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* Avoid spamming the client with multiple ParameterStatus messages.Tom Lane2020-11-25
| | | | | | | | | | | | | | | | | | Up to now, we sent a ParameterStatus message to the client immediately upon any change in the active value of any GUC_REPORT variable. This was only barely okay when the feature was designed; now that we have things like function SET clauses, there are very plausible use-cases where a GUC_REPORT variable might change many times within a query --- and even end up back at its original value, perhaps. Fortunately most of our GUC_REPORT variables are unlikely to be changed often; but there are proposals in play to enlarge that set, or even make it user-configurable. Hence, let's fix things to not generate more than one ParameterStatus message per variable per query, and to not send any message at all unless the end-of-query value is different from what we last reported. Discussion: https://postgr.es/m/5708.1601145259@sss.pgh.pa.us
* Further fixes for CREATE TABLE LIKE: cope with self-referential FKs.Tom Lane2020-11-19
| | | | | | | | | | | | | | | | | | | | | | | Commit 502898192 was too careless about the order of execution of the additional ALTER TABLE operations generated by expandTableLikeClause. It just stuck them all at the end, which seems okay for most purposes. But it falls down in the case where LIKE is importing a primary key or unique index and the outer CREATE TABLE includes a FOREIGN KEY constraint that needs to depend on that index. Weird as that is, it used to work, so we ought to keep it working. To fix, make parse_utilcmd.c insert LIKE clauses between index-creation and FK-creation commands in the transformed list of commands, and change utility.c so that the commands generated by expandTableLikeClause are executed immediately not at the end. One could imagine scenarios where this wouldn't work either; but currently expandTableLikeClause only makes column default expressions, CHECK constraints, and indexes, and this ordering seems fine for those. Per bug #16730 from Sofoklis Papasofokli. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/16730-b902f7e6e0276b30@postgresql.org
* Remove -o option to postmasterMagnus Hagander2020-11-10
| | | | | | | This option was declared obsolete many years ago. Reviewed-By: Tom Lane Discussion: https://postgr.es/m/CABUevEyOE=9CQwZm2j=vwP5+6OLCSoxn9pBjK8gyRdkTzMfqtQ@mail.gmail.com
* Remove pg_collation.collversion.Thomas Munro2020-11-03
| | | | | | | | | | | | This model couldn't be extended to cover the default collation, and didn't have any information about the affected database objects when the version changed. Remove, in preparation for a follow-up commit that will add a new mechanism. Author: Thomas Munro <thomas.munro@gmail.com> Reviewed-by: Julien Rouhaud <rjuju123@gmail.com> Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com> Discussion: https://postgr.es/m/CAEepm%3D0uEQCpfq_%2BLYFBdArCe4Ot98t1aR4eYiYTe%3DyavQygiQ%40mail.gmail.com
* Fix bogus completion tag usage in walsenderAlvaro Herrera2020-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit fd5942c18f97 (2012, 9.3-era), walsender has been sending completion tags for certain replication commands twice -- and they're not even consistent. Apparently neither libpq nor JDBC have a problem with it, but it's not kosher. Fix by remove the EndCommand() call in the common code path for them all, and inserting specific calls to EndReplicationCommand() specifically in those places where it's needed. EndReplicationCommand() is a new simple function to send the completion tag for replication commands. Do this instead of sending a generic SELECT completion tag for them all, which was also pretty bogus (if innocuous). While at it, change StartReplication() to use EndReplicationCommand() instead of pg_puttextmessage(). In commit 2f9661311b83, I failed to realize that replication commands are not close-enough kin of regular SQL commands, so the DROP_REPLICATION_SLOT tag I added is undeserved and a type pun. Take it out. Backpatch to 13, where the latter commit appeared. The duplicate tag has been sent since 9.3, but since nothing is broken, it doesn't seem worth fixing. Per complaints from Tom Lane. Discussion: https://postgr.es/m/1347966.1600195735@sss.pgh.pa.us
* Centralize setup of SIGQUIT handling for postmaster child processes.Tom Lane2020-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | We decided that the policy established in commit 7634bd4f6 for the bgwriter, checkpointer, walwriter, and walreceiver processes, namely that they should accept SIGQUIT at all times, really ought to apply uniformly to all postmaster children. Therefore, get rid of the duplicative and inconsistent per-process code for establishing that signal handler and removing SIGQUIT from BlockSig. Instead, make InitPostmasterChild do it. The handler set up by InitPostmasterChild is SignalHandlerForCrashExit, which just summarily does _exit(2). In interactive backends, we almost immediately replace that with quickdie, since we would prefer to try to tell the client that we're dying. However, this patch is changing the behavior of autovacuum (both launcher and workers), as well as walsenders. Those processes formerly also used quickdie, but AFAICS that was just mindless copy-and-paste: they don't have any interactive client that's likely to benefit from being told this. The stats collector continues to be an outlier, in that it thinks SIGQUIT means normal exit. That should probably be changed for consistency, but there's another patch set where that's being dealt with, so I didn't do so here. Discussion: https://postgr.es/m/644875.1599933441@sss.pgh.pa.us
* Use the properly transformed RangeVar for expandTableLikeClause().Tom Lane2020-09-13
