The SGML docs claimed that 1-byte integers could be sent or received with
the "isint" options, but no such behavior has ever been implemented in
pqGetInt() or pqPutInt(). The in-code documentation header for PQfn() was
even less in tune with reality, and the code itself used parameter names
matching neither the SGML docs nor its libpq-fe.h declaration. Do a bit
of additional wordsmithing on the SGML docs while at it.
Since the business about 1-byte integers is a clear documentation bug,
back-patch to all supported branches.
Since 9.1, we've provided extensions with a way to denote
"configuration" tables- tables created by an extension which the user
may modify. By marking these as "configuration" tables, the extension
is asking for the data in these tables to be pg_dump'd (tables which
are not marked in this way are assumed to be entirely handled during
CREATE EXTENSION and are not included at all in a pg_dump).
Unfortunately, pg_dump neglected to consider foreign key relationships
between extension configuration tables and therefore could end up
trying to reload the data in an order which would cause FK violations.
This patch teaches pg_dump about these dependencies, so that the data
dumped out is done so in the best order possible. Note that there's no
way to handle circular dependencies, but those have yet to be seen in
the wild.
The release notes for this should include a caution to users that
existing pg_dump-based backups may be invalid due to this issue. The
data is all there, but restoring from it will require extracting the
data for the configuration tables and then loading them in the correct
order by hand.
Discussed initially back in bug #6738, more recently brought up by
Gilles Darold, who provided an initial patch which was further reworked
by Michael Paquier. Further modifications and documentation updates
by me.
Back-patch to 9.1 where we added the concept of extension configuration
tables.
If libpq output buffer is full, pqSendSome() function tries to drain any
incoming data. This avoids deadlock, if the server e.g. sends a lot of
NOTICE messages, and blocks until we read them. However, pqSendSome() only
did that in blocking mode. In non-blocking mode, the deadlock could still
happen.
To fix, take a two-pronged approach:
1. Change the documentation to instruct that when PQflush() returns 1, you
should wait for both read- and write-ready, and call PQconsumeInput() if it
becomes read-ready. That fixes the deadlock, but applications are not going
to change overnight.
2. In pqSendSome(), drain the input buffer before returning 1. This
alleviates the problem for applications that only wait for write-ready. In
particular, a slow but steady stream of NOTICE messages during COPY FROM
STDIN will no longer cause a deadlock. The risk remains that the server
attempts to send a large burst of data and fills its output buffer, and at
the same time the client also sends enough data to fill its output buffer.
The application will deadlock if it goes to sleep, waiting for the socket
to become write-ready, before the server's data arrives. In practice,
NOTICE messages and such that the server might be sending are usually
short, so it's highly unlikely that the server would fill its output buffer
so quickly.
Backpatch to all supported versions.
In investigating yesterday's crash report from Hugo Osvaldo Barrera, I only
looked back as far as commit f3aec2c7f5 where the breakage occurred
(which is why I thought the IPv4-in-IPv6 business was undocumented). But
actually the logic dates back to commit 3c9bb8886d and was simply
broken by erroneous refactoring in the later commit. A bit of archives
excavation shows that we added the whole business in response to a report
that some 2003-era Linux kernels would report IPv4 connections as having
IPv4-in-IPv6 addresses. The fact that we've had no complaints since 9.0
seems to be sufficient confirmation that no modern kernels do that, so
let's just rip it all out rather than trying to fix it.
Do this in the back branches too, thus essentially deciding that our
effective behavior since 9.0 is correct. If there are any platforms on
which the kernel reports IPv4-in-IPv6 addresses as such, yesterday's fix
would have made for a subtle and potentially security-sensitive change in
the effective meaning of IPv4 pg_hba.conf entries, which does not seem like
a good thing to do in minor releases. So let's let the post-9.0 behavior
stand, and change the documentation to match it.
In passing, I failed to resist the temptation to wordsmith the description
of pg_hba.conf IPv4 and IPv6 address entries a bit. A lot of this text
hasn't been touched since we were IPv4-only.
When ecpg was rewritten to the new protocol version not all variable types
were corrected. This patch rewrites the code for these types to fix that. It
also fixes the documentation to correctly tell the status of array handling.
When beginning streaming replication, the client usually issues the
IDENTIFY_SYSTEM command, which used to return the current WAL insert
position. That's not suitable for the intended purpose of that field,
however. pg_receivexlog uses it to start replication from the reported
point, but if it hasn't been flushed to disk yet, it will fail. Change
IDENTIFY_SYSTEM to report the flush position instead.
Backpatch to 9.1 and above. 9.0 doesn't report any WAL position.
