When running a repeat query with \watch in psql, it can be
helpful to be able to stop the watch process when the query
no longer returns the expected amount of rows. An example
would be to watch for the presence of a certain event in
pg_stat_activity and stopping when the event is no longer
present, or to watch an index creation and stop when the
index is created.
This adds a min_rows=MIN parameter to \watch which can be
set to a non-negative integer, and the watch query will
stop executing when it returns less than MIN rows.
Author: Greg Sabino Mullane <htamfids@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/CAKAnmmKStATuddYxP71L+p0DHtp9Rvjze3XRoy0Dyw67VQ45UA@mail.gmail.com
With the addition of INHERIT and SET options for role grants,
the historical display of role memberships in \du/\dg is woefully
inadequate. Besides those options, there are pre-existing
shortcomings that you can't see the ADMIN option nor the grantor.
To fix this, remove the "Member of" column from \du/\dg altogether
(making that output usefully narrower), and invent a new meta-command
"\drg" that is specifically for displaying role memberships. It
shows one row for each role granted to the selected role(s), with
the grant options and grantor.
We would not normally back-patch such a feature addition post
feature freeze, but in this case the change is mainly driven by
v16 changes in the server, so it seems appropriate to include it
in v16.
Pavel Luzanov, with bikeshedding and review from a lot of people,
but particularly David Johnston
Discussion: https://postgr.es/m/b9be2d0e-a9bc-0a30-492f-a4f68e4f7740@postgrespro.ru
\watch can now be told to stop after N executions of the query.
With the idea that we might want to add more options to \watch
in future, this patch generalizes the command's syntax to a list
of name=value options, with the interval allowed to omit the name
for backwards compatibility.
Andrey Borodin, reviewed by Kyotaro Horiguchi, Nathan Bossart,
Michael Paquier, Yugo Nagata, and myself
Discussion: https://postgr.es/m/CAAhFRxiZ2-n_L1ErMm9AZjgmUK=qS6VHb+0SaMn8sqqbhF7How@mail.gmail.com
These are set after a \! command or a backtick substitution.
SHELL_ERROR is just "true" for error (nonzero exit status) or "false"
for success, while SHELL_EXIT_CODE records the actual exit status
following standard shell/system(3) conventions.
Corey Huinker, reviewed by Maxim Orlov and myself
Discussion: https://postgr.es/m/CADkLM=cWao2x2f+UDw15W1JkVFr_bsxfstw=NGea7r9m4j-7rQ@mail.gmail.com
This adds a new psql command \bind that sets query parameters and
causes the next query to be sent using the extended query protocol.
Example:
SELECT $1, $2 \bind 'foo' 'bar' \g
This may be useful for psql scripting, but one of the main purposes is
also to be able to test various aspects of the extended query protocol
from psql and to write tests more easily.
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/e8dd1cd5-0e04-3598-0518-a605159fe314@enterprisedb.com
The hard-wired PageOutput arguments in usage() and sibling functions
have been a perennial maintenance gotcha, and there's no reason to
think we'll ever get any better about that. Let's get rid of those
magic constants by constructing the output in a buffer where we can
count the newlines before calling PageOutput. (Perhaps this is
microscopically slower; but none of these functions are performance
critical, and anyway we might well be buying back all the cost by
avoiding having to pass most of the data through snprintf.c. I could
not detect any speed difference in a desultory check.) This also
gets rid of the need to assume that platform-specific variations in
the output are insignificant.
While at it, make the code shorter and more abstract by inventing
helper macros HELP0() and HELPN() to encapsulate the specific
output actions being invoked.
Discussion: https://postgr.es/m/365160.1654289490@sss.pgh.pa.us
Provide a gloss of which command does what, as all other backslash
commands have. Put the large-object command section into a more
considered spot in the list.
In passing, update the output-lines count in helpVariables()
(oversight in 7844c9918, looks like).
Thibaud Walkowiak, reviewed by Nathan Bossart and myself
Discussion: https://postgr.es/m/43f0439c-df3e-a045-ac99-af33523cc2d4@dalibo.com
Get rid of the separate "FATAL" log level, as it was applied
so inconsistently as to be meaningless. This mostly involves
s/pg_log_fatal/pg_log_error/g.
Create a macro pg_fatal() to handle the common use-case of
pg_log_error() immediately followed by exit(1). Various
modules had already invented either this or equivalent macros;
standardize on pg_fatal() and apply it where possible.
Invent the ability to add "detail" and "hint" messages to a
frontend message, much as we have long had in the backend.
Except where rewording was needed to convert existing coding
to detail/hint style, I have (mostly) resisted the temptation
to change existing message wording.
Patch by me. Design and patch reviewed at various stages by
Robert Haas, Kyotaro Horiguchi, Peter Eisentraut and
Daniel Gustafsson.
Discussion: https://postgr.es/m/1363732.1636496441@sss.pgh.pa.us
Plain \dconfig is basically equivalent to SHOW except that you can
give it a pattern with wildcards, either to match multiple GUCs or
because you don't exactly remember the name you want.
