Regular aggregate functions in combination with, or within the arguments
of, window functions are OK per spec; they have the semantics that the
aggregate output rows are computed and then we run the window functions
over that row set. (Thus, this combination is not really useful unless
there's a GROUP BY so that more than one aggregate output row is possible.)
The case without GROUP BY could fail, as recently reported by Jeff Davis,
because sloppy construction of the Agg node's targetlist resulted in extra
references to possibly-ungrouped Vars appearing outside the aggregate
function calls themselves. See the added regression test case for an
example.
Fixing this requires modifying the API of flatten_tlist and its underlying
function pull_var_clause. I chose to make pull_var_clause's API for
aggregates identical to what it was already doing for placeholders, since
the useful behaviors turn out to be the same (error, report node as-is, or
recurse into it). I also tightened the error checking in this area a bit:
if it was ever valid to see an uplevel Var, Aggref, or PlaceHolderVar here,
that was a long time ago, so complain instead of ignoring them.
Backpatch into 9.1. The failure exists in 8.4 and 9.0 as well, but seeing
that it only occurs in a basically-useless corner case, it doesn't seem
worth the risks of changing a function API in a minor release. There might
be third-party code using pull_var_clause.
This enables us to test that blocking commands (such as foreign keys
checks that conflict with some other lock) act as intended. The set of
tests that this adds is pretty minimal, but can easily be extended by
adding new specs.
The intention is that this will serve as a basis for ensuring that
further tweaks of locking implementation preserve (or improve) existing
behavior.
Author: Noah Misch
The fields were previously wrongly typed as character_data; change to
cardinal_number. Update the documentation and the implementation to
show more clearly that this applies to a feature not available in
PostgreSQL, rather than just not yet being implemented in the
information schema.
In the previous coding, we would look up a relation in RangeVarGetRelid,
lock the resulting OID, and then AcceptInvalidationMessages(). While
this was sufficient to ensure that we noticed any changes to the
relation definition before building the relcache entry, it didn't
handle the possibility that the name we looked up no longer referenced
the same OID. This was particularly problematic in the case where a
table had been dropped and recreated: we'd latch on to the entry for
the old relation and fail later on. Now, we acquire the relation lock
inside RangeVarGetRelid, and retry the name lookup if we notice that
invalidation messages have been processed meanwhile. Many operations
that would previously have failed with an error in the presence of
concurrent DDL will now succeed.
There is a good deal of work remaining to be done here: many callers
of RangeVarGetRelid still pass NoLock for one reason or another. In
addition, nothing in this patch guards against the possibility that
the meaning of an unqualified name might change due to the creation
of a relation in a schema earlier in the user's search path than the
one where it was previously found. Furthermore, there's nothing at
all here to guard against similar race conditions for non-relations.
For all that, it's a start.
Noah Misch and Robert Haas
We were using GetConfigOption to collect the old value of each setting,
overlooking the possibility that it didn't exist yet. This does happen
in the case of adding a new entry within a custom variable class, as
exhibited in bug #6097 from Maxim Boguk.
To fix, add a missing_ok parameter to GetConfigOption, but only in 9.1
and HEAD --- it seems possible that some third-party code is using that
function, so changing its API in a minor release would cause problems.
In 9.0, create a near-duplicate function instead.
detect postmaster death. Postmaster keeps the write-end of the pipe open,
so when it dies, children get EOF in the read-end. That can conveniently
be waited for in select(), which allows eliminating some of the polling
loops that check for postmaster death. This patch doesn't yet change all
the loops to use the new mechanism, expect a follow-on patch to do that.
This changes the interface to WaitLatch, so that it takes as argument a
bitmask of events that it waits for. Possible events are latch set, timeout,
postmaster death, and socket becoming readable or writeable.
The pipe method behaves slightly differently from the kill() method
previously used in PostmasterIsAlive() in the case that postmaster has died,
but its parent has not yet read its exit code with waitpid(). The pipe
returns EOF as soon as the process dies, but kill() continues to return
true until waitpid() has been called (IOW while the process is a zombie).
Because of that, change PostmasterIsAlive() to use the pipe too, otherwise
WaitLatch() would return immediately with WL_POSTMASTER_DEATH, while
PostmasterIsAlive() would claim it's still alive. That could easily lead to
busy-waiting while postmaster is in zombie state.
