On Sun, Sep 14, 2008 at 8:16 PM, Tom Lane <[EMAIL PROTECTED]> wrote: > BTW, one thing I noticed was that the hash index build time for the > "wide column" case got a lot worse after applying the patch (from 56 to > 237 sec). The reason for this turned out to be that with the smaller > predicted index size, the code decided not to use the pre-sorting method > that was recently added. Reducing effective_cache_size to less than the > index size brought the time back down, to about 54 sec. So it would > seem that effective_cache_size is too large a cutoff value. I'm > considering changing hashbuild to switch over at shared_buffers instead > of effective_cache_size --- any thoughts about that?
Switching to shared_buffers gets my vote, on my test table with 50,000,000 rows it takes about 8 minutes to create an index using the default effective_cache_size. With effective_cache_size set to 6GB (machine has 8GB) its still going an hour later. -- Sent via pgsql-patches mailing list (pgsql-patches@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-patches
