Re: Index trouble with 8.3b4

"Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

> Oooh ... I can't be sure that this is what's biting you, but I
> definitely see a bug that seems to match the symptoms. As the comments
> in index.c point out, CREATE INDEX CONCURRENTLY works like this:
>
> * validate_index() works by first gathering all the TIDs currently in the
> * index, using a bulkdelete callback that just stores the TIDs and doesn't
> * ever say "delete it". (This should be faster than a plain indexscan;
> * also, not all index AMs support full-index indexscan.) Then we sort the
> * TIDs, and finally scan the table doing a "merge join" against the TID list
> * to see which tuples are missing from the index.
>
> The scan is done using the regular heapscan code, which in 8.3 has been
> modified to enable "synchronized scanning", which means it might start
> from the middle of the table and wrap around.

Wow, I'm glad we caught this in beta. Thanks a lot to Hannes Dorbath for
testing and reporting it.

--
Gregory Stark
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