| | | | | | | | | | | | | | | transformCreateStmt() adjusts the transformed statement's RangeVar to specify the target schema explicitly, for the express reason of making sure that auxiliary statements derived by parse transformation operate on the right table. But the refactoring I did in commit 502898192 got this wrong and passed the untransformed RangeVar to expandTableLikeClause(). This could lead to assertion failures or weird misbehavior if the wrong table was accessed. Per report from Alexander Lakhin. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/05051f9d-b32b-cb35-6735-0e9f2ab86b5f@gmail.com
* Add support for partitioned tables and indexes in REINDEXMichael Paquier2020-09-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Until now, REINDEX was not able to work with partitioned tables and indexes, forcing users to reindex partitions one by one. This extends REINDEX INDEX and REINDEX TABLE so as they can accept a partitioned index and table in input, respectively, to reindex all the partitions assigned to them with physical storage (foreign tables, partitioned tables and indexes are then discarded). This shares some logic with schema and database REINDEX as each partition gets processed in its own transaction after building a list of relations to work on. This choice has the advantage to minimize the number of invalid indexes to one partition with REINDEX CONCURRENTLY in the event a cancellation or failure in-flight, as the only indexes handled at once in a single REINDEX CONCURRENTLY loop are the ones from the partition being working on. Isolation tests are added to emulate some cases I bumped into while developing this feature, particularly with the concurrent drop of a leaf partition reindexed. However, this is rather limited as LOCK would cause REINDEX to block in the first transaction building the list of partitions. Per its multi-transaction nature, this new flavor cannot run in a transaction block, similarly to REINDEX SCHEMA, SYSTEM and DATABASE. Author: Justin Pryzby, Michael Paquier Reviewed-by: Anastasia Lubennikova Discussion: https://postgr.es/m/db12e897-73ff-467e-94cb-4af03705435f.adger.lj@alibaba-inc.com
* Remove variable "concurrent" from ReindexStmtMichael Paquier2020-09-04
| | | | | | | | | | This node already handles multiple options using a bitmask, so having a separate boolean flag is not necessary. This simplifies the code a bit with less arguments to give to the reindex routines, by replacing the boolean with an equivalent bitmask value. Reviewed-by: Julien Rouhaud Discussion: https://postgr.es/m/20200902110326.GA14963@paquier.xyz
* Fix handling of CREATE TABLE LIKE with inheritance.Tom Lane2020-08-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a CREATE TABLE command uses both LIKE and traditional inheritance, Vars in CHECK constraints and expression indexes that are absorbed from a LIKE parent table tended to get mis-numbered, resulting in wrong answers and/or bizarre error messages (though probably not any actual crashes, thanks to validation occurring in the executor). In v12 and up, the same could happen to Vars in GENERATED expressions, even in cases with no LIKE clause but multiple traditional-inheritance parents. The cause of the problem for LIKE is that parse_utilcmd.c supposed it could renumber such Vars correctly during transformCreateStmt(), which it cannot since we have not yet accounted for columns added via inheritance. Fix that by postponing processing of LIKE INCLUDING CONSTRAINTS, DEFAULTS, GENERATED, INDEXES till after we've performed DefineRelation(). The error with GENERATED and multiple inheritance is a simple oversight in MergeAttributes(); it knows it has to renumber Vars in inherited CHECK constraints, but forgot to apply the same processing to inherited GENERATED expressions (a/k/a defaults). Per bug #16272 from Tom Gottfried. The non-GENERATED variants of the issue are ancient, presumably dating right back to the addition of CREATE TABLE LIKE; hence back-patch to all supported branches. Discussion: https://postgr.es/m/16272-6e32da020e9a9381@postgresql.org
* Rename field "relkind" to "objtype" for CTAS and ALTER TABLE nodesMichael Paquier2020-07-11
| | | | | | | | | | | | | | | | | | | "relkind" normally refers to the char field from pg_class. However, in the parse nodes AlterTableStmt and CreateTableAsStmt, "relkind" was used for a field of type enum ObjectType, that could refer to other object types than those possible for a relkind. Such fields being usually named "objtype", switch the name in both structures to make things more consistent. Note that this led to some confusion in functions that also operate on a RangeTableEntry object, which also has a field named "relkind". This naming goes back to commit 09d4e96, where only OBJECT_TABLE and OBJECT_INDEX were used. This got extended later to use as well OBJECT_TYPE with e440e12, not really a relation kind. Author: Mark Dilger Reviewed-by: Daniel Gustafsson, Álvaro Herrera, Michael Paquier Discussion: https://postgr.es/m/609181AE-E399-47C7-9221-856E0F96BF93@enterprisedb.com
