On Thu, Aug 09, 2007 at 06:04:09PM +0530, Merlin Moncure wrote: > That said, 'update' is the slowest operation for postgresql relative > to other databases that are not MVCC. Actually, it depends on how you do MVCC. In Oracle, DELETE is actually the most expensive operation, because they have to not only remove the row from the heap, they have to copy it to the undo log. And they need to do something with indexes as well. Whereas we just update 4 bytes in the heap and that's it. An UPDATE in Oracle OTOH just needs to store whatever fields have changed in the undo log. If you haven't messed with indexed fields, it doesn't have to touch those either. -- Decibel!, aka Jim Nasby decibel@xxxxxxxxxxx EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
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