\dconfig+ adds type, context, and access-privilege information,
mainly because every other kind of object privilege has a psql command
to show it, so GUC privileges should too. (A form of this command was
in some versions of the patch series leading up to commit a0ffa885e.
We pulled it out then because of doubts that the design and code were
up to snuff, but I think subsequent work has resolved that.)
In passing, fix incorrect completion of GUC names in GRANT/REVOKE
ON PARAMETER: a0ffa885e neglected to use the VERBATIM form of
COMPLETE_WITH_QUERY, so it misbehaved for custom (qualified) GUC
names.
Mark Dilger and Tom Lane
Discussion: https://postgr.es/m/3118455.1649267333@sss.pgh.pa.us
The ACL is printed when you add + to the command, similarly to
various other psql backslash commands.
Along the way, move the code for this into describe.c,
where it is a better fit (and can share some code).
Pavel Luzanov, reviewed by Georgios Kokolatos
Discussion: https://postgr.es/m/6d722115-6297-bc53-bb7f-5f150e765299@postgrespro.ru
Allow a pager to be used by the \watch command. This works but isn't
very useful with traditional pagers like "less", so use a different
environment variable. The popular open source tool "pspg" (also by
Pavel) knows how to display the output if you set PSQL_WATCH_PAGER="pspg
--stream".
To make \watch react quickly when the user quits the pager or presses
^C, and also to increase the accuracy of its timing and decrease the
rate of useless context switches, change the main loop of the \watch
command to use sigwait() rather than a sleeping/polling loop, on Unix.
Supported on Unix only for now (like pspg).
Author: Pavel Stehule <pavel.stehule@gmail.com>
Author: Thomas Munro <thomas.munro@gmail.com>
Discussion: https://postgr.es/m/CAFj8pRBfzUUPz-3gN5oAzto9SDuRSq-TQPfXU_P6h0L7hO%2BEhg%40mail.gmail.com
The set of subcommands supported by \dAp, \do and \dy was described
incorrectly in psql's --help. The documentation was already consistent
with the code.
Reported-by: inoas, from IRC
Author: Matthijs van der Vleuten
Reviewed-by: Neil Chen
Discussion: https://postgr.es/m/6a984e24-2171-4039-9050-92d55e7b23fe@www.fastmail.com
Backpatch-through: 9.6
When dealing with overloaded function or operator names, having
to look through a long list of matches is tedious. Let's extend
these commands to allow specification of (input) argument types
to let such results be trimmed down. Each additional argument
is treated the same as the pattern argument of \dT and matched
against the appropriate argument's type name.
While at it, fix \dT (and these new options) to recognize the
usual notation of "foo[]" for "the array type over foo", and
to handle the special abbreviations allowed by the backend
grammar, such as "int" for "integer".
Greg Sabino Mullane, revised rather significantly by me
Discussion: https://postgr.es/m/CAKAnmmLF9Hhu02N+s7uAyLc5J1xZReg72HQUoiKhNiJV3_jACQ@mail.gmail.com
There is now a per-column COMPRESSION option which can be set to pglz
(the default, and the only option in up until now) or lz4. Or, if you
like, you can set the new default_toast_compression GUC to lz4, and
then that will be the default for new table columns for which no value
is specified. We don't have lz4 support in the PostgreSQL code, so
to use lz4 compression, PostgreSQL must be built --with-lz4.
In general, TOAST compression means compression of individual column
values, not the whole tuple, and those values can either be compressed
inline within the tuple or compressed and then stored externally in
the TOAST table, so those properties also apply to this feature.
Prior to this commit, a TOAST pointer has two unused bits as part of
the va_extsize field, and a compessed datum has two unused bits as
part of the va_rawsize field. These bits are unused because the length
of a varlena is limited to 1GB; we now use them to indicate the
compression type that was used. This means we only have bit space for
2 more built-in compresison types, but we could work around that
problem, if necessary, by introducing a new vartag_external value for
any further types we end up wanting to add. Hopefully, it won't be
too important to offer a wide selection of algorithms here, since
each one we add not only takes more coding but also adds a build
dependency for every packager. Nevertheless, it seems worth doing
at least this much, because LZ4 gets better compression than PGLZ
with less CPU usage.
It's possible for LZ4-compressed datums to leak into composite type
values stored on disk, just as it is for PGLZ. It's also possible for
LZ4-compressed attributes to be copied into a different table via SQL
commands such as CREATE TABLE AS or INSERT .. SELECT. It would be
expensive to force such values to be decompressed, so PostgreSQL has
never done so. For the same reasons, we also don't force recompression
of already-compressed values even if the target table prefers a
different compression method than was used for the source data. These
architectural decisions are perhaps arguable but revisiting them is
well beyond the scope of what seemed possible to do as part of this
project. However, it's relatively cheap to recompress as part of
VACUUM FULL or CLUSTER, so this commit adjusts those commands to do
so, if the configured compression method of the table happens not to
match what was used for some column value stored therein.
