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* 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
* 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
* Represent Lists as expansible arrays, not chains of cons-cells.Tom Lane2019-07-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Originally, Postgres Lists were a more or less exact reimplementation of Lisp lists, which consist of chains of separately-allocated cons cells, each having a value and a next-cell link. We'd hacked that once before (commit d0b4399d8) to add a separate List header, but the data was still in cons cells. That makes some operations -- notably list_nth() -- O(N), and it's bulky because of the next-cell pointers and per-cell palloc overhead, and it's very cache-unfriendly if the cons cells end up scattered around rather than being adjacent. In this rewrite, we still have List headers, but the data is in a resizable array of values, with no next-cell links. Now we need at most two palloc's per List, and often only one, since we can allocate some values in the same palloc call as the List header. (Of course, extending an existing List may require repalloc's to enlarge the array. But this involves just O(log N) allocations not O(N).) Of course this is not without downsides. The key difficulty is that addition or deletion of a list entry may now cause other entries to move, which it did not before. For example, that breaks foreach() and sister macros, which historically used a pointer to the current cons-cell as loop state. We can repair those macros transparently by making their actual loop state be an integer list index; the exposed "ListCell *" pointer is no longer state carried across loop iterations, but is just a derived value. (In practice, modern compilers can optimize things back to having just one loop state value, at least for simple cases with inline loop bodies.) In principle, this is a semantics change for cases where the loop body inserts or deletes list entries ahead of the current loop index; but I found no such cases in the Postgres code. The change is not at all transparent for code that doesn't use foreach() but chases lists "by hand" using lnext(). The largest share of such code in the backend is in loops that were maintaining "prev" and "next" variables in addition to the current-cell pointer, in order to delete list cells efficiently using list_delete_cell(). However, we no longer need a previous-cell pointer to delete a list cell efficiently. Keeping a next-cell pointer doesn't work, as explained above, but we can improve matters by changing such code to use a regular foreach() loop and then using the new macro foreach_delete_current() to delete the current cell. (This macro knows how to update the associated foreach loop's state so that no cells will be missed in the traversal.) There remains a nontrivial risk of code assuming that a ListCell * pointer will remain good over an operation that could now move the list contents. To help catch such errors, list.c can be compiled with a new define symbol DEBUG_LIST_MEMORY_USAGE that forcibly moves list contents whenever that could possibly happen. This makes list operations significantly more expensive so it's not normally turned on (though it is on by default if USE_VALGRIND is on). There are two notable API differences from the previous code: * lnext() now requires the List's header pointer in addition to the current cell's address. * list_delete_cell() no longer requires a previous-cell argument. These changes are somewhat unfortunate, but on the other hand code using either function needs inspection to see if it is assuming anything it shouldn't, so it's not all bad. Programmers should be aware of these significant performance changes: * list_nth() and related functions are now O(1); so there's no major access-speed difference between a list and an array. * Inserting or deleting a list element now takes time proportional to the distance to the end of the list, due to moving the array elements. (However, it typically *doesn't* require palloc or pfree, so except in long lists it's probably still faster than before.) Notably, lcons() used to be about the same cost as lappend(), but that's no longer true if the list is long. Code that uses lcons() and list_delete_first() to maintain a stack might usefully be rewritten to push and pop at the end of the list rather than the beginning. * There are now list_insert_nth...() and list_delete_nth...