Josh Harrison escribió:
> Another quick question...When you issue a query like this
> select * from dummy limit 10
> What 10 rows are fetched? like first 10 or last 10 or the first 10 from
> first block or.... ?
Any 10. (First 10 in the physical table _if_ a seqscan is used).
> And this query always returns the same 10 rows (when there are no
> updates/deletes)
Yes, assuming there is no VACUUM or CLUSTER either. And no inserts
either if there is free space on the first pages.
You really shouldn't trust it.
--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.