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* tableam: introduce table AM infrastructure.Andres Freund2019-03-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This introduces the concept of table access methods, i.e. CREATE ACCESS METHOD ... TYPE TABLE and CREATE TABLE ... USING (storage-engine). No table access functionality is delegated to table AMs as of this commit, that'll be done in following commits. Subsequent commits will incrementally abstract table access functionality to be routed through table access methods. That change is too large to be reviewed & committed at once, so it'll be done incrementally. Docs will be updated at the end, as adding them incrementally would likely make them less coherent, and definitely is a lot more work, without a lot of benefit. Table access methods are specified similar to index access methods, i.e. pg_am.amhandler returns, as INTERNAL, a pointer to a struct with callbacks. In contrast to index AMs that struct needs to live as long as a backend, typically that's achieved by just returning a pointer to a constant struct. Psql's \d+ now displays a table's access method. That can be disabled with HIDE_TABLEAM=true, which is mainly useful so regression tests can be run against different AMs. It's quite possible that this behaviour still needs to be fine tuned. For now it's not allowed to set a table AM for a partitioned table, as we've not resolved how partitions would inherit that. Disallowing allows us to introduce, if we decide that's the way forward, such a behaviour without a compatibility break. Catversion bumped, to add the heap table AM and references to it. Author: Haribabu Kommi, Andres Freund, Alvaro Herrera, Dimitri Golgov and others Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de https://postgr.es/m/20160812231527.GA690404@alvherre.pgsql https://postgr.es/m/20190107235616.6lur25ph22u5u5av@alap3.anarazel.de https://postgr.es/m/20190304234700.w5tmhducs5wxgzls@alap3.anarazel.de
* Removed unused variable, openLogOff.Robert Haas2019-03-06
| | | | | | Antonin Houska Discussion: http://postgr.es/m/30413.1551870730@localhost
* Scan GiST indexes in physical order during VACUUM.Heikki Linnakangas2019-03-05
| | | | | | | | | | | | Scanning an index in physical order is faster than walking it in logical order, because sequential I/O is faster than random I/O. The idea and code structure is borrowed from B-tree vacuum code. Patch by Andrey Borodin, with changes by me. Based on early work by Konstantin Kuznetsov, although the patch has been rewritten multiple times since his original version. Discussion: https://www.postgresql.org/message-id/1B9FAC6F-FA19-4A24-8C1B-F4F574844892%40yandex-team.ru
* Note case where nbtree VACUUM finishes splits.Peter Geoghegan2019-03-04
| | | | | | | | The nbtree README claims that VACUUM can never finish interrupted page splits by design. That isn't entirely accurate, though. Note an exception to the general rule. Discussion: https://postgr.es/m/CAH2-Wz=_Xvv8byzK_LvY4ci76OgsHCQzoKF7We8yG9waO7j6rA@mail.gmail.com
* Correct obsolete nbtree page split WAL comment.Peter Geoghegan2019-03-04
| | | | | Commit 2c03216d831, which revamped the WAL record format, failed to update a comment referencing the old API. Update the comment.
