Re: New FSM patch

Tom Lane wrote:
> Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
>> Let me describe this test case first:
>> - The test program calls RecordAndGetPageWithFreeSpace in a tight loop, 
>> with random values.
> 
> What's the distribution of the random values, exactly?  In particular,
> how do the request sizes compare to available free space per-page?

The request, and "old avail" sizes are in the range of 0-8100 
(random()%8100).

> The design intent for FSM was that we'd not bother to record pages that
> have less free space than the average request size, so as to (usually)
> avoid the problem of uselessly searching a lot of entries.  I can't tell
> whether your test case models that behavior at all.  If it does then
> there may be something else that needs fixing.

Probably not. The test case starts with a table that's practically 
empty, so all pages are put into the FSM.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com