Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
handy to prevent core dump files from disappearing, but it's useless now
because (a) we don't drop core in individual DB subdirectories anymore,
and (b) CREATE DATABASE forces an internal checkpoint anyway.
Fix all the standard PLs to be able to return tuples from FOO_RETURNING
statements as well as utility statements that return tuples. Also,
fix oversight that SPI_processed wasn't set for a utility statement
returning tuples. Per recent discussion.
loaded libraries: call functions _PG_init() and _PG_fini() if the library
defines such symbols. Hence we no longer need to specify an initialization
function in preload_libraries: we can assume that the library used the
_PG_init() convention, instead. This removes one source of pilot error
in use of preloaded libraries. Original patch by Ralf Engelschall,
preload_libraries changes by me.
pg_regress: there's no other way to cope with testing a relocated
installation. Seems better to call it --psqldir though, since the
only thing we need to find in that case is psql. It'd be better if
we could use find_other_exec, but that's not happening unless we are
willing to install pg_regress alongside psql, which seems unlikely
to happen.
This allows it to be used on Windows without installing mingw
(though you do still need 'diff'), and opens the door to future
improvements such as message localization.
Magnus Hagander and Tom Lane.
by creating a reference-count mechanism, similar to what we did a long time
ago for catcache entries. The back branches have an ugly solution involving
lots of extra copies, but this way is more efficient. Reference counting is
only applied to tupdescs that are actually in caches --- there seems no need
to use it for tupdescs that are generated in the executor, since they'll go
away during plan shutdown by virtue of being in the per-query memory context.
Neil Conway and Tom Lane
kept but now deprecated. Patch from Adam Sjøgren. Add regression test to
show plperl trigger data (Andrew).
TBD: apply similar changes to plpgsql, plpython and pltcl.
functions are not strict, they will be called (passing a NULL first parameter)
during any attempt to input a NULL value of their datatype. Currently, all
our input functions are strict and so this commit does not change any
behavior. However, this will make it possible to build domain input functions
that centralize checking of domain constraints, thereby closing numerous holes
in our domain support, as per previous discussion.
While at it, I took the opportunity to introduce convenience functions
InputFunctionCall, OutputFunctionCall, etc to use in code that calls I/O
functions. This eliminates a lot of grotty-looking casts, but the main
motivation is to make it easier to grep for these places if we ever need
to touch them again.
during parse analysis, not only errors detected in the flex/bison stages.
This is per my earlier proposal. This commit includes all the basic
infrastructure, but locations are only tracked and reported for errors
involving column references, function calls, and operators. More could
be done later but this seems like a good set to start with. I've also
moved the ReportSyntaxErrorPosition logic out of psql and into libpq,
which should make it available to more people --- even within psql this
is an improvement because warnings weren't handled by ReportSyntaxErrorPosition.
memory in the executor's per-query memory context. It also inefficient:
it invokes get_call_result_type() and TupleDescGetAttInMetadata() for
every call to return_next, rather than invoking them once (per PL/Perl
function call) and memoizing the result.
This patch makes the following changes:
- refactor the code to include all the "per PL/Perl function call" data
inside a single struct, "current_call_data". This means we don't need to
save and restore N pointers for every recursive call into PL/Perl, we
can just save and restore one.
- lookup the return type metadata needed by plperl_return_next() once,
and then stash it in "current_call_data", so as to avoid doing the
lookup for every call to return_next.
- create a temporary memory context in which to evaluate the return
type's input functions. This memory context is reset for each call to
return_next.
The patch appears to fix the memory leak, and substantially reduces
the overhead imposed by return_next.
comment line where output as too long, and update typedefs for /lib
directory. Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).
Backpatch to 8.1.X.
return arays nicely without having to make the plperl programmer aware
of anything. The attached patch allows plperl to return an arrayref
where the function returns an array type. It silently calls a perl
function to stringify the array before passing it to the pg array
parser. Non-array returns are handled as before (i.e. passed through
this process) so it is backwards compatible. I will presently submit
regression tests and docs.
example:
andrew=# create or replace function blah() returns text[][] language
plperl as $$ return [['a"b','c,d'],['e\\f','g']]; $$;
CREATE FUNCTION
andrew=# select blah();
blah
-----------------------------
{{"a\"b","c,d"},{"e\\f",g}}
This would complete half of the TODO item:
. Pass arrays natively instead of as text between plperl and postgres
(The other half is translating pg array arguments to perl arrays - that
will have to wait for 8.1).
Some of this patch is adapted from a previously submitted patch from
Sergej Sergeev. Both he and Abhijit Menon-Sen have looked it over
briefly and tentatively said it looks ok.
Andrew Dunstan
for PL/Perl, to avoid loading the entire result set into memory as the
existing spi_exec_query() function does.
Here's how one might use the new functions:
$x = spi_query("select ...");
while (defined ($y = spi_fetchrow($x))) {
...
return_next(...);
}
The changes do not affect the spi_exec_query() interface in any way.
Abhijit Menon-Sen
plperl - the attached small patch remedies that omission, and adds a
small regression test for error and warning output - the new regression
input and expected output are in separate attached files.
