Until now, these functions have only supported encoding conversions using
lookup tables, which is fine as long as there's not too many code points
to convert. However, GB18030 expects all 1.1 million Unicode code points
to be convertible, which would require a ridiculously-sized lookup table.
Fortunately, a large fraction of those conversions can be expressed through
arithmetic, ie the conversions are one-to-one in certain defined ranges.
To support that, provide a callback function that is used after consulting
the lookup tables. (This patch doesn't actually change anything about the
GB18030 conversion behavior, just provide infrastructure for fixing it.)
Since this requires changing the APIs of UtfToLocal/LocalToUtf anyway,
take the opportunity to rearrange their argument lists into what seems
to me a saner order. And beautify the call sites by using lengthof()
instead of error-prone sizeof() arithmetic.
In passing, also mark all the lookup tables used by these calls "const".
This moves an impressive amount of stuff into the text segment, at least
on my machine, and is safer anyhow.
In pg_audit, set client_min_messages up to warning, then reset the role
attributes, to completely reset the session while not making the
regression tests depend on being run by any particular user.
Instead of creating a new superuser role, extract out what the current
user is and use that user instead. Further, clean up and drop all
objects created by the regression test.
Pointed out by Tom.
This patch introduces the ability for complex datatypes to have an
in-memory representation that is different from their on-disk format.
On-disk formats are typically optimized for minimal size, and in any case
they can't contain pointers, so they are often not well-suited for
computation. Now a datatype can invent an "expanded" in-memory format
that is better suited for its operations, and then pass that around among
the C functions that operate on the datatype. There are also provisions
(rudimentary as yet) to allow an expanded object to be modified in-place
under suitable conditions, so that operations like assignment to an element
of an array need not involve copying the entire array.
The initial application for this feature is arrays, but it is not hard
to foresee using it for other container types like JSON, XML and hstore.
I have hopes that it will be useful to PostGIS as well.
In this initial implementation, a few heuristics have been hard-wired
into plpgsql to improve performance for arrays that are stored in
plpgsql variables. We would like to generalize those hacks so that
other datatypes can obtain similar improvements, but figuring out some
appropriate APIs is left as a task for future work. (The heuristics
themselves are probably not optimal yet, either, as they sometimes
force expansion of arrays that would be better left alone.)
Preliminary performance testing shows impressive speed gains for plpgsql
functions that do element-by-element access or update of large arrays.
There are other cases that get a little slower, as a result of added array
format conversions; but we can hope to improve anything that's annoyingly
bad. In any case most applications should see a net win.
Tom Lane, reviewed by Andres Freund
Also, use a function to load the extension ahead of all other calls,
simulating load from shared_libraries_preload, to make sure the
hooks are in place before logging start.
Remove the check that pg_audit be installed by
shared_preload_libraries as that's not going to work when running the
regressions tests in the buildfarm. That check was primairly a nice to
have and isn't required anyway.
This extension provides detailed logging classes, ability to control
logging at a per-object level, and includes fully-qualified object
names for logged statements (DML and DDL) in independent fields of the
log output.
Authors: Ian Barwick, Abhijit Menon-Sen, David Steele
Reviews by: Robert Haas, Tatsuo Ishii, Sawada Masahiko, Fujii Masao,
Simon Riggs
Discussion with: Josh Berkus, Jaime Casanova, Peter Eisentraut,
David Fetter, Yeb Havinga, Alvaro Herrera, Petr Jelinek, Tom Lane,
MauMau, Bruce Momjian, Jim Nasby, Michael Paquier,
Fabrízio de Royes Mello, Neil Tiffin
The top-level makefile removes tmp_install in its "clean" target, but the
distclean and maintainer-clean targets overlooked that (and they don't
simply invoke clean, because that would result in an extra tree traversal).
While at it, let's just make sure that removing GNUmakefile itself is the
very last step of the recipe.
If a postgres_fdw foreign table is a non-locked source relation in an
UPDATE, DELETE, or SELECT FOR UPDATE/SHARE, and the query selects its
ctid column, the wrong value would be returned if an EvalPlanQual
recheck occurred. This happened because the foreign table's result row
was copied via the ROW_MARK_COPY code path, and EvalPlanQualFetchRowMarks
just unconditionally set the reconstructed tuple's t_self to "invalid".
