From cf7ee638a742474f92d40c0d6f1326bb8b06506e Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <ishii@postgresql.org>
Date: Fri, 23 Aug 2002 08:19:49 +0000
Subject: [PATCH] Adapt for SRF(Set Returning Function).
---
contrib/pgstattuple/README.pgstattuple | 62 ++++----
contrib/pgstattuple/README.pgstattuple.euc_jp | 65 +++++----
contrib/pgstattuple/pgstattuple.c | 138 +++++++++++++-----
contrib/pgstattuple/pgstattuple.sql.in | 20 ++-
4 files changed, 196 insertions(+), 89 deletions(-)
diff --git a/contrib/pgstattuple/README.pgstattuple b/contrib/pgstattuple/README.pgstattuple
index 7237b9a4dc8..804c37c6a91 100644
--- a/contrib/pgstattuple/README.pgstattuple
+++ b/contrib/pgstattuple/README.pgstattuple
@@ -1,27 +1,36 @@
-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
diff --git a/contrib/pgstattuple/README.pgstattuple.euc_jp b/contrib/pgstattuple/README.pgstattuple.euc_jp
index 5142e9b6a92..00a4bcbc749 100644
--- a/contrib/pgstattuple/README.pgstattuple.euc_jp
+++ b/contrib/pgstattuple/README.pgstattuple.euc_jp
@@ -1,34 +1,39 @@
-$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
diff --git a/contrib/pgstattuple/pgstattuple.c b/contrib/pgstattuple/pgstattuple.c
index 498f8209525..a357f6f412a 100644
--- a/contrib/pgstattuple/pgstattuple.c
+++ b/contrib/pgstattuple/pgstattuple.c
@@ -1,7 +1,7 @@
/*
- * $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);
}
diff --git a/contrib/pgstattuple/pgstattuple.sql.in b/contrib/pgstattuple/pgstattuple.sql.in
index b49a13483f7..7c661a8ee3c 100644
--- a/contrib/pgstattuple/pgstattuple.sql.in
+++ b/contrib/pgstattuple/pgstattuple.sql.in
@@ -1,4 +1,16 @@
-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);
--
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