The previous wording claimed that the file was always in /etc, but of
course this varies with the installation layout. Write instead that it
can be found via `pg_config --sysconfdir`. Even though this is still
somewhat incorrect because it doesn't account of moved installations, it
at least conveys that the location depends on the installation.
"ECHO all" is ignored for interactive input, and has been for a very long
time, though possibly not for as long as the documentation has claimed the
opposite. Fix that, and also note that empty lines aren't echoed, which
while dubious is another longstanding behavior (it's embedded in our
regression test files for one thing). Per bug #12721 from Hans Ginzel.
In HEAD, also improve the code comments in this area, and suppress an
unnecessary fflush(stdout) when we're not echoing. That would likely
be safe to back-patch, but I'll not risk it mere hours before a release
wrap.
We've been trying to support \u0000 in JSON values since commit
78ed8e03c6, and have introduced increasingly worse hacks to try to
make it work, such as commit 0ad1a81632. However, it fundamentally
can't work in the way envisioned, because the stored representation looks
the same as for \\u0000 which is not the same thing at all. It's also
entirely bogus to output \u0000 when de-escaped output is called for.
The right way to do this would be to store an actual 0x00 byte, and then
throw error only if asked to produce de-escaped textual output. However,
getting to that point seems likely to take considerable work and may well
never be practical in the 9.4.x series.
To preserve our options for better behavior while getting rid of the nasty
side-effects of 0ad1a81632, revert that commit in toto and instead
throw error if \u0000 is used in a context where it needs to be de-escaped.
(These are the same contexts where non-ASCII Unicode escapes throw error
if the database encoding isn't UTF8, so this behavior is by no means
without precedent.)
In passing, make both the \u0000 case and the non-ASCII Unicode case report
ERRCODE_UNTRANSLATABLE_CHARACTER / "unsupported Unicode escape sequence"
rather than claiming there's something wrong with the input syntax.
Back-patch to 9.4, where we have to do something because 0ad1a81632
broke things for many cases having nothing to do with \u0000. 9.3 also has
bogus behavior, but only for that specific escape value, so given the lack
of field complaints it seems better to leave 9.3 alone.
At one point in the development of this feature, it was claimed that
allowing negative values would be useful to compensate for timezone
differences between master and slave servers. That was based on a mistaken
assumption that commit timestamps are recorded in local time; but of course
they're in UTC. Nor is a negative apply delay likely to be a sane way of
coping with server clock skew. However, the committed patch still treated
negative delays as doing something, and the timezone misapprehension
survived in the user documentation as well.
If recovery_min_apply_delay were a proper GUC we'd just set the minimum
allowed value to be zero; but for the moment it seems better to treat
negative settings as if they were zero.
In passing do some extra wordsmithing on the parameter's documentation,
including correcting a second misstatement that the parameter affects
processing of Restore Point records.
Issue noted by Michael Paquier, who also provided the code patch; doc
changes by me. Back-patch to 9.4 where the feature was introduced.
Use the phraseology "ISO 8601 week-numbering year" in place of just
"ISO year", and make related adjustments to other terminology.
The point of this change is that it seems some people see "ISO year"
and think "standard year", whereupon they're surprised when constructs
like to_char(..., "IYYY-MM-DD") produce nonsensical results. Perhaps
hanging a few more adjectives on it will discourage them from jumping
to false conclusions. I put in an explicit warning against that
specific usage, too, though the main point is to discourage people
who haven't read this far down the page.
In passing fix some nearby markup and terminology inconsistencies.
For simple boolean variables such as ON_ERROR_STOP, psql has for a long
time recognized variant spellings of "on" and "off" (such as "1"/"0"),
and it also made a point of warning you if you'd misspelled the setting.
But these conveniences did not exist for other keyword-valued variables.
In particular, though ECHO_HIDDEN and ON_ERROR_ROLLBACK include "on" and
"off" as possible values, none of the alternative spellings for those were
recognized; and to make matters worse the code would just silently assume
"on" was meant for any unrecognized spelling. Several people have reported
getting bitten by this, so let's fix it. In detail, this patch:
* Allows all spellings recognized by ParseVariableBool() for ECHO_HIDDEN
and ON_ERROR_ROLLBACK.
* Reports a warning for unrecognized values for COMP_KEYWORD_CASE, ECHO,
ECHO_HIDDEN, HISTCONTROL, ON_ERROR_ROLLBACK, and VERBOSITY.
* Recognizes all values for all these variables case-insensitively;
previously there was a mishmash of case-sensitive and case-insensitive
behaviors.
Back-patch to all supported branches. There is a small risk of breaking
existing scripts that were accidentally failing to malfunction; but the
consensus is that the chance of detecting real problems and preventing
future mistakes outweighs this.