* Avoid using a cursor in plpgsql's RETURN QUERY statement.Tom Lane2020-06-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | plpgsql has always executed the query given in a RETURN QUERY command by opening it as a cursor and then fetching a few rows at a time, which it turns around and dumps into the function's result tuplestore. The point of this was to keep from blowing out memory with an oversized SPITupleTable result (note that while a tuplestore can spill tuples to disk, SPITupleTable cannot). However, it's rather inefficient, both because of extra data copying and because of executor entry/exit overhead. In recent versions, a new performance problem has emerged: use of a cursor prevents use of a parallel plan for the executed query. We can improve matters by skipping use of a cursor and having the executor push result tuples directly into the function's result tuplestore. However, a moderate amount of new infrastructure is needed to make that idea work: * We can use the existing tstoreReceiver.c DestReceiver code to funnel executor output to the tuplestore, but it has to be extended to support plpgsql's requirement for possibly applying a tuple conversion map. * SPI needs to be extended to allow use of a caller-supplied DestReceiver instead of its usual receiver that puts tuples into a SPITupleTable. Two new API calls are needed to handle both the RETURN QUERY and RETURN QUERY EXECUTE cases. I also felt that I didn't want these new API calls to use the legacy method of specifying query parameter values with "char" null flags (the old ' '/'n' convention); rather they should accept ParamListInfo objects containing the parameter type and value info. This required a bit of additional new infrastructure since we didn't yet have any parse analysis callback that would interpret $N parameter symbols according to type data supplied in a ParamListInfo. There seems to be no harm in letting makeParamList install that callback by default, rather than leaving a new ParamListInfo's parserSetup hook as NULL. (Indeed, as of HEAD, I couldn't find anyplace that was using the parserSetup field at all; plpgsql was using parserSetupArg for its own purposes, but parserSetup seemed to be write-only.) We can actually get plpgsql out of the business of using legacy null flags altogether, and using ParamListInfo instead of its ad-hoc PreparedParamsData structure; but this requires inventing one more SPI API call that can replace SPI_cursor_open_with_args. That seems worth doing, though. SPI_execute_with_args and SPI_cursor_open_with_args are now unused anywhere in the core PG distribution. Perhaps someday we could deprecate/remove them. But cleaning up the crufty bits of the SPI API is a task for a different patch. Per bug #16040 from Jeremy Smith. This is unfortunately too invasive to consider back-patching. Patch by me; thanks to Hamid Akhtar for review. Discussion: https://postgr.es/m/16040-eaacad11fecfb198@postgresql.org
* Spelling adjustmentsPeter Eisentraut2020-06-07
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* Initial pgindent and pgperltidy run for v13.Tom Lane2020-05-14
| | | | | | | | | | | Includes some manual cleanup of places that pgindent messed up, most of which weren't per project style anyway. Notably, it seems some people didn't absorb the style rules of commit c9d297751, because there were a bunch of new occurrences of function calls with a newline just after the left paren, all with faulty expectations about how the rest of the call would get indented.
* Dial back -Wimplicit-fallthrough to level 3Alvaro Herrera2020-05-13
| | | | | | | | | The additional pain from level 4 is excessive for the gain. Also revert all the source annotation changes to their original wordings, to avoid back-patching pain. Discussion: https://postgr.es/m/31166.1589378554@sss.pgh.pa.us
* Add -Wimplicit-fallthrough to CFLAGS and CXXFLAGSAlvaro Herrera2020-05-12
| | | | | | | | | | | | | | | Use it at level 4, a bit more restrictive than the default level, and tweak our commanding comments to FALLTHROUGH. (However, leave zic.c alone, since it's external code; to avoid the warnings that would appear there, change CFLAGS for that file in the Makefile.) Author: Julien Rouhaud <rjuju123@gmail.com> Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/20200412081825.qyo5vwwco3fv4gdo@nol Discussion: https://postgr.es/m/flat/E1fDenm-0000C8-IJ@gemulon.postgresql.org
* Revert 0f5ca02f53Alexander Korotkov2020-04-08
| | | | | | | | 0f5ca02f53 introduces 3 new keywords. It appears to be too much for relatively small feature. Given now we past feature freeze, it's already late for discussion of the new syntax. So, revert. Discussion: https://postgr.es/m/28209.1586294824%40sss.pgh.pa.us
* Implement waiting for given lsn at transaction startAlexander Korotkov2020-04-07
| | | | | | | | | | | | | | | | | | | | This commit adds following optional clause to BEGIN and START TRANSACTION commands. WAIT FOR LSN lsn [ TIMEOUT timeout ] New clause pospones transaction start till given lsn is applied on standby. This clause allows user be sure, that changes previously made on primary would be visible on standby. New shared memory struct is used to track awaited lsn per backend. Recovery process wakes up backend once required lsn is applied. Author: Ivan Kartyshov, Anna Akenteva Reviewed-by: Craig Ringer, Thomas Munro, Robert Haas, Kyotaro Horiguchi Reviewed-by: Masahiko Sawada, Ants Aasma, Dmitry Ivanov, Simon Riggs Reviewed-by: Amit Kapila, Alexander Korotkov Discussion: https://postgr.es/m/0240c26c-9f84-30ea-fca9-93ab2df5f305%40postgrespro.ru
* Improve user control over truncation of logged bind-parameter values.Tom Lane2020-04-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces the boolean GUC log_parameters_on_error introduced by commit ba79cb5dc with an integer log_parameter_max_length_on_error, adding the ability to specify how many bytes to trim each logged parameter value to. (The previous coding hard-wired that choice at 64 bytes.) In addition, add a new parameter log_parameter_max_length that provides similar control over truncation of query parameters that are logged in response to statement-logging options, as opposed to errors. Previous releases always logged such parameters in full, possibly causing log bloat. For backwards compatibility with prior releases, log_parameter_max_length defaults to -1 (log in full), while log_parameter_max_length_on_error defaults to 0 (no logging). Per discussion, log_parameter_max_length is SUSET since the DBA should control routine logging behavior, but log_parameter_max_length_on_error is USERSET because it also affects errcontext data sent back to the client. Alexey Bashtanov, editorialized a little by me Discussion: https://postgr.es/m/b10493cc-a399-a03a-67c7-068f2791ee50@imap.cc
