[btilly]

This is all good optimization advice, but I don't think it is applicable to my specific case.

My problem is not that PostgreSQL does not understand the distribution of my data. It does. The problem is that it comes up with a query plan without realizing that I'm only querying for a very small range of timestamps.

If this happens again, I'll have to try rewriting code to send it queries with hard-coded timestamps, cross fingers and pray. I find prayer quite essential with PostgreSQL sometimes because as ineffective as it is, at times I've got nothing else.

[koide]

Have you talked about this in the dev mailing list? I'm sure they would help and likely consider adding something to improve the next version.

[anarazel]

> My problem is not that PostgreSQL does not understand the distribution of my data. It does. The problem is that it comes up with a query plan without realizing that I'm only querying for a very small range of timestamps.

Which version did you reproduce that on? While the problem has not been generally addressed, the specifically bad case of looking up values at the "growing" end of a monotonically increasing data range has been improved a bit over the years (9.0 and then some incremental improvement in 9.0.4).

[btilly]

PostgreSQL 9.4.4 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.8.2 20140120 (Red Hat 4.8.2-16), 64-bit

If it matters, it is an Amazon RDS instance.