Document the long forms of \H \i \ir \o \p \r \w ... apparently, we have
a long and dishonorable history of leaving out the unabbreviated names of
psql backslash commands.
Avoid saying "Unix shell"; we can just say "shell" with equal clarity,
and not leave Windows users wondering whether the feature works for them.
Improve consistency of documentation of \g \o \w metacommands. There's
no reason to use slightly different wording or markup for each one.
json_agg was originally designed to aggregate records. However, it soon
became clear that it is useful for aggregating all kinds of values and
that's what we have on 9.3 and 9.4, and in head for it and jsonb_agg.
The documentation suggested otherwise, so this fixes it.
Explain that you have to use "VARIADIC ARRAY[]" to pass an empty array
to a variadic parameter position. This was already implicit in the text
but it seems better to spell it out.
Per a suggestion from David Johnston, though I didn't use his proposed
wording. Back-patch to all supported branches.
The possibility that constant subexpressions of a CASE might be evaluated
at planning time was touched on in 9.17.1 (CASE expressions), but it really
ought to be explained in 4.2.14 (Expression Evaluation Rules) which is the
primary discussion of such topics. Add text and an example there, and
revise the <note> under CASE to link there.
Back-patch to all supported branches, since it's acted like this for a
long time (though 9.2+ is probably worse because of its more aggressive
use of constant-folding via replanning of nominally-prepared statements).
Pre-9.4, also back-patch text added in commit 0ce627d4 about CASE versus
aggregate functions.
Tom Lane and David Johnston, per discussion of bug #12273.
Use SSPI authentication to allow connections exclusively from the OS
user that launched the test suite. This closes on Windows the
vulnerability that commit be76a6d39e
closed on other platforms. Users of "make installcheck" or custom test
harnesses can run "pg_regress --config-auth=DATADIR" to activate the
same authentication configuration that "make check" would use.
Back-patch to 9.0 (all supported versions).
Security: CVE-2014-0067
The ALTER SYSTEM ref page hadn't been held to a very high standard, nor
was the feature well integrated into section 18.1 (parameter setting).
Also, though commit 4c4654afe had improved the structure of 18.1, it also
introduced a lot of poor wording, imprecision, and outright falsehoods.
Try to clean that up.
Commit 815d71dee hadn't bothered to update the documentation to match the
behavioral change, and a lot of other text in this section was badly in
need of copy-editing.
This reverts commit 9f80f4835a. The
function returned the raw value of a connection parameter, a task served
by PQconninfo(). The next commit will reimplement the psql \conninfo
change that way. Back-patch to 9.4, where that commit first appeared.
If the "dbname" attribute in PQconnectDBParams contained a connection string
or URI (and expand_dbname = TRUE), the database name from the connection
string could not be overridden by a subsequent "dbname" keyword in the
array. That was not intentional; all other options can be overridden.
Furthermore, any subsequent "dbname" caused the connection string from the
first dbname value to be processed again, overriding any values for the same
options that were given between the connection string and the second dbname
option.
In the passing, clarify in the docs that only the first dbname option in the
array is parsed as a connection string.
Alex Shulgin. Backpatch to all supported versions.
In bug #12000, Andreas Kunert complained that the documentation was
misleading in saying "FROM T1 CROSS JOIN T2 is equivalent to FROM T1, T2".
That's correct as far as it goes, but the equivalence doesn't hold when
you consider three or more tables, since JOIN binds more tightly than
comma. I added a <note> to explain this, and ended up rearranging some
of the existing text so that the note would make sense in context.
In passing, rewrite the description of JOIN USING, which was unnecessarily
vague, and hadn't been helped any by somebody's reliance on markup as a
substitute for clear writing. (Mostly this involved reintroducing a
concrete example that was unaccountably removed by commit 032f3b7e166cfa28.)
Back-patch to all supported branches.
The SELECT reference page didn't really address the question of when
aggregate function evaluation occurs, nor did the "expression evaluation
rules" documentation mention that CASE can't be used to control whether
an aggregate gets evaluated or not. Improve that.
Per discussion of bug #11661. Original text by Marti Raudsepp and Michael
Paquier, rewritten significantly by me.
When ALTER TABLESPACE MOVE ALL was changed to be ALTER TABLE ALL IN
TABLESPACE, the ALTER TABLESPACE summary should have been adjusted back
to its original definition.
Patch by Thom Brown (thanks!).
pgp_sym_encrypt's option is spelled "sess-key", not "enable-session-key".
Spotted by Jeff Janes.
In passing, improve a comment in pgp-pgsql.c to make it clearer that
the debugging options are intentionally undocumented.
