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* Fix inconsistencies in the codeMichael Paquier2019-07-08
| | | | | | | | | | | This addresses a couple of issues in the code: - Typos and inconsistencies in comments and function declarations. - Removal of unreferenced function declarations. - Removal of unnecessary compile flags. - A cleanup error in regressplans.sh. Author: Alexander Lakhin Discussion: https://postgr.es/m/0c991fdf-2670-1997-c027-772a420c4604@gmail.com
* Use consistent style for checking return from system callsPeter Eisentraut2019-07-07
| | | | | | | | | | | | | | | | | Use if (something() != 0) error ... instead of just if (something) error ... The latter is not incorrect, but it's a bit confusing and not the common style. Discussion: https://www.postgresql.org/message-id/flat/5de61b6b-8be9-7771-0048-860328efe027%402ndquadrant.com
* Unwind some workarounds for lack of portable int64 format specifierPeter Eisentraut2019-07-04
| | | | | | | | | | | | | | Because there is no portable int64/uint64 format specifier and we can't stick macros like INT64_FORMAT into the middle of a translatable string, we have been using various workarounds that put the number to be printed into a string buffer first. Now that we always use our own sprintf(), we can rely on %lld and %llu to work, so we can use those. This patch undoes this workaround in a few places where it was egregiously verbose. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/CAH2-Wz%3DWbNxc5ob5NJ9yqo2RMJ0q4HXDS30GVCobeCvC9A1L9A%40mail.gmail.com
* Don't call data type input functions in GUC check hooksPeter Eisentraut2019-06-30
| | | | | | | | | | | | | | | | | | | | Instead of calling pg_lsn_in() in check_recovery_target_lsn and timestamptz_in() in check_recovery_target_time, reorganize the respective code so that we don't raise any errors in the check hooks. The previous code tried to use PG_TRY/PG_CATCH to handle errors in a way that is not safe, so now the code contains no ereport() calls and can operate safely within the GUC error handling system. Moreover, since the interpretation of the recovery_target_time string may depend on the time zone, we cannot do the final processing of that string until all the GUC processing is done. Instead, check_recovery_target_time() now does some parsing for syntax checking, but the actual conversion to a timestamptz value is done later in the recovery code that uses it. Reported-by: Andres Freund <andres@anarazel.de> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/20190611061115.njjwkagvxp4qujhp%40alap3.anarazel.de
* Fix more typos and inconsistencies in the treeMichael Paquier2019-06-17
| | | | | Author: Alexander Lakhin Discussion: https://postgr.es/m/0a5419ea-1452-a4e6-72ff-545b1a5a8076@gmail.com
* Update stale comments, and fix comment typos.Noah Misch2019-06-08
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* Fix assorted inconsistencies.Amit Kapila2019-06-08
| | | | | | | | | | There were a number of issues in the recent commits which include typos, code and comments mismatch, leftover function declarations. Fix them. Reported-by: Alexander Lakhin Author: Alexander Lakhin, Amit Kapila and Amit Langote Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/ef0c0232-0c1d-3a35-63d4-0ebd06e31387@gmail.com
* Phase 2 pgindent run for v12.Tom Lane2019-05-22
| | | | | | | | | Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
* Initial pgindent run for v12.Tom Lane2019-05-22
| | | | | | | | This is still using the 2.0 version of pg_bsd_indent. I thought it would be good to commit this separately, so as to document the differences between 2.0 and 2.1 behavior. Discussion: https://postgr.es/m/16296.1558103386@sss.pgh.pa.us
* Fix comment for issue_xlog_fsync().Fujii Masao2019-05-21
| | | | | | | "segno" is the argument for the function, not "log" and "seg". Author: Antonin Houska Discussion: https://postgr.es/m/11863.1558361020@spoje.net