Peter Geoghegan with further changes by me, reviewed by Fujii Masao and
Florian Pflug.
on the finished list, and we shouldn't flag it as a potential conflict
if so. We can also skip adding a doomed transaction to the list of
possible conflicts because we know it won't commit.
Dan Ports and Kevin Grittner.
transactions might not match the order the work done in those transactions
become visible to others. The logic in SSI, however, assumed that it does.
Fix that by having two sequence numbers for each serializable transaction,
one taken before a transaction becomes visible to others, and one after it.
This is easier than trying to make the the transition totally atomic, which
would require holding ProcArrayLock and SerializableXactHashLock at the same
time. By using prepareSeqNo instead of commitSeqNo in a few places where
commit sequence numbers are compared, we can make those comparisons err on
the safe side when we don't know for sure which committed first.
Per analysis by Kevin Grittner and Dan Ports, but this approach to fix it
is different from the original patch.
Per discussion, this structure seems more understandable than what was
there before. Make config.sgml and postgresql.conf.sample agree.
In passing do a bit of editorial work on the variable descriptions.
The value when BLCKSZ = 8192 is unchanged, but with larger-than-normal
block sizes we might need to crank things back a bit, as we'll have
more entries per page than normal in that case.
Kevin Grittner
If there's a dangerous structure T0 ---> T1 ---> T2, and T2 commits first,
we need to abort something. If T2 commits before both conflicts appear,
then it should be caught by OnConflict_CheckForSerializationFailure. If
both conflicts appear before T2 commits, it should be caught by
PreCommit_CheckForSerializationFailure. But that is actually run when
T2 *prepares*. Fix that in OnConflict_CheckForSerializationFailure, by
treating a prepared T2 as if it committed already.
This is mostly a problem for prepared transactions, which are in prepared
state for some time, but also for regular transactions because they also go
through the prepared state in the SSI code for a short moment when they're
committed.
Kevin Grittner and Dan Ports
In the process, remove almost all knowledge of individual .y and .l files,
and instead get invocation settings from the relevant make files.
The exception is plpgsql's gram.y, which has a target with a different
name. It is hoped that this will make the scripts more future-proof,
so that they won't require adjustment every time we add a new .l or .y
file.
The logic is also notably less tortured than that forced on us
by the idiosyncrasies of the Windows command processor.
The .bat files are kept as thin wrappers for the perl scripts.
get_op_btree_interpretation assumed this in order to save some duplication
of code, but it's not true in general anymore because we added <> support
to btree_gist. (We still assume it for btree opclasses, though.)
Also, essentially the same logic was baked into predtest.c. Get rid of
that duplication by generalizing get_op_btree_interpretation so that it
can be used by predtest.c.
Per bug report from Denis de Bernardy and investigation by Jeff Davis,
though I didn't use Jeff's patch exactly as-is.
Back-patch to 9.1; we do not support this usage before that.
\ir is short for "include relative"; when used from a script, the
supplied pathname will be interpreted relative to the input file,
rather than to the current working directory.
Gurjeet Singh, reviewed by Josh Kupershmidt, with substantial further
cleanup by me.
Most queries end with a backslash, but not a newline, so try to
standardize on that, for the convenience of people using psql -E to
extract queries.
Josh Kupershmidt, reviewed by Merlin Moncure.
This is useful since a validator might want to require certain options
to be provided. The passed array is an empty text array in this case.
Per suggestion by Laurenz Albe, though this is not quite his patch.
handleCopyIn incremented pset.lineno for each line of COPY data read from
a file. This is correct when reading from the current script file (i.e.,
we are doing COPY FROM STDIN followed by in-line data), but it's wrong if
the data is coming from some other file. Per bug #6083 from Steve Haslam.
Back-patch to all supported versions.
The bug that caused this to be discovered is that the code was trying to
dereference a NULL or ill-defined pointer, as reported by Michael Mueller;
but what it was doing was wrong anyway, per Heikki.
This patch is Heikki's suggested fix.
postmaster.log", or nohup.
There was a small issue with LINUX_OOM_ADJ and silent_mode, namely that with
silent_mode the postmaster process incorrectly used the OOM settings meant
for backend processes. We certainly could've fixed that directly, but since
silent_mode was redundant anyway, we might as well just remove it.