* Improve performance of index-only scans with many index columns.Tom Lane2019-03-03
| | | | | | | | | | | | | | | | | | | | StoreIndexTuple was a loop over index_getattr, which is O(N^2) if the index columns are variable-width, and the performance impact is already quite visible at ten columns. The obvious move is to replace that with a call to index_deform_tuple ... but that's *also* a loop over index_getattr. Improve it to be essentially a clone of heap_deform_tuple. (There are a few other places that loop over all index columns with index_getattr, and perhaps should be changed likewise, but most of them don't seem performance-critical. Anyway, the rest would mostly only be interested in the index key columns, which there aren't likely to be so many of. Wide index tuples are a new thing with INCLUDE.) Konstantin Knizhnik Discussion: https://postgr.es/m/e06b2d27-04fc-5c0e-bb8c-ecd72aa24959@postgrespro.ru
* Clear the local map when not used.Amit Kapila2019-03-01
| | | | | | | | | | | | | | | | | After commit b0eaa4c51b, we use a local map of pages to find the required space for small relations. We do clear this map when we have found a block with enough free space, when we extend the relation, or on transaction abort so that it can be used next time. However, we miss to clear it when we didn't find any pages to try from the map which leads to an assertion failure when we later tried to use it after relation extension. In the passing, I have improved some comments in this area. Reported-by: Tom Lane based on buildfarm results Author: Amit Kapila Reviewed-by: John Naylor Tested-by: Kuntal Ghosh Discussion: https://postgr.es/m/32368.1551114120@sss.pgh.pa.us
* Standardize some more loops that chase down parallel lists.Tom Lane2019-02-28
| | | | | | | | | | | | | | | | | | | | | | | | | We have forboth() and forthree() macros that simplify iterating through several parallel lists, but not everyplace that could reasonably use those was doing so. Also invent forfour() and forfive() macros to do the same for four or five parallel lists, and use those where applicable. The immediate motivation for doing this is to reduce the number of ad-hoc lnext() calls, to reduce the footprint of a WIP patch. However, it seems like good cleanup and error-proofing anyway; the places that were combining forthree() with a manually iterated loop seem particularly illegible and bug-prone. There was some speculation about restructuring related parsetree representations to reduce the need for parallel list chasing of this sort. Perhaps that's a win, or perhaps not, but in any case it would be considerably more invasive than this patch; and it's not particularly related to my immediate goal of improving the List infrastructure. So I'll leave that question for another day. Patch by me; thanks to David Rowley for review. Discussion: https://postgr.es/m/11587.1550975080@sss.pgh.pa.us
* Remove unneeded argument from _bt_getstackbuf().Peter Geoghegan2019-02-25
| | | | | | | | | _bt_getstackbuf() is called at exactly two points following commit efada2b8e92 (one call site is concerned with page splits, while the other is concerned with page deletion). The parent buffer returned by _bt_getstackbuf() is write-locked in both cases. Remove the 'access' argument and make _bt_getstackbuf() assume that callers require a write-lock.
* Correct obsolete nbtree page deletion comment.Peter Geoghegan2019-02-25
| | | | | | | | | Commit efada2b8e92, which made the nbtree page deletion algorithm more robust, removed _bt_getstackbuf() calls from _bt_pagedel(). It failed to update a comment that referenced the earlier approach. Update the comment to explain that the _bt_getstackbuf() page deletion call site mirrors the only other remaining _bt_getstackbuf() call site, which is reached during page splits.
* 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
* Make use of compiler builtins and/or assembly for CLZ, CTZ, POPCNT.Tom Lane2019-02-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test for the compiler builtins __builtin_clz, __builtin_ctz, and __builtin_popcount, and make use of these in preference to handwritten C code if they're available. Create src/port infrastructure for "leftmost one", "rightmost one", and "popcount" so as to centralize these decisions. On x86_64, __builtin_popcount generally won't make use of the POPCNT opcode because that's not universally supported yet. Provide code that checks CPUID and then calls POPCNT via asm() if available. This requires indirecting through a function pointer, which is an annoying amount of overhead for a one-instruction operation, but it's probably not worth working harder than this for our current use-cases. I'm not sure we've found all the existing places that could profit from this new infrastructure; but we at least touched all the ones that used copied-and-pasted versions of the bitmapset.c code, and got rid of multiple copies of the associated constant arrays. While at it, replace c-compiler.m4's one-per-builtin-function macros with a single one that can handle all the cases we need to worry about so far. Also, because I'm paranoid, make those checks into AC_LINK checks rather than just AC_COMPILE; the former coding failed to verify that libgcc has support for the builtin, in cases where it's not inline code. David Rowley, Thomas Munro, Alvaro Herrera, Tom Lane Discussion: https://postgr.es/m/CAKJS1f9WTAGG1tPeJnD18hiQW5gAk59fQ6WK-vfdAKEHyRg2RA@mail.gmail.com
* Revert attempts to use POPCNT etc instructionsAlvaro Herrera2019-02-15
| | | | | | | | | | | This reverts commits fc6c72747ae6, 109de05cbb03, d0b4663c23b7 and 711bab1e4d19. Somebody will have to try harder before submitting this patch again. I've spent entirely too much time on it already, and the #ifdef maze yet to be written in order for it to build at all got on my nerves. The amount of work needed to get a platform-specific performance improvement that's barely above the noise level is not worth it.