* Fix assorted typosMagnus Hagander2020-03-31
| | | | Author: Daniel Gustafsson <daniel@yesql.se>
* Allow the planner-related functions and hook to accept the query string.Fujii Masao2020-03-30
| | | | | | | | | | | | | | | | | | This commit adds query_string argument into the planner-related functions and hook and allows us to pass the query string to them. Currently there is no user of the query string passed. But the upcoming patch for the planning counters will add the planning hook function into pg_stat_statements and the function will need the query string. So this change will be necessary for that patch. Also this change is useful for some extensions that want to use the query string in their planner hook function. Author: Pascal Legrand, Julien Rouhaud Reviewed-by: Yoshikazu Imai, Tom Lane, Fujii Masao Discussion: https://postgr.es/m/CAOBaU_bU1m3_XF5qKYtSj1ua4dxd=FWDyh2SH4rSJAUUfsGmAQ@mail.gmail.com Discussion: https://postgr.es/m/1583789487074-0.post@n3.nabble.com
* Re-implement the ereport() macro using __VA_ARGS__.Tom Lane2020-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we require C99, we can depend on __VA_ARGS__ to work, and revising ereport() to use it has several significant benefits: * The extra parentheses around the auxiliary function calls are now optional. Aside from being a bit less ugly, this removes a common gotcha for new contributors, because in some cases the compiler errors you got from forgetting them were unintelligible. * The auxiliary function calls are now evaluated as a comma expression list rather than as extra arguments to errfinish(). This means that compilers can be expected to warn about no-op expressions in the list, allowing detection of several other common mistakes such as forgetting to add errmsg(...) when converting an elog() call to ereport(). * Unlike the situation with extra function arguments, comma expressions are guaranteed to be evaluated left-to-right, so this removes platform dependency in the order of the auxiliary function calls. While that dependency hasn't caused us big problems in the past, this change does allow dropping some rather shaky assumptions around errcontext() domain handling. There's no intention to make wholesale changes of existing ereport calls, but as proof-of-concept this patch removes the extra parens from a couple of calls in postgres.c. While new code can be written either way, code intended to be back-patched will need to use extra parens for awhile yet. It seems worth back-patching this change into v12, so as to reduce the window where we have to be careful about that by one year. Hence, this patch is careful to preserve ABI compatibility; a followup HEAD-only patch will make some additional simplifications. Andres Freund and Tom Lane Discussion: https://postgr.es/m/CA+fd4k6N8EjNvZpM8nme+y+05mz-SM8Z_BgkixzkA34R+ej0Kw@mail.gmail.com
* Refactor ps_status.c APIPeter Eisentraut2020-03-11
| | | | | | | | | | | | | | | | | | | | | | The init_ps_display() arguments were mostly lies by now, so to match typical usage, just use one argument and let the caller assemble it from multiple sources if necessary. The only user of the additional arguments is BackendInitialize(), which was already doing string assembly on the caller side anyway. Remove the second argument of set_ps_display() ("force") and just handle that in init_ps_display() internally. BackendInitialize() also used to set the initial status as "authentication", but that was very far from where authentication actually happened. So now it's set to "initializing" and then "authentication" just before the actual call to ClientAuthentication(). Reviewed-by: Julien Rouhaud <rjuju123@gmail.com> Reviewed-by: Kuntal Ghosh <kuntalghosh.2007@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/flat/c65e5196-4f04-4ead-9353-6088c19615a3@2ndquadrant.com
* Allow ALTER TYPE to change some properties of a base type.Tom Lane2020-03-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Specifically, this patch allows ALTER TYPE to: * Change the default TOAST strategy for a toastable base type; * Promote a non-toastable type to toastable; * Add/remove binary I/O functions for a type; * Add/remove typmod I/O functions for a type; * Add/remove a custom ANALYZE statistics functions for a type. The first of these can be done by the type's owner; all the others require superuser privilege since misuse could cause problems. The main motivation for this patch is to allow extensions to upgrade the feature sets of their data types, so the set of alterable properties is biased towards that use-case. However it's also true that changing some other properties would be a lot harder, as they get baked into physical storage and/or stored expressions that depend on the type. Along the way, refactor GenerateTypeDependencies() to make it easier to call, refactor DefineType's volatility checks so they can be shared by AlterType, and teach typcache.c that it might have to reload data from the type's pg_type row, a scenario it never handled before. Also rearrange alter_type.sgml a bit for clarity (put the composite-type operations together). Tomas Vondra and Tom Lane Discussion: https://postgr.es/m/20200228004440.b23ein4qvmxnlpht@development
* Represent command completion tags as structsAlvaro Herrera2020-03-02
