This indeed is a very interesting question. At http://wiki.postgresql.org/wiki/CTEReadme it seems to suggest that a CTE is just rewritten and the resulting query is executed.
Kind regards/met vriendelijke groet, Serge Fonville http://www.sergefonville.nl Convince Microsoft! They need to add TRUNCATE PARTITION in SQL Server https://connect.microsoft.com/SQLServer/feedback/details/417926/truncate-partition-of-partitioned-table 2012/10/9 Craig Ringer <ring...@ringerc.id.au> > On 10/06/2012 08:45 AM, Liam Caffrey wrote: > >> Hi, >> >> If I run a CTE does that materialize the resulting data in the same (or >> a similar) way as if I created a temp table and referred to that >> instead? Or does the CTE keep the set in memory? >> > > Really good question, I too would be interested in this. > > I'd expect it'd materialize to RAM if the result is within `work_mem` but > I'd love to know for sure. > > -- > Craig Ringer > > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/**mailpref/pgsql-general<http://www.postgresql.org/mailpref/pgsql-general> >