* Add basic support for using the POPCNT and SSE4.2s LZCNT opcodesAlvaro Herrera2019-02-13
| | | | | | | | | | | | | These opcodes have been around in the AMD world since 2007, and 2008 in the case of intel. They're supported in GCC and Clang via some __builtin macros. The opcodes may be unavailable during runtime, in which case we fall back on a C-based implementation of the code. In order to get the POPCNT instruction we must pass the -mpopcnt option to the compiler. We do this only for the pg_bitutils.c file. David Rowley (with fragments taken from a patch by Thomas Munro) Discussion: https://postgr.es/m/CAKJS1f9WTAGG1tPeJnD18hiQW5gAk59fQ6WK-vfdAKEHyRg2RA@mail.gmail.com
* 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
* Fix description of WAL record XLOG_PARAMETER_CHANGEMichael Paquier2019-02-12
| | | | | | | | max_wal_senders and max_worker_processes got reversed in the output generated because of ea92368. Reported-by: Kevin Hale Boyes Discussion: https://postgr.es/m/CADAecHVAD4=26KAx4nj5DBvxqqvJkuwsy+riiiNhQqwnZg2K8Q@mail.gmail.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
* Fix heap_getattr() handling of fast defaults.Andres Freund2019-02-06
| | | | | | | | | | | | | | | | | | | | | | | Previously heap_getattr() returned NULL for attributes with a fast default value (c.f. 16828d5c0273), as it had no handling whatsoever for that case. A previous fix, 7636e5c60f, attempted to fix issues caused by this oversight, but just expanding OLD tuples for triggers doesn't actually solve the underlying issue. One known consequence of this bug is that the check for HOT updates can return the wrong result, when a previously fast-default'ed column is set to NULL. Which in turn means that an index over a column with fast default'ed columns might be corrupt if the underlying column(s) allow NULLs. Fix by handling fast default columns in heap_getattr(), remove now superfluous expansion in GetTupleForTrigger(). Author: Andres Freund Discussion: https://postgr.es/m/20190201162404.onngi77f26baem4g@alap3.anarazel.de Backpatch: 11, where fast defaults were introduced
* Remove unused macroPeter Eisentraut2019-02-04
| | | | | Use was removed in 6d46f4783efe457f74816a75173eb23ed8930020 but definition was forgotten.
