Remove flatfiles.c, which is now obsolete.

Recent commits have removed the various uses it was supporting.  It was a
performance bottleneck, according to bug report #4919 by Lauris Ulmanis; seems
it slowed down user creation after a billion users.

Author: alvherre

src/backend/access/transam/twophase_rmgr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/transam/twophase_rmgr.c,v 1.8 2009/01/01 17:23:36 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/transam/twophase_rmgr.c,v 1.9 2009/09/01 02:54:51 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,7 +18,6 @@
 #include "commands/async.h"
 #include "pgstat.h"
 #include "storage/lock.h"
-#include "utils/flatfiles.h"
 #include "utils/inval.h"
 
 
@@ -27,7 +26,6 @@ const TwoPhaseCallback twophase_recover_callbacks[TWOPHASE_RM_MAX_ID + 1] =
 	NULL,						/* END ID */
 	lock_twophase_recover,		/* Lock */
 	NULL,						/* Inval */
-	NULL,						/* flat file update */
 	NULL,						/* notify/listen */
 	NULL						/* pgstat */
 };
@@ -37,7 +35,6 @@ const TwoPhaseCallback twophase_postcommit_callbacks[TWOPHASE_RM_MAX_ID + 1] =
 	NULL,						/* END ID */
 	lock_twophase_postcommit,	/* Lock */
 	inval_twophase_postcommit,	/* Inval */
-	flatfile_twophase_postcommit,		/* flat file update */
 	notify_twophase_postcommit, /* notify/listen */
 	pgstat_twophase_postcommit	/* pgstat */
 };
@@ -47,7 +44,6 @@ const TwoPhaseCallback twophase_postabort_callbacks[TWOPHASE_RM_MAX_ID + 1] =
 	NULL,						/* END ID */
 	lock_twophase_postabort,	/* Lock */
 	NULL,						/* Inval */
-	NULL,						/* flat file update */
 	NULL,						/* notify/listen */
 	pgstat_twophase_postabort	/* pgstat */
 };

src/backend/access/transam/xact.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.274 2009/06/11 14:48:54 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.275 2009/09/01 02:54:51 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -43,7 +43,6 @@
 #include "storage/sinvaladt.h"
 #include "storage/smgr.h"
 #include "utils/combocid.h"
-#include "utils/flatfiles.h"
 #include "utils/guc.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
@@ -1608,12 +1607,6 @@ CommitTransaction(void)
 	/* NOTIFY commit must come before lower-level cleanup */
 	AtCommit_Notify();
 
-	/*
-	 * Update flat files if we changed pg_database, pg_authid or
-	 * pg_auth_members.  This should be the last step before commit.
-	 */
-	AtEOXact_UpdateFlatFiles(true);
-
 	/* Prevent cancel/die interrupt while cleaning up */
 	HOLD_INTERRUPTS();
 
@@ -1797,7 +1790,7 @@ PrepareTransaction(void)
 	/* close large objects before lower-level cleanup */
 	AtEOXact_LargeObject(true);
 
-	/* NOTIFY and flatfiles will be handled below */
+	/* NOTIFY will be handled below */
 
 	/*
 	 * Don't allow PREPARE TRANSACTION if we've accessed a temporary table in
@@ -1860,7 +1853,6 @@ PrepareTransaction(void)
 	StartPrepare(gxact);
 
 	AtPrepare_Notify();
-	AtPrepare_UpdateFlatFiles();
 	AtPrepare_Inval();
 	AtPrepare_Locks();
 	AtPrepare_PgStat();
@@ -1909,7 +1901,7 @@ PrepareTransaction(void)
 	/* Clean up the snapshot manager */
 	AtEarlyCommit_Snapshot();
 
-	/* notify and flatfiles don't need a postprepare call */
+	/* notify doesn't need a postprepare call */
 
 	PostPrepare_PgStat();
 
@@ -2036,7 +2028,6 @@ AbortTransaction(void)
 	AtAbort_Portals();
 	AtEOXact_LargeObject(false);	/* 'false' means it's abort */
 	AtAbort_Notify();
-	AtEOXact_UpdateFlatFiles(false);
 
 	/*
 	 * Advertise the fact that we aborted in pg_clog (assuming that we got as
@@ -3764,8 +3755,6 @@ CommitSubTransaction(void)
 	AtEOSubXact_LargeObject(true, s->subTransactionId,
 							s->parent->subTransactionId);
 	AtSubCommit_Notify();
-	AtEOSubXact_UpdateFlatFiles(true, s->subTransactionId,
-								s->parent->subTransactionId);
 
 	CallSubXactCallbacks(SUBXACT_EVENT_COMMIT_SUB, s->subTransactionId,
 						 s->parent->subTransactionId);
@@ -3885,8 +3874,6 @@ AbortSubTransaction(void)
 		AtEOSubXact_LargeObject(false, s->subTransactionId,
 								s->parent->subTransactionId);
 		AtSubAbort_Notify();
-		AtEOSubXact_UpdateFlatFiles(false, s->subTransactionId,
-									s->parent->subTransactionId);
 
