Hi, all,
When using 'create index concurrently', we use a MVCC snaptshot, we should not see tuples that is HEAPTUPLE_INSERT_IN_PROGRESS. I think we should report an ERROR in this case. But, we report WARNING now.
In the early days, it indeed report ERROR, but the behaviour is changed by commit 1ddc2703a936d03953657f43345460b9242bbed1.
I am not very clear about it. Could anyone explain it?
The following are the related codes:
Earlier PG versions: the code is in function IndexBuildHeapScan
case HEAPTUPLE_DELETE_IN_PROGRESS:
/*
* As with INSERT_IN_PROGRESS case, this is unexpected
* unless it's our own deletion or a system catalog.
*/
Assert(!(heapTuple->t_data->t_infomask & HEAP_XMAX_IS_MULTI));
xwait = HeapTupleHeaderGetXmax(heapTuple->t_data);
if (!TransactionIdIsCurrentTransactionId(xwait))
{
if (!is_system_catalog)
elog(WARNING, "concurrent delete in progress within table \"%s\"",
RelationGetRelationName(heapRelation));
Newest PG version: the code in function heapam_index_build_range_scan
Thanks all!
Regards,
Meng Qingzhong