() functions that add or remove a list cell identified by index. These have the data-movement penalty explained above, but there's no search penalty. * list_concat() and variants now copy the second list's data into storage belonging to the first list, so there is no longer any sharing of cells between the input lists. The second argument is now declared "const List *" to reflect that it isn't changed. This patch just does the minimum needed to get the new implementation in place and fix bugs exposed by the regression tests. As suggested by the foregoing, there's a fair amount of followup work remaining to do. Also, the ENABLE_LIST_COMPAT macros are finally removed in this commit. Code using those should have been gone a dozen years ago. Patch by me; thanks to David Rowley, Jesper Pedersen, and others for review. Discussion: https://postgr.es/m/11587.1550975080@sss.pgh.pa.us
* Reduce memory consumption for multi-statement query strings.Tom Lane2019-07-10
| | | | | | | | | | | | | | | | | | | | | | | | | | Previously, exec_simple_query always ran parse analysis, rewrite, and planning in MessageContext, allowing all the data generated thereby to persist until the end of processing of the whole query string. That's fine for single-command strings, but if a client sends many commands in a single simple-Query message, this strategy could result in annoying memory bloat, as complained of by Andreas Seltenreich. To fix, create a child context to do this work in, and reclaim it after each command. But we only do so for parsetrees that are not last in their query string. That avoids adding any memory management overhead for the typical case of a single-command string. Memory allocated for the last parsetree would be freed immediately after finishing the command string anyway. Similarly, adjust extension.c's execute_sql_string() to reclaim memory after each command. In that usage, multi-command strings are the norm, so it's a bit surprising that no one has yet complained of bloat --- especially since the bloat extended to whatever data ProcessUtility execution might leak. Amit Langote, reviewed by Julien Rouhaud Discussion: https://postgr.es/m/87ftp6l2qr.fsf@credativ.de
* Log all statements from a sample of transactionsAlvaro Herrera2019-04-03
| | | | | | | | This is useful to obtain a view of the different transaction types in an application, regardless of the durations of the statements each runs. Author: Adrien Nayrat Reviewed-by: Masahiko Sawada, Hayato Kuroda, Andres Freund
* Refactor ParamListInfo initializationPeter Eisentraut2019-03-14
| | | | | There were six copies of identical nontrivial code. Put it into a function.
* More unconstify usePeter Eisentraut2019-02-13
| | | | | | | Replace casts whose only purpose is to cast away const with the unconstify() macro. Discussion: https://www.postgresql.org/message-id/flat/53a28052-f9f3-1808-fed9-460fd43035ab%402ndquadrant.com
* Refactor planner's header files.Tom Lane2019-01-29
| | | | | | | | | | | | | | | | | | | | | | | | Create a new header optimizer/optimizer.h, which exposes just the planner functions that can be used "at arm's length", without need to access Paths or the other planner-internal data structures defined in nodes/relation.h. This is intended to provide the whole planner API seen by most of the rest of the system; although FDWs still need to use additional stuff, and more thought is also needed about just what selfuncs.c should rely on. The main point of doing this now is to limit the amount of new #include baggage that will be needed by "planner support functions", which I expect to introduce later, and which will be in relevant datatype modules rather than anywhere near the planner. This commit just moves relevant declarations into optimizer.h from other header files (a couple of which go away because everything got moved), and adjusts #include lists to match. There's further cleanup that could be done if we want to decide that some stuff being exposed by optimizer.h doesn't belong in the planner at all, but I'll leave that for another day. Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us
* Fix misc typos in comments.Heikki Linnakangas2019-01-23
| | | | | | Spotted mostly by Fabien Coelho. Discussion: https://www.postgresql.org/message-id/alpine.DEB.2.21.1901230947050.16643@lancre
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Silence compiler warningAlvaro Herrera2018-11-30
| | | | | | | My original coding was questionable anyway. Reported-by: Sergei Kornilov Discussion: https://postgr.es/m/9645101543575886@myt6-27270b78ac4f.qloud-c.yandex.net
* Add log_statement_sample_rate parameterAlvaro Herrera2018-11-29
