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path: root/src/backend/access/heap/heapam_handler.c
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* Remove HeapBitmapScan's skip_fetch optimizationAndres Freund2025-04-02
| | | | | | | | | | | | | | | | | | | | | The optimization does not take the removal of TIDs by a concurrent vacuum into account. The concurrent vacuum can remove dead TIDs and make pages ALL_VISIBLE while those dead TIDs are referenced in the bitmap. This can lead to a skip_fetch scan returning too many tuples. It likely would be possible to implement this optimization safely, but we don't have the necessary infrastructure in place. Nor is it clear that it's worth building that infrastructure, given how limited the skip_fetch optimization is. In the backbranches we just disable the optimization by always passing need_tuples=true to table_beginscan_bm(). We can't perform API/ABI changes in the backbranches and we want to make the change as minimal as possible. Author: Matthias van de Meent <boekewurm+postgres@gmail.com> Reported-By: Konstantin Knizhnik <knizhnik@garret.ru> Discussion: https://postgr.es/m/CAEze2Wg3gXXZTr6_rwC+s4-o2ZVFB5F985uUSgJTsECx6AmGcQ@mail.gmail.com Backpatch-through: 13
* Fix bitmapheapscan incorrect recheck of NULL tuplesMelanie Plageman2025-03-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | The bitmap heap scan skip fetch optimization skips fetching the heap block when a page is set all-visible in the visibility map and no columns from the table are needed to satisfy the query. 2b73a8cd33b and c3953226a07 changed the control flow of bitmap heap scan to use the read stream API. The read stream API returns buffers containing blocks to the user. To make this work with the skip fetch optimization, we keep a count of the empty tuples we need to emit for all the blocks skipped and only emit the empty tuples after processing the next block fetched from the heap or at the end of the scan. It's incorrect to recheck NULL tuples, so we must set `recheck` to false before yielding control back to BitmapHeapNext(). This was done before emitting any remaining empty tuples at the end of the scan but not for empty tuples emitted during the scan. This meant that if a page fetched from the heap did require recheck and set `recheck` to true and then we emitted empty tuples for subsequent blocks, we would get wrong results. Fix this by always setting `recheck` to false before emitting empty tuples. Reported-by: Alexander Lakhin <exclusion@gmail.com> Tested-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/496f7acd-881c-4df3-9bd3-8f8534dfec26%40gmail.com
* Remove table AM callback scan_bitmap_next_blockMelanie Plageman2025-03-15
| | | | | | | | | | | | | | | After pushing the bitmap iterator into table-AM specific code (as part of making bitmap heap scan use the read stream API in 2b73a8cd33b7), scan_bitmap_next_block() no longer returns the current block number. Since scan_bitmap_next_block() isn't returning any relevant information to bitmap table scan code, it makes more sense to get rid of it. Now, bitmap table scan code only calls table_scan_bitmap_next_tuple(), and the heap AM implementation of scan_bitmap_next_block() is a local helper in heapam_handler.c. Reviewed-by: Tomas Vondra <tomas@vondra.me> Discussion: https://postgr.es/m/flat/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com
* BitmapHeapScan uses the read stream APIMelanie Plageman2025-03-15
| | | | | | | | | | | | | | | | | | | | | | | | Make Bitmap Heap Scan use the read stream API instead of invoking ReadBuffer() for each block indicated by the bitmap. The read stream API handles prefetching, so remove all of the explicit prefetching from bitmap heap scan code. Now, heap table AM implements a read stream callback which uses the bitmap iterator to return the next required block to the read stream code. Tomas Vondra conducted extensive regression testing of this feature. Andres Freund, Thomas Munro, and I analyzed regressions and Thomas Munro patched the read stream API. Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Tomas Vondra <tomas@vondra.me> Tested-by: Tomas Vondra <tomas@vondra.me> Tested-by: Andres Freund <andres@anarazel.de> Tested-by: Thomas Munro <thomas.munro@gmail.com> Tested-by: Nazir Bilal Yavuz <byavuz81@gmail.com> Discussion: https://postgr.es/m/flat/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com
