database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-28 23:42:10 +03:00
Code Activity

Improve handling of prune/no-prune decisions by storing a page's oldest

Browse Source 
unpruned XMAX in its header.  At the cost of 4 bytes per page, this keeps us
from performing heap_page_prune when there's no chance of pruning anything.
Seems to be necessary per Heikki's preliminary performance testing.
This commit is contained in:
Tom Lane
2007-09-21 21:25:42 +00:00
parent 386a5d4268
commit cc59049daf
10 changed files with 92 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
contrib/pageinspect/README.pageinspect
View File

@ -23,14 +23,14 @@ only by superusers.
A page image obtained with get_raw_page should be passed as argument:
test=# SELECT * FROM page_header(get_raw_page('pg_class',0));
lsn | tli | flags | lower | upper | special | pagesize | version
----------+-----+-------+-------+-------+---------+----------+---------
0/3C5614 | 1 | 1 | 216 | 256 | 8192 | 8192 | 4
regression=# SELECT * FROM page_header(get_raw_page('pg_class',0));
lsn | tli | flags | lower | upper | special | pagesize | version | prune_xid
-----------+-----+-------+-------+-------+---------+----------+---------+-----------
0/24A1B50 | 1 | 1 | 232 | 368 | 8192 | 8192 | 4 | 0
(1 row)
The returned columns correspond to the fields in the PageHeaderData-struct,
see src/include/storage/bufpage.h for more details.
The returned columns correspond to the fields in the PageHeaderData struct.
See src/include/storage/bufpage.h for details.
heap_page_items
---------------

3
contrib/pageinspect/pageinspect.sql.in
View File

@ -20,7 +20,8 @@ CREATE OR REPLACE FUNCTION page_header(IN page bytea,
OUT upper smallint,
OUT special smallint,
OUT pagesize smallint,
OUT version smallint)
OUT version smallint,
OUT prune_xid xid)
AS 'MODULE_PATHNAME', 'page_header'
LANGUAGE C STRICT;

7
contrib/pageinspect/rawpage.c
View File

@ -8,7 +8,7 @@
* Copyright (c) 2007, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $PostgreSQL: pgsql/contrib/pageinspect/rawpage.c,v 1.1 2007/05/17 19:11:24 momjian Exp $
* $PostgreSQL: pgsql/contrib/pageinspect/rawpage.c,v 1.2 2007/09/21 21:25:42 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -110,8 +110,8 @@ page_header(PG_FUNCTION_ARGS)
Datum result;
HeapTuple tuple;
Datum values[8];
bool nulls[8];
Datum values[9];
bool nulls[9];
PageHeader page;
XLogRecPtr lsn;
@ -152,6 +152,7 @@ page_header(PG_FUNCTION_ARGS)
values[5] = UInt16GetDatum(page->pd_special);
values[6] = UInt16GetDatum(PageGetPageSize(page));
values[7] = UInt16GetDatum(PageGetPageLayoutVersion(page));
values[8] = TransactionIdGetDatum(page->pd_prune_xid);
/* Build and return the tuple. */