| | | | | | | | | | This allows to set a lower log_min_duration_statement value without incurring excessive log traffic (which reduces performance). This can be useful to analyze workloads with lots of short queries. Author: Adrien Nayrat Reviewed-by: David Rowley, Vik Fearing Discussion: https://postgr.es/m/c30ee535-ee1e-db9f-fa97-146b9f62caed@anayrat.info
* Server-side fix for delayed NOTIFY and SIGTERM processing.Tom Lane2018-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4f85fde8e introduced some code that was meant to ensure that we'd process cancel, die, sinval catchup, and notify interrupts while waiting for client input. But there was a flaw: it supposed that the process latch would be set upon arrival at secure_read() if any such interrupt was pending. In reality, we might well have cleared the process latch at some earlier point while those flags remained set -- particularly notifyInterruptPending, which can't be handled as long as we're within a transaction. To fix the NOTIFY case, also attempt to process signals (except ProcDiePending) before trying to read. Also, if we see that ProcDiePending is set before we read, forcibly set the process latch to ensure that we will handle that signal promptly if no data is available. I also made it set the process latch on the way out, in case there is similar logic elsewhere. (It remains true that we won't service ProcDiePending here unless we need to wait for input.) The code for handling ProcDiePending during a write needs those changes, too. Also be a little more careful about when to reset whereToSendOutput, and improve related comments. Back-patch to 9.5 where this code was added. I'm not entirely convinced that older branches don't have similar issues, but the complaint at hand is just about the >= 9.5 code. Jeff Janes and Tom Lane Discussion: https://postgr.es/m/CAOYf6ec-TmRYjKBXLLaGaB-jrd=mjG1Hzn1a1wufUAR39PQYhw@mail.gmail.com
* Refactor pid, random seed and start time initialization.Thomas Munro2018-10-19
| | | | | | | | | | | | | | | | | | | | | | | | Background workers, including parallel workers, were generating the same sequence of numbers in random(). This showed up as DSM handle collisions when Parallel Hash created multiple segments, but any code that calls random() in background workers could be affected if it cares about different backends generating different numbers. Repair by making sure that all new processes initialize the seed at the same time as they set MyProcPid and MyStartTime in a new function InitProcessGlobals(), called by the postmaster, its children and also standalone processes. Also add a new high resolution MyStartTimestamp as a potentially useful by-product, and remove SessionStartTime from struct Port as it is now redundant. No back-patch for now, as the known consequences so far are just a bunch of harmless shm_open(O_EXCL) collisions. Author: Thomas Munro Reviewed-by: Tom Lane Discussion: https://postgr.es/m/CAEepm%3D2eJj_6%3DB%2B2tEpGu2nf1BjthCf9nXXUouYvJJ4C5WSwhg%40mail.gmail.com
* Add a debugging option to stress-test outfuncs.c and readfuncs.c.Tom Lane2018-09-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the normal course of operation, query trees will be serialized only if they are stored as views or rules; and plan trees will be serialized only if they get passed to parallel-query workers. This leaves an awful lot of opportunity for bugs/oversights to not get detected, as indeed we've just been reminded of the hard way. To improve matters, this patch adds a new compile option WRITE_READ_PARSE_PLAN_TREES, which is modeled on the longstanding option COPY_PARSE_PLAN_TREES; but instead of passing all parse and plan trees through copyObject, it passes them through nodeToString + stringToNode. Enabling this option in a buildfarm animal or two will catch problems at least for cases that are exercised by the regression tests. A small problem with this idea is that readfuncs.c historically has discarded location fields, on the reasonable grounds that parse locations in a retrieved view are not relevant to the current query. But doing that in WRITE_READ_PARSE_PLAN_TREES breaks pg_stat_statements, and it could cause problems for future improvements that might try to report error locations at runtime. To fix that, provide a variant behavior in readfuncs.c that makes it restore location fields when told to. In passing, const-ify the string arguments of stringToNode and its subsidiary functions, just because it annoyed me that they weren't const already. Discussion: https://postgr.es/m/17114.1537138992@sss.pgh.pa.us
* Introduce minimal C99 usage to verify compiler support.Andres Freund2018-08-23
