や再利用可能領域
-   overhead		管理のための領域がテーブル全体に占める比率
+   要があるという判断の助けになるわけです．これ以外にもいろいろな情報
+   が返ります．
+
+test=# \x
+Expanded display is on.
+test=# select * from pgstattuple('pg_proc');
+-[ RECORD 1 ]------+-------
+table_len          | 458752
+tuple_count        | 1470
+tuple_len          | 438896
+tuple_percent      | 95.67
+dead_tuple_count   | 11
+dead_tuple_len     | 3157
+dead_tuple_percent | 0.69
+free_space         | 8932
+free_percent       | 1.95
+
+各項目の説明です．
+
+table_len		-- テーブルの物理的な大きさ(バイト)
+tuple_count		-- タプル数
+tuple_len		-- タプル長の合計(バイト)
+tuple_percent		-- タプルの割合．table_lenに対するtuple_lenの比率．
+dead_tuple_len		-- デッドタプル数
+dead_tuple_percent	-- デッドタプルの割合．table_lenに対するtuple_lenの比率．
+free_space		-- 再利用可能な領域(バイト)
+free_percent		-- 再利用可能な領域．table_lenに対するfree_spaceの比率．
 
 2. pgstattupleのインストール
 
@@ -47,12 +52,14 @@ NOTICE:  physical length: 0.08MB live tuples: 20 (0.00MB, 1.17%) dead tuples: 32
 
    pgstattupleの呼び出し形式は以下です．
 
-   pgstattuple(NAME) RETURNS FLOAT8
+   CREATE OR REPLACE FUNCTION pgstattuple(text) RETURNS SETOF pgstattuple_view
+     AS 'MODULE_PATHNAME', 'pgstattuple'
+     LANGUAGE 'c' WITH (isstrict);
 
    第一引数: テーブル名
 
-   関数の戻りはUPDATEやDELETEで作られたテーブルのゴミ領域の大きさで，
-   テーブルの物理的な大きさに対する割合(パーセント)で返却します．
+   関数の戻りはpgstattuple_view型です．また，pgstattupleは1行しか行を
+   返しません．
 
    なお，pgstattupleはテーブルにAccessShareLockしかかけないので，
    pgstattuple を実行中に該当テーブルに更新や削除が発生すると，正しく
@@ -69,6 +76,10 @@ NOTICE:  physical length: 0.08MB live tuples: 20 (0.00MB, 1.17%) dead tuples: 32
 
 5. 改訂履歴
 
+   2002/08/23
+
+	SRF(Set Returning Function)を使って7.3用に書き換え．
+
    2001/12/20 Tom Laneによる修正
 
    	Fix pgstattuple to acquire a read lock on the target table.  This

contrib/pgstattuple/pgstattuple.c

 /*
- * $Header: /cvsroot/pgsql/contrib/pgstattuple/pgstattuple.c,v 1.6 2002/05/20 23:51:40 tgl Exp $
+ * $Header: /cvsroot/pgsql/contrib/pgstattuple/pgstattuple.c,v 1.7 2002/08/23 08:19:49 ishii Exp $
  *
- * Copyright (c) 2001  Tatsuo Ishii
+ * Copyright (c) 2001,2002  Tatsuo Ishii
  *
  * Permission to use, copy, modify, and distribute this software and
  * its documentation for any purpose, without fee, and without a
@@ -28,6 +28,7 @@
 #include "access/heapam.h"
 #include "access/transam.h"
 #include "catalog/namespace.h"
+#include "funcapi.h"
 #include "utils/builtins.h"
 
 
@@ -37,16 +38,22 @@ extern Datum pgstattuple(PG_FUNCTION_ARGS);
 
