Revert "Fix replay of create database records on standby"

This reverts commit 49d9cfc68bf4.  The approach taken by this patch has
problems, so we'll come up with a radically different fix.

Discussion: https://postgr.es/m/CA+TgmoYcUPL+WOJL2ZzhH=zmrhj0iOQ=iCFM0SuYqBbqZEamEg@mail.gmail.com

1 files changed, 1 insertions, 158 deletions

diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index 8c1b8216be5..511f2f186f5 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -54,164 +54,6 @@ bool		InRecovery = false;
 /* Are we in Hot Standby mode? Only valid in startup process, see xlogutils.h */
 HotStandbyState standbyState = STANDBY_DISABLED;
 
-
-/*
- * If a create database WAL record is being replayed more than once during
- * crash recovery on a standby, it is possible that either the tablespace
- * directory or the template database directory is missing.  This happens when
- * the directories are removed by replay of subsequent drop records.  Note
- * that this problem happens only on standby and not on master.  On master, a
- * checkpoint is created at the end of create database operation. On standby,
- * however, such a strategy (creating restart points during replay) is not
- * viable because it will slow down WAL replay.
- *
- * The alternative is to track references to each missing directory
- * encountered when performing crash recovery in the following hash table.
- * Similar to invalid page table above, the expectation is that each missing
- * directory entry should be matched with a drop database or drop tablespace
- * WAL record by the end of crash recovery.
- */
-typedef struct xl_missing_dir_key
-{
-	Oid			spcNode;
-	Oid			dbNode;
-} xl_missing_dir_key;
-
-typedef struct xl_missing_dir
-{
-	xl_missing_dir_key key;
-	char		path[MAXPGPATH];
-} xl_missing_dir;
-
-static HTAB *missing_dir_tab = NULL;
-
-
-/*
- * Keep track of a directory that wasn't found while replaying database
- * creation records.  These should match up with tablespace removal records
- * later in the WAL stream; we verify that before reaching consistency.
- */
-void
-XLogRememberMissingDir(Oid spcNode, Oid dbNode, char *path)
-{
-	xl_missing_dir_key key;
-	bool		found;
-	xl_missing_dir *entry;
-
-	/*
-	 * Database OID may be invalid but tablespace OID must be valid.  If
-	 * dbNode is InvalidOid, we are logging a missing tablespace directory,
-	 * otherwise we are logging a missing database directory.
-	 */
-	Assert(OidIsValid(spcNode));
-
-	if (missing_dir_tab == NULL)
-	{
-		/* create hash table when first needed */
-		HASHCTL		ctl;
-
-		memset(&ctl, 0, sizeof(ctl));
-		ctl.keysize = sizeof(xl_missing_dir_key);
-		ctl.entrysize = sizeof(xl_missing_dir);
-
-		missing_dir_tab = hash_create("XLOG missing directory table",
-									  100,
-									  &ctl,
-									  HASH_ELEM | HASH_BLOBS);
-	}
-
-	key.spcNode = spcNode;
-	key.dbNode = dbNode;
-
-	entry = hash_search(missing_dir_tab, &key, HASH_ENTER, &found);
-
-	if (found)
-	{
-		if (dbNode == InvalidOid)
-			elog(DEBUG1, "missing directory %s (tablespace %u) already exists: %s",
-				 path, spcNode, entry->path);
-		else
-			elog(DEBUG1, "missing directory %s (tablespace %u database %u) already exists: %s",
-				 path, spcNode, dbNode, entry->path);
-	}
-	else
-	{
-		strlcpy(entry->path, path, sizeof(entry->path));
-		if (dbNode == InvalidOid)
-			elog(DEBUG1, "logged missing dir %s (tablespace %u)",
-				 path, spcNode);
-		else
-			elog(DEBUG1, "logged missing dir %s (tablespace %u database %u)",
-				 path, spcNode, dbNode);
-	}
-}
-
-/*
- * Remove an entry from the list of directories not found.  This is to be done
- * when the matching tablespace removal WAL record is found.
- */
-void
-XLogForgetMissingDir(Oid spcNode, Oid dbNode)
-{
-	xl_missing_dir_key key;
-
-	key.spcNode = spcNode;
-	key.dbNode = dbNode;
-
-	/* Database OID may be invalid but tablespace OID must be valid. */
-	Assert(OidIsValid(spcNode));
-
-	if (missing_dir_tab == NULL)
-		return;
-
-	if (hash_search(missing_dir_tab, &key, HASH_REMOVE, NULL) != NULL)
-	{
-		if (dbNode == InvalidOid)
-		{
-			elog(DEBUG2, "forgot missing dir (tablespace %u)", spcNode);
-		}
-		else
-		{
-			char	   *path = GetDatabasePath(dbNode, spcNode);
-
-			elog(DEBUG2, "forgot missing dir %s (tablespace %u database %u)",
-				 path, spcNode, dbNode);
-			pfree(path);
-		}
-	}
-}
-
-/*
- * This is called at the end of crash recovery, before entering archive
- * recovery on a standby.  PANIC if the hash table is not empty.
- */
-void
-XLogCheckMissingDirs(void)
-{
-	HASH_SEQ_STATUS status;
-	xl_missing_dir *hentry;
-	bool		foundone = false;
-
-	if (missing_dir_tab == NULL)
-		return;					/* nothing to do */
-
-	hash_seq_init(&status, missing_dir_tab);
-
-	while ((hentry = (xl_missing_dir *) hash_seq_search(&status)) != NULL)
-	{
-		elog(WARNING, "missing directory \"%s\" tablespace %u database %u",
-			 hentry->path, hentry->key.spcNode, hentry->key.dbNode);
-		foundone = true;
-	}
-
-	if (foundone)
-		elog(PANIC, "WAL contains references to missing directories");
-
-	hash_destroy(missing_dir_tab);
-	missing_dir_tab = NULL;
-}
-
-
 /*
  * During XLOG replay, we may see XLOG records for incremental updates of
  * pages that no longer exist, because their relation was later dropped or
@@ -237,6 +79,7 @@ typedef struct xl_invalid_page
 
 static HTAB *invalid_page_tab = NULL;
 
+
 /* Report a reference to an invalid page */
 static void
 report_invalid_page(int elevel, RelFileNode node, ForkNumber forkno,