* 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
* Move page initialization from RelationAddExtraBlocks() to use, take 2.Andres Freund2019-02-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously we initialized pages when bulk extending in RelationAddExtraBlocks(). That has a major disadvantage: It ties RelationAddExtraBlocks() to heap, as other types of storage are likely to need different amounts of special space, have different amount of free space (previously determined by PageGetHeapFreeSpace()). That we're relying on initializing pages, but not WAL logging the initialization, also means the risk for getting "WARNING: relation \"%s\" page %u is uninitialized --- fixing" style warnings in vacuums after crashes/immediate shutdowns, is considerably higher. The warning sounds much more serious than what they are. Fix those two issues together by not initializing pages in RelationAddExtraPages() (but continue to do so in RelationGetBufferForTuple(), which is linked much more closely to heap), and accepting uninitialized pages as normal in vacuumlazy.c. When vacuumlazy encounters an empty page it now adds it to the FSM, but does nothing else. We chose to not issue a debug message, much less a warning in that case - it seems rarely useful, and quite likely to scare people unnecessarily. For now empty pages aren't added to the VM, because standbys would not re-discover such pages after a promotion. In contrast to other sources for empty pages, there's no corresponding WAL records triggering FSM updates during replay. Previously when extending the relation, there was a moment between extending the relation, and acquiring an exclusive lock on the new page, in which another backend could lock the page. To avoid new content being put on that new page, vacuumlazy needed to acquire the extension lock for a brief moment when encountering a new page. A second corner case, only working somewhat by accident, was that RelationGetBufferForTuple() sometimes checks the last page in a relation for free space, without consulting the FSM; that only worked because PageGetHeapFreeSpace() interprets the zero page header in a new page as no free space. The lack of handling this properly required reverting the previous attempt in 684200543b. This issue can be solved by using RBM_ZERO_AND_LOCK when extending the relation, thereby avoiding this window. There's some added complexity when RelationGetBufferForTuple() is called with another buffer (for updates), to avoid deadlocks, but that's rarely hit at runtime. Author: Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/20181219083945.6khtgm36mivonhva@alap3.anarazel.de
* Avoid possible deadlock while locking multiple heap pages.Amit Kapila2019-02-02
| | | | | | | | | | | | | | | | | To avoid deadlock, backend acquires a lock on heap pages in block number order. In certain cases, lock on heap pages is dropped and reacquired. In this case, the locks are dropped for reading in corresponding VM page/s. The issue is we re-acquire locks in bufferId order whereas the intention was to acquire in blockid order. This commit ensures that we will always acquire locks on heap pages in blockid order. Reported-by: Nishant Fnu Author: Nishant Fnu Reviewed-by: Amit Kapila and Robert Haas Backpatch-through: 9.4 Discussion: https://postgr.es/m/5883C831-2ED1-47C8-BFAC-2D5BAE5A8CAE@amazon.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
* Fix use of dangling pointer in heap_delete() when logging replica identityMichael Paquier2019-02-01
| | | | | | | | | | | | | | When logging the replica identity of a deleted tuple, XLOG_HEAP_DELETE records include references of the old tuple. Its data is stored in an intermediate variable used to register this information for the WAL record, but this variable gets away from the stack when the record gets actually inserted. Spotted by clang's AddressSanitizer. Author: Stas Kelvish Discussion: https://postgr.es/m/085C8825-AD86-4E93-AF80-E26CDF03D1EA@postgrespro.ru Backpatch-through: 9.4
* 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 "Move page initialization from RelationAddExtraBlocks() to use."Andres Freund2019-01-28
| | | | | | | | | | | | This reverts commit fc02e6724f3ce069b33284bce092052ab55bd751 and e6799d5a53011985d916fdb48fe014a4ae70422e. Parts of the buildfarm error out with ERROR: page %u of relation "%s" should be empty but is not errors, and so far I/we do not know why. fc02e672 didn't fix the issue. As I cannot reproduce the issue locally, it seems best to get the buildfarm green again, and reproduce the issue without time pressure.