* Separate TBM[Shared|Private]Iterator and TBMIterateResultMelanie Plageman2025-03-15
| | | | | | | | | | | | | | Remove the TBMIterateResult member from the TBMPrivateIterator and TBMSharedIterator and make tbm_[shared|private_]iterate() take a TBMIterateResult as a parameter. This allows tidbitmap API users to manage multiple TBMIterateResults per scan. This is required for bitmap heap scan to use the read stream API, with which there may be multiple I/Os in flight at once, each one with a TBMIterateResult. Reviewed-by: Tomas Vondra <tomas@vondra.me> Discussion: https://postgr.es/m/d4bb26c9-fe07-439e-ac53-c0e244387e01%40vondra.me
* Add GUC option to log lock acquisition failures.Fujii Masao2025-03-14
| | | | | | | | | | | | | | | | | | | | | | This commit introduces a new GUC, log_lock_failure, which controls whether a detailed log message is produced when a lock acquisition fails. Currently, it only supports logging lock failures caused by SELECT ... NOWAIT. The log message includes information about all processes holding or waiting for the lock that couldn't be acquired, helping users analyze and diagnose the causes of lock failures. Currently, this option does not log failures from SELECT ... SKIP LOCKED, as that could generate excessive log messages if many locks are skipped, causing unnecessary noise. This mechanism can be extended in the future to support for logging lock failures from other commands, such as LOCK TABLE ... NOWAIT. Author: Yuki Seino <seinoyu@oss.nttdata.com> Co-authored-by: Fujii Masao <masao.fujii@gmail.com> Reviewed-by: Jelte Fennema-Nio <postgres@jeltef.nl> Discussion: https://postgr.es/m/411280a186cc26ef7034e0f2dfe54131@oss.nttdata.com
* Show index search count in EXPLAIN ANALYZE, take 2.Peter Geoghegan2025-03-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Expose the count of index searches/index descents in EXPLAIN ANALYZE's output for index scan/index-only scan/bitmap index scan nodes. This information is particularly useful with scans that use ScalarArrayOp quals, where the number of index searches can be unpredictable due to implementation details that interact with physical index characteristics (at least with nbtree SAOP scans, since Postgres 17 commit 5bf748b8). The information shown also provides useful context when EXPLAIN ANALYZE runs a plan with an index scan node that successfully applied the skip scan optimization (set to be added to nbtree by an upcoming patch). The instrumentation works by teaching all index AMs to increment a new nsearches counter whenever a new index search begins. The counter is incremented at exactly the same point that index AMs already increment the pg_stat_*_indexes.idx_scan counter (we're counting the same event, but at the scan level rather than the relation level). Parallel queries have workers copy their local counter struct into shared memory when an index scan node ends -- even when it isn't a parallel aware scan node. An earlier version of this patch that only worked with parallel aware scans became commit 5ead85fb (though that was quickly reverted by commit d00107cd following "debug_parallel_query=regress" buildfarm failures). Our approach doesn't match the approach used when tracking other index scan related costs (e.g., "Rows Removed by Filter:"). It is comparable to the approach used in similar cases involving costs that are only readily accessible inside an access method, not from the executor proper (e.g., "Heap Blocks:" output for a Bitmap Heap Scan, which was recently enhanced to show per-worker costs by commit 5a1e6df3, using essentially the same scheme as the one used here). It is necessary for index AMs to have direct responsibility for maintaining the new counter, since the counter might need to be incremented multiple times per amgettuple call (or per amgetbitmap call). But it is also necessary for the executor proper to manage the shared memory now used to transfer each worker's counter struct to the leader. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Robert Haas <robertmhaas@gmail.com> Reviewed-By: Tomas Vondra <tomas@vondra.me> Reviewed-By: Masahiro Ikeda <ikedamsh@oss.nttdata.com> Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com> Discussion: https://postgr.es/m/CAH2-WzkRqvaqR2CTNqTZP0z6FuL4-3ED6eQB0yx38XBNj1v-4Q@mail.gmail.com Discussion: https://postgr.es/m/CAH2-Wz=PKR6rB7qbx+Vnd7eqeB5VTcrW=iJvAsTsKbdG+kW_UA@mail.gmail.com
* Delay extraction of TIDBitmap per page offsetsMelanie Plageman2025-02-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pages from the bitmap created by the TIDBitmap API can be exact or lossy. The TIDBitmap API extracts the tuple offsets from exact pages into an array for the convenience of the caller. This was done in tbm_private|shared_iterate() right after advancing the iterator. However, as long as tbm_private|shared_iterate() set a reference to the PagetableEntry in the TBMIterateResult, the offset extraction can be done later. Waiting to extract the tuple offsets has a few benefits. For the shared iterator case, it allows us to extract the offsets after dropping the shared iterator state lock, reducing time spent holding a contended lock. Separating the iteration step and extracting the offsets later also allows us to avoid extracting the offsets for prefetched blocks. Those offsets were never used, so the overhead of extracting and storing them was wasted. The real motivation for this change, however, is that future commits will make bitmap heap scan use the read stream API. This requires a TBMIterateResult per issued block. By removing the array of tuple offsets from the TBMIterateResult and only extracting the offsets when they are used, we reduce the memory required for per buffer data substantially. Suggested-by: Thomas Munro <thomas.munro@gmail.com> Reviewed-by: Thomas Munro <thomas.munro@gmail.com> Discussion: https://postgr.es/m/CA%2BhUKGLHbKP3jwJ6_%2BhnGi37Pw3BD5j2amjV3oSk7j-KyCnY7Q%40mail.gmail.com
* Add lossy indicator to TBMIterateResultMelanie Plageman2025-02-24
| | | | | | | | TBMIterateResult->ntuples is -1 when the page in the bitmap is lossy. Add an explicit lossy indicator so that we can move ntuples out of the TBMIterateResult in a future commit. Discussion: https://postgr.es/m/CA%2BhUKGLHbKP3jwJ6_%2BhnGi37Pw3BD5j2amjV3oSk7j-KyCnY7Q%40mail.gmail.com
* Virtual generated columnsPeter Eisentraut2025-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a new variant of generated columns that are computed on read (like a view, unlike the existing stored generated columns, which are computed on write, like a materialized view). The syntax for the column definition is ... GENERATED ALWAYS AS (...) VIRTUAL and VIRTUAL is also optional. VIRTUAL is the default rather than STORED to match various other SQL products. (The SQL standard makes no specification about this, but it also doesn't know about VIRTUAL or STORED.) (Also, virtual views are the default, rather than materialized views.) Virtual generated columns are stored in tuples as null values. (A very early version of this patch had the ambition to not store them at all. But so much stuff breaks or gets confused if you have tuples where a column in the middle is completely missing. This is a compromise, and it still saves space over being forced to use stored generated columns. If we ever find a way to improve this, a bit of pg_upgrade cleverness could allow for upgrades to a newer scheme.) The capabilities and restrictions of virtual generated