* Clean up the behavior and API of catalog.c's is-catalog-relation tests.Tom Lane2019-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The right way for IsCatalogRelation/Class to behave is to return true for OIDs less than FirstBootstrapObjectId (not FirstNormalObjectId), without any of the ad-hoc fooling around with schema membership. The previous code was wrong because (1) it claimed that information_schema tables were not catalog relations but their toast tables were, which is silly; and (2) if you dropped and recreated information_schema, which is a supported operation, the behavior changed. That's even sillier. With this definition, "catalog relations" are exactly the ones traceable to the postgres.bki data, which seems like what we want. With this simplification, we don't actually need access to the pg_class tuple to identify a catalog relation; we only need its OID. Hence, replace IsCatalogClass with "IsCatalogRelationOid(oid)". But keep IsCatalogRelation as a convenience function. This allows fixing some arguably-wrong semantics in contrib/sepgsql and ReindexRelationConcurrently, which were using an IsSystemNamespace test where what they really should be using is IsCatalogRelationOid. The previous coding failed to protect toast tables of system catalogs, and also was not on board with the general principle that user-created tables do not become catalogs just by virtue of being renamed into pg_catalog. We can also get rid of a messy hack in ReindexMultipleTables. While we're at it, also rename IsSystemNamespace to IsCatalogNamespace, because the previous name invited confusion with the more expansive semantics used by IsSystemRelation/Class. Also improve the comments in catalog.c. There are a few remaining places in replication-related code that are special-casing OIDs below FirstNormalObjectId. I'm inclined to think those are wrong too, and if there should be any special case it should just extend to FirstBootstrapObjectId. But first we need to debate whether a FOR ALL TABLES publication should include information_schema. Discussion: https://postgr.es/m/21697.1557092753@sss.pgh.pa.us Discussion: https://postgr.es/m/15150.1557257111@sss.pgh.pa.us
* Remove leftover reference to old "flat file" mechanism in a comment.Heikki Linnakangas2019-05-08
| | | | The flat file mechanism was removed in PostgreSQL 9.0.
* Revert "Avoid the creation of the free space map for small heap relations".Amit Kapila2019-05-07
| | | | | | | | | | | | | | | | | | | | | This feature was using a process local map to track the first few blocks in the relation. The map was reset each time we get the block with enough freespace. It was discussed that it would be better to track this map on a per-relation basis in relcache and then invalidate the same whenever vacuum frees up some space in the page or when FSM is created. The new design would be better both in terms of API design and performance. List of commits reverted, in reverse chronological order: 06c8a5090e Improve code comments in b0eaa4c51b. 13e8643bfc During pg_upgrade, conditionally skip transfer of FSMs. 6f918159a9 Add more tests for FSM. 9c32e4c350 Clear the local map when not used. 29d108cdec Update the documentation for FSM behavior.. 08ecdfe7e5 Make FSM test portable. b0eaa4c51b Avoid creation of the free space map for small heap relations. Discussion: https://postgr.es/m/20190416180452.3pm6uegx54iitbt5@alap3.anarazel.de
* Message style fixesAlvaro Herrera2019-04-30
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* Simplify some ERROR paths clearing wait events and transient filesMichael Paquier2019-04-17
| | | | | | | | | | | | | | Transient files and wait events get normally cleaned up when seeing an exception (be it in the context of a transaction for a backend or another process like the checkpointer), hence there is little point in complicating error code paths to do this work. This shaves a bit of code, and removes some extra handling with errno which needed to be preserved during the cleanup steps done. Reported-by: Masahiko Sawada Author: Michael Paquier Reviewed-by: Tom Lane, Masahiko Sawada Discussion: https://postgr.es/m/CAD21AoDhHYVq5KkXfkaHhmjA-zJYj-e4teiRAJefvXuKJz1tKQ@mail.gmail.com
* Fix GetNewTransactionId()'s interaction with xidVacLimit.Thomas Munro2019-04-12
| | | | | | | | | | | | | | | Commit ad308058 switched to returning a FullTransactionId, but failed to load the potentially updated value in the case where xidVacLimit is reached and we release and reacquire the lock. Repair, closing bug #15727. While reviewing that commit, also fix the size computation used by EstimateTransactionStateSize() and switch to the mul_size() macro traditionally used in such expressions. Author: Thomas Munro Reported-by: Roman Zharkov Discussion: https://postgr.es/m/15727-0be246e7d852d229%40postgresql.org
