On Tue, Mar 03, 2020 at 06:25:51PM +0900, Michael Paquier wrote: > Or actually, a more simple solution is to abuse of the two existing > routines so as the dependency switch is done the other way around, > from the new index to the old one. That would visibly work because > there is no CCI between each scan, and that's faster because the scan > of pg_depend is done only on the entries in need of an update. I'll > look at that again tomorrow, it is late here and I may be missing > something obvious.
It was a good inspiration. I have been torturing this patch today and played with it by injecting elog(ERROR) calls in the middle of reindex concurrently for all the phases, and checked manually the handling of entries in pg_depend for the new and old indexes, and these correctly map. So this is taking care of your problem. Attached is an updated patch with an updated comment about the dependency of this code with CCIs. I'd like to go fix this issue first. -- Michael
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index 1681f61727..7223679033 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -1675,12 +1675,13 @@ index_concurrently_swap(Oid newIndexId, Oid oldIndexId, const char *oldName) } /* - * Move all dependencies of and on the old index to the new one. First - * remove any dependencies that the new index may have to provide an - * initial clean state for the dependency switch, and then move all the - * dependencies from the old index to the new one. + * Swap all dependencies of and on the old index to the new one, and + * vice-versa. Note that a call to CommandCounterIncrement() would cause + * duplicate entries in pg_depend, so this should not be done. */ - deleteDependencyRecordsFor(RelationRelationId, newIndexId, false); + changeDependenciesOf(RelationRelationId, newIndexId, oldIndexId); + changeDependenciesOn(RelationRelationId, newIndexId, oldIndexId); + changeDependenciesOf(RelationRelationId, oldIndexId, newIndexId); changeDependenciesOn(RelationRelationId, oldIndexId, newIndexId);
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