pasman pasma*ski<pasman.p@xxxxxxxxx> wrote: > How to use tid scans? Write a query where they are the fastest way to retrieve the data, and make sure your PostgreSQL installation is properly configured. > This below not works :-( Always is used merge join. > SELECT * FROM test1 join test2 on(test1.ctid=test2.ct) You're reading through the entirety of two tables matching rows between them. What makes you think random access would be faster than sequential? If all this data is cached, then maybe random access could win, but you would need to configure your PostgreSQL to expect that. Have you read this page: http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server -Kevin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