 /* ----------
  * pgstattuple:
- * returns the percentage of dead tuples
+ * returns live/dead tuples info
  *
  * C FUNCTION definition
- * pgstattuple(NAME) returns FLOAT8
+ * pgstattuple(TEXT) returns setof pgstattuple_view
+ * see pgstattuple.sql for pgstattuple_view
  * ----------
  */
+
+#define DUMMY_TUPLE "pgstattuple_view"
+#define NCOLUMNS 9
+#define NCHARS 32
+
 Datum
 pgstattuple(PG_FUNCTION_ARGS)
 {
-	text	   *relname = PG_GETARG_TEXT_P(0);
+	text	   *relname;
 	RangeVar   *relrv;
 	Relation	rel;
 	HeapScanDesc scan;
@@ -55,7 +62,7 @@ pgstattuple(PG_FUNCTION_ARGS)
 	BlockNumber block = 0;		/* next block to count free space in */
 	BlockNumber tupblock;
 	Buffer		buffer;
-	double		table_len;
+	uint64		table_len;
 	uint64		tuple_len = 0;
 	uint64		dead_tuple_len = 0;
 	uint64		tuple_count = 0;
@@ -65,13 +72,67 @@ pgstattuple(PG_FUNCTION_ARGS)
 	uint64		free_space = 0; /* free/reusable space in bytes */
 	double		free_percent;	/* free/reusable space in % */
 
-	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname,
-														"pgstattuple"));
+	FuncCallContext	   *funcctx;
+	int					call_cntr;
+	int					max_calls;
+	TupleDesc			tupdesc;
+	TupleTableSlot	   *slot;
+	AttInMetadata	   *attinmeta;
+
+	char **values;
+	int i;
+	Datum		result;
+
+	/* stuff done only on the first call of the function */
+	if(SRF_IS_FIRSTCALL())
+	{
+		/* create a function context for cross-call persistence */
+		funcctx = SRF_FIRSTCALL_INIT();
+    
+		/* total number of tuples to be returned */
+		funcctx->max_calls = 1;
+    
+		/*
+		 * Build a tuple description for a pgstattupe_view tuple
+		 */
+		tupdesc = RelationNameGetTupleDesc(DUMMY_TUPLE);
+    
+		/* allocate a slot for a tuple with this tupdesc */
+		slot = TupleDescGetSlot(tupdesc);
+    
+		/* assign slot to function context */
+		funcctx->slot = slot;
+    
+		/*
+		 * Generate attribute metadata needed later to produce tuples from raw
+		 * C strings
+		 */
+		attinmeta = TupleDescGetAttInMetadata(tupdesc);
+		funcctx->attinmeta = attinmeta;
+	}
+
+	/* stuff done on every call of the function */
+	funcctx = SRF_PERCALL_SETUP();
+	call_cntr = funcctx->call_cntr;
+	max_calls = funcctx->max_calls;
+	slot = funcctx->slot;
+	attinmeta = funcctx->attinmeta;
+
+	/* Are we done? */
+	if (call_cntr >= max_calls)
+	{
+		SRF_RETURN_DONE(funcctx);
+	}
+
+	/* open relation */
+	relname = PG_GETARG_TEXT_P(0);
+	relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname,"pgstattuple"));
 	rel = heap_openrv(relrv, AccessShareLock);
 
 	nblocks = RelationGetNumberOfBlocks(rel);
 	scan = heap_beginscan(rel, SnapshotAny, 0, NULL);
 
+	/* scan the relation */
 	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		if (HeapTupleSatisfiesNow(tuple->t_data))
@@ -113,7 +174,7 @@ pgstattuple(PG_FUNCTION_ARGS)
 
 	heap_close(rel, AccessShareLock);
 
-	table_len = (double) nblocks *BLCKSZ;
+	table_len = (uint64)nblocks *BLCKSZ;
 
 	if (nblocks == 0)
 	{
@@ -128,28 +189,39 @@ pgstattuple(PG_FUNCTION_ARGS)
 		free_percent = (double) free_space *100.0 / table_len;
 	}
 