To fix that, we can have EvalPlanQualFetchRowMarks copy the composite
datum's t_ctid field, and be sure to initialize that along with t_self
when postgres_fdw constructs a tuple to return.
If we just did that much then EvalPlanQualFetchRowMarks would start
returning "(0,0)" as ctid for all other ROW_MARK_COPY cases, which perhaps
does not matter much, but then again maybe it might. The cause of that is
that heap_form_tuple, which is the ultimate source of all composite datums,
simply leaves t_ctid as zeroes in newly constructed tuples. That seems
like a bad idea on general principles: a field that's really not been
initialized shouldn't appear to have a valid value. So let's eat the
trivial additional overhead of doing "ItemPointerSetInvalid(&(td->t_ctid))"
in heap_form_tuple.
This closes out our handling of Etsuro Fujita's report that tableoid and
ctid weren't correctly set in postgres_fdw EvalPlanQual cases. Along the
way we did a great deal of work to improve FDWs' ability to control row
locking behavior; which was not wasted effort by any means, but it didn't
end up being a fix for this problem because that feature would be too
expensive for postgres_fdw to use all the time.
Although the fix for the tableoid misbehavior was back-patched, I'm
hesitant to do so here; it seems far less likely that people would care
about remote ctid than tableoid, and even such a minor behavioral change
as this in heap_form_tuple is perhaps best not back-patched. So commit
to HEAD only, at least for the moment.
Etsuro Fujita, with some adjustments by me
These operations now error out if attempted on scalars, and simply
return the input if attempted on empty arrays or objects. Along the way
we remove the unnecessary cloning of the input when it's known to be
unchanged. Regression tests covering these cases are added.
The new function allows to estimate bloat and other table level statics
in a faster, but approximate, way. It does so by using information from
the free space map for pages marked as all visible in the visibility
map. The rest of the table is actually read and free space/bloat is
measured accurately. In many cases that allows to get bloat information
much quicker, causing less IO.
Author: Abhijit Menon-Sen
Reviewed-By: Andres Freund, Amit Kapila and Tomas Vondra
Discussion: 20140402214144.GA28681@kea.toroid.org
This was added to react to changes in the pg_transform catalog, but
building with CLOBBER_CACHE_ALWAYS showed that PL/Python was not
prepared for having its procedure cache cleared. Since this is a
marginal use case, and we don't do this for other catalogs anyway, we
can postpone this to another day.
Specifically the tlist and rti of the pseudo "excluded" relation weren't
properly treated by expression_tree_walker, which lead to errors when
excluded was referenced inside a rule because the varnos where not
properly adjusted. Similar omissions in OffsetVarNodes and
expression_tree_mutator had less impact, but should obviously be fixed
nonetheless.
A couple tests of for ON CONFLICT UPDATE into INSERT rule bearing
relations have been added.
In passing I updated a couple comments.
jsonb_pretty(jsonb) produces nicely indented json output.
jsonb || jsonb concatenates two jsonb values.
jsonb - text removes a key and its associated value from the json
jsonb - int removes the designated array element
jsonb - text[] removes a key and associated value or array element at
the designated path
jsonb_replace(jsonb,text[],jsonb) replaces the array element designated
by the path or the value associated with the key designated by the path
with the given value.
Original work by Dmitry Dolgov, adapted and reworked for PostgreSQL core
by Andrew Dunstan, reviewed and tidied up by Petr Jelinek.
Previously, FDWs could only do "early row locking", that is lock a row as
soon as it's fetched, even though local restriction/join conditions might
discard the row later. This patch adds callbacks that allow FDWs to do
late locking in the same way that it's done for regular tables.
To make use of this feature, an FDW must support the "ctid" column as a
unique row identifier. Currently, since ctid has to be of type TID,
the feature is of limited use, though in principle it could be used by
postgres_fdw. We may eventually allow FDWs to specify another data type
for ctid, which would make it possible for more FDWs to use this feature.