 		/* Advertise the fact that we aborted in pg_clog. */
 		(void) RecordTransactionAbort(true);

src/backend/access/transam/xlog.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.350 2009/08/31 02:23:22 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.351 2009/09/01 02:54:51 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -49,7 +49,6 @@
 #include "storage/smgr.h"
 #include "storage/spin.h"
 #include "utils/builtins.h"
-#include "utils/flatfiles.h"
 #include "utils/guc.h"
 #include "utils/ps_status.h"
 #include "pg_trace.h"
@@ -8077,8 +8076,6 @@ StartupProcessMain(void)
 
 	StartupXLOG();
 
-	BuildFlatFiles(false);
-
 	/*
 	 * Exit normally. Exit code 0 tells postmaster that we completed recovery
 	 * successfully.

src/backend/commands/dbcommands.c

@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.225 2009/06/11 14:48:55 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.226 2009/09/01 02:54:51 alvherre Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -49,7 +49,6 @@
 #include "storage/smgr.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
-#include "utils/flatfiles.h"
 #include "utils/fmgroids.h"
 #include "utils/guc.h"
 #include "utils/lsyscache.h"
@@ -691,19 +690,17 @@ createdb(const CreatedbStmt *stmt)
 		RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT);
 
 		/*
-		 * Close pg_database, but keep lock till commit (this is important to
-		 * prevent any risk of deadlock failure while updating flat file)
+		 * Close pg_database, but keep lock till commit.
 		 */
 		heap_close(pg_database_rel, NoLock);
 
 		/*
-		 * Set flag to update flat database file at commit.  Note: this also
-		 * forces synchronous commit, which minimizes the window between
+		 * Force synchronous commit, thus minimizing the window between
 		 * creation of the database files and commital of the transaction. If
 		 * we crash before committing, we'll have a DB that's taking up disk
 		 * space but is not in pg_database, which is not good.
 		 */
-		database_file_update_needed();
+		ForceSyncCommit();
 	}
 	PG_END_ENSURE_ERROR_CLEANUP(createdb_failure_callback,
 								PointerGetDatum(&fparms));
@@ -862,19 +859,17 @@ dropdb(const char *dbname, bool missing_ok)
 	remove_dbtablespaces(db_id);
 
 	/*
-	 * Close pg_database, but keep lock till commit (this is important to
-	 * prevent any risk of deadlock failure while updating flat file)
+	 * Close pg_database, but keep lock till commit.
 	 */
 	heap_close(pgdbrel, NoLock);
 
 	/*
-	 * Set flag to update flat database file at commit.  Note: this also
-	 * forces synchronous commit, which minimizes the window between removal
+	 * Force synchronous commit, thus minimizing the window between removal
 	 * of the database files and commital of the transaction. If we crash
 	 * before committing, we'll have a DB that's gone on disk but still there
 	 * according to pg_database, which is not good.
 	 */
-	database_file_update_needed();
+	ForceSyncCommit();
 }
 
 
@@ -957,15 +952,9 @@ RenameDatabase(const char *oldname, const char *newname)
 	CatalogUpdateIndexes(rel, newtup);
 
 	/*
-	 * Close pg_database, but keep lock till commit (this is important to
-	 * prevent any risk of deadlock failure while updating flat file)
+	 * Close pg_database, but keep lock till commit.
 	 */
 	heap_close(rel, NoLock);
-
-	/*
-	 * Set flag to update flat database file at commit.
-	 */
-	database_file_update_needed();
 }
 
 
@@ -1212,17 +1201,15 @@ movedb(const char *dbname, const char *tblspcname)
 		RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT);
 
 		/*
-		 * Set flag to update flat database file at commit.  Note: this also
-		 * forces synchronous commit, which minimizes the window between
+		 * Force synchronous commit, thus minimizing the window between
 		 * copying the database files and commital of the transaction. If we
 		 * crash before committing, we'll leave an orphaned set of files on
 		 * disk, which is not fatal but not good either.
 		 */
-		database_file_update_needed();
+		ForceSyncCommit();
 
 		/*
-		 * Close pg_database, but keep lock till commit (this is important to
-		 * prevent any risk of deadlock failure while updating flat file)
+		 * Close pg_database, but keep lock till commit.
 		 */
 		heap_close(pgdbrel, NoLock);
 	}
@@ -1401,11 +1388,6 @@ AlterDatabase(AlterDatabaseStmt *stmt, bool isTopLevel)
 
 	/* Close pg_database, but keep lock till commit */
 	heap_close(rel, NoLock);
-
-	/*
-	 * We don't bother updating the flat file since the existing options for
-	 * ALTER DATABASE don't affect it.
-	 */
 }
 
 
@@ -1494,11 +1476,6 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 
 	/* Close pg_database, but keep lock till commit */
 	heap_close(rel, NoLock);
-
-	/*
-	 * We don't bother updating the flat file since ALTER DATABASE SET doesn't
-	 * affect it.
-	 */
 }
 
 
@@ -1608,11 +1585,6 @@ AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
 
 	/* Close pg_database, but keep lock till commit */
 	heap_close(rel, NoLock);
-
-	/*
-	 * We don't bother updating the flat file since ALTER DATABASE OWNER
-	 * doesn't affect it.
-	 */
 }