(1) Keep a pin on the scan's current buffer and mark buffer. This
avoids the need to do a ReadBuffer() for each tuple produced by the
scan. Since ReadBuffer() is expensive, this is a significant win.
(2) Convert a ReleaseBuffer(); ReadBuffer() pair into
ReleaseAndReadBuffer(). Surely not a huge win, but it saves a lock
acquire/release...
(3) Remove a bunch of duplicated code in rtget.c; make rtnext() handle
both the "initial result" and "subsequent result" cases.
(4) Add support for index tuple killing
(5) Remove rtscancache(): it is dead code, for the same reason that
gistscancache() is dead code (an index scan ought not be invoked with
NoMovementScanDirection).
The end result is about a 10% improvement in rtree index scan perf,
according to contrib/rtree_gist/bench.
per Andrew Dunstan. Also, don't override the user's value of PGHOST
in the 'make installcheck' case. I think the latter was an ill-considered
workaround for the Windows code back when libpq didn't properly default
to localhost on Unix-socket-less platforms.
MemoryContextAllocZero back to MemoryContextAlloc, same as it was in 7.4.
The zeroing is unnecessary since all the meaningful fields are filled in
just below. I had made it do that out of neatnik-ism, but some testing
with an example provided by Pavel Stehule showed that the zeroing was
accounting for about 5% of the runtime in a compute-intensive plpgsql
function. That seems a bit high of a price for neatnik-ism...
got it wrong when the JOIN was in an outer query level. Per example from
Laurie Burrow. Also fix same issue in markTargetListOrigin. I think the
latter is only a latent bug since we currently don't apply markTargetListOrigin
except at the outer level ... but should do it right anyway.
CASE 'a' WHEN 'a' THEN 1 ELSE 2 END. This worked in 7.4 and before
but had been broken due to premature freezing of the type of the test
expression. Per gripe from GÄbor SzÃcs.
few 'listen_addresses' as possible --- on most systems, none at all,
just the Unix socket. This avoids spurious check failures due to bogus
DNS setups, and is probably a good idea from a security standpoint anyway.
Per trouble report from Jean-GÅrard Pailloncy.
so that we can get the size of a shared inval message back down to what it
was in 7.4 (and simplify the logic too). Phase 2 of fixing the
'SMgrRelation hashtable corrupted' problem.
is the minimum required fix. I want to look next at taking advantage of
it by simplifying the message semantics in the shared inval message queue,
but that part can be held over for 8.1 if it turns out too ugly.
releases, a nonzero 'c' argument meant that the input string could be
terminated by either that character or \0. Recent refactoring broke
that, causing the thing to scan for 'c' only. This went undetected
because no part of the main code actually passes nonzero 'c'. However
it broke tsearch2 and possibly other user-written code that assumed
the old definition. Per report from Tom Hebbron.
