fail on zero-length inputs. This isn't an issue in normal use because the
conversion infrastructure skips calling the converters for empty strings.
However a problem was created by yesterday's patch to check whether the
right conversion function is supplied in CREATE CONVERSION. The most
future-proof fix seems to be to make the converters safe for this corner case.
input lists before we grovel through the lists. This doesn't save much,
but testing shows that the case of both inputs NIL is common enough that
it saves something. And this is used enough to be a hotspot.
to 100ms (from 1000). This still seems to be comfortably larger than the
useful range of the parameter, and it should help discourage people from
picking uselessly large values. Tweak the documentation to recommend small
values, too. Per discussion of a couple weeks ago.
the ON clause of an outer join. Doing so is semantically correct but results
in de-optimizing queries that were structured to take advantage of the sublink
style of execution, as seen in recent complaint from Kevin Grittner. Since
the user can get the other behavior by reorganizing his query, having the
flattening happen automatically is just a convenience, and that doesn't
justify breaking existing applications. Eventually it would be nice to
re-enable this, but that seems to require a significantly different approach
to outer joins in the executor.
function for the specified source and destination encodings. We do that by
calling the function with an empty string. If it can't perform the requested
conversion, it will throw an error.
Backport to 7.4 - 8.3. Per bug report #4680 by Denis Afonin.
missing.
Since this touches most lines of the help output, also change the mix of
puts and printf calls to printf everywhere, for easier code editing and
reviewing.
to be syntactically part of a semijoin clause. For example given
WHERE EXISTS(SELECT ... WHERE upper.var = lower.var AND some-condition)
where some-condition is just a restriction on the lower relation, we can
use unique-ification on lower.var after having applied some-condition within
the scan on lower.
been broken for more than a month, so evidently it's not needed, at
least not for any configuration in the buildfarm. We can correct it
and replace it later if we find something that still needs it.
looks for a CaseTestExpr to figure out what the parser did, but it failed to
consider the possibility that an implicit coercion might be inserted above
the CaseTestExpr. This could result in an Assert failure in some cases
(but correct results if Asserts weren't enabled), or an "unexpected CASE WHEN
clause" error in other cases. Per report from Alan Li.
Back-patch to 8.1; problem doesn't exist before that because CASE was
implemented differently.
making pull_up_sublinks() construct a full-blown JoinExpr tree representation
of IN/EXISTS SubLinks that it is able to convert to semi or anti joins.
This makes pull_up_sublinks() a shade more complex, but the gain in semantic
clarity is worth it. I still have more to do in this area to address the
previously-discussed problems, but this commit in itself fixes at least one
bug in HEAD, as shown by added regression test case.
wrappers (similar to procedural languages). This way we don't need to retain
the nearly empty libraries, and we are more free in how to implement the
wrapper API in the future.
TABLE: if the command is executed by someone other than the table owner (eg,
a superuser) and the table has a toast table, the toast table's pg_type row
ends up with the wrong typowner, ie, the command issuer not the table owner.
This is quite harmless for most purposes, since no interesting permissions
checks consult the pg_type row. However, it could lead to unexpected failures
if one later tries to drop the role that issued the command (in 8.1 or 8.2),
or strange warnings from pg_dump afterwards (in 8.3 and up, which will allow
the DROP ROLE because we don't create a "redundant" owner dependency for table
rowtypes). Problem identified by Cott Lang.
Back-patch to 8.1. The problem is actually far older --- the CLUSTER variant
can be demonstrated in 7.0 --- but it's mostly cosmetic before 8.1 because we
didn't track ownership dependencies before 8.1. Also, fixing it before 8.1
would require changing the call signature of heap_create_with_catalog(), which
seems to carry a nontrivial risk of breaking add-on modules.
IS NULL condition is rendered redundant by detection of an antijoin.
If we know that a join is an antijoin, then *any* Var coming out of its
righthand side must be NULL, not only the joining column(s). Also,
it's still gonna be null after being passed up through higher joins,
whether they're outer joins or not. I was misled by a faulty analogy
to reduce_outer_joins() in the original coding. But consider
select * from a left join b on a.x = b.y where b.y is null and b.z is null;
The first IS NULL condition justifies deciding that the join is an antijoin
(if the = is strict) and then the second one is just plain redundant.
selectively mark up their arguments for translation, the Perl xsubpp tool
generates a bunch of additional Perl_croak calls that we cannot control,
so we'd be creating a confusing mix of translated and untranslated messages
of a similar kind. This is something that might deserve a more
comprehensive solution later.
Also remove _ from gettext triggers, because it wasn't used.
Use SPI.c instead of SPI.xs as source file for xgettext, because the .xs
format isn't really supported in xgettext.
unary minus operators. We weren't attempting to prevent minus zero anywhere
else; in view of our gradual trend to make the float datatypes more IEEE
standard compliant, we should allow minus zero here rather than disallow it
elsewhere.
We don't, however, expect that all platforms will produce minus zero, so
we need to adjust the one affected regression test to allow both results.
Per discussion of bug #4660.
(In passing, clean up a couple other minor infelicities in float.c.)
its usual buffer cleaning duties during archive recovery, and it's responsible
for performing restartpoints.
This requires some changes in postmaster. When the startup process has done
all the initialization and is ready to start WAL redo, it signals the
postmaster to launch the background writer. The postmaster is signaled again
when the point in recovery is reached where we know that the database is in
consistent state. Postmaster isn't interested in that at the moment, but
that's the point where we could let other backends in to perform read-only
queries. The postmaster is signaled third time when the recovery has ended,
so that postmaster knows that it's safe to start accepting connections.
The startup process now traps SIGTERM, and performs a "clean" shutdown. If
you do a fast shutdown during recovery, a shutdown restartpoint is performed,
like a shutdown checkpoint, and postmaster kills the processes cleanly. You
still have to continue the recovery at next startup, though.
Currently, the background writer is only launched during archive recovery.
We could launch it during crash recovery as well, but it seems better to keep
that codepath as simple as possible, for the sake of robustness. And it
couldn't do any restartpoints during crash recovery anyway, so it wouldn't be
that useful.
log_restartpoints is gone. Use log_checkpoints instead. This is yet to be
documented.
This whole operation is a pre-requisite for Hot Standby, but has some value of
its own whether the hot standby patch makes 8.4 or not.
Simon Riggs, with lots of modifications by me.
Tom Lane