Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit9cc2756

Browse files
committed
Fix pgstattuple's handling of unused hash pages.
Hash indexes can contain both pages which are all-zeroes (i.e.PageIsNew()) and pages which have been initialized but currentlyaren't used. The latter category can happen either when a pagehas been reserved but not yet used or when it is used for a timeand then freed. pgstattuple was only prepared to deal with thepages that are actually-zeroes, which it called zero_pages.Rename the column to unused_pages (extension version 1.5 isas-yet-unreleased) and make it count both kinds of unused pages.Along the way, slightly tidy up the way we test for pages ofvarious types.Robert Haas and Ashutosh Sharma, reviewed by Amit KapilaDiscussion:http://postgr.es/m/CAE9k0PkTtKFB3YndOyQMjwuHx+-FtUP1ynK8E-nHtetoow3NtQ@mail.gmail.com
1 parent1d5fede commit9cc2756

File tree

4 files changed

+22
-16
lines changed

4 files changed

+22
-16
lines changed

‎contrib/pgstattuple/expected/pgstattuple.out‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -132,9 +132,9 @@ select * from pgstatginindex('test_ginidx');
132132

133133
create index test_hashidx on test using hash (b);
134134
select * from pgstathashindex('test_hashidx');
135-
version | bucket_pages | overflow_pages | bitmap_pages |zero_pages | live_items | dead_items | free_percent
136-
---------+--------------+----------------+--------------+------------+------------+------------+--------------
137-
3 | 4 | 0 | 1 | 0 | 0 | 0 | 100
135+
version | bucket_pages | overflow_pages | bitmap_pages |unused_pages | live_items | dead_items | free_percent
136+
---------+--------------+----------------+--------------+--------------+------------+------------+--------------
137+
3 | 4 | 0 | 1 |0 | 0 | 0 | 100
138138
(1 row)
139139

140140
-- these should error with the wrong type

‎contrib/pgstattuple/pgstatindex.c‎

Lines changed: 15 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -119,7 +119,7 @@ typedef struct HashIndexStat
119119
BlockNumberbucket_pages;
120120
BlockNumberoverflow_pages;
121121
BlockNumberbitmap_pages;
122-
BlockNumberzero_pages;
122+
BlockNumberunused_pages;
123123

124124
int64live_items;
125125
int64dead_items;
@@ -634,7 +634,6 @@ pgstathashindex(PG_FUNCTION_ARGS)
634634
{
635635
Bufferbuf;
636636
Pagepage;
637-
HashPageOpaqueopaque;
638637

639638
CHECK_FOR_INTERRUPTS();
640639

@@ -644,7 +643,7 @@ pgstathashindex(PG_FUNCTION_ARGS)
644643
page= (Page)BufferGetPage(buf);
645644

646645
if (PageIsNew(page))
647-
stats.zero_pages++;
646+
stats.unused_pages++;
648647
elseif (PageGetSpecialSize(page)!=
649648
MAXALIGN(sizeof(HashPageOpaqueData)))
650649
ereport(ERROR,
@@ -654,19 +653,26 @@ pgstathashindex(PG_FUNCTION_ARGS)
654653
BufferGetBlockNumber(buf))));
655654
else
656655
{
656+
HashPageOpaqueopaque;
657+
intpagetype;
658+
657659
opaque= (HashPageOpaque)PageGetSpecialPointer(page);
658-
if (opaque->hasho_flag&LH_BUCKET_PAGE)
660+
pagetype=opaque->hasho_flag&LH_PAGE_TYPE;
661+
662+
if (pagetype==LH_BUCKET_PAGE)
659663
{
660664
stats.bucket_pages++;
661665
GetHashPageStats(page,&stats);
662666
}
663-
elseif (opaque->hasho_flag&LH_OVERFLOW_PAGE)
667+
elseif (pagetype==LH_OVERFLOW_PAGE)
664668
{
665669
stats.overflow_pages++;
666670
GetHashPageStats(page,&stats);
667671
}
668-
elseif (opaque->hasho_flag&LH_BITMAP_PAGE)
672+
elseif (pagetype==LH_BITMAP_PAGE)
669673
stats.bitmap_pages++;
674+
elseif (pagetype==LH_UNUSED_PAGE)
675+
stats.unused_pages++;
670676
else
671677
ereport(ERROR,
672678
(errcode(ERRCODE_INDEX_CORRUPTED),
@@ -680,8 +686,8 @@ pgstathashindex(PG_FUNCTION_ARGS)
680686
/* Done accessing the index */
681687
index_close(rel,AccessShareLock);
682688

683-
/* Countzero pages as free space. */
684-
stats.free_space+=stats.zero_pages*stats.space_per_page;
689+
/* Countunused pages as free space. */
690+
stats.free_space+=stats.unused_pages*stats.space_per_page;
685691

686692
/*
687693
* Total space available for tuples excludes the metapage and the bitmap
@@ -710,7 +716,7 @@ pgstathashindex(PG_FUNCTION_ARGS)
710716
values[1]=Int64GetDatum((int64)stats.bucket_pages);
711717
values[2]=Int64GetDatum((int64)stats.overflow_pages);
712718
values[3]=Int64GetDatum((int64)stats.bitmap_pages);
713-
values[4]=Int64GetDatum((int64)stats.zero_pages);
719+
values[4]=Int64GetDatum((int64)stats.unused_pages);
714720
values[5]=Int64GetDatum(stats.live_items);
715721
values[6]=Int64GetDatum(stats.dead_items);
716722
values[7]=Float8GetDatum(free_percent);

‎contrib/pgstattuple/pgstattuple--1.4--1.5.sql‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -125,7 +125,7 @@ CREATE OR REPLACE FUNCTION pgstathashindex(IN relname regclass,
125125
OUT bucket_pagesBIGINT,
126126
OUT overflow_pagesBIGINT,
127127
OUT bitmap_pagesBIGINT,
128-
OUTzero_pagesBIGINT,
128+
OUTunused_pagesBIGINT,
129129
OUT live_itemsBIGINT,
130130
OUT dead_itemsBIGINT,
131131
OUT free_percent FLOAT8)

‎doc/src/sgml/pgstattuple.sgml‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -372,7 +372,7 @@ version | 2
372372
bucket_pages | 33081
373373
overflow_pages | 0
374374
bitmap_pages | 1
375-
zero_pages | 32455
375+
unused_pages | 32455
376376
live_items | 10204006
377377
dead_items | 0
378378
free_percent | 61.8005949100872
@@ -418,9 +418,9 @@ free_percent | 61.8005949100872
418418
</row>
419419

420420
<row>
421-
<entry><structfield>zero_pages</structfield></entry>
421+
<entry><structfield>unused_pages</structfield></entry>
422422
<entry><type>bigint</type></entry>
423-
<entry>Number ofnew or zero pages</entry>
423+
<entry>Number ofunused pages</entry>
424424
</row>
425425

426426
<row>

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp