On Mon, 2008-01-28 at 23:13 +0000, Heikki Linnakangas wrote: > Tables that are seq scanned are typically very small, like a summary > table with just a few rows, or huge tables in a data warehousing > system. Between the extremes, I don't think the threshold actually has > a very big impact.
And if you have a partitioned table with partitions inconveniently sized? You'd need to *reduce* shared_buffers specifically to get synch scans and BAS to kick in. Or increase partition size. Both of which reduce the impact of the benefits we've added. I don't think the argument that "a table is smaller than shared buffers therefore it is already in shared buffers" holds true in all cases. I/O does matter. -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