| | | | | | | | | This just converts a few for loops in postgres.c to declare variables in the loop initializer, and uses designated initializers in smgr.c's definition of smgr callbacks. Author: Andres Freund Discussion: https://postgr.es/m/97d4b165-192d-3605-749c-f614a0c4e783@2ndquadrant.com
* Don't run atexit callbacks in quickdie signal handlers.Heikki Linnakangas2018-08-08
| | | | | | | | | | | | | | | | | exit() is not async-signal safe. Even if the libc implementation is, 3rd party libraries might have installed unsafe atexit() callbacks. After receiving SIGQUIT, we really just want to exit as quickly as possible, so we don't really want to run the atexit() callbacks anyway. The original report by Jimmy Yih was a self-deadlock in startup_die(). However, this patch doesn't address that scenario; the signal handling while waiting for the startup packet is more complicated. But at least this alleviates similar problems in the SIGQUIT handlers, like that reported by Asim R P later in the same thread. Backpatch to 9.3 (all supported versions). Discussion: https://www.postgresql.org/message-id/CAOMx_OAuRUHiAuCg2YgicZLzPVv5d9_H4KrL_OFsFP%3DVPekigA%40mail.gmail.com
* Fix SPI error cleanup and memory leakPeter Eisentraut2018-05-03
| | | | | | | | | | | | Since the SPI stack has been moved from TopTransactionContext to TopMemoryContext, setting _SPI_stack to NULL in AtEOXact_SPI() leaks memory. In fact, we don't need to do that anymore: We just leave the allocated stack around for the next SPI use. Also, refactor the SPI cleanup so that it is run both at transaction end and when returning to the main loop on an exception. The latter is necessary when a procedure calls a COMMIT or ROLLBACK command that itself causes an error.
* Clean up warnings from -Wimplicit-fallthrough.Tom Lane2018-05-01
| | | | | | | | | | | | | | | | | | | | | | | | | Recent gcc can warn about switch-case fall throughs that are not explicitly labeled as intentional. This seems like a good thing, so clean up the warnings exposed thereby by labeling all such cases with comments that gcc will recognize. In files that already had one or more suitable comments, I generally matched the existing style of those. Otherwise I went with /* FALLTHROUGH */, which is one of the spellings approved at the more-restrictive-than-default level -Wimplicit-fallthrough=4. (At the default level you can also spell it /* FALL ?THRU */, and it's not picky about case. What you can't do is include additional text in the same comment, so some existing comments containing versions of this aren't good enough.) Testing with gcc 8.0.1 (Fedora 28's current version), I found that I also had to put explicit "break"s after elog(ERROR) or ereport(ERROR); apparently, for this purpose gcc doesn't recognize that those don't return. That seems like possibly a gcc bug, but it's fine because in most places we did that anyway; so this amounts to a visit from the style police. Discussion: https://postgr.es/m/15083.1525207729@sss.pgh.pa.us
* Allow group access on PGDATAStephen Frost2018-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | Allow the cluster to be optionally init'd with read access for the group. This means a relatively non-privileged user can perform a backup of the cluster without requiring write privileges, which enhances security. The mode of PGDATA is used to determine whether group permissions are enabled for directory and file creates. This method was chosen as it's simple and works well for the various utilities that write into PGDATA. Changing the mode of PGDATA manually will not automatically change the mode of all the files contained therein. If the user would like to enable group access on an existing cluster then changing the mode of all the existing files will be required. Note that pg_upgrade will automatically change the mode of all migrated files if the new cluster is init'd with the -g option. Tests are included for the backend and all the utilities which operate on the PG data directory to ensure that the correct mode is set based on the data directory permissions. Author: David Steele <david@pgmasters.net> Reviewed-By: Michael Paquier, with discussion amongst many others. Discussion: https://postgr.es/m/ad346fe6-b23e-59f1-ecb7-0e08390ad629%40pgmasters.net
* Allow background workers to bypass datallowconnMagnus Hagander2018-04-05
| | | | | | | THis adds a "flags" field to the BackgroundWorkerInitializeConnection() and BackgroundWorkerInitializeConnectionByOid(). For now only one flag, BGWORKER_BYPASS_ALLOWCONN, is defined, which allows the worker to ignore datallowconn.