* Avoid counting transaction stats for parallel worker cooperatingAmit Kapila2019-04-10
| | | | | | | | | | | | | | | | | | | | | | transaction. The transaction that is initiated by the parallel worker to cooperate with the actual transaction started by the main backend to complete the query execution should not be counted as a separate transaction. The other internal transactions started and committed by the parallel worker are still counted as separate transactions as we that is what we do in other places like autovacuum. This will partially fix the bloat in transaction stats due to additional transactions performed by parallel workers. For a complete fix, we need to decide how we want to show all the transactions that are started internally for various operations and that is a matter of separate patch. Reported-by: Haribabu Kommi Author: Haribabu Kommi Reviewed-by: Amit Kapila, Jamison Kirk and Rahila Syed Backpatch-through: 9.6 Discussion: https://postgr.es/m/CAJrrPGc9=jKXuScvNyQ+VNhO0FZk7LLAShAJRyZjnedd2D61EQ@mail.gmail.com
* Refactor the fsync queue for wider use.Thomas Munro2019-04-04
| | | | | | | | | | | | | | | | | | | | | | | Previously, md.c and checkpointer.c were tightly integrated so that fsync calls could be handed off and processed in the background. Introduce a system of callbacks and file tags, so that other modules can hand off fsync work in the same way. For now only md.c uses the new interface, but other users are being proposed. Since there may be use cases that are not strictly SMGR implementations, use a new function table for sync handlers rather than extending the traditional SMGR one. Instead of using a bitmapset of segment numbers for each RelFileNode in the checkpointer's hash table, make the segment number part of the key. This requires sending explicit "forget" requests for every segment individually when relations are dropped, but suits the file layout schemes of proposed future users better (ie sparse or high segment numbers). Author: Shawn Debnath and Thomas Munro Reviewed-by: Thomas Munro, Andres Freund Discussion: https://postgr.es/m/CAEepm=2gTANm=e3ARnJT=n0h8hf88wqmaZxk0JYkxw+b21fNrw@mail.gmail.com
* 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
* Generate less WAL during GiST, GIN and SP-GiST index build.Heikki Linnakangas2019-04-03
| | | | | | | | | | | | | | | | | | | | Instead of WAL-logging every modification during the build separately, first build the index without any WAL-logging, and make a separate pass through the index at the end, to write all pages to the WAL. This significantly reduces the amount of WAL generated, and is usually also faster, despite the extra I/O needed for the extra scan through the index. WAL generated this way is also faster to replay. For GiST, the LSN-NSN interlock makes this a little tricky. All pages must be marked with a valid (i.e. non-zero) LSN, so that the parent-child LSN-NSN interlock works correctly. We now use magic value 1 for that during index build. Change the fake LSN counter to begin from 1000, so that 1 is safely smaller than any real or fake LSN. 2 would've been enough for our purposes, but let's reserve a bigger range, in case we need more special values in the future. Author: Anastasia Lubennikova, Andrey V. Lepikhov Reviewed-by: Heikki Linnakangas, Dmitry Dolgov
* Add support for partial TOAST decompressionStephen Frost2019-04-02
| | | | | | | | | | | | | | | | When asked for a slice of a TOAST entry, decompress enough to return the slice instead of decompressing the entire object. For use cases where the slice is at, or near, the beginning of the entry, this avoids a lot of unnecessary decompression work. This changes the signature of pglz_decompress() by adding a boolean to indicate if it's ok for the call to finish before consuming all of the source or destination buffers. Author: Paul Ramsey Reviewed-By: Rafia Sabih, Darafei Praliaskouski, Regina Obe Discussion: https://postgr.es/m/CACowWR07EDm7Y4m2kbhN_jnys%3DBBf9A6768RyQdKm_%3DNpkcaWg%40mail.gmail.com
* Add wal_recycle and wal_init_zero GUCs.Thomas Munro2019-04-02