| | | | | | | | | | | | | | | | | | | | | | The backend was using strings to represent command tags and doing string comparisons in multiple places, but that's slow and unhelpful. Create a new command list with a supporting structure to use instead; this is stored in a tag-list-file that can be tailored to specific purposes with a caller-definable C macro, similar to what we do for WAL resource managers. The first first such uses are a new CommandTag enum and a CommandTagBehavior struct. Replace numerous occurrences of char *completionTag with a QueryCompletion struct so that the code no longer stores information about completed queries in a cstring. Only at the last moment, in EndCommand(), does this get converted to a string. EventTriggerCacheItem no longer holds an array of palloc’d tag strings in sorted order, but rather just a Bitmapset over the CommandTags. Author: Mark Dilger, with unsolicited help from Álvaro Herrera Reviewed-by: John Naylor, Tom Lane Discussion: https://postgr.es/m/981A9DB4-3F0C-4DA5-88AD-CB9CFF4D6CAD@enterprisedb.com
* Add comments on avoid reuse of parse-time snapshotAlvaro Herrera2020-02-28
| | | | | | | | | | | | | Apparently, reusing the parse-time query snapshot for later steps (execution) is a frequently considered optimization ... but it doesn't work, for reasons discovered in thread [1]. Adding some comments about why it doesn't really work can relieve some future hackers from wasting time reimplementing it again. [1] https://postgr.es/m/flat/5075D8DF.6050500@fuzzy.cz Author: Michail Nikolaev Discussion: https://postgr.es/m/CANtu0ogp6cTvMJObXP8n=k+JtqxY1iT9UV5MbGCpjjPa5crCiw@mail.gmail.com
* Clean up newlines following left parenthesesAlvaro Herrera2020-01-30
| | | | | | | | | | | | 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
* Silence minor compiler warnings.Tom Lane2020-01-19
| | | | | | | | | | | | Ensure that ClassifyUtilityCommandAsReadOnly() has defined behavior even if TransactionStmt.kind has a value that's not one of the declared values for its enum. Suppress warnings from compilers that don't know that elog(ERROR) doesn't return, in ClassifyUtilityCommandAsReadOnly() and jsonb_set_lax(). Per Coverity and buildfarm.
* Fix problems with "read only query" checks, and refactor the code.Robert Haas2020-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, check_xact_readonly() was responsible for determining which types of queries could not be run in a read-only transaction, standard_ProcessUtility() was responsibility for prohibiting things which were allowed in read only transactions but not in recovery, and utility commands were basically prohibited in bulk in parallel mode by calls to CommandIsReadOnly() in functions.c and spi.c. This situation was confusing and error-prone. Accordingly, move all the checks to a new function ClassifyUtilityCommandAsReadOnly(), which determines the degree to which a given statement is read only. In the old code, check_xact_readonly() inadvertently failed to handle several statement types that actually should have been prohibited, specifically T_CreatePolicyStmt, T_AlterPolicyStmt, T_CreateAmStmt, T_CreateStatsStmt, T_AlterStatsStmt, and T_AlterCollationStmt. As a result, thes statements were erroneously allowed in read only transactions, parallel queries, and standby operation. Generally, they would fail anyway due to some lower-level error check, but we shouldn't rely on that. In the new code structure, future omissions of this type should cause ClassifyUtilityCommandAsReadOnly() to complain about an unrecognized node type. As a fringe benefit, this means we can allow certain types of utility commands in parallel mode, where it's safe to do so. This allows ALTER SYSTEM, CALL, DO, CHECKPOINT, COPY FROM, EXPLAIN, and SHOW. It might be possible to allow additional commands with more work and thought. Along the way, document the thinking process behind the current set of checks, as per discussion especially with Peter Eisentraut. There is some interest in revising some of these rules, but that seems like a job for another patch. Patch by me, reviewed by Tom Lane, Stephen Frost, and Peter Eisentraut. Discussion: http://postgr.es/m/CA+TgmoZ_rLqJt5sYkvh+JpQnfX0Y+B2R+qfi820xNih6x-FQOQ@mail.gmail.com
* Restructure ALTER TABLE execution to fix assorted bugs.Tom Lane2020-01-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We've had numerous bug reports about how (1) IF NOT EXISTS clauses in ALTER TABLE don't behave as-expected, and (2) combining certain actions into one ALTER TABLE doesn't work, though executing the same actions as separate statements does. This patch cleans up all of the cases so far reported from the field, though there are still some oddities associated with identity columns. The core problem behind all of these bugs is that we do parse analysis of ALTER TABLE subcommands too soon, before starting execution of the statement. The root of the bugs in group (1) is that parse analysis schedules derived commands (such as a CREATE SEQUENCE for a serial column) before it's known whether the IF NOT EXISTS clause should cause a subcommand to be skipped. The root of the bugs in group (2) is that earlier subcommands may change the catalog state that later subcommands need to be parsed against. Hence, postpone parse analysis of ALTER TABLE's subcommands, and do that one subcommand at a time, during "phase 2" of ALTER TABLE which is the phase that does catalog rewrites. Thus the catalog effects of earlier subcommands are already visible when we analyze later ones. (The sole exception is that we do parse analysis for ALTER COLUMN TYPE subcommands during phase 1, so that their USING expressions can be parsed against the table's original state, which is what we need. Arguably, these bugs stem from