Dilip Kumar. The original patches on which this work was based were
written by Ildus Kurbangaliev, and those were patches were based on
even earlier work by Nikita Glukhov, but the design has since changed
very substantially, since allow a potentially large number of
compression methods that could be added and dropped on a running
system proved too problematic given some of the architectural issues
mentioned above; the choice of which specific compression method to
add first is now different; and a lot of the code has been heavily
refactored. More recently, Justin Przyby helped quite a bit with
testing and reviewing and this version also includes some code
contributions from him. Other design input and review from Tomas
Vondra, Álvaro Herrera, Andres Freund, Oleg Bartunov, Alexander
Korotkov, and me.
Discussion: http://postgr.es/m/20170907194236.4cefce96%40wp.localdomain
Discussion: http://postgr.es/m/CAFiTN-uUpX3ck%3DK0mLEk-G_kUQY%3DSNOTeqdaNRR9FMdQrHKebw%40mail.gmail.com
The loops to identify word boundaries could access past the end of
the input string. Likely that would never result in an actual
crash, but it makes valgrind unhappy.
The logic to try different numbers of words didn't work when the
input has two words but we only have a match to the first, eg
"\h with select". (We must "continue" the pass loop, not "break".)
The logic to compute nl_count was bizarrely managed, and in at
least two code paths could end up calling PageOutput with
nl_count = 0, resulting in failing to paginate output that should
have been fed to the pager. Also, in v12 and up, the nl_count
calculation hadn't been updated to account for the addition of a URL.
The PQExpBuffer holding the command syntax details wasn't freed,
resulting in a session-lifespan memory leak.
While here, improve some comments, choose a more descriptive name
for a variable, fix inconsistent datatype choice for another variable.
Per bug #16837 from Alexander Lakhin. This code is very old,
so back-patch to all supported branches.
Kyotaro Horiguchi and Tom Lane
Discussion: https://postgr.es/m/16837-479bcd56040c71b3@postgresql.org
The new command lists extended statistics objects. All past releases
with extended statistics are supported.
This is a simplified version of commit 891a1d0bca, which had to be
reverted due to not considering pg_statistic_ext_data is not accessible
by regular users. Fields requiring access to this catalog were removed.
It's possible to add them, but it'll require changes to core.
Author: Tatsuro Yamada
Reviewed-by: Julien Rouhaud, Alvaro Herrera, Tomas Vondra, Noriyoshi Shinoda
Discussion: https://postgr.es/m/c027a541-5856-75a5-0868-341301e1624b%40nttcom.co.jp_1
The new command lists extended statistics objects, possibly with their
sizes. All past releases with extended statistics are supported.
Author: Tatsuro Yamada
Reviewed-by: Julien Rouhaud, Alvaro Herrera, Tomas Vondra
Discussion: https://postgr.es/m/c027a541-5856-75a5-0868-341301e1624b%40nttcom.co.jp_1
The preferred terminology has been support "function", not procedure,
for some time, so change that over. The command stays \dAp, since
\dAf is already something else.
We invented \gx to allow the "\pset expanded" flag to be forced on
for the duration of one command output, but that turns out to not
be nearly enough to satisfy the demand for variant output formats.
Hence, make it possible to change any pset option(s) for the duration
of a single command output, by writing "option=value ..." inside
parentheses, for example
\g (format=csv csv_fieldsep='\t') somefile
\gx can now be understood as a shorthand for including expanded=on
inside the parentheses.
Patch by me, expanding on a proposal by Pavel Stehule
Discussion: https://postgr.es/m/CAFj8pRBx9OnBPRJVtfA5ycUpySge-XootAXAsv_4rrkHxJ8eRg@mail.gmail.com
This commit provides psql commands for listing operator classes, operator
families and its contents in psql. New commands will be useful for exploring
capabilities of both builtin opclasses/opfamilies as well as
opclasses/opfamilies defined in extensions.
Discussion: https://postgr.es/m/1529675324.14193.5.camel%40postgrespro.ru
Author: Sergey Cherkashin, Nikita Glukhov, Alexander Korotkov
Reviewed-by: Michael Paquier, Alvaro Herrera, Arthur Zakirov
Reviewed-by: Kyotaro Horiguchi, Andres Freund
We used to strategically place newlines after some function call left
parentheses to make pgindent move the argument list a few chars to the
left, so that the whole line would fit under 80 chars. However,
pgindent no longer does that, so the newlines just made the code
vertically longer for no reason. Remove those newlines, and reflow some
of those lines for some extra naturality.
Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/20200129200401.GA6303@alvherre.pgsql
This is like \echo except that the text is sent to stderr not stdout.
In passing, fix a pre-existing bug in \echo and \qecho: per documentation
the -n switch should only be recognized when it is the first argument,
but actually any argument matching "-n" was treated as a switch.
(Should we back-patch that?)
David Fetter (bug fix by me), reviewed by Fabien Coelho
Discussion: https://postgr.es/m/20190421183115.GA4311@fetter.org