| | | | | | | | | | | | On at least ZFS, it can be beneficial to create new WAL files every time and not to bother zero-filling them. Since it's not clear which other filesystems might benefit from one or both of those things, add individual GUCs to control those two behaviors independently and make only very general statements in the docs. Author: Jerry Jelinek, with some adjustments by Thomas Munro Reviewed-by: Alvaro Herrera, Andres Freund, Tomas Vondra, Robert Haas and others Discussion: https://postgr.es/m/CACPQ5Fo00QR7LNAcd1ZjgoBi4y97%2BK760YABs0vQHH5dLdkkMA%40mail.gmail.com
* Unified logging system for command-line programsPeter Eisentraut2019-04-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This unifies the various ad hoc logging (message printing, error printing) systems used throughout the command-line programs. Features: - Program name is automatically prefixed. - Message string does not end with newline. This removes a common source of inconsistencies and omissions. - Additionally, a final newline is automatically stripped, simplifying use of PQerrorMessage() etc., another common source of mistakes. - I converted error message strings to use %m where possible. - As a result of the above several points, more translatable message strings can be shared between different components and between frontends and backend, without gratuitous punctuation or whitespace differences. - There is support for setting a "log level". This is not meant to be user-facing, but can be used internally to implement debug or verbose modes. - Lazy argument evaluation, so no significant overhead if logging at some level is disabled. - Some color in the messages, similar to gcc and clang. Set PG_COLOR=auto to try it out. Some colors are predefined, but can be customized by setting PG_COLORS. - Common files (common/, fe_utils/, etc.) can handle logging much more simply by just using one API without worrying too much about the context of the calling program, requiring callbacks, or having to pass "progname" around everywhere. - Some programs called setvbuf() to make sure that stderr is unbuffered, even on Windows. But not all programs did that. This is now done centrally. Soft goals: - Reduces vertical space use and visual complexity of error reporting in the source code. - Encourages more deliberate classification of messages. For example, in some cases it wasn't clear without analyzing the surrounding code whether a message was meant as an error or just an info. - Concepts and terms are vaguely aligned with popular logging frameworks such as log4j and Python logging. This is all just about printing stuff out. Nothing affects program flow (e.g., fatal exits). The uses are just too varied to do that. Some existing code had wrappers that do some kind of print-and-exit, and I adapted those. I tried to keep the output mostly the same, but there is a lot of historical baggage to unwind and special cases to consider, and I might not always have succeeded. One significant change is that pg_rewind used to write all error messages to stdout. That is now changed to stderr. Reviewed-by: Donald Dong <xdong@csumb.edu> Reviewed-by: Arthur Zakirov <a.zakirov@postgrespro.ru> Discussion: https://www.postgresql.org/message-id/flat/6a609b43-4f57-7348-6480-bd022f924310@2ndquadrant.com
* Warn more strongly about the dangers of exclusive backup mode.Robert Haas2019-03-29
| | | | | | | | | | | Especially, warn about the hazards of mishandling the backup_label file. Adjust a couple of server messages to be more clear about the hazards associated with removing backup_label files, too. David Steele and Robert Haas, reviewed by Laurenz Albe, Martín Marqués, Peter Eisentraut, and Magnus Hagander. Discussion: http://postgr.es/m/7d85c387-000e-16f0-e00b-50bf83c22127@pgmasters.net
* Fix typo.Thomas Munro2019-03-29
| | | | Author: Masahiko Sawada
* Use FullTransactionId for the transaction stack.Thomas Munro2019-03-28
| | | | | | | | | | | | | | | | Provide GetTopFullTransactionId() and GetCurrentFullTransactionId(). The intended users of these interfaces are access methods that use xids for visibility checks but don't want to have to go back and "freeze" existing references some time later before the 32 bit xid counter wraps around. Use a new struct to serialize the transaction state for parallel query, because FullTransactionId doesn't fit into the previous serialization scheme very well. Author: Thomas Munro Reviewed-by: Heikki Linnakangas Discussion: https://postgr.es/m/CAA4eK1%2BMv%2Bmb0HFfWM9Srtc6MVe160WFurXV68iAFMcagRZ0dQ%40mail.gmail.com