falsely concluding that because ALTER COLUMN TYPE must do early parse analysis, every other command subtype can too.) This means that ALTER TABLE itself must deal with execution of any non-ALTER-TABLE derived statements that are generated by parse analysis. Add a suitable entry point to utility.c to accept those recursive calls, and create a struct to pass through the information needed by the recursive call, rather than making the argument lists of AlterTable() and friends even longer. Getting this to work correctly required a little bit of fiddling with the subcommand pass structure, in particular breaking up AT_PASS_ADD_CONSTR into multiple passes. But otherwise it's mostly a pretty straightforward application of the above ideas. Fixing the residual issues for identity columns requires refactoring of where the dependency link from an identity column to its sequence gets set up. So that seems like suitable material for a separate patch, especially since this one is pretty big already. Discussion: https://postgr.es/m/10365.1558909428@sss.pgh.pa.us
* Make better use of ParseState in ProcessUtilityPeter Eisentraut2020-01-04
| | | | | | | | | | | Pass ParseState into the functions called from standard_ProcessUtility() instead passing the query string and query environment separately. No functionality change, but it makes the notation consistent. We had already started moving things into that direction piece by piece, and this completes it. Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/6e7aa4a1-be6a-1a75-b1f9-83a678e5184a@2ndquadrant.com
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Extend the ProcSignal mechanism to support barriers.Robert Haas2019-12-19
| | | | | | | | | | | | | | | | | | | | | | A new function EmitProcSignalBarrier() can be used to emit a global barrier which all backends that participate in the ProcSignal mechanism must absorb, and a new function WaitForProcSignalBarrier() can be used to wait until all relevant backends have in fact absorbed the barrier. This can be used to coordinate global state changes, such as turning checksums on while the system is running. There's no real client of this mechanism yet, although two are proposed, but an enum has to have at least one element, so this includes a placeholder type (PROCSIGNAL_BARRIER_PLACEHOLDER) which should be replaced by the first real client of this mechanism to get committed. Andres Freund and Robert Haas, reviewed by Daniel Gustafsson and, in earlier versions, by Magnus Hagander. Discussion: http://postgr.es/m/CA+TgmoZwDk=BguVDVa+qdA6SBKef=PKbaKDQALTC_9qoz1mJqg@mail.gmail.com
* Partially deduplicate interrupt handling for background processes.Robert Haas2019-12-17
| | | | | | | | | | | | | | | | Where possible, share signal handler code and main loop interrupt checking. This saves quite a bit of code and should simplify maintenance, too. This commit intends not to change the way anything works, even though that might allow more code to be unified. It does unify a bunch of individual variables into a ShutdownRequestPending flag that has is now used by a bunch of different process types, though. Patch by me, reviewed by Andres Freund and Daniel Gustafsson. Discussion: http://postgr.es/m/CA+TgmoZwDk=BguVDVa+qdA6SBKef=PKbaKDQALTC_9qoz1mJqg@mail.gmail.com
* Emit parameter values during query bind/execute errorsAlvaro Herrera2019-12-11
| | | | | | | | | This makes such log entries more useful, since the cause of the error can be dependent on the parameter values. Author: Alexey Bashtanov, Álvaro Herrera Discussion: https://postgr.es/m/0146a67b-a22a-0519-9082-bc29756b93a2@imap.cc Reviewed-by: Peter Eisentraut, Andres Freund, Tom Lane
* Add backend-only appendStringInfoStringQuotedAlvaro Herrera2019-12-10
| | | | | | | | | | | | | | | | This provides a mechanism to emit literal values in informative messages, such as query parameters. The new code is more complex than what it replaces, primarily because it wants to be more efficient. It also has the (currently unused) additional optional capability of specifying a maximum size to print. The new function lives out of common/stringinfo.c so that frontend users of that file need not pull in unnecessary multibyte-encoding support code. Author: Álvaro Herrera and Alexey Bashtanov, after a suggestion from Andres Freund Reviewed-by: Tom Lane Discussion: https://postgr.es/m/20190920203905.xkv5udsd5dxfs6tr@alap3.anarazel.de
* Stabilize NOTIFY behavior by transmitting notifies before ReadyForQuery.Tom Lane2019-11-24
| | | | | | | | | | | | | | | | | | | | | | This patch ensures that, if any notify messages were received during a just-finished transaction, they get sent to the frontend just before not just after the ReadyForQuery message. With libpq and other client libraries that act similarly, this guarantees that the client will see the notify messages as available as soon as it thinks the transaction is done. This probably makes no difference in practice, since in realistic use-cases the application would have to cope with asynchronous arrival of notify events anyhow. However, it makes it a lot easier to build cross-session-notify test cases with stable behavior. I'm a bit surprised now that we've not seen any buildfarm instability with the test cases added by commit b10f40bf0. Tests that I intend to add in an upcoming bug fix are definitely unstable without this. Back-patch to 9.6, which is as far back as we can do NOTIFY testing with the isolationtester infrastructure. Discussion: https://postgr.es/m/13881.1574557302@sss.pgh.pa.us
* Introduce the 'force' option for the Drop Database command.Amit Kapila2019-11-13
