Remove PageSetTLI and rename pd_tli to pd_checksum

Remove use of PageSetTLI() from all page manipulation functions
and adjust README to indicate change in the way we make changes
to pages. Repurpose those bytes into the pd_checksum field and
explain how that works in comments about page header.

Refactoring ahead of actual feature patch which would make use
of the checksum field, arriving later.

Jeff Davis, with comments and doc changes by Simon Riggs
Direction suggested by Robert Haas; many others providing
review comments.

4 files changed, 0 insertions, 9 deletions

diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index eba95f1866..99cbcaa58e 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -410,7 +410,6 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
 		for (ptr = dist; ptr; ptr = ptr->next)
 		{
 			PageSetLSN(ptr->page, recptr);
-			PageSetTLI(ptr->page, ThisTimeLineID);
 		}
 
 		/*
@@ -458,7 +457,6 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
 									leftchildbuf);
 
 			PageSetLSN(page, recptr);
-			PageSetTLI(page, ThisTimeLineID);
 		}
 		else
 		{
@@ -491,7 +489,6 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
 		GistClearFollowRight(leftpg);
 
 		PageSetLSN(leftpg, recptr);
-		PageSetTLI(leftpg, ThisTimeLineID);
 	}
 
 	END_CRIT_SECTION();
diff --git a/src/backend/access/gist/gistbuild.c b/src/backend/access/gist/gistbuild.c
index 0cf22cdf3a..46f7ce6563 100644
--- a/src/backend/access/gist/gistbuild.c
+++ b/src/backend/access/gist/gistbuild.c
@@ -191,7 +191,6 @@ gistbuild(PG_FUNCTION_ARGS)
 
 		recptr = XLogInsert(RM_GIST_ID, XLOG_GIST_CREATE_INDEX, &rdata);
 		PageSetLSN(page, recptr);
-		PageSetTLI(page, ThisTimeLineID);
 	}
 	else
 		PageSetLSN(page, gistGetFakeLSN(heap));
diff --git a/src/backend/access/gist/gistvacuum.c b/src/backend/access/gist/gistvacuum.c
index 1d9f832016..59c3105b08 100644
--- a/src/backend/access/gist/gistvacuum.c
+++ b/src/backend/access/gist/gistvacuum.c
@@ -235,7 +235,6 @@ gistbulkdelete(PG_FUNCTION_ARGS)
 											todelete, ntodelete,
 											NULL, 0, InvalidBuffer);
 					PageSetLSN(page, recptr);
-					PageSetTLI(page, ThisTimeLineID);
 				}
 				else
 					PageSetLSN(page, gistGetFakeLSN(rel));
diff --git a/src/backend/access/gist/gistxlog.c b/src/backend/access/gist/gistxlog.c
index c18065a780..3daeea396b 100644
--- a/src/backend/access/gist/gistxlog.c
+++ b/src/backend/access/gist/gistxlog.c
@@ -70,7 +70,6 @@ gistRedoClearFollowRight(XLogRecPtr lsn, XLogRecord *record, int block_index,
 		GistClearFollowRight(page);
 
 		PageSetLSN(page, lsn);
-		PageSetTLI(page, ThisTimeLineID);
 		MarkBufferDirty(buffer);
 	}
 	UnlockReleaseBuffer(buffer);
@@ -185,7 +184,6 @@ gistRedoPageUpdateRecord(XLogRecPtr lsn, XLogRecord *record)
 
 	GistPageGetOpaque(page)->rightlink = InvalidBlockNumber;
 	PageSetLSN(page, lsn);
-	PageSetTLI(page, ThisTimeLineID);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);
 }
@@ -289,7 +287,6 @@ gistRedoPageSplitRecord(XLogRecPtr lsn, XLogRecord *record)
 		}
 
 		PageSetLSN(page, lsn);
-		PageSetTLI(page, ThisTimeLineID);
 		MarkBufferDirty(buffer);
 
 		if (i == 0)
@@ -324,7 +321,6 @@ gistRedoCreateIndex(XLogRecPtr lsn, XLogRecord *record)
 	GISTInitBuffer(buffer, F_LEAF);
 
 	PageSetLSN(page, lsn);
-	PageSetTLI(page, ThisTimeLineID);
 
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);