* Add basic infrastructure for 64 bit transaction IDs.Thomas Munro2019-03-28
| | | | | | | | | | | | | | | | | | | | | | | | Instead of inferring epoch progress from xids and checkpoints, introduce a 64 bit FullTransactionId type and use it to track xid generation. This fixes an unlikely bug where the epoch is reported incorrectly if the range of active xids wraps around more than once between checkpoints. The only user-visible effect of this commit is to correct the epoch used by txid_current() and txid_status(), also visible with pg_controldata, in those rare circumstances. It also creates some basic infrastructure so that later patches can use 64 bit transaction IDs in more places. The new type is a struct that we pass by value, as a form of strong typedef. This prevents the sort of accidental confusion between TransactionId and FullTransactionId that would be possible if we were to use a plain old uint64. Author: Thomas Munro Reported-by: Amit Kapila Reviewed-by: Andres Freund, Tom Lane, Heikki Linnakangas Discussion: https://postgr.es/m/CAA4eK1%2BMv%2Bmb0HFfWM9Srtc6MVe160WFurXV68iAFMcagRZ0dQ%40mail.gmail.com
* Transaction chainingPeter Eisentraut2019-03-24
| | | | | | | | | | | | | Add command variants COMMIT AND CHAIN and ROLLBACK AND CHAIN, which start new transactions with the same transaction characteristics as the just finished one, per SQL standard. Support for transaction chaining in PL/pgSQL is also added. This functionality is especially useful when running COMMIT in a loop in PL/pgSQL. Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr> Discussion: https://www.postgresql.org/message-id/flat/28536681-324b-10dc-ade8-ab46f7645a5a@2ndquadrant.com
* Refactor more code logic to update the control fileMichael Paquier2019-03-18
| | | | | | | | | | | | | | | | | | | | | | ce6afc6 has begun the refactoring work by plugging pg_rewind into a central routine to update the control file, and left around two extra copies, with one in xlog.c for the backend and one in pg_resetwal.c. By adding an extra option to the central routine in controldata_utils.c to control if a flush of the control file needs to be done, it is proving to be straight-forward to make xlog.c and pg_resetwal.c use the central code path at the condition of moving the wait event tracking there. Hence, this allows to have only one central code path to update the control file, shaving the code from the duplicates. This refactoring actually fixes a problem in pg_resetwal. Previously, the control file was first removed before being recreated. So if a crash happened between the moment the file was removed and the moment the file was created, then it would have been possible to not have a control file anymore in the database folder. Author: Fabien Coelho Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/alpine.DEB.2.21.1903170935210.2506@lancre
* Avoid casting away a constPeter Eisentraut2019-03-16
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* Enable parallel query with SERIALIZABLE isolation.Thomas Munro2019-03-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, the SERIALIZABLE isolation level prevented parallel query from being used. Allow the two features to be used together by sharing the leader's SERIALIZABLEXACT with parallel workers. An extra per-SERIALIZABLEXACT LWLock is introduced to make it safe to share, and new logic is introduced to coordinate the early release of the SERIALIZABLEXACT required for the SXACT_FLAG_RO_SAFE optimization, as follows: The first backend to observe the SXACT_FLAG_RO_SAFE flag (set by some other transaction) will 'partially release' the SERIALIZABLEXACT, meaning that the conflicts and locks it holds are released, but the SERIALIZABLEXACT itself will remain active because other backends might still have a pointer to it. Whenever any backend notices the SXACT_FLAG_RO_SAFE flag, it clears its own MySerializableXact variable and frees local resources so that it can skip SSI checks for the rest of the transaction. In the special case of the leader process, it transfers the SERIALIZABLEXACT to a new variable SavedSerializableXact, so that it can be completely released at the end of the transaction after all workers have exited. Remove the serializable_okay flag added to CreateParallelContext() by commit 9da0cc35, because it's now redundant. Author: Thomas Munro Reviewed-by: Haribabu Kommi, Robert Haas, Masahiko Sawada, Kevin Grittner Discussion: https://postgr.es/m/CAEepm=0gXGYhtrVDWOTHS8SQQy_=S9xo+8oCxGLWZAOoeJ=yzQ@mail.gmail.com