* Fix race condition between relation extension and vacuum.Andres Freund2019-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | In e6799d5a5301 I removed vacuumlazy.c trickery around re-checking whether a page is actually empty after acquiring an extension lock on the relation, because the page is not PageInit()ed anymore, and entries in the FSM ought not to lead to user-visible errors. As reported by various buildfarm animals that is not correct, given the way to code currently stands: If vacuum processes a page that's just been newly added by either RelationGetBufferForTuple() or RelationAddExtraBlocks(), it could add that page to the FSM and it could be reused by other backends, before those two functions check whether the newly added page is actually new. That's a relatively narrow race, but several buildfarm machines appear to be able to hit it. While it seems wrong that the FSM, given it's lack of durability and approximative nature, can trigger errors like this, that seems better fixed in a separate commit. Especially given that a good portion of the buildfarm is red, and this is just re-introducing logic that existed a few hours ago. Author: Andres Freund Discussion: https://postgr.es/m/20190128222259.zhi7ovzgtkft6em6@alap3.anarazel.de
* Move page initialization from RelationAddExtraBlocks() to use.Andres Freund2019-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously we initialized pages when bulk extending in RelationAddExtraBlocks(). That has a major disadvantage: It ties RelationAddExtraBlocks() to heap, as other types of storage are likely to need different amounts of special space, have different amount of free space (previously determined by PageGetHeapFreeSpace()). That we're relying on initializing pages, but not WAL logging the initialization, also means the risk for getting "WARNING: relation \"%s\" page %u is uninitialized --- fixing" style warnings in vacuums after crashes/immediate shutdowns, is considerably higher. The warning sounds much more serious than what they are. Fix those two issues together by not initializing pages in RelationAddExtraPages() (but continue to do so in RelationGetBufferForTuple(), which is linked much more closely to heap), and accepting uninitialized pages as normal in vacuumlazy.c. When vacuumlazy encounters an empty page it now adds it to the FSM, but does nothing else. We chose to not issue a debug message, much less a warning in that case - it seems rarely useful, and quite likely to scare people unnecessarily. For now empty pages aren't added to the VM, because standbys would not re-discover such pages after a promotion. In contrast to other sources for empty pages, there's no corresponding WAL records triggering FSM updates during replay. Author: Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/20181219083945.6khtgm36mivonhva@alap3.anarazel.de
* 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
* 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
* Rename RelationData.rd_amroutine to rd_indam.Andres Freund2019-01-21
| | | | | | | | | The upcoming table AM support makes rd_amroutine to generic, as its only about index AMs. The new name makes that clear, and is shorter to boot. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
* Rephrase references to "time qualification".Andres Freund2019-01-21
| | | | | | | | | Now that the relevant code has, for other reasons, moved out of tqual.[ch], it seems time to refer to visiblity rather than time qualification. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
* 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
* Move generic snapshot related code from tqual.h to snapmgr.h.Andres Freund2019-01-21
| | | | | | | | | | | | | | | | The code in tqual.c is largely heap specific. Due to the upcoming pluggable storage work, it therefore makes sense to move it into access/heap/ (as the file's header notes, the tqual name isn't very good). But the various statically allocated snapshot and snapshot initialization functions are now (see previous commit) generic and do not depend on functions declared in tqual.h anymore. Therefore move. Also move XidInMVCCSnapshot as that's useful for future AMs, and already used outside of tqual.c. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
* Change snapshot type to be determined by enum rather than callback.Andres Freund2019-01-21
| | | | | | | | | | | | | | | | | | | | | | This is in preparation for allowing the same snapshot be used for different table AMs. With the current callback based approach we would need one callback for each supported AM, which clearly would not be extensible. Thus add a new Snapshot->snapshot_type field, and move the dispatch into HeapTupleSatisfiesVisibility() (which is now a function). Later work will then dispatch calls to HeapTupleSatisfiesVisibility() and other AMs visibility functions depending on the type of the table. The central SnapshotType enum also seems like a good location to centralize documentation about the intended behaviour of various types of snapshots. As tqual.h isn't included by bufmgr.h any more (as HeapTupleSatisfies* isn't referenced by TestForOldSnapshot() anymore) a few files now need to include it directly. Author: Andres Freund, loosely based on earlier work by Haribabu Kommi Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de https://postgr.es/m/20160812231527.GA690404@alvherre.pgsql