This commit does not modify postgres_fdw to use late locking. We've
tested some prototype code for that, but it's not in committable shape,
and besides it's quite unclear whether it actually makes sense to do late
locking against a remote server. The extra round trips required are likely
to outweigh any benefit from improved concurrency.
Etsuro Fujita, reviewed by Ashutosh Bapat, and hacked up a lot by me
In pgbench, report, but ignore, any errors returned when attempting to
vacuum/truncate the default tables during startup. If the tables are
needed, we'll error out soon enough anyway.
Per discussion with Tatsuo, David Rowley, Jim Nasby, Robert, Andres,
Fujii, Fabrízio de Royes Mello, Tomas Vondra, Michael Paquier, Peter,
based on a suggestion from Jeff Janes, patch from Robert, additional
message wording from Tom.
Windows can't reliably restore symbolic links from a tar format, so
instead during backup start we create a tablespace_map file, which is
used by the restoring postgres to create the correct links in pg_tblspc.
The backup protocol also now has an option to request this file to be
included in the backup stream, and this is used by pg_basebackup when
operating in tar mode.
This is done on all platforms, not just Windows.
This means that pg_basebackup will not not work in tar mode against 9.4
and older servers, as this protocol option isn't implemented there.
Amit Kapila, reviewed by Dilip Kumar, with a little editing from me.
This feature lets user code inspect and take action on DDL events.
Whenever a ddl_command_end event trigger is installed, DDL actions
executed are saved to a list which can be inspected during execution of
a function attached to ddl_command_end.
The set-returning function pg_event_trigger_ddl_commands can be used to
list actions so captured; it returns data about the type of command
executed, as well as the affected object. This is sufficient for many
uses of this feature. For the cases where it is not, we also provide a
"command" column of a new pseudo-type pg_ddl_command, which is a
pointer to a C structure that can be accessed by C code. The struct
contains all the info necessary to completely inspect and even
reconstruct the executed command.
There is no actual deparse code here; that's expected to come later.
What we have is enough infrastructure that the deparsing can be done in
an external extension. The intention is that we will add some deparsing
code in a later release, as an in-core extension.
A new test module is included. It's probably insufficient as is, but it
should be sufficient as a starting point for a more complete and
future-proof approach.
Authors: Álvaro Herrera, with some help from Andres Freund, Ian Barwick,
Abhijit Menon-Sen.
Reviews by Andres Freund, Robert Haas, Amit Kapila, Michael Paquier,
Craig Ringer, David Steele.
Additional input from Chris Browne, Dimitri Fontaine, Stephen Frost,
Petr Jelínek, Tom Lane, Jim Nasby, Steven Singer, Pavel Stěhule.
Based on original work by Dimitri Fontaine, though I didn't use his
code.
Discussion:
https://www.postgresql.org/message-id/m2txrsdzxa.fsf@2ndQuadrant.frhttps://www.postgresql.org/message-id/20131108153322.GU5809@eldon.alvh.no-ip.orghttps://www.postgresql.org/message-id/20150215044814.GL3391@alvh.no-ip.org
INSERT acquires RowExclusiveLock during normal operation and therefore
it makes sense to allow LOCK TABLE .. ROW EXCLUSIVE MODE to be executed
by users who have INSERT rights on a table (even if they don't have
UPDATE or DELETE).
Not back-patching this as it's a behavior change which, strictly
speaking, loosens security restrictions.
Per discussion with Tom and Robert (circa 2013).
If a row that potentially violates a deferred exclusion constraint is
HOT-updated later in the same transaction, the exclusion constraint would
be reported as violated when the check finally occurs, even if the row(s)
the new row originally conflicted with have since been removed. This
happened because the wrong TID was passed to check_exclusion_constraint(),
causing the live HOT-updated row to be seen as a conflicting row rather
than recognized as the row-under-test.
Per bug #13148 from Evan Martin. It's been broken since exclusion
constraints were invented, so back-patch to all supported branches.
