I have one query in my postgresql 9.2.3 that took 137 ms to me executed and looking a way what I can do to optimize it. I have one table generated numbers from 1 to 1 000 000 and I need to get first free id, meanwhile id's when is taken can be free (deleted data and id is free for next job). Table is simple:
id serial, jobid text, valids int default 0
(Yes, I have index).
my query is: SELECT jobid FROM mytable WHERE valids = 0 ORDER BY id ASC LIMIT 1
I need the first id only.
My question is: Is there a way how I can avoid using ORDER BY to receive the first free id from mytable ?