* Allow committing inside cursor loopPeter Eisentraut2018-03-28
| | | | | | | | | | | | | | | Previously, committing or aborting inside a cursor loop was prohibited because that would close and remove the cursor. To allow that, automatically convert such cursors to holdable cursors so they survive commits or rollbacks. Portals now have a new state "auto-held", which means they have been converted automatically from pinned. An auto-held portal is kept on transaction commit or rollback, but is still removed when returning to the main loop on error. This supports all languages that have cursor loop constructs: PL/pgSQL, PL/Python, PL/Perl. Reviewed-by: Ildus Kurbangaliev <i.kurbangaliev@postgrespro.ru>
* Basic JIT provider and error handling infrastructure.Andres Freund2018-03-21
| | | | | | | | | | | | | | | | | | | | This commit introduces: 1) JIT provider abstraction, which allows JIT functionality to be implemented in separate shared libraries. That's desirable because it allows to install JIT support as a separate package, and because it allows experimentation with different forms of JITing. 2) JITContexts which can be, using functions introduced in follow up commits, used to emit JITed functions, and have them be cleaned up on error. 3) The outline of a LLVM JIT provider, which will be fleshed out in subsequent commits. Documentation for GUCs added, and for JIT in general, will be added in later commits. Author: Andres Freund, with architectural input from Jeff Davis Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de
* Clear stmt_timeout_active if we disable_all_timeouts.Robert Haas2018-02-09
| | | | | | | | | | | Otherwise, we can end up with the flag set when the timeout is actually disabled, leading to misbehavior. Commit f8e5f156b30efee5d0038b03e38735773abcb7ed introduced this bug. Reported by Peter Eisentraut. Analysis and fix by Thomas Munro, tweaked by me. Discussion: http://postgr.es/m/6a909374-2602-7136-8c70-397330a418f3@2ndquadrant.com
* Update portal-related memory context names and APIPeter Eisentraut2018-01-09
| | | | | | | | | | | | | Rename PortalMemory to TopPortalContext, to avoid confusion with PortalContext and align naming with similar top-level memory contexts. Rename PortalData's "heap" field to portalContext. The "heap" naming seems quite antiquated and confusing. Also get rid of the PortalGetHeapMemory() macro and access the field directly, which we do for other portal fields, so this abstraction doesn't buy anything. Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Rearrange execution of PARAM_EXTERN Params for plpgsql's benefit.Tom Lane2017-12-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch does three interrelated things: * Create a new expression execution step type EEOP_PARAM_CALLBACK and add the infrastructure needed for add-on modules to generate that. As discussed, the best control mechanism for that seems to be to add another hook function to ParamListInfo, which will be called by ExecInitExpr if it's supplied and a PARAM_EXTERN Param is found. For stand-alone expressions, we add a new entry point to allow the ParamListInfo to be specified directly, since it can't be retrieved from the parent plan node's EState. * Redesign the API for the ParamListInfo paramFetch hook so that the ParamExternData array can be entirely virtual. This also lets us get rid of ParamListInfo.paramMask, instead leaving it to the paramFetch hook to decide which param IDs should be accessible or not. plpgsql_param_fetch was already doing the identical masking check, so having callers do it too seemed redundant. While I was at it, I added a "speculative" flag to paramFetch that the planner can specify as TRUE to avoid unwanted failures. This solves an ancient problem for plpgsql that it couldn't provide values of non-DTYPE_VAR variables to the planner for fear of triggering premature "record not assigned yet" or "field not found" errors during planning. * Rework plpgsql to get rid of the need for "unshared" parameter lists, by dint of turning the single ParamListInfo per estate into a nearly read-only data structure that doesn't instantiate any per-variable data. Instead, the paramFetch hook controls access to per-variable data and can make the right decisions on the fly, replacing the cases that we used to need multiple ParamListInfos for. This might perhaps have been a performance loss on its own, but by using a paramCompile hook we can bypass plpgsql_param_fetch entirely during normal query execution. (It's now only called when, eg, we copy the ParamListInfo into a