-	elog(DEBUG3, "physical length: %.2fMB live tuples: %.0f (%.2fMB, %.2f%%) dead tuples: %.0f (%.2fMB, %.2f%%) free/reusable space: %.2fMB (%.2f%%) overhead: %.2f%%",
-
-		 table_len / (1024 * 1024),		/* physical length in MB */
-
-		 (double) tuple_count,	/* number of live tuples */
-		 (double) tuple_len / (1024 * 1024),		/* live tuples in MB */
-		 tuple_percent,			/* live tuples in % */
-
-		 (double) dead_tuple_count,	/* number of dead tuples */
-		 (double) dead_tuple_len / (1024 * 1024), /* dead tuples in MB */
-		 dead_tuple_percent,	/* dead tuples in % */
-
-		 (double) free_space / (1024 * 1024), /* free/available space in
-											   * MB */
-
-		 free_percent,			/* free/available space in % */
-
-	/* overhead in % */
-		 (nblocks == 0) ? 0.0 : 100.0
-		 - tuple_percent
-		 - dead_tuple_percent
-		 - free_percent);
-
-	PG_RETURN_FLOAT8(dead_tuple_percent);
+	/*
+	 * Prepare a values array for storage in our slot.
+	 * This should be an array of C strings which will
+	 * be processed later by the appropriate "in" functions.
+	 */
+	values = (char **) palloc(NCOLUMNS * sizeof(char *));
+	for (i=0;i<NCOLUMNS;i++)
+	{
+		values[i] = (char *) palloc(NCHARS * sizeof(char));
+	}
+	i = 0;
+	snprintf(values[i++], NCHARS, "%lld", table_len);
+	snprintf(values[i++], NCHARS, "%lld", tuple_count);
+	snprintf(values[i++], NCHARS, "%lld", tuple_len);
+	snprintf(values[i++], NCHARS, "%.2f", tuple_percent);
+	snprintf(values[i++], NCHARS, "%lld", dead_tuple_count);
+	snprintf(values[i++], NCHARS, "%lld", dead_tuple_len);
+	snprintf(values[i++], NCHARS, "%.2f", dead_tuple_percent);
+	snprintf(values[i++], NCHARS, "%lld", free_space);
+	snprintf(values[i++], NCHARS, "%.2f", free_percent);
+    
+	/* build a tuple */
+	tuple = BuildTupleFromCStrings(attinmeta, values);
+    
+	/* make the tuple into a datum */
+	result = TupleGetDatum(slot, tuple);
+    
+	/* Clean up */
+	for (i=0;i<NCOLUMNS;i++)
+	{
+		pfree(values[i]);
+	}
+	pfree(values);
+    
+	SRF_RETURN_NEXT(funcctx, result);
 }

contrib/pgstattuple/pgstattuple.sql.in

-DROP FUNCTION pgstattuple(text);
-CREATE FUNCTION pgstattuple(text) RETURNS float8
-AS 'MODULE_PATHNAME', 'pgstattuple'
-LANGUAGE 'c' WITH (isstrict);
+DROP VIEW pgstattuple_view CASCADE;
+CREATE VIEW pgstattuple_view AS
+  SELECT
+    0::BIGINT AS table_len,		-- physical table length in bytes
+    0::BIGINT AS tuple_count,		-- number of live tuples
+    0::BIGINT AS tuple_len,		-- total tuples length in bytes
+    0.0::FLOAT AS tuple_percent,	-- live tuples in %
+    0::BIGINT AS dead_tuple_count,	-- number of dead tuples
+    0::BIGINT AS dead_tuple_len,	-- total dead tuples length in bytes
+    0.0::FLOAT AS dead_tuple_percent,	-- dead tuples in %
+    0::BIGINT AS free_space,		-- free space in bytes
+    0.0::FLOAT AS free_percent;		-- free space in %
+
+CREATE OR REPLACE FUNCTION pgstattuple(text) RETURNS SETOF pgstattuple_view
+  AS 'MODULE_PATHNAME', 'pgstattuple'
+  LANGUAGE 'c' WITH (isstrict);