On Thu, Aug 09, 2007 at 10:22:57AM -0400, Vivek Khera wrote: > > On Aug 9, 2007, at 9:38 AM, Brad Nicholson wrote: > > >I have the times that it takes to to do a regular > >vacuum on the clusters, will vacuum full take longer? > > almost certainly it will, since it has to move data to compact pages > rather than just tagging the rows as reusable. > > you can speed things up by dropping your indexes first, then running > vacuum full, then re-creating your indexes. this will make for > better (more compact) indexes too. > > as for how much longer, I don't know how to estimate that. A generally easier approach would be to cluster the tables on an appropriate index. That does re-write the table from scratch, but in cases of bad bloat that can actually be a lot faster. One thing you can do to test this out is to setup another copy of the database using PITR or some other file-based copy mechanism and try running VACUUM FULL vs CLUSTER. Note that a copy obtained via pg_dump obviously won't work for this. :) -- Decibel!, aka Jim Nasby decibel@xxxxxxxxxxx EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
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