* Adjust error message for partial writes in WAL segmentsMichael Paquier2019-03-11
| | | | | | | | | | | | 93473c6 has removed openLogOff, changing on the way the error message which is used to report partial writes to WAL segments. The newly-introduced error message used the offset up to which the write has happened, keeping always the same total length to write. This changes the error message so as the number of bytes left to write are reported. Reported-by: Michael Paquier Author: Robert Haas Discussion: https://postgr.es/m/20190306235251.GA17293@paquier.xyz
* Tighten use of OpenTransientFile and CloseTransientFileMichael Paquier2019-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | This fixes two sets of issues related to the use of transient files in the backend: 1) OpenTransientFile() has been used in some code paths with read-write flags while read-only is sufficient, so switch those calls to be read-only where necessary. These have been reported by Joe Conway. 2) When opening transient files, it is up to the caller to close the file descriptors opened. In error code paths, CloseTransientFile() gets called to clean up things before issuing an error. However in normal exit paths, a lot of callers of CloseTransientFile() never actually reported errors, which could leave a file descriptor open without knowing about it. This is an issue I complained about a couple of times, but never had the courage to write and submit a patch, so here we go. Note that one frontend code path is impacted by this commit so as an error is issued when fetching control file data, making backend and frontend to be treated consistently. Reported-by: Joe Conway, Michael Paquier Author: Michael Paquier Reviewed-by: Álvaro Herrera, Georgios Kokolatos, Joe Conway Discussion: https://postgr.es/m/20190301023338.GD1348@paquier.xyz Discussion: https://postgr.es/m/c49b69ec-e2f7-ff33-4f17-0eaa4f2cef27@joeconway.com
* Removed unused variable, openLogOff.Robert Haas2019-03-06
| | | | | | Antonin Houska Discussion: http://postgr.es/m/30413.1551870730@localhost
* Make release of 2PC identifier and locks consistent in COMMIT PREPAREDMichael Paquier2019-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When preparing a transaction in two-phase commit, a dummy PGPROC entry holding the GID used for the transaction is registered, which gets released once COMMIT PREPARED is run. Prior releasing its shared memory state, all the locks taken in the prepared transaction are released using a dedicated set of callbacks (pgstat and multixact having similar callbacks), which may cause the locks to be released before the GID is set free. Hence, there is a small window where lock conflicts could happen, for example: - Transaction A releases its locks, still holding its GID in shared memory. - Transaction B held a lock which conflicted with locks of transaction A. - Transaction B continues its processing, reusing the same GID as transaction A. - Transaction B fails because of a conflicting GID, already in use by transaction A. This commit changes the shared memory state release so as post-commit callbacks and predicate lock cleanup happen consistently with the shared memory state cleanup for the dummy PGPROC entry. The race window is small and 2PC had this issue from the start, so no backpatch is done. On top if that fixes discussed involved ABI breakages, which are not welcome in stable branches. Reported-by: Oleksii Kliukin, Ildar Musin Diagnosed-by: Oleksii Kliukin, Ildar Musin Author: Michael Paquier Reviewed-by: Masahiko Sawada, Oleksii Kliukin Discussion: https://postgr.es/m/BF9B38A4-2BFF-46E8-BA87-A2D00A8047A6@hintbits.com
* Fix incorrect function reference in comment of twophase.cMichael Paquier2019-02-23
| | | | | | | | The header block of TwoPhaseGetDummyBackendId mentioned incorrectly TwoPhaseGetDummyProc. Reported-by: Oleksii Kliukin Discussion: https://postgr.es/m/D8336E40-BBE1-4954-98BB-7830D3F5CB36@hintbits.com
* Avoid some unnecessary block reads in WAL readerMichael Paquier2019-02-18