Unlike the relistemp field which it replaced, relpersistence must be
set correctly quite early during the table creation process, as we
rely on it quite early on for a number of purposes, including security
checks. Normally, this is set based on whether the user enters CREATE
TABLE, CREATE UNLOGGED TABLE, or CREATE TEMPORARY TABLE, but a
relation may also be made implicitly temporary by creating it in
pg_temp. This patch fixes the handling of that case, and also
disables creation of unlogged tables in temporary tablespace (such
table indeed skip WAL-logging, but we reject an explicit
specification) and creation of relations in the temporary schemas of
other sessions (which is not very sensible, and didn't work right
anyway).
Report by Amit Khandekar.
Certain subdirectories do not get built if corresponding options are not
selected at configure time. However, "make distprep" should visit such
directories anyway, so that constructing derived files to be included in
the tarball happens without requiring all configure options to be given
in the tarball build script. Likewise, it's better if cleanup actions
unconditionally visit all directories (for example, this ensures proper
cleanup if someone has done a manual make in such a subdirectory).
To handle this, set up a convention that subdirectories that are
conditionally included in SUBDIRS should be added to ALWAYS_SUBDIRS
instead when they are excluded.
Back-patch to 9.1, so that plpython's spiexceptions.h will get provided
in 9.1 tarballs. There don't appear to be any instances where distprep
actions got missed in previous releases, and anyway this fix requires
gmake 3.80 so we don't want to apply it before 9.1.
This is the proper fix for bug #6082 about
pg_stat_reset_shared(NULL) causing a crash, and it reverts
commit 79aa44536f on head.
The workaround of throwing an error from inside the function is
left on backbranches (including 9.1) since this change requires
a new initdb.
This means that they can initially be added to a large existing table
without checking its initial contents, but new tuples must comply to
them; a separate pass invoked by ALTER TABLE / VALIDATE can verify
existing data and ensure it complies with the constraint, at which point
it is marked validated and becomes a normal part of the table ecosystem.
An non-validated CHECK constraint is ignored in the planner for
constraint_exclusion purposes; when validated, cached plans are
recomputed so that partitioning starts working right away.
This patch also enables domains to have unvalidated CHECK constraints
attached to them as well by way of ALTER DOMAIN / ADD CONSTRAINT / NOT
VALID, which can later be validated with ALTER DOMAIN / VALIDATE
CONSTRAINT.
Thanks to Thom Brown, Dean Rasheed and Jaime Casanova for the various
reviews, and Robert Hass for documentation wording improvement
suggestions.
This patch was sponsored by Enova Financial.
Such a condition is unsatisfiable in combination with any other type of
btree-indexable condition (since we assume btree operators are always
strict). 8.3 and 8.4 had an explicit test for this, which I removed in
commit 29c4ad9829, mistakenly thinking that
the case would be subsumed by the more general handling of IS (NOT) NULL
added in that patch. Put it back, and improve the comments about it, and
add a regression test case.
Per bug #6079 from Renat Nasyrov, and analysis by Dean Rasheed.
more consistent that way, since all the other PredicateLock* calls are
made in various heapam.c and index AM functions. The call in nodeSeqscan.c
was unnecessarily aggressive anyway, there's no need to try to lock the
relation every time a tuple is fetched, it's enough to do it once.
This has the user-visible effect that if a seq scan is initialized in the
executor, but never executed, we now acquire the predicate lock on the heap
relation anyway. We could avoid that by taking the lock on the first
heap_getnext() call instead, but it doesn't seem worth the trouble given
that it feels more natural to do it in heap_beginscan().
Also, remove the retail PredicateLockTuple() calls from heap_getnext(). In
a seqscan, started with heap_begin(), we're holding a whole-relation
predicate lock on the heap so there's no need to lock the tuples
individually.
Kevin Grittner and me
XLOG_XACT_COMMIT_COMPACT leaves out invalidation messages and relfilenodes,
saving considerable space for the vast majority of transaction commits.
XLOG_XACT_COMMIT keeps same definition as XLOG_PAGE_MAGIC 0xD067 and earlier.
Leonardo Francalanci and Simon Riggs
Peter Eisentraut