I would like to optimize my query, I’m currently sub-querying a table loaded with a sequence of SMALLINT values from 0 to 9999.
I would like to optimize my query, I’m currently sub-querying a table loaded with
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I would like to optimize my query, I’m currently sub-querying a table loaded with a sequence of SMALLINT values from 0 to 9999.
The only way you can tell for sure is to test it.
I did similar tests using PostgreSQL a few months ago. The question was whether it made sense to replace a calendar table with generate_series().
In our case, the table was faster. But if you test, you’ll probably find that generate_series() becomes faster at a certain number of rows. (That’s what we found, but the number of rows was well over anything we used.) My guess is that, at that point, the time it takes to generate the series becomes less than the time it takes to read the index and rows off the disk.
That’s a guess, because PostgreSQL’s EXPLAIN ANALYZE doesn’t give you much detail about disk I/O.