cursor portal. copyParamList() or SerializeParamList() effectively instantiate the virtual parameter array as a simple physical array without a paramFetch hook, which is what we want in those cases.) This allows reverting most of commit 6c82d8d1f, though I kept the cosmetic code-consolidation aspects of that (eg the assign_simple_var function). Performance testing shows this to be at worst a break-even change, and it can provide wins ranging up to 20% in test cases involving accesses to fields of "record" variables. The fact that values of such variables can now be exposed to the planner might produce wins in some situations, too, but I've not pursued that angle. In passing, remove the "parent" pointer from the arguments to ExecInitExprRec and related functions, instead storing that pointer in a transient field in ExprState. The ParamListInfo pointer for a stand-alone expression is handled the same way; we'd otherwise have had to add yet another recursively-passed-down argument in expression compilation. Discussion: https://postgr.es/m/32589.1513706441@sss.pgh.pa.us
* Update typedefs.list and re-run pgindentRobert Haas2017-11-29
| | | | Discussion: http://postgr.es/m/CA+TgmoaA9=1RWKtBWpDaj+sF3Stgc8sHgf5z=KGtbjwPLQVDMA@mail.gmail.com
* Back out the session_start and session_end hooks feature.Andrew Dunstan2017-11-16
| | | | | | | | | | It's become apparent during testing that there are problems with at least the testing regime. I don't think we should have it without a working test regime, and the difficulties might indicate implementation problems anyway, so I'm backing out the whole thing until that's sorted out. This reverts commits 7459484 9989f92 cd8ce3a
* Add hooks for session start and session endAndrew Dunstan2017-11-15
| | | | | | | | | | These hooks can be used in loadable modules. A simple test module is included. Discussion: https://postgr.es/m/20170720204733.40f2b7eb.nagata@sraoss.co.jp Fabrízio de Royes Mello and Yugo Nagata Reviewed by Michael Paquier and Aleksandr Parfenov
* Change TRUE/FALSE to true/falsePeter Eisentraut2017-11-08
| | | | | | | | | | | | | | The lower case spellings are C and C++ standard and are used in most parts of the PostgreSQL sources. The upper case spellings are only used in some files/modules. So standardize on the standard spellings. The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so those are left as is when using those APIs. In code comments, we use the lower-case spelling for the C concepts and keep the upper-case spelling for the SQL concepts. Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
* Replace remaining uses of pq_sendint with pq_sendint{8,16,32}.Andres Freund2017-10-11
| | | | | | | pq_sendint() remains, so extension code doesn't unnecessarily break. Author: Andres Freund Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
* Improve performance of SendRowDescriptionMessage.Andres Freund2017-10-11
| | | | | | | | | | | | | | | There's three categories of changes leading to better performance: - Splitting the per-attribute part of SendRowDescriptionMessage into a v2 and a v3 version allows avoiding branches for every attribute. - Preallocating the size of the buffer to be big enough for all attributes and then using pq_write* avoids unnecessary buffer size checks & resizing. - Reusing a persistently allocated StringInfo for all SendRowDescriptionMessage() invocations avoids repeated allocations & reallocations. Author: Andres Freund Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
* Prevent idle in transaction session timeout from sometimes being ignored.Andres Freund2017-10-11
| | | | | | | | | | | | | | | | | | | | | | | The previous coding in ProcessInterrupts() could lead to idle_in_transaction_session_timeout being ignored, when statement_timeout occurred earlier. The problem was that ProcessInterrupts() would return before processing the transaction timeout if QueryCancelPending was set while QueryCancelHoldoffCount != 0 - which is the case when reading new commands from the client. Ergo when the idle transaction timeout would hit. Fix that by removing the early return. Alternatively the transaction timeout code could have been moved up, but that early return seems like an issue that could hit other cases too. Author: Lukas Fittl Bug: #14821 Discussion: https://www.postgresql.org/message-id/20170921010956.17345.61461%40wrigleys.postgresql.org https://www.postgresql.org/message-id/CAP53PkxQnv3OWJpyNPGJYT62uY=n1=2CF_Lpc6gVOFnc0-gazw@mail.gmail.com Backpatch: 9.6-, where idle_in_transaction_session_timeout was introduced.