| | | | | | | | | | | | | This new option terminates the other sessions connected to the target database and then drop it. To terminate other sessions, the current user must have desired permissions (same as pg_terminate_backend()). We don't allow to terminate the sessions if prepared transactions, active logical replication slots or subscriptions are present in the target database. Author: Pavel Stehule with changes by me Reviewed-by: Dilip Kumar, Vignesh C, Ibrar Ahmed, Anthony Nowocien, Ryan Lambert and Amit Kapila Discussion: https://postgr.es/m/CAP_rwwmLJJbn70vLOZFpxGw3XD7nLB_7+NKz46H5EOO2k5H7OQ@mail.gmail.com
* Make the order of the header file includes consistent in backend modules.Amit Kapila2019-11-12
| | | | | | | | | | | Similar to commits 7e735035f2 and dddf4cdc33, this commit makes the order of header file inclusion consistent for backend modules. In the passing, removed a couple of duplicate inclusions. Author: Vignesh C Reviewed-by: Kuntal Ghosh and Amit Kapila Discussion: https://postgr.es/m/CALDaNm2Sznv8RR6Ex-iJO6xAdsxgWhCoETkaYX=+9DW3q0QCfA@mail.gmail.com
* Allow sampling of statements depending on durationTomas Vondra2019-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows logging a sample of statements, without incurring excessive log traffic (which may impact performance). This can be useful when analyzing workloads with lots of short queries. The sampling is configured using two new GUC parameters: * log_min_duration_sample - minimum required statement duration * log_statement_sample_rate - sample rate (0.0 - 1.0) Only statements with duration exceeding log_min_duration_sample are considered for sampling. To enable sampling, both those GUCs have to be set correctly. The existing log_min_duration_statement GUC has a higher priority, i.e. statements with duration exceeding log_min_duration_statement will be always logged, irrespectedly of how the sampling is configured. This means only configurations log_min_duration_sample < log_min_duration_statement do actually sample the statements, instead of logging everything. Author: Adrien Nayrat Reviewed-by: David Rowley, Vik Fearing, Tomas Vondra Discussion: https://postgr.es/m/bbe0a1a8-a8f7-3be2-155a-888e661cc06c@anayrat.info
* Correct the command tags for ALTER ... RENAME COLUMN.Fujii Masao2019-11-06
| | | | | | | | | | | | | | | | Previously ALTER MATERIALIZED VIEW / FOREIGN TABLE ... RENAME COLUMN ... returned "ALTER TABLE" as a command tag. This commit fixes them so that they return "ALTER MATERIALIZED VIEW" and "ALTER FOREIGN TABLE" as command tags, respectively. This issue exists in all supported versions, but we don't back-patch this because it's not enough of a bug to justify taking any compatibility risks for. Otherwise, the back-patch would cause minor version update to break, for example, the existing event trigger functions using TG_TAG. Author: Fujii Masao Reviewed-by: Ibrar Ahmed Discussion: https://postgr.es/m/CAHGQGwGUaC03FFdTFoHsCuDrrNvFvNVQ6xyd40==P25WvuBJjg@mail.gmail.com
* Split all OBJS style lines in makefiles into one-line-per-entry style.Andres Freund2019-11-05
| | | | | | | | | | | | | | | When maintaining or merging patches, one of the most common sources for conflicts are the list of objects in makefiles. Especially when the split across lines has been changed on both sides, which is somewhat common due to attempting to stay below 80 columns, those conflicts are unnecessarily laborious to resolve. By splitting, and alphabetically sorting, OBJS style lines into one object per line, conflicts should be less frequent, and easier to resolve when they still occur. Author: Andres Freund Discussion: https://postgr.es/m/20191029200901.vww4idgcxv74cwes@alap3.anarazel.de
* PG_FINALLYPeter Eisentraut2019-11-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This gives an alternative way of catching exceptions, for the common case where the cleanup code is the same in the error and non-error cases. So instead of PG_TRY(); { ... code that might throw ereport(ERROR) ... } PG_CATCH(); { cleanup(); PG_RE_THROW(); } PG_END_TRY(); cleanup(); one can write PG_TRY(); { ... code that might throw ereport(ERROR) ... } PG_FINALLY(); { cleanup(); } PG_END_TRY(); Discussion: https://www.postgresql.org/message-id/flat/95a822c3-728b-af0e-d7e5-71890507ae0c%402ndquadrant.com
* Improve management of statement timeouts.Tom Lane2019-10-25
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit f8e5f156b added private state in postgres.c to track whether a statement timeout is running. This seems like bad design to me; timeout.c's private state should be the single source of truth about that. We already fixed one bug associated with failure to keep those states in sync (cf. be42015fc), and I've got little faith that we won't find more in future. So get rid of postgres.c's local variable by exposing a way to ask timeout.c whether a timeout is running. (Obviously, such an inquiry is subject to race conditions, but it seems fine for the purpose at hand.) To make get_timeout_active() as cheap as possible, add a flag in the per-timeout struct showing whether that timeout is active. This allows some small savings elsewhere in timeout.c, mainly elimination of unnecessary searches of the active_timeouts array. While at it, fix enable_statement_timeout to not call disable_timeout when statement_timeout is 0 and the timeout is not running. This avoids a useless deschedule-and-reschedule-timeouts cycle, which represents a significant savings (at least one kernel call) when there is any other active timeout. Right now, there usually isn't, but there are proposals around to change that. Discussion: https://postgr.es/m/16035-456e6e69ebfd4374@postgresql.org