* Remove superfluous tqual.h includes.Andres Freund2019-01-21
| | | | | | | | | | | | Most of these had been obsoleted by 568d4138c / the SnapshotNow removal. This is is preparation for moving most of tqual.[ch] into either snapmgr.h or heapam.h, which in turn is in preparation for pluggable table AMs. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
* Replace uses of heap_open et al with the corresponding table_* function.Andres Freund2019-01-21
| | | | | Author: Andres Freund Discussion: https://postgr.es/m/20190111000539.xbv7s6w7ilcvm7dp@alap3.anarazel.de
* Replace heapam.h includes with {table, relation}.h where applicable.Andres Freund2019-01-21
| | | | | | | | | A lot of files only included heapam.h for relation_open, heap_open etc - replace the heapam.h include in those files with the narrower header. Author: Andres Freund Discussion: https://postgr.es/m/20190111000539.xbv7s6w7ilcvm7dp@alap3.anarazel.de
* Introduce access/{table.h, relation.h}, for generic functions from heapam.h.Andres Freund2019-01-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | access/heapam contains functions that are very storage specific (say heap_insert() and a lot of lower level functions), and fairly generic infrastructure like relation_open(), heap_open() etc. In the upcoming pluggable storage work we're introducing a layer between table accesses in general and heapam, to allow for different storage methods. For a bit cleaner separation it thus seems advantageous to move generic functions like the aforementioned to their own headers. access/relation.h will contain relation_open() etc, and access/table.h will contain table_open() (formerly known as heap_open()). I've decided for table.h not to include relation.h, but we might change that at a later stage. relation.h already exists in another directory, but the other plausible name (rel.h) also conflicts. It'd be nice if there were a non-conflicting name, but nobody came up with a suggestion. It's possible that the appropriate way to address the naming conflict would be to rename nodes/relation.h, which isn't particularly well named. To avoid breaking a lot of extensions that just use heap_open() etc, table.h has macros mapping the old names to the new ones, and heapam.h includes relation, table.h. That also allows to keep the bulk renaming of existing callers in a separate commit. Author: Andres Freund Discussion: https://postgr.es/m/20190111000539.xbv7s6w7ilcvm7dp@alap3.anarazel.de
* Adjust some more comments for WITH OIDS removal.Andres Freund2019-01-21
| | | | | | I missed these in 578b229718e8f. Author: Andres Freund
* Fix incorrect relation name in comment of vacuumlazy.cMichael Paquier2019-01-18
| | | | | Author: Masahiko Sawada Discussion: https://postgr.es/m/CAD21AoBiOiapB7YGbWRfNZji3cs1gkEwv=uGLTemaZ9yNKK1DA@mail.gmail.com
* 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
* Don't duplicate parallel seqscan shmem sizing logic in nbtree.Andres Freund2019-01-15
| | | | | | | | | | | This is architecturally mildly problematic, which becomes more pronounced with the upcoming introduction of pluggable storage. To fix, teach heap_parallelscan_estimate() to deal with SnapshotAny snapshots, and then use it from _bt_parallel_estimate_shared(). Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
* Move vacuumlazy.c into access/heap.Andres Freund2019-01-15
| | | | | | | | It's heap table storage specific code that can't realistically be generalized into table AM agnostic code. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
* Finish reverting "recheck_on_update" patch.Tom Lane2019-01-15
| | | | | | | | | | | | This reverts commit c203d6cf8 and some follow-on fixes, completing the task begun in commit 5d28c9bd7. If that feature is ever resurrected, the code will look quite a bit different from this, so it seems best to start from a clean slate. The v11 branch is not touched; in that branch, the recheck_on_update storage option remains present, but nonfunctional and undocumented. Discussion: https://postgr.es/m/20190114223409.3tcvejfhlvbucrv5@alap3.anarazel.de
* Don't include genam.h from execnodes.h and relscan.h anymore.Andres Freund2019-01-14
| | | | | | | | | | | | | | | | | | | This is the genam.h equivalent of 4c850ecec649c (which removed heapam.h from a lot of other headers). There's still a few header includes of genam.h, but not from central headers anymore. As a few headers are not indirectly included anymore, execnodes.h and relscan.h need a few additional includes. Some of the depended on types were replacable by using the underlying structs, but e.g. for Snapshot in execnodes.h that'd have gotten more invasive than reasonable in this commit. Like the aforementioned commit 4c850ecec649c, this requires adding new genam.h includes to a number of backend files, which likely is also required in a few external projects. Author: Andres Freund Discussion: https://postgr.es/m/20190114000701.y4ttcb74jpskkcfb@alap3.anarazel.de