Commit61b22d3

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btree page recycling can be done as soon as page's next-xact label is

older than current Xmin; we don't have to wait till it's older thanGlobalXmin.

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+13

-8

lines changed

+13

-8

lines changed

Lines changed: 2 additions & 2 deletions

Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,7 @@`
`9`	`9`	`*`
`10`	`10`	`*`
`11`	`11`	`* IDENTIFICATION`
`12`		`- * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.62 2003/02/2322:43:08 tgl Exp $`
	`12`	`+ * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.63 2003/02/2323:20:52 tgl Exp $`
`13`	`13`	`*`
`14`	`14`	`*NOTES`
`15`	`15`	`* Postgres btree pages look like ordinary relation pages.The opaque`
`@@ -544,7 +544,7 @@ _bt_page_recyclable(Page page)`
`544`	`544`	`*/`
`545`	`545`	`opaque= (BTPageOpaque)PageGetSpecialPointer(page);`
`546`	`546`	`if (P_ISDELETED(opaque)&&`
`547`		`-TransactionIdPrecedesOrEquals(opaque->btpo.xact,RecentGlobalXmin))`
	`547`	`+TransactionIdPrecedesOrEquals(opaque->btpo.xact,RecentXmin))`
`548`	`548`	`return true;`
`549`	`549`	`return false;`
`550`	`550`	`}`

Lines changed: 6 additions & 3 deletions

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.53 2002/11/21 06:36:08 tgl Exp $`
	`11`	`+ * $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.54 2003/02/23 23:20:52 tgl Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -298,9 +298,10 @@ GetOldestXmin(bool allDbs)`
`298`	`298`	`* This ensures that the set of transactions seen as "running" by the`
`299`	`299`	`* current xact will not change after it takes the snapshot.`
`300`	`300`	`*`
`301`		`- *Also, we compute the current global xmin (oldest xmin across all running`
	`301`	`+ *We also compute the current global xmin (oldest xmin across all running`
`302`	`302`	`* transactions) and save it in RecentGlobalXmin. This is the same`
`303`		`- * computation done by GetOldestXmin(TRUE).`
	`303`	`+ * computation done by GetOldestXmin(TRUE). The xmin value is also stored`
	`304`	`+ * into RecentXmin.`
`304`	`305`	`*----------`
`305`	`306`	`*/`
`306`	`307`	`Snapshot`
`@@ -419,7 +420,9 @@ GetSnapshotData(bool serializable)`
`419`	`420`	`if (TransactionIdPrecedes(xmin,globalxmin))`
`420`	`421`	`globalxmin=xmin;`
`421`	`422`
	`423`	`+/* Update globals for use by VACUUM */`
`422`	`424`	`RecentGlobalXmin=globalxmin;`
	`425`	`+RecentXmin=xmin;`
`423`	`426`
`424`	`427`	`snapshot->xmin=xmin;`
`425`	`428`	`snapshot->xmax=xmax;`

Lines changed: 3 additions & 2 deletions

Original file line number	Diff line number	Diff line change
`@@ -16,7 +16,7 @@`
`16`	`16`	`* Portions Copyright (c) 1994, Regents of the University of California`
`17`	`17`	`*`
`18`	`18`	`* IDENTIFICATION`
`19`		`- * $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.61 2002/10/08 17:17:19 tgl Exp $`
	`19`	`+ * $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.62 2003/02/23 23:20:52 tgl Exp $`
`20`	`20`	`*`
`21`	`21`	`*-------------------------------------------------------------------------`
`22`	`22`	`*/`
`@@ -33,7 +33,8 @@ SnapshotSnapshotDirty = &SnapshotDirtyData;`
`33`	`33`	`SnapshotQuerySnapshot=NULL;`
`34`	`34`	`SnapshotSerializableSnapshot=NULL;`
`35`	`35`
`36`		`-/* This is updated by GetSnapshotData: */`
	`36`	`+/* These are updated by GetSnapshotData: */`
	`37`	`+TransactionIdRecentXmin=InvalidTransactionId;`
`37`	`38`	`TransactionIdRecentGlobalXmin=InvalidTransactionId;`
`38`	`39`
`39`	`40`	`boolReferentialIntegritySnapshotOverride= false;`

Lines changed: 2 additions & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group`
`9`	`9`	`* Portions Copyright (c) 1994, Regents of the University of California`
`10`	`10`	`*`
`11`		`- * $Id: tqual.h,v 1.43 2002/09/0420:31:46 momjian Exp $`
	`11`	`+ * $Id: tqual.h,v 1.44 2003/02/23 23:20:52 tgl Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -41,6 +41,7 @@ extern DLLIMPORT Snapshot SnapshotDirty;`
`41`	`41`	`externDLLIMPORTSnapshotQuerySnapshot;`
`42`	`42`	`externDLLIMPORTSnapshotSerializableSnapshot;`
`43`	`43`
	`44`	`+externTransactionIdRecentXmin;`
`44`	`45`	`externTransactionIdRecentGlobalXmin;`
`45`	`46`
`46`	`47`	`externboolReferentialIntegritySnapshotOverride;`

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