columns are mostly the same as for stored generated columns. In some cases, this patch keeps virtual generated columns more restricted than they might technically need to be, to keep the two kinds consistent. Some of that could maybe be relaxed later after separate careful considerations. Some functionality that is currently not supported, but could possibly be added as incremental features, some easier than others: - index on or using a virtual column - hence also no unique constraints on virtual columns - extended statistics on virtual columns - foreign-key constraints on virtual columns - not-null constraints on virtual columns (check constraints are supported) - ALTER TABLE / DROP EXPRESSION - virtual column cannot have domain type - virtual columns are not supported in logical replication The tests in generated_virtual.sql have been copied over from generated_stored.sql with the keyword replaced. This way we can make sure the behavior is mostly aligned, and the differences can be visible. Some tests for currently not supported features are currently commented out. Reviewed-by: Jian He <jian.universality@gmail.com> Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Tested-by: Shlok Kyal <shlok.kyal.oss@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/a368248e-69e4-40be-9c07-6c3b5880b0a6@eisentraut.org
* Add and use BitmapHeapScanDescData structMelanie Plageman2025-01-16
| | | | | | | | | | | | | Move the several members of HeapScanDescData which are specific to Bitmap Heap Scans into a new struct, BitmapHeapScanDescData, which inherits from HeapScanDescData. This reduces the size of the HeapScanDescData for other types of scans and will allow us to add additional bitmap heap scan-specific members in the future without fear of bloating the HeapScanDescData. Reviewed-by: Tomas Vondra Discussion: https://postgr.es/m/c736f6aa-8b35-4e20-9621-62c7c82e2168%40vondra.me
* Update copyright for 2025Bruce Momjian2025-01-01
| | | | Backpatch-through: 13
* Fix overflow danger in SampleHeapTupleVisible(), take 2Melanie Plageman2024-12-20
| | | | | | | | | | 28328ec87b45725 addressed one overflow danger in SampleHeapTupleVisible() but introduced another, albeit a less likely one. Modify the binary search code to remove this danger. Reported-by: Richard Guo Reviewed-by: Richard Guo, Ranier Vilela Discussion: https://postgr.es/m/CAMbWs4_bE%2BNscChbKWzw6HZOipCUyXfA5133qvoXQ654D3B2gQ%40mail.gmail.com
* Introduce CompactAttribute array in TupleDesc, take 2David Rowley2024-12-20
| | | | | | | | | | | | | | | | | | | | | | | | The new compact_attrs array stores a few select fields from FormData_pg_attribute in a more compact way, using only 16 bytes per column instead of the 104 bytes that FormData_pg_attribute uses. Using CompactAttribute allows performance-critical operations such as tuple deformation to be performed without looking at the FormData_pg_attribute element in TupleDesc which means fewer cacheline accesses. For some workloads, tuple deformation can be the most CPU intensive part of processing the query. Some testing with 16 columns on a table where the first column is variable length showed around a 10% increase in transactions per second for an OLAP type query performing aggregation on the 16th column. However, in certain cases, the increases were much higher, up to ~25% on one AMD Zen4 machine. This also makes pg_attribute.attcacheoff redundant. A follow-on commit will remove it, thus shrinking the FormData_pg_attribute struct by 4 bytes. Author: David Rowley Reviewed-by: Andres Freund, Victor Yegorov Discussion: https://postgr.es/m/CAApHDvrBztXP3yx=NKNmo3xwFAFhEdyPnvrDg3=M0RhDs+4vYw@mail.gmail.com
* Bitmap Table Scans use unified TBMIteratorMelanie Plageman2024-12-18