Analysis by Noah Misch shows that the 25% threshold set by commit
53bb309d2d is lower than any other,
similar autovac threshold. While we don't know exactly what value
will be optimal for all users, it is better to err a little on the
high side than on the low side. A higher value increases the risk
that users might exhaust the available space and start seeing errors
before autovacuum can clean things up sufficiently, but a user who
hits that problem can compensate for it by reducing
autovacuum_multixact_freeze_max_age to a value dependent on their
average multixact size. On the flip side, if the emergency cap
imposed by that patch kicks in too early, the user will experience
excessive wraparound scanning and will be unable to mitigate that
problem by configuration. The new value will hopefully reduce the
risk of such bad experiences while still providing enough headroom
to avoid multixact member exhaustion for most users.
Along the way, adjust the documentation to reflect the effects of
commit 04e6d3b877, which taught
autovacuum to run for multixact wraparound even when autovacuum
is configured off.
Commit b69bf30b9b advanced the stop point
at vacuum time, but this has subsequently been shown to be unsafe as a
result of analysis by myself and Thomas Munro and testing by Thomas
Munro. The crux of the problem is that the SLRU deletion logic may
get confused about what to remove if, at exactly the right time during
the checkpoint process, the head of the SLRU crosses what used to be
the tail.
This patch, by me, fixes the problem by advancing the stop point only
following a checkpoint. This has the additional advantage of making
the removal logic work during recovery more like the way it works during
normal running, which is probably good.
At least one of the calls to DetermineSafeOldestOffset which this patch
removes was already dead, because MultiXactAdvanceOldest is called only
during recovery and DetermineSafeOldestOffset was set up to do nothing
during recovery. That, however, is inconsistent with the principle that
recovery and normal running should work similarly, and was confusing to
boot.
Along the way, fix some comments that previous patches in this area
neglected to update. It's not clear to me whether there's any
concrete basis for the decision to use only half of the multixact ID
space, but it's neither necessary nor sufficient to prevent multixact
member wraparound, so the comments should not say otherwise.
Commit b69bf30b9b failed to take into
account the possibility that there might be no multixacts in existence
at all.
Report by Thomas Munro; patch by me.
Commit e7cb7ee145 included some design
decisions that seem pretty questionable to me, and there was quite a lot
of stuff not to like about the documentation and comments. Clean up
as follows:
* Consider foreign joins only between foreign tables on the same server,
rather than between any two foreign tables with the same underlying FDW
handler function. In most if not all cases, the FDW would simply have had
to apply the same-server restriction itself (far more expensively, both for
lack of caching and because it would be repeated for each combination of
input sub-joins), or else risk nasty bugs. Anyone who's really intent on
doing something outside this restriction can always use the
set_join_pathlist_hook.
* Rename fdw_ps_tlist/custom_ps_tlist to fdw_scan_tlist/custom_scan_tlist
to better reflect what they're for, and allow these custom scan tlists
to be used even for base relations.
* Change make_foreignscan() API to include passing the fdw_scan_tlist
value, since the FDW is required to set that. Backwards compatibility
doesn't seem like an adequate reason to expect FDWs to set it in some
ad-hoc extra step, and anyway existing FDWs can just pass NIL.
* Change the API of path-generating subroutines of add_paths_to_joinrel,
and in particular that of GetForeignJoinPaths and set_join_pathlist_hook,
so that various less-used parameters are passed in a struct rather than
as separate parameter-list entries. The objective here is to reduce the
probability that future additions to those parameter lists will result in
source-level API breaks for users of these hooks. It's possible that this
is even a small win for the core code, since most CPU architectures can't
pass more than half a dozen parameters efficiently anyway. I kept root,
joinrel, outerrel, innerrel, and jointype as separate parameters to reduce
code churn in joinpath.c --- in particular, putting jointype into the
struct would have been problematic because of the subroutines' habit of
changing their local copies of that variable.
* Avoid ad-hocery in ExecAssignScanProjectionInfo. It was probably all
right for it to know about IndexOnlyScan, but if the list is to grow
we should refactor the knowledge out to the callers.
* Restore nodeForeignscan.c's previous use of the relcache to avoid
extra GetFdwRoutine lookups for base-relation scans.
* Lots of cleanup of documentation and missed comments. Re-order some
code additions into more logical places.
Tom Lane
Simon Riggs
Bruce Momjian
Peter Eisentraut
Stephen Frost
Robert Haas
Andrew Dunstan
Andres Freund
Alvaro Herrera