* Reset statement_timeout between queries of a multi-query string.Tom Lane2019-10-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically, we started the timer (if StatementTimeout > 0) at the beginning of a simple-Query message and usually let it run until the end, so that the timeout limit applied to the entire query string, and intra-string changes of the statement_timeout GUC had no effect. But, confusingly, a COMMIT within the string would reset the state and allow a fresh timeout cycle to start with the current setting. Commit f8e5f156b changed the behavior of statement_timeout for extended query protocol, and as an apparently-unintended side effect, a change in the statement_timeout GUC during a multi-statement simple-Query message might have an effect immediately --- but only if it was going from "disabled" to "enabled". This is all pretty confusing, not to mention completely undocumented. Let's change things so that the timeout is always reset between queries of a multi-query string, whether they're transaction control commands or not. Thus the active timeout setting is applied to each query in the string, separately. This costs a few more cycles if statement_timeout is active, but it provides much more intuitive behavior, especially if one changes statement_timeout in one of the queries of the string. Also, add something to the documentation to explain all this. Per bug #16035 from Raj Mohite. Although this is a bug fix, I'm hesitant to back-patch it; conceivably somebody has worked out the old behavior and is depending on it. (But note that this change should make the behavior less restrictive in most cases, since the timeout will now be applied to shorter segments of code.) Discussion: https://postgr.es/m/16035-456e6e69ebfd4374@postgresql.org
* Revert hooks for session start and end, take twoMichael Paquier2019-10-02
| | | | | | | | | | | The location of the session end hook has been chosen so as it is possible to allow modules to do their own transactions, however any trying to any any subsystem which went through before_shmem_exit() would cause issues, limiting the pluggability of the hook. Per discussion with Tom Lane and Andres Freund. Discussion: https://postgr.es/m/18722.1569906636@sss.pgh.pa.us
* Add hooks for session start and session end, take twoMichael Paquier2019-10-01
| | | | | | | | | | | | | | | | These hooks can be used in loadable modules. A simple test module is included. The first attempt was done with cd8ce3a but we lacked handling for NO_INSTALLCHECK in the MSVC scripts (problem solved afterwards by 431f1599) so the buildfarm got angry. This also fixes a couple of issues noticed upon review compared to the first attempt, so the code has slightly changed, resulting in a more simple test module. Author: Fabrízio de Royes Mello, Yugo Nagata Reviewed-by: Andrew Dunstan, Michael Paquier, Aleksandr Parfenov Discussion: https://postgr.es/m/20170720204733.40f2b7eb.nagata@sraoss.co.jp Discussion: https://postgr.es/m/20190823042602.GB5275@paquier.xyz
* Allow setting statistics target for extended statisticsTomas Vondra2019-09-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building statistics, we need to decide how many rows to sample and how accurate the resulting statistics should be. Until now, it was not possible to explicitly define statistics target for extended statistics objects, the value was always computed from the per-attribute targets with a fallback to the system-wide default statistics target. That's a bit inconvenient, as it ties together the statistics target set for per-column and extended statistics. In some cases it may be useful to require larger sample / higher accuracy for extended statics (or the other way around), but with this approach that's not possible. So this commit introduces a new command, allowing to specify statistics target for individual extended statistics objects, overriding the value derived from per-attribute targets (and the system default). ALTER STATISTICS stat_name SET STATISTICS target_value; When determining statistics target for an extended statistics object we first look at this explicitly set value. When this value is -1, we fall back to the old formula, looking at the per-attribute targets first and then the system default. This means the behavior is backwards compatible with older PostgreSQL releases. Author: Tomas Vondra Discussion: https://postgr.es/m/20190618213357.vli3i23vpkset2xd@development Reviewed-by: Kirk Jamison, Dean Rasheed
* Revert "Add log_statement_sample_rate parameter"Tomas Vondra2019-08-04
| | | | | | | | | | | | | | This reverts commit 88bdbd3f746049834ae3cc972e6e650586ec3c9d. As committed, statement sampling used the existing duration threshold (log_min_duration_statement) when decide which statements to sample. The issue is that even the longest statements are subject to sampling, and so may not end up logged. An improvement was proposed, introducing a second duration threshold, but it would not be backwards compatible. So we've decided to revert this feature - the separate threshold should be part of the feature itself. Discussion: https://postgr.es/m/CAFj8pRDS8tQ3Wviw9%3DAvODyUciPSrGeMhJi_WPE%2BEB8%2B4gLL-Q%40mail.gmail.com
* Revert "Silence compiler warning"Tomas Vondra2019-08-04
| | | | | | | | | | | | | | This reverts commit 9dc122585551516309c9362e673effdbf3bd79bd. As committed, statement sampling used the existing duration threshold (log_min_duration_statement) when decide which statements to sample. The issue is that even the longest statements are subject to sampling, and so may not end up logged. An improvement was proposed, introducing a second duration threshold, but it would not be backwards compatible. So we've decided to revert this feature - the separate threshold should be part of the feature itself. Discussion: https://postgr.es/m/CAFj8pRDS8tQ3Wviw9%3DAvODyUciPSrGeMhJi_WPE%2BEB8%2B4gLL-Q%40mail.gmail.com