| | | | | | | | | | | | | | With the repurposing of TBMIterator as an interface for both parallel and serial iteration through TIDBitmaps in commit 7f9d4187e7bab10329cc, bitmap table scans may now use it. Modify bitmap table scan code to use the TBMIterator. This requires moving around a bit of code, so a few variables are initialized elsewhere. Author: Melanie Plageman Reviewed-by: Tomas Vondra Discussion: https://postgr.es/m/c736f6aa-8b35-4e20-9621-62c7c82e2168%40vondra.me
* Add common interface for TBMIteratorsMelanie Plageman2024-12-18
| | | | | | | | | | | | | Add and use TBMPrivateIterator, which replaces the current TBMIterator for serial use cases, and repurpose TBMIterator to be a unified interface for both the serial ("private") and parallel ("shared") TID Bitmap iterator interfaces. This encapsulation simplifies call sites for callers supporting both parallel and serial TID Bitmap access. TBMIterator is not yet used in this commit. Author: Melanie Plageman Reviewed-by: Tomas Vondra, Heikki Linnakangas Discussion: https://postgr.es/m/063e4eb4-32d9-439e-a0b1-75565a9835a8%40iki.fi
* Fix overflow danger in SampleHeapTupleVisible()Melanie Plageman2024-12-18
| | | | | | | | | | | 68d9662be1c4b70 made HeapScanDesc->rs_ntuples unsigned but neglected to change how it was being used in SampleHeapTupleVisible(). Return early if rs_ntuples is 0 to avoid overflowing and incorrectly executing the loop code in SampleHeapTupleVisible(). Reported-by: Ranier Vilela Discussion: https://postgr.es/m/CAEudQAot_xQoZyPZjpj1aBUPrPykY5mOPHGyvfe%3Djz%2BWowdA3A%40mail.gmail.com
* Make rs_cindex and rs_ntuples unsignedMelanie Plageman2024-12-18
| | | | | | | | | | | | | | | | | HeapScanDescData.rs_cindex and rs_ntuples can't be less than 0. All scan types using the heap scan descriptor expect these values to be >= 0. Make that expectation clear by making rs_cindex and rs_ntuples unsigned. Also remove the test in heapam_scan_bitmap_next_tuple() that checks if rs_cindex < 0. This was never true, but now that rs_cindex is unsigned, it makes even less sense. While we are at it, initialize both rs_cindex and rs_ntuples to 0 in initscan(). Author: Melanie Plageman Reviewed-by: Dilip Kumar Discussion: https://postgr.es/m/CAAKRu_ZxF8cDCM_BFi_L-t%3DRjdCZYP1usd1Gd45mjHfZxm0nZw%40mail.gmail.com
* Make table_scan_bitmap_next_block() async-friendlyMelanie Plageman2024-10-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move all responsibility for indicating a block is exhuasted into table_scan_bitmap_next_tuple() and advance the main iterator in heap-specific code. This flow control makes more sense and is a step toward using the read stream API for bitmap heap scans. Previously, table_scan_bitmap_next_block() returned false to indicate table_scan_bitmap_next_tuple() should not be called for the tuples on the page. This happened both when 1) there were no visible tuples on the page and 2) when the block returned by the iterator was past the end of the table. BitmapHeapNext() (generic bitmap table scan code) handled the case when the bitmap was exhausted. It makes more sense for table_scan_bitmap_next_tuple() to return false when there are no visible tuples on the page and table_scan_bitmap_next_block() to return false when the bitmap is exhausted or there are no more blocks in the table. As part of this new design, TBMIterateResults are no longer used as a flow control mechanism in BitmapHeapNext(), so we removed table_scan_bitmap_next_tuple's TBMIterateResult parameter. Note that the prefetch iterator is still saved in the BitmapHeapScanState node and advanced in generic bitmap table scan code. This is because 1) it was not necessary to change the prefetch iterator location to change the flow control in BitmapHeapNext() 2) modifying prefetch iterator management requires several more steps better split over multiple commits and 3) the prefetch iterator will be removed once the read stream API is used. Author: Melanie Plageman Reviewed-by: Tomas Vondra, Andres Freund, Heikki Linnakangas, Mark Dilger Discussion: https://postgr.es/m/063e4eb4-32d9-439e-a0b1-75565a9835a8%40iki.fi
* Move EXPLAIN counter increment to heapam_scan_bitmap_next_blockMelanie Plageman2024-10-25