* Rearm statement_timeout after each executed query.Andres Freund2017-09-18
| | | | | | | | | | | | | | | | | | Previously statement_timeout, in the extended protocol, affected all messages till a Sync message. For clients that pipeline/batch query execution that's problematic. Instead disable timeout after each Execute message, and enable, if necessary, the timer in start_xact_command(). As that's done only for Execute and not Parse / Bind, pipelining the latter two could still cause undesirable timeouts. But a survey of protocol implementations shows that all drivers issue Sync messages when preparing, and adding timeout rearming to both is fairly expensive for the common parse / bind / execute sequence. Author: Tatsuo Ishii, editorialized by Andres Freund Reviewed-By: Takayuki Tsunakawa, Andres Freund Discussion: https://postgr.es/m/20170222.115044.1665674502985097185.t-ishii@sraoss.co.jp
* Fix crash restart bug introduced in 8356753c212.Andres Freund2017-09-18
| | | | | | | | | | | | | | | | | | The bug was caused by not re-reading the control file during crash recovery restarts, which lead to an attempt to pfree() shared memory contents. The fix is to re-read the control file, which seems good anyway. It's unclear as of this moment, whether we want to keep the refactoring introduced in the commit referenced above, or come up with an alternative approach. But fixing the bug in the mean time seems like a good idea regardless. A followup commit will introduce regression test coverage for crash restarts. Reported-By: Tom Lane Discussion: https://postgr.es/m/14134.1505572349@sss.pgh.pa.us
* Perform only one ReadControlFile() during startup.Andres Freund2017-09-14
| | | | | | | | | | | | | Previously we read the control file in multiple places. But soon the segment size will be configurable and stored in the control file, and that needs to be available earlier than it currently is needed. Instead of adding yet another place where it's read, refactor things so there's a single processing of the control file during startup (in EXEC_BACKEND that's every individual backend's startup). Author: Andres Freund Discussion: http://postgr.es/m/20170913092828.aozd3gvvmw67gmyc@alap3.anarazel.de
* Reduce excessive dereferencing of function pointersPeter Eisentraut2017-09-07
| | | | | | | | | | | | It is equivalent in ANSI C to write (*funcptr) () and funcptr(). These two styles have been applied inconsistently. After discussion, we'll use the more verbose style for plain function pointer variables, to make it clear that it's a variable, and the shorter style when the function pointer is in a struct (s.func() or s->func()), because then it's clear that it's not a plain function name, and otherwise the excessive punctuation makes some of those invocations hard to read. Discussion: https://www.postgresql.org/message-id/f52c16db-14ed-757d-4b48-7ef360b1631d@2ndquadrant.com
* Fix handling of savepoint commands within multi-statement Query strings.Tom Lane2017-09-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Issuing a savepoint-related command in a Query message that contains multiple SQL statements led to a FATAL exit with a complaint about "unexpected state STARTED". This is a shortcoming of commit 4f896dac1, which attempted to prevent such misbehaviors in multi-statement strings; its quick hack of marking the individual statements as "not top-level" does the wrong thing in this case, and isn't a very accurate description of the situation anyway. To fix, let's introduce into xact.c an explicit model of what happens for multi-statement Query strings. This is an "implicit transaction block in progress" state, which for many purposes works like the normal TBLOCK_INPROGRESS state --- in particular, IsTransactionBlock returns true, causing the desired result that PreventTransactionChain will throw error. But in case of error abort it works like TBLOCK_STARTED, allowing the transaction to be cancelled without need for an explicit ROLLBACK command. Commit 4f896dac1 is reverted in toto, so that we go back to treating the