From 23c4978e6c3bea403408949f9b7ab0949d76bc3f Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 5 Feb 2007 04:22:18 +0000 Subject: Rename MaxTupleSize to MaxHeapTupleSize to clarify that it's not meant to describe the maximum size of index tuples (which is typically AM-dependent anyway); and consequently remove the bogus deduction for "special space" that was built into it. Adjust TOAST_TUPLE_THRESHOLD and TOAST_MAX_CHUNK_SIZE to avoid wasting two bytes per toast chunk, and to ensure that the calculation correctly tracks any future changes in page header size. The computation had been inaccurate in a way that didn't cause any harm except space wastage, but future changes could have broken it more drastically. Fix the calculation of BTMaxItemSize, which was formerly computed as 1 byte more than it could safely be. This didn't cause any harm in practice because it's only compared against maxalign'd lengths, but future changes in the size of page headers or btree special space could have exposed the problem. initdb forced because of change in TOAST_MAX_CHUNK_SIZE, which alters the storage of toast tables. --- src/backend/access/heap/hio.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'src/backend/access/heap/hio.c') diff --git a/src/backend/access/heap/hio.c b/src/backend/access/heap/hio.c index 4e033be4e0d..0bb617a8cdc 100644 --- a/src/backend/access/heap/hio.c +++ b/src/backend/access/heap/hio.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/heap/hio.c,v 1.64 2007/01/05 22:19:22 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/access/heap/hio.c,v 1.65 2007/02/05 04:22:18 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -118,12 +118,12 @@ RelationGetBufferForTuple(Relation relation, Size len, /* * If we're gonna fail for oversize tuple, do it right away */ - if (len > MaxTupleSize) + if (len > MaxHeapTupleSize) ereport(ERROR, (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), errmsg("row is too big: size %lu, maximum size %lu", (unsigned long) len, - (unsigned long) MaxTupleSize))); + (unsigned long) MaxHeapTupleSize))); /* Compute desired extra freespace due to fillfactor option */ saveFreeSpace = RelationGetTargetPageFreeSpace(relation, @@ -147,7 +147,7 @@ RelationGetBufferForTuple(Relation relation, Size len, * When use_fsm is false, we either put the tuple onto the existing target * page or extend the relation. */ - if (len + saveFreeSpace <= MaxTupleSize) + if (len + saveFreeSpace <= MaxHeapTupleSize) targetBlock = relation->rd_targblock; else { -- cgit v1.2.3