which I had removed in the first cut of the EquivalenceClass rewrite to
simplify that patch a little. But it's still important --- in a four-way
join problem mergejoinscansel() was eating about 40% of the planning time
according to gprof. Also, improve the EquivalenceClass code to re-use
join RestrictInfos rather than generating fresh ones for each join
considered. This saves some memory space but more importantly improves
the effectiveness of caching planning info in RestrictInfos.
columns procost and prorows, to allow simple user adjustment of the estimated
cost of a function call, as well as control of the estimated number of rows
returned by a set-returning function. We might eventually wish to extend this
to allow function-specific estimation routines, but there seems to be
consensus that we should try a simple constant estimate first. In particular
this provides a relatively simple way to control the order in which different
WHERE clauses are applied in a plan node, which is a Good Thing in view of the
fact that the recent EquivalenceClass planner rewrite made that much less
predictable than before.
provide just a boolean 'amcanorder', instead of fields that specify the
sort operator strategy numbers. We have decided to require ordering-capable
AMs to use btree-compatible strategy numbers, so the old fields are
overkill (and indeed misleading about what's allowed).
match the postgresql.conf file. Also add units to descriptions that
lacked them. Wording improvements. Mention pg_settings.unit as the way
to find the default units for setting.
Backpatch to 8.2.X.
representation of equivalence classes of variables. This is an extensive
rewrite, but it brings a number of benefits:
* planner no longer fails in the presence of "incomplete" operator families
that don't offer operators for every possible combination of datatypes.
* avoid generating and then discarding redundant equality clauses.
* remove bogus assumption that derived equalities always use operators
named "=".
* mergejoins can work with a variety of sort orders (e.g., descending) now,
instead of tying each mergejoinable operator to exactly one sort order.
* better recognition of redundant sort columns.
* can make use of equalities appearing underneath an outer join.
currentMarkData from IndexScanDesc to the opaque structs for the
AMs that need this information (currently gist and hash).
Patch from Heikki Linnakangas, fixes by Neil Conway.
the generated files, to help Visual C++ to run these tests. The tests still
pass in VPATH and normal builds.
Patch from Magnus Hagander, editorialized by me.
is deleted. A backend about to unlink a file now sends a "revoke fsync"
request to the bgwriter to make it clean out pending fsync requests. There
is still a race condition where the bgwriter may try to fsync after the unlink
has happened, but we can resolve that by rechecking the fsync request queue
to see if a revoke request arrived meanwhile. This eliminates the former
kluge of "just assuming" that an ENOENT failure is okay, and lets us handle
the fact that on Windows it might be EACCES too without introducing any
questionable assumptions. After an idea of mine improved by Magnus.
The HEAD patch doesn't apply cleanly to 8.2, but I'll see about a back-port
later. In the meantime this could do with some testing on Windows; I've been
able to force it through the code path via ENOENT, but that doesn't prove that
it actually fixes the Windows problem ...
* After Markos patch, now builds pgcrypto without zlib again
* Updates README with xml info
* xml requires xslt and iconv
* disable unnecessary warning about __cdecl()
* Add a buildenv.bat called from all other bat files to set up things
like PATH for flex/bison. (Can't just set it before calling, doesn't
always work when building from the GUI)
The implementation is somewhat ugly logic-wise, but I don't see an
easy way to make it more concise.
When writing this, I noticed that my previous implementation of
width_bucket() doesn't handle NaN correctly:
postgres=# select width_bucket('NaN', 1, 5, 5);
width_bucket
--------------
6
(1 row)
AFAICS SQL:2003 does not define a NaN value, so it doesn't address how
width_bucket() should behave here. The patch changes width_bucket() so
that ereport(ERROR) is raised if NaN is specified for the operand or the
lower or upper bounds to width_bucket(). For float8, NaN is disallowed
for any of the floating-point inputs, and +/- infinity is disallowed
for the histogram bounds (but allowed for the operand).
Update docs and regression tests, bump the catversion.
Tom Lane
Bruce Momjian
Peter Eisentraut
Neil Conway
Alvaro Herrera