On Wed, Feb 20, 2008 at 12:56:54AM -0800, Postgres User wrote: > a final question: why does this syntax do a seq scan + filter: > > select * from tablea where fielda = fielda -or- select * from > tablea where fielda in (fielda) > > while this syntax results in no filter, seq scan only > > select * from tablea where 1 = 1 > > it seems that both where clauses should be ignored by the optimizer- > or am i missing something WHERE fielda = fielda will only match non-null rows... Have a nice day, -- Martijn van Oosterhout <kleptog@xxxxxxxxx> http://svana.org/kleptog/ > Those who make peaceful revolution impossible will make violent revolution inevitable. > -- John F Kennedy
Attachment:
signature.asc
Description: Digital signature