| | | | | | | | | | | | | | | | Increment the lossy and exact page counters for EXPLAIN of bitmap heap scans in heapam_scan_bitmap_next_block(). Note that other table AMs will need to do this as well Pushing the counters into heapam_scan_bitmap_next_block() is required to be able to use the read stream API for bitmap heap scans. The bitmap iterator must be advanced from inside the read stream callback, so TBMIterateResults cannot be used as a flow control mechanism in BitmapHeapNext(). Author: Melanie Plageman Reviewed-by: Tomas Vondra, Heikki Linnakangas Discussion: https://postgr.es/m/063e4eb4-32d9-439e-a0b1-75565a9835a8%40iki.fi
* Remove unused code for unlogged materialized views.Fujii Masao2024-10-18
| | | | | | | | | | | | | | | | | Commit 3bf3ab8c56 initially introduced support for unlogged materialized views, but this was later disallowed by commit 3223b25ff7. Additionally, commit d25f519107 added more code for handling unlogged materialized views. This commit cleans up all unused code related to them. If unlogged materialized views had been supported in any official release, psql would need to retain code to handle them for compatibility with older servers. However, since they were never included in an official release, this code is no longer necessary. Author: Pixian Shi Reviewed-by: Yugo Nagata, Fujii Masao Discussion: https://postgr.es/m/CAAccyYKRZ=OvAvgowiSH+OELbStLP=p2Ht=R3CgT=OaNSH5DAA@mail.gmail.com
* Fix comments on wal_level=minimal, CREATE TABLESPACE and CREATE DATABASE.Noah Misch2024-08-18
| | | | | | | | | | | | | | | | | Commit 97ddda8a82ac470ae581d0eb485b6577707678bc removed the rmtree() behavior from XLOG_TBLSPC_CREATE, obsoleting that part of the comment. The comment's point about XLOG_DBASE_CREATE was wrong when commit fa0f466d5329e10b16f3b38c8eaf5306f7e234e8 introduced the point. (It would have been accurate if that commit had predated commit fbcbc5d06f53aea412130deb52e216aa3883fb8d introducing the second checkpoint of CREATE DATABASE.) Nothing can skip log_smgrcreate() on the basis of wal_level=minimal, so don't comment on that. Commit c6b92041d38512a4176ed76ad06f713d2e6c01a8 expanded WAL skipping from five specific operations to relfilenodes generally, hence the CreateDatabaseUsingFileCopy() comment change. Discussion: https://postgr.es/m/20231008022204.cc@rfd.leadboat.com
* Remove unnecessary declaration of heapam_methodsMichael Paquier2024-08-06
| | | | | | | | This overlaps with the declaration at the end of heapam_handler.c that lists all the callback routines for the heap table AM. Author: Japin Li Discussion: https://postgr.es/m/ME0P300MB04459456D5C4E70D48116896B6B12@ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM
* revert: Generalize relation analyze in table AM interfaceAlexander Korotkov2024-04-16
| | | | | | This commit reverts 27bc1772fc and dd1f6b0c17. Per review by Andres Freund. Discussion: https://postgr.es/m/20240415201057.khoyxbwwxfgzomeo%40awork3.anarazel.de
* Revert: Allow table AM to store complex data structures in rd_amcacheAlexander Korotkov2024-04-11
| | | | | | This commit reverts 02eb07ea89 per review by Andres Freund. Discussion: https://postgr.es/m/20240410165236.rwyrny7ihi4ddxw4%40awork3.anarazel.de
* Revert: Allow table AM tuple_insert() method to return the different slotAlexander Korotkov2024-04-11
| | | | | | This commit reverts c35a3fb5e0 per review by Andres Freund. Discussion: https://postgr.es/m/20240410165236.rwyrny7ihi4ddxw4%40awork3.anarazel.de
* Revert: Allow locking updated tuples in tuple_update() and tuple_delete()Alexander Korotkov2024-04-11
| | | | | | This commit reverts 87985cc925 and 818861eb57 per review by Andres Freund. Discussion: https://postgr.es/m/20240410165236.rwyrny7ihi4ddxw4%40awork3.anarazel.de
* Revert: Let table AM insertion methods control index insertionAlexander Korotkov2024-04-11
| | | | | | This commit reverts b1484a3f19 per review by Andres Freund. Discussion: https://postgr.es/m/20240