individual statements as "top level". We could have left it as-is, but this allows sharpening the error message for PreventTransactionChain calls inside functions. Except for getting a normal error instead of a FATAL exit for savepoint commands, this patch should result in no user-visible behavioral change (other than that one error message rewording). There are some things we might want to do in the line of changing the appearance or wording of error and warning messages around this behavior, which would be much simpler to do now that it's an explicitly modeled state. But I haven't done them here. Although this fixes a long-standing bug, no backpatch. The consequences of the bug don't seem severe enough to justify the risk that this commit itself creates some new issue. Patch by me, but it owes something to previous investigation by Takayuki Tsunakawa, who also reported the bug in the first place. Also thanks to Michael Paquier for reviewing. Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F6BE40D@G01JPEXMBYT05
* Add memory info to getrusage outputPeter Eisentraut2017-09-01
| | | | | | | | Add the maxrss field to the getrusage output (log_*_stats). This was previously omitted because of portability concerns, but we feel this might not be a concern anymore. based on patch by Justin Pryzby <pryzby@telsasoft.com>
* Phase 3 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Phase 2 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Restart logical replication launcher when killedPeter Eisentraut2017-06-21
| | | | Author: Yugo Nagata <nagata@sraoss.co.jp>
* Initial pgindent run with pg_bsd_indent version 2.0.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new indent version includes numerous fixes thanks to Piotr Stefaniak. The main changes visible in this commit are: * Nicer formatting of function-pointer declarations. * No longer unexpectedly removes spaces in expressions using casts, sizeof, or offsetof. * No longer wants to add a space in "struct structname *varname", as well as some similar cases for const- or volatile-qualified pointers. * Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely. * Fixes bug where comments following declarations were sometimes placed with no space separating them from the code. * Fixes some odd decisions for comments following case labels. * Fixes some cases where comments following code were indented to less than the expected column 33. On the less good side, it now tends to put more whitespace around typedef names that are not listed in typedefs.list. This might encourage us to put more effort into typedef name collection; it's not really a bug in indent itself. There are more changes coming after this round, having to do with comment indentation and alignment of lines appearing within parentheses. I wanted to limit the size of the diffs to something that could be reviewed without one's eyes completely glazing over, so it seemed better to split up the changes as much as practical. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Re-run pgindent.Tom Lane2017-06-13
| | | | | | | | This is just to have a clean base state for testing of Piotr Stefaniak's latest version of FreeBSD indent. I fixed up a couple of places where pgindent would have changed format not-nicely. perltidy not included. Discussion: https://postgr.es/m/VI1PR03MB119959F4B65F000CA7CD9F6BF2CC0@VI1PR03MB1199.eurprd03.prod.outlook.com
* Use standard interrupt handling in logical replication launcher.Andres Freund2017-06-08
| | | | | | | | | | | | | | | Previously the exit handling was only able to exit from within the main loop, and not from within the backend code it calls. Fix that by using the standard die() SIGTERM handler, and adding the necessary CHECK_FOR_INTERRUPTS() call. This requires adding yet another process-type-specific branch to ProcessInterrupts(), which hints that we probably should generalize that handling. But that's work for another day. Author: Petr Jelinek Reviewed-By: Andres Freund Discussion: https://postgr.es/m/fe072153-babd-3b5d-8052-73527a6eb657@2ndquadrant.com