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.

1 files changed, 0 insertions, 12 deletions

diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c
index cd2a6c60a53..4aabdba3d9e 100644
--- a/src/backend/access/nbtree/nbtxlog.c
+++ b/src/backend/access/nbtree/nbtxlog.c
@@ -186,7 +186,6 @@ _bt_restore_meta(RelFileNode rnode, XLogRecPtr lsn,
 		((char *) md + sizeof(BTMetaPageData)) - (char *) metapg;
 
 	PageSetLSN(metapg, lsn);
-	PageSetTLI(metapg, ThisTimeLineID);
 	MarkBufferDirty(metabuf);
 	UnlockReleaseBuffer(metabuf);
 }
@@ -241,7 +240,6 @@ btree_xlog_insert(bool isleaf, bool ismeta,
 					elog(PANIC, "btree_insert_redo: failed to add item");
 
 				PageSetLSN(page, lsn);
-				PageSetTLI(page, ThisTimeLineID);
 				MarkBufferDirty(buffer);
 				UnlockReleaseBuffer(buffer);
 			}
@@ -358,7 +356,6 @@ btree_xlog_split(bool onleft, bool isroot,
 	}
 
 	PageSetLSN(rpage, lsn);
-	PageSetTLI(rpage, ThisTimeLineID);
 	MarkBufferDirty(rbuf);
 
 	/* don't release the buffer yet; we touch right page's first item below */
@@ -430,7 +427,6 @@ btree_xlog_split(bool onleft, bool isroot,
 				lopaque->btpo_cycleid = 0;
 
 				PageSetLSN(lpage, lsn);
-				PageSetTLI(lpage, ThisTimeLineID);
 				MarkBufferDirty(lbuf);
 			}
 
@@ -466,7 +462,6 @@ btree_xlog_split(bool onleft, bool isroot,
 				pageop->btpo_prev = xlrec->rightsib;
 
 				PageSetLSN(page, lsn);
-				PageSetTLI(page, ThisTimeLineID);
 				MarkBufferDirty(buffer);
 			}
 			UnlockReleaseBuffer(buffer);
@@ -563,7 +558,6 @@ btree_xlog_vacuum(XLogRecPtr lsn, XLogRecord *record)
 	opaque->btpo_flags &= ~BTP_HAS_GARBAGE;
 
 	PageSetLSN(page, lsn);
-	PageSetTLI(page, ThisTimeLineID);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);
 }
@@ -780,7 +774,6 @@ btree_xlog_delete(XLogRecPtr lsn, XLogRecord *record)
 	opaque->btpo_flags &= ~BTP_HAS_GARBAGE;
 
 	PageSetLSN(page, lsn);
-	PageSetTLI(page, ThisTimeLineID);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);
 }
@@ -851,7 +844,6 @@ btree_xlog_delete_page(uint8 info, XLogRecPtr lsn, XLogRecord *record)
 				}
 
 				PageSetLSN(page, lsn);
-				PageSetTLI(page, ThisTimeLineID);
 				MarkBufferDirty(buffer);
 				UnlockReleaseBuffer(buffer);
 			}
@@ -877,7 +869,6 @@ btree_xlog_delete_page(uint8 info, XLogRecPtr lsn, XLogRecord *record)
 				pageop->btpo_prev = leftsib;
 
 				PageSetLSN(page, lsn);
-				PageSetTLI(page, ThisTimeLineID);
 				MarkBufferDirty(buffer);
 				UnlockReleaseBuffer(buffer);
 			}
@@ -905,7 +896,6 @@ btree_xlog_delete_page(uint8 info, XLogRecPtr lsn, XLogRecord *record)
 					pageop->btpo_next = rightsib;
 
 					PageSetLSN(page, lsn);
-					PageSetTLI(page, ThisTimeLineID);
 					MarkBufferDirty(buffer);
 					UnlockReleaseBuffer(buffer);
 				}
@@ -928,7 +918,6 @@ btree_xlog_delete_page(uint8 info, XLogRecPtr lsn, XLogRecord *record)
 	pageop->btpo_cycleid = 0;
 
 	PageSetLSN(page, lsn);
-	PageSetTLI(page, ThisTimeLineID);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);
 
@@ -992,7 +981,6 @@ btree_xlog_newroot(XLogRecPtr lsn, XLogRecord *record)
 	}
 
 	PageSetLSN(page, lsn);
-	PageSetTLI(page, ThisTimeLineID);
 	MarkBufferDirty(buffer);
 	UnlockReleaseBuffer(buffer);