On Mon, Feb 22, 2010 at 1:30 PM, Richard Broersma <richard.broer...@gmail.com> wrote: > On Mon, Feb 22, 2010 at 10:17 AM, Frank Heikens <frankheik...@mac.com> wrote: > >> There is no index on the column transactionid in your PostgreSQL-table, as >> there is in your MySQL-table. This explains the difference. >> >> CREATE INDEX i_transactionid ON public.metarelcloud_transactionlog >> (transactionid); > > Does an index help a sort operation in PostgreSQL?
I also share the same doubt. An external merge-sort needs to make complete passes over the entire dataset, with no index-directed accesses. -- Yang Zhang http://www.mit.edu/~y_z/ -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
