postgres.git / summary / log / commit / refs

commit    77a1ba20aa7b7caae4396e2afa5d86132fd36f6b
Author:   Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date:     Wed Dec 12 11:34:03 2012 +0000

    In multi-insert, don't go into infinite loop on a huge tuple and fillfactor.
    
    If a tuple is larger than page size minus space reserved for fillfactor,
    heap_multi_insert would never find a page that it fits in and repeatedly ask
    for a new page from RelationGetBufferForTuple. If a tuple is too large to
    fit on any page, taking fillfactor into account, RelationGetBufferForTuple
    will always expand the relation. In a normal insert, heap_insert will accept
    that and put the tuple on the new page. heap_multi_insert, however, does a
    fillfactor check of its own, and doesn't accept the newly-extended page
    RelationGetBufferForTuple returns, even though there is no other choice to
    make the tuple fit.
    
    Fix that by making the logic in heap_multi_insert more like the heap_insert
    logic. The first tuple is always put on the page RelationGetBufferForTuple
    gives us, and the fillfactor check is only applied to the subsequent tuples.
    
    Report from David Gould, although I didn't use his patch.


 src/backend/access/heap/heapam.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index ff903bdb96a..595dead3c54 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2172,8 +2172,12 @@ heap_multi_insert(Relation relation, HeapTuple *tuples, int ntuples,
 		/* NO EREPORT(ERROR) from here till changes are logged */
 		START_CRIT_SECTION();
 
-		/* Put as many tuples as fit on this page */
-		for (nthispage = 0; ndone + nthispage < ntuples; nthispage++)
+		/*
+		 * RelationGetBufferForTuple has ensured that the first tuple fits.
+		 * Put that on the page, and then as many other tuples as fit.
+		 */
+		RelationPutHeapTuple(relation, buffer, heaptuples[ndone]);
+		for (nthispage = 1; ndone + nthispage < ntuples; nthispage++)
 		{
 			HeapTuple	heaptup = heaptuples[ndone + nthispage];
 


[parent: 8bb937cc53a4]