lock, not exclusive, if the desired page is already in memory. This can
be demonstrated to be a significant win on the pg_subtrans cache when there
is a large window of open transactions. It should be useful for pg_clog
as well. I didn't try to make GetMultiXactIdMembers() use the code, as
that would have taken some restructuring, and what with the local cache
for multixact contents it probably wouldn't really make a difference.
Per my recent proposal.
clauses even if it's an outer join. This is a corner case since such
clauses could only arise from weird OUTER JOIN ON conditions, but worth
fixing. Per example from Ron at cheapcomplexdevices.com.
incorrect implementation of argument reordering, arbitrary limit of output
size for sprintf and fprintf, willingness to access more bytes than "%.Ns"
specification allows, wrong formatting of LONGLONG_MIN, various field-padding
bugs and omissions. I believe it now accurately implements a subset of
the Single Unix Spec requirements (remaining unimplemented features are
documented, too). Bruce Momjian and Tom Lane.
< Win32 API, and we have to make sure MinGW handles it.
> Win32 API, and we have to make sure MinGW handles it. Another
> option is to wait for the MinGW project to fix it, or use the
> code from the LibGW32C project as a guide.
> o Add long file support for binary pg_dump output
>
> While Win32 supports 64-bit files, the MinGW API does not,
> meaning we have to build an fseeko replacement on top of the
> Win32 API, and we have to make sure MinGW handles it.
than owned by nobody. This results in cleaner display of language ACLs,
since the backend's aclchk.c uses the same convention. AFAICS there is
no practical difference but it's nice to avoid emitting SET SESSION
AUTHORIZATION; also this will make it easier to transition pg_dump to
some future version in which we may include an explicit ownership column
in pg_language. Per gripe from David Begley.
Map them to a single day, so '30 hours' is 'AM'.
Have to_char(interval) and to_char(time) use "HH", "HH12" as 12-hour
intervals, rather than bypass and print the full interval hours. This
is neeeded because to_char(time) is mapped to interval in this function.
Intervals should use "HH24", and document suggestion.
Allow "D" format specifiers for interval/time.
if we already have a stronger lock due to the index's table being the
update target table of the query. Same optimization I applied earlier
at the table level. There doesn't seem to be much interest in the more
radical idea of not locking indexes at all, so do what we can ...
relation if it's already been locked by execMain.c as either a result
relation or a FOR UPDATE/SHARE relation. This avoids an extra trip to
the shared lock manager state. Per my suggestion yesterday.
< be cleared when a heap tuple is expired. Another idea is to maintain
< a bitmap of heap pages where all rows are visible to all backends,
< and allow index lookups to reference that bitmap to avoid heap
< lookups, perhaps the same bitmap we might add someday to determine
< which heap pages need vacuuming.
> be cleared when a heap tuple is expired.
>
> Another idea is to maintain a bitmap of heap pages where all rows
> are visible to all backends, and allow index lookups to reference
> that bitmap to avoid heap lookups, perhaps the same bitmap we might
> add someday to determine which heap pages need vacuuming. Frequently
> accessed bitmaps would have to be stored in shared memory. One 8k
> page of bitmaps could track 512MB of heap pages.
child plan nodes until we have acquired lock on the relation to scan.
The relative order of initialization of plan nodes isn't real important in
other cases, but it's critical here because one is supposed to lock a
relation before its indexes, not vice versa. The original coding was at
least vulnerable to deadlock against DROP INDEX, and perhaps worse things.
< the heap. One way to allow this is to set a bit to index tuples
> the heap. One way to allow this is to set a bit on index tuples
< be cleared when a heap tuple is expired.
<
> be cleared when a heap tuple is expired. Another idea is to maintain
> a bitmap of heap pages where all rows are visible to all backends,
> and allow index lookups to reference that bitmap to avoid heap
> lookups, perhaps the same bitmap we might add someday to determine
> which heap pages need vacuuming.
< * Add MERGE command that does UPDATE/DELETE, or on failure, INSERT (rules,
< triggers?)
> * Add SQL-standard MERGE command, typically used to merge two tables
>
> This is similar to UPDATE, then for unmatched rows, INSERT.
> Whether concurrent access allows modifications which could cause
> row loss is implementation independent.
>
> * Add REPLACE or UPSERT command that does UPDATE, or on failure, INSERT
Also add a retry for Unixen returning EINTR, which hasn't been reported
as an issue but at least theoretically could be. Patch by Qingqing Zhou,
some minor adjustments by me.
#2075: consider an index redundant if any of its index conditions were already
used, rather than if all of them were. Also, make the selectivity comparison
a bit fuzzy, so that very small differences in estimated selectivities don't
skew the results.
< #A hyphen, "-", marks changes that will appear in the upcoming 8.1 release.#
> #A hyphen, "-", marks changes that will appear in the upcoming 8.2 release.#
it's worth probing the outer relation for emptiness before building the
hash table. To wit, if we're rescanning a join previously performed,
remember whether we found it nonempty the previous time, and don't bother
with the probe if it was nonempty. This buys back the performance lost
in examples like Mario Weilguni's.
Teodor Sigaev
Tom Lane
Bruce Momjian
Michael Meskes
Neil Conway
Alvaro Herrera