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.
This makes it possible to query for things like the SSL version and cipher
used, without depending on OpenSSL functions or macros. That is a good
thing if we ever get another SSL implementation.
PQgetssl() still works, but it should be considered as deprecated as it
only works with OpenSSL. In particular, PQgetSslInUse() should be used to
check if a connection uses SSL, because as soon as we have another
implementation, PQgetssl() will return NULL even if SSL is in use.
Sometimes it's useful for a background worker to be able to initialize
its database connection by OID rather than by name, so provide a way
to do that.
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.
As usual, the release notes for older branches will be made by cutting
these down, but put them up for community review first.
Note: a significant fraction of these items don't apply to 9.4.1, only to
older branches, because the fixes already appeared in 9.4.0. These can be
distinguished by noting the branch commits in the associated SGML comments.
This will be adjusted tomorrow while copying items into the older
release-X.Y.sgml files. In a few cases I've made two separate entries with
different wordings for 9.4 than for the equivalent commits in the older
branches.
In ALTER POLICY, use 'check_expression' instead of 'expression' for the
parameter, to match up with the recent CREATE POLICY change.
In CREATE POLICY, frame the discussion as granting access to rows
instead of limiting access to rows. Further, clarify that the
expression must return true for rows to be visible/allowed and that a
false or NULL result will mean the row is not visible/allowed.
Per discussion with Dean Rasheed and Robert.
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.
The parameter description for the using_expression and check_expression
in CREATE POLICY were unclear and arguably included a typo. Clarify
and improve the consistency of that language.
Pointed out by Dean Rasheed.
The syntax for CREATE POLICY simply used "expression" for the USING
expression, while the WITH CHECK expression was "check_expression".
Given that we have two expressions, it's sensible to explcitly name both
to maintain clarity.
This patch simply changes the generic "expression" to be
"using_expression".
Pointed out by Peter Geoghegan.
The CREATE POLICY documention didn't sufficiently clarify what happens
when a given command type (eg: ALL or UPDATE) accepts both USING and
WITH CHECK clauses, but only the USING clause is defined. Add language
to clarify that, in such a case, the USING clause will be used for both
USING and WITH CHECK cases.
Pointed out by Peter Geoghegan.
The row level security patches didn't add the 'usebypassrls' columns to
the pg_user and pg_shadow views on the belief that they were deprecated,
but we havn't actually said they are and therefore we should include it.
This patch corrects that, adds missing documentation for rolbypassrls
into the system catalog page for pg_authid, along with the entries for
pg_user and pg_shadow, and cleans up a few other uses of 'row-level'
cases to be 'row level' in the docs.
Pointed out by Amit Kapila.
Catalog version bump due to system view changes.
gist_poly_compress() and gist_circle_compress() checked for a NULL-pointer
key argument, but that was dead code; the gist code never passes a
NULL-pointer to the "compress" method.
This commit also removes a documentation note added in commit a0a3883,
about doing NULL-pointer checks in the "compress" method. It was added
based on the fact that some implementations were doing NULL-pointer
checks, but those checks were unnecessary in the first place.
The NULL-pointer check in gbt_var_same() function was also unnecessary.
The arguments to the "same" method come from the "compress", "union", or
"picksplit" methods, but none of them return a NULL pointer.
None of this is to be confused with SQL NULL values. Those are dealt with
by the gist machinery, and are never passed to the GiST opclass methods.
Michael Paquier
Fix unsafe coding around PG_TRY in RelationBuildRowSecurity: can't change
a variable inside PG_TRY and then use it in PG_CATCH without marking it
"volatile". In this case though it seems saner to avoid that by doing
a single assignment before entering the TRY block.
I started out just intending to fix that, but the more I looked at the
row-security code the more distressed I got. This patch also fixes
incorrect construction of the RowSecurityPolicy cache entries (there was
not sufficient care taken to copy pass-by-ref data into the cache memory
context) and a whole bunch of sloppiness around the definition and use of
pg_policy.polcmd. You can't use nulls in that column because initdb will
mark it NOT NULL --- and I see no particular reason why a null entry would
be a good idea anyway, so changing initdb's behavior is not the right
answer. The internal value of '\0' wouldn't be suitable in a "char" column
either, so after a bit of thought I settled on using '*' to represent ALL.
Chasing those changes down also revealed that somebody wasn't paying
attention to what the underlying values of ACL_UPDATE_CHR etc really were,
and there was a great deal of lackadaiscalness in the catalogs.sgml
documentation for pg_policy and pg_policies too.
This doesn't pretend to be a complete code review for the row-security
stuff, it just fixes the things that were in my face while dealing with
the bugs in RelationBuildRowSecurity.
This mode allows vacuumdb to open several server connections to vacuum
or analyze several tables simultaneously.
Author: Dilip Kumar. Some reworking by Álvaro Herrera
Reviewed by: Jeff Janes, Amit Kapila, Magnus Hagander, Andres Freund
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.
These columns can be passed to pg_get_object_address() and used to
reconstruct the dropped objects identities in a remote server containing
similar objects, so that the drop can be replicated.
Reviewed by Stephen Frost, Heikki Linnakangas, Abhijit Menon-Sen, Andres
Freund.
This function returns object type and objname/objargs arrays, which can
be passed to pg_get_object_address. This is especially useful because
the textual representation can be copied to a remote server in order to
obtain the corresponding OID-based address. In essence, this function
is the inverse of recently added pg_get_object_address().
Catalog version bumped due to the addition of the new function.
Also add docs to pg_get_object_address.
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.
This reverts commit 1826987a46.
The overall design was deemed unacceptable, in discussion following the
previous commit message; we might find some parts of it still
salvageable, but I don't want to be on the hook for fixing it, so let's
wait until we have a new patch.
The previous representation using a boolean column for each attribute
would not scale as well as we want to add further attributes.
Extra auxilliary functions are added to go along with this change, to
make up for the lost convenience of access of the old representation.
Catalog version bumped due to change in catalogs and the new functions.
Author: Adam Brightwell, minor tweaks by Álvaro
Reviewed by: Stephen Frost, Andres Freund, Álvaro Herrera
Apart from enabling comments on domain constraints, this enables a
future project to replicate object dropping to remote servers: with the
current mechanism there's no way to distinguish between the two types of
constraints, so there's no way to know what to drop.
Also added support for the domain constraint comments in psql's \dd and
pg_dump.
Catalog version bumped due to the change in ObjectType enum.
This allows it to be used with ALTER ROLE SET.
Although the old setting of PGC_BACKEND prevented changes after session
start, after discussion it was more useful to allow ALTER ROLE SET
instead and just document that changes during a session have no effect.
This is similar to how session_preload_libraries works already.
An alternative would be to change things to allow PGC_BACKEND and
PGC_SU_BACKEND settings to be changed by ALTER ROLE SET. But that might
need further research (e.g., log_connections would probably not work).
based on patch by Kyotaro Horiguchi
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.
Add "normal" and "original" flags as output columns to the
pg_event_trigger_dropped_objects() function. With this it's possible to
distinguish which objects, among those listed, need to be explicitely
referenced when trying to replicate a deletion.
This is necessary so that the list of objects can be pruned to the
minimum necessary to replicate the DROP command in a remote server that
might have slightly different schema (for instance, TOAST tables and
constraints with different names and such.)
Catalog version bumped due to change of function definition.
Reviewed by: Abhijit Menon-Sen, Stephen Frost, Heikki Linnakangas,
Robert Haas.
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.