Andrew Dunstan
> against rc1. It simply checks with GetDatabaseEncoding() if the current
> database is in UTF-8, and if so, sets the UTF-8 flag on the arguments
> that are passed to perl. This means that it isn't necessary to
> utf8::upgrade() every string, as perl has no way of knowing offhand
> that a string is UTF-8 -- but postgres does, because the database
> encoding is specified, so it makes sense to turn the flag on. You
> should also be able to properly manipulate UTF-8 strings now from
> plperl as opposed to plperlu, because otherwise you'd have to use
> encoding 'utf8' which was not allowed. It could also eliminate some
> unexpected bugs if you assume that perl knows the string is unicode.
It
> is enabled only for perl 5.6 and higher, so earlier versions will not
> be affected.
>
> I have been assured by crab that the patch is quite harmless and will
> not break anything. It would be great to see it in 8 final! :-)
David Kamholz
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
>
> > 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
for testing PLs and contrib_regression for testing contrib, instead of
overwriting the core system's regression database as formerly done.
Andrew Dunstan
which is neither needed by nor related to that header. Remove the bogus
inclusion and instead include the header in those C files that actually
need it. Also fix unnecessary inclusions and bad inclusion order in
tsearch2 files.
only one argument. (Per recent discussion, the option to accept multiple
arguments is pretty useless for user-defined types, and would be a likely
source of security holes if it was used.) Simplify call sites of
output/send functions to not bother passing more than one argument.
change saves a great deal of space in pg_proc and its primary index,
and it eliminates the former requirement that INDEX_MAX_KEYS and
FUNC_MAX_ARGS have the same value. INDEX_MAX_KEYS is still embedded
in the on-disk representation (because it affects index tuple header
size), but FUNC_MAX_ARGS is not. I believe it would now be possible
to increase FUNC_MAX_ARGS at little cost, but haven't experimented yet.
There are still a lot of vestigial references to FUNC_MAX_ARGS, which
I will clean up in a separate pass. However, getting rid of it
altogether would require changing the FunctionCallInfoData struct,
and I'm not sure I want to buy into that.
data returned from Perl. Consolidate multiple bits of code to convert
a Perl hash to a tuple, and drive the conversion off the keys present
in the hash rather than the tuple column names, so we detect error if
the hash contains keys it shouldn't. (This means keys not in the hash
will silently default to NULL, which seems ok to me.) Fix a bunch of
reference-count leaks too.
operations are now run as subtransactions, so that errors in them
can be reported as ordinary Perl or Tcl errors and caught by the
normal error handling convention of those languages. Also do some
minor code cleanup in pltcl.c: extract a large chunk of duplicated
code in pltcl_SPI_execute and pltcl_SPI_execute_plan into a shared
subroutine.
rather than longjmp'ing clear out of Perl and thereby leaving Perl in
a broken state. Also some minor prettification of error messages.
Still need to do something with spi_exec_query() error handling.
for the languages even when not installed in a standard directory.
pltcl may need this treatment as well, but we don't have the right path
conveniently available, so I'll leave it alone as long as there aren't
actual reports of trouble.
may expand the Perl stack, therefore we must SPAGAIN to reload the local
stack pointer after calling it. Also a couple other marginal readability
improvements.
some of the bugs exposed thereby. The remaining 'might be used uninitialized'
warnings look like live bugs, but I am not familiar enough with Perl/C hacking
to tell how to fix them.
1. Two minor cleanups:
- We don't need to call hv_exists+hv_fetch; we should just check the
return value of hv_fetch.
- newSVpv("undef",0) is the string "undef", not a real undef.
2. This should fix the bug Andrew Dunstan described in a recent -hackers
post. It replaces three bogus "eval_pv(key, 0)" calls with newSVpv,
and eliminates another redundant hv_exists+hv_fetch pair.
3. plperl_build_tuple_argument builds up a string of Perl code to create
a hash representing the tuple. This patch creates the hash directly.
4. Another minor cleanup: replace a couple of av_store()s with av_push.
5. Analogous to #3 for plperl_trigger_build_args. This patch removes the
static sv_add_tuple_value function, which does much the same as two
other utility functions defined later, and merges the functionality
into plperl_hash_from_tuple.
I have tested the patches to the best of my limited ability, but I would
appreciate it very much if someone else could review and test them too.
(Thanks to Andrew and David Fetter for their help with some testing.)
Abhijit Menon-Sen
mode see a fresh snapshot for each command in the function, rather than
using the latest interactive command's snapshot. Also, suppress fresh
snapshots as well as CommandCounterIncrement inside STABLE and IMMUTABLE
functions, instead using the snapshot taken for the most closely nested
regular query. (This behavior is only sane for read-only functions, so
the patch also enforces that such functions contain only SELECT commands.)
As per my proposal of 6-Sep-2004; I note that I floated essentially the
same proposal on 19-Jun-2002, but that discussion tailed off without any
action. Since 8.0 seems like the right place to be taking possibly
nontrivial backwards compatibility hits, let's get it done now.
Create a shared function to convert a SPI error code into a string
(replacing near-duplicate code in several PLs), and use it anywhere
that a SPI function call error is reported.
possible to trap an error inside a function rather than letting it
propagate out to PostgresMain. You still have to use AbortCurrentTransaction
to clean up, but at least the error handling itself will cooperate.