| | | | | | | | | | | | | | | | When reading a new page internally and depending on the way the WAL reader facility gets used by plugins, the current implementation of the WAL reader may finish by reading a block multiple times while it is not actually necessary as the requested data length may be equal to what has been already read. This can happen for any size, but is more likely to happen at the end of a page. This can cause performance penalties in plugins which rely on the block reads to be purely sequential, zlib not liking backward reads for example. The new behavior also shaves some cycles when doing recovery. Author: Arthur Zakirov Reviewed-by: Andrey Lepikhov, Michael Paquier, Grigory Smolkin Discussion: https://postgr.es/m/2ddf4a32-517e-d6f4-d992-4a63b6035bfd@postgrespro.ru
* 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
* Move max_wal_senders out of max_connections for connection slot handlingMichael Paquier2019-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since its introduction, max_wal_senders is counted as part of max_connections when it comes to define how many connection slots can be used for replication connections with a WAL sender context. This can lead to confusion for some users, as it could be possible to block a base backup or replication from happening because other backend sessions are already taken for other purposes by an application, and superuser-only connection slots are not a correct solution to handle that case. This commit makes max_wal_senders independent of max_connections for its handling of PGPROC entries in ProcGlobal, meaning that connection slots for WAL senders are handled using their own free queue, like autovacuum workers and bgworkers. One compatibility issue that this change creates is that a standby now requires to have a value of max_wal_senders at least equal to its primary. So, if a standby created enforces the value of max_wal_senders to be lower than that, then this could break failovers. Normally this should not be an issue though, as any settings of a standby are inherited from its primary as postgresql.conf gets normally copied as part of a base backup, so parameters would be consistent. Author: Alexander Kukushkin Reviewed-by: Kyotaro Horiguchi, Petr Jelínek, Masahiko Sawada, Oleksii Kliukin Discussion: https://postgr.es/m/CAFh8B=nBzHQeYAu0b8fjK-AF1X4+_p6GRtwG+cCgs6Vci2uRuQ@mail.gmail.com
* Avoid creation of the free space map for small heap relations, take 2.Amit Kapila2019-02-04
| | | | | | | | | | | | | | | | | | | | | | | | Previously, all heaps had FSMs. For very small tables, this means that the FSM took up more space than the heap did. This is wasteful, so now we refrain from creating the FSM for heaps with 4 pages or fewer. If the last known target block has insufficient space, we still try to insert into some other page before giving up and extending the relation, since doing otherwise leads to table bloat. Testing showed that trying every page penalized performance slightly, so we compromise and try every other page. This way, we visit at most two pages. Any pages with wasted free space become visible at next relation extension, so we still control table bloat. As a bonus, directly attempting one or two pages can even be faster than consulting the FSM would have been. Once the FSM is created for a heap we don't remove it even if somebody deletes all the rows from the corresponding relation. We don't think it is a useful optimization as it is quite likely that relation will again grow to the same size. Author: John Naylor, Amit Kapila Reviewed-by: Amit Kapila Tested-by: Mithun C Y Discussion: https://www.postgresql.org/message-id/CAJVSVGWvB13PzpbLEecFuGFc5V2fsO736BsdTakPiPAcdMM5tQ@mail.gmail.com
* Adjust comment about timeout when waiting for WAL at recoveryMichael Paquier2019-02-01
| | | | | | | | | | A timeout of 5s is used when waiting for WAL to become available at recovery so as the startup process is able to react promptly if a trigger file shows up. However this missed the fact that the startup process also relies on the timeout to check periodically the status of any active WAL receiver. Discussion: https://postgr.es/m/20190131070956.GE13429@paquier.xyz
* 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
* Revert "Avoid creation of the free space map for small heap relations."Amit Kapila2019-01-28
| | | | This reverts commit ac88d2962a96a9c7e83d5acfc28fe49a72812086.
