FWIW, I vote with Tatsuo-san. Such a change will break comparability of results
I would not classify a performance measure as a "result compatibility" issue. What matters is the *correction* of the results.
When a bug is fixed anywhere in pg it may change performance significantly for some tests, and I have never seen this as a relevant consideration not to fix a problem...
with all previous versions, which means it's not something to do in minor releases, even if we now believe the previous results were somewhat bogus. Arguing that it's "not a behavioral change" seems quite loony to me: for most people, the TPS numbers are the only interesting output of pgbench.
I think that if people are interested in tps without reconnecting on each transaction they would not run with "-C" to trigger reconnections and then look at the "tps without connections" for the figure they want... so I do not think that keeping this error is worth anything.
On the other hand, and on the principle, keeping the bug looks wrong. I cannot agree with the logic behind shipping something which is known bad, especially to display *optimistic* performances... It looks too much like the VW way:-)
I think we should fix it in 9.5 and document it as an incompatible change.
(Note: I've not read the patch, so this is not an opinion about its correctness.)
That is another question:-) -- Fabien. -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers