Tom Lane wrote: > "Scott Marlowe" <scott.marlowe@xxxxxxxxx> writes: >> Note that, at least in older versions, MySQL completely materialized a >> temporary table from a view, then used that for the view. This is >> horribly inefficient, and results in a lot of people thinking views >> are slow. Not sure if this has been addressed in MySQL yet, don't >> really care anymore, since I rarely use mysql for anything anymore. > > Some simple experiments with mysql 5.0.67 suggest that this meme is > obsolete there too. I found some cases where it looks like we optimize > a bit better than they do, but for simple views you seem to get the > same plan as if you'd written out the equivalent query in-line. > This is true of simple queries, but as soon as your query starts becoming "complex" (e.g. involving subselects) it just dumps the result of the view query into a temporary table and uses that. (Tested with 5.0.67 too). -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
