Hi, On 11 November 2011 00:04, Jay Levitt <jay.levitt@xxxxxxxxx> wrote: > Sometimes the planner can't find the most efficient way to execute your > query. Thanks to relational algebra, there may be other, logically > equivalent queries that it DOES know how to optimize. > > But I don't know relational algebra. yet. (Date/Codd is a sleeping pill.) > I need more experience first. > > Are there blogs, guides, rules of thumb, common refactoring patterns out > there somewhere? I'm looking for a list of basic equalities, the SQL > equivalent of: Have a look here: http://en.wikipedia.org/wiki/Relational_algebra plus "External links" section -- Ondrej Ivanic (ondrej.ivanic@xxxxxxxxx) -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
