< cleaned up properly. A new signal is needed for safe termination.
> cleaned up properly. A new signal is needed for safe termination
> because backends must first do a query cancel, then exit once they
> have run the query cancel cleanup routine.
1. Rename spi_return_next to return_next.
2. Add a new test for return_next.
3. Update the expected output.
4. Update the documentation.
Abhijit Menon-Sen
representation as the jointree) with two lists of RTEs, one showing
the RTEs accessible by qualified names, and the other showing the RTEs
accessible by unqualified names. I think this is conceptually simpler
than what we did before, and it's sure a whole lot easier to search.
This seems to eliminate the parse-time bottleneck for deeply nested
JOIN structures that was exhibited by phil@vodafone.
< logs
> logs [pitr]
130c130
< * Allow a warm standby system to also allow read-only queries
> * Allow a warm standby system to also allow read-only queries [pitr]
---------------------------------------------------------------------------
Tom Lane <tgl@sss.pgh.pa.us> writes:
> a_ogawa <a_ogawa@hi-ho.ne.jp> writes:
> > It is a reasonable idea. However, the majority part of MemSet was not
> > able to be avoided by this idea. Because the per-tuple contexts are used
> > at the early stage of executor.
>
> Drat. Well, what about changing that? We could introduce additional
> contexts or change the startup behavior so that the ones that are
> frequently reset don't have any data in them unless you are working
> with pass-by-ref values inside the inner loop.
That might be possible. However, I think that we should change only
aset.c about this article.
I thought further: We can check whether context was used from the last
reset even when blocks list is not empty. Please see attached patch.
>
> > The second issue is where plperl returns a large result set.
I have attached the following seven patches to address this problem:
1. Trivial. Replaces some errant spaces with tabs.
2. Trivial. Fixes the spelling of Jan's name, and gets rid of many
inane, useless, annoying, and often misleading comments. Here's
a sample: "plperl_init_all() - Initialize all".
(I have tried to add some useful comments here and there, and will
continue to do so now and again.)
3. Trivial. Splits up some long lines.
4. Converts SRFs in PL/Perl to use a Tuplestore and SFRM_Materialize
to return the result set, based on the PL/PgSQL model.
There are two major consequences: result sets will spill to disk when
they can no longer fit in work_mem; and "select foo_srf()" no longer
works. (I didn't lose sleep over the latter, since that form is not
valid in PL/PgSQL, and it's not documented in PL/Perl.)
5. Trivial, but important. Fixes use of "undef" instead of undef. This
would cause empty functions to fail in bizarre ways. I suspect that
there's still another (old) bug here. I'll investigate further.
6. Moves the majority of (4) out into a new plperl_return_next()
function, to make it possible to expose the functionality to
Perl; cleans up some of the code besides.
7. Add an spi_return_next function for use in Perl code.
If you want to apply the patches and try them out, 8-composite.diff is
what you should use. (Note: my patches depend upon Andrew's use-strict
and %_SHARED patches being applied.)
Here's something to try:
create or replace function foo() returns setof record as $$
$i = 0;
for ("World", "PostgreSQL", "PL/Perl") {
spi_return_next({f1=>++$i, f2=>'Hello', f3=>$_});
}
return;
$$ language plperl;
select * from foo() as (f1 integer, f2 text, f3 text);
(Many thanks to Andrews Dunstan and Supernews for their help.)
Abhijit Menon-Sen
> a_ogawa <a_ogawa@hi-ho.ne.jp> writes:
> > It is a reasonable idea. However, the majority part of MemSet was not
> > able to be avoided by this idea. Because the per-tuple contexts are used
> > at the early stage of executor.
>
> Drat. Well, what about changing that? We could introduce additional
> contexts or change the startup behavior so that the ones that are
> frequently reset don't have any data in them unless you are working
> with pass-by-ref values inside the inner loop.
That might be possible. However, I think that we should change only
aset.c about this article.
I thought further: We can check whether context was used from the last
reset even when blocks list is not empty. Please see attached patch.
The effect of the patch that I measured is as follows:
o Execution time that executed the SQL ten times.
(1)Linux(CPU: Pentium III, Compiler option: -O2)
- original: 24.960s
- patched : 23.114s
(2)Linux(CPU: Pentium 4, Compiler option: -O2)
- original: 8.730s
- patched : 7.962s
(3)Solaris(CPU: Ultra SPARC III, Compiler option: -O2)
- original: 37.0s
- patched : 33.7s
Atsushi Ogawa (a_ogawa)
RTE of interest, rather than the whole rangetable list. This makes
the API more understandable and avoids duplicate RTE lookups. This
patch reverts no-longer-needed portions of my patch of 2004-08-19.
> * Allow pg_ctl to work properly with configuration files located outside
> the PGDATA directory
>
> pg_ctl can not read the pid file because it isn't located in the
> config directory but in the PGDATA directory. The solution is to
> allow pg_ctl to read and understand postgresql.conf to find the
> data_directory value.
>
performance problem pointed out by phil@vodafone: to wit, we were
spending O(N^2) time to check dropped-ness in an N-deep join tree,
even in the case where the tree was freshly constructed and couldn't
possibly mention any dropped columns. Instead of recursing in
get_rte_attribute_is_dropped(), change the data structure definition:
the joinaliasvars list of a JOIN RTE must have a NULL Const instead
of a Var at any position that references a now-dropped column. This
costs nothing during normal parse-rewrite-plan path, and instead we
have a linear-time update to make when loading a stored rule that
might contain now-dropped columns. While at it, move the responsibility
for acquring locks on relations referenced by rules into this separate
function (which I therefore chose to call AcquireRewriteLocks).
This saves effort --- namely, duplicated lock grabs in parser and rewriter
--- in the normal path at a cost of one extra non-locked heap_open()
in the stored-rule path; seems a good tradeoff. A fringe benefit is
that it is now *much* clearer that we acquire lock on relations referenced
in rules before we make any rewriter decisions based on their properties.
(I don't know of any bug of that ilk, but it wasn't exactly clear before.)
to just around the bare recv() call that gets a command from the client.
The former placement in PostgresMain was unsafe because the intermediate
processing layers (especially SSL) use facilities such as malloc that are
not necessarily re-entrant. Per report from counterstorm.com.
Instead of a separate CRC on each backup block, include backup blocks
in their parent WAL record's CRC; this is important to ensure that the
backup block really goes with the WAL record, ie there was not a page
tear right at the start of the backup block. Implement a simple form
of compression of backup blocks: drop any run of zeroes starting at
pd_lower, so as not to store the unused 'hole' that commonly exists in
PG heap and index pages. Tweak PageRepairFragmentation and related
routines to ensure they keep the unused space zeroed, so that the above
compression method remains effective. All per recent discussions.
Bruce Momjian