* Avoid creation of the free space map for small heap relations.Amit Kapila2019-01-28
| | | | | | | | | | | | | | | | | | | | | | | | Previously, all heaps had FSMs. For very small tables, this means that the FSM took up more space than the heap did. This is wasteful, so now we refrain from creating the FSM for heaps with 4 pages or fewer. If the last known target block has insufficient space, we still try to insert into some other page before giving up and extending the relation, since doing otherwise leads to table bloat. Testing showed that trying every page penalized performance slightly, so we compromise and try every other page. This way, we visit at most two pages. Any pages with wasted free space become visible at next relation extension, so we still control table bloat. As a bonus, directly attempting one or two pages can even be faster than consulting the FSM would have been. Once the FSM is created for a heap we don't remove it even if somebody deletes all the rows from the corresponding relation. We don't think it is a useful optimization as it is quite likely that relation will again grow to the same size. Author: John Naylor with design inputs and some code contribution by Amit Kapila Reviewed-by: Amit Kapila Tested-by: Mithun C Y Discussion: https://www.postgresql.org/message-id/CAJVSVGWvB13PzpbLEecFuGFc5V2fsO736BsdTakPiPAcdMM5tQ@mail.gmail.com
* Simplify restriction handling of two-phase commit for temporary objectsMichael Paquier2019-01-26
| | | | | | | | | | | | There were two flags used to track the access to temporary tables and to the temporary namespace of a session which are used to restrict PREPARE TRANSACTION, however the first control flag is a concept included in the second. This removes the flag for temporary table tracking, keeping around only the one at namespace level. Author: Michael Paquier Reviewed-by: Álvaro Herrera Discussion: https://postgr.es/m/20190118053126.GH1883@paquier.xyz
* Move remaining code from tqual.[ch] to heapam.h / heapam_visibility.c.Andres Freund2019-01-21
| | | | | | | | | | | | | | Given these routines are heap specific, and that there will be more generic visibility support in via table AM, it makes sense to move the prototypes to heapam.h (routines like HeapTupleSatisfiesVacuum will not be exposed in a generic fashion, because they are too storage specific). Similarly, the code in tqual.c is specific to heap, so moving it into access/heap/ makes sense. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
* Restrict the use of temporary namespace in two-phase transactionsMichael Paquier2019-01-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Attempting to use a temporary table within a two-phase transaction is forbidden for ages. However, there have been uncovered grounds for a couple of other object types and commands which work on temporary objects with two-phase commit. In short, trying to create, lock or drop an object on a temporary schema should not be authorized within a two-phase transaction, as it would cause its state to create dependencies with other sessions, causing all sorts of side effects with the existing session or other sessions spawned later on trying to use the same temporary schema name. Regression tests are added to cover all the grounds found, the original report mentioned function creation, but monitoring closer there are many other patterns with LOCK, DROP or CREATE EXTENSION which are involved. One of the symptoms resulting in combining both is that the session which used the temporary schema is not able to shut down completely, waiting for being able to drop the temporary schema, something that it cannot complete because of the two-phase transaction involved with temporary objects. In this case the client is able to disconnect but the session remains alive on the backend-side, potentially blocking connection backend slots from being used. Other problems reported could also involve server crashes. This is back-patched down to v10, which is where 9b013dc has introduced MyXactFlags, something that this patch relies on. Reported-by: Alexey Bashtanov Author: Michael Paquier Reviewed-by: Masahiko Sawada Discussion: https://postgr.es/m/5d910e2e-0db8-ec06-dd5f-baec420513c3@imap.cc Backpatch-through: 10
* Change default of recovery_target_timeline to 'latest'Peter Eisentraut2019-01-13
| | | | | | | | | This is what one usually wants for recovery and almost always wants for a standby. Discussion: https://www.postgresql.org/message-id/flat/6dd2c23a-4162-8469-410f-bfe146e28c0c@2ndquadrant.com/ Reviewed-by: David Steele <david@pgmasters.net> Reviewed-by: Michael Paquier <michael@paquier.xyz>
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Remove configure switch --disable-strong-randomMichael Paquier2019-01-01
| | | | | | | | | | | | | | | | This removes a portion of infrastructure introduced by fe0a0b5 to allow compilation of Postgres in environments where no strong random source is available, meaning that there is no linking to OpenSSL and no /dev/urandom (Windows having its own CryptoAPI). No systems shipped this century lack /dev/urandom, and the buildfarm is actually not testing this switch at all, so just remove it. This simplifies particularly some backend code which included a fallback implementation using shared memory, and removes a set of alternate regression output files from pgcrypto. Author: Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/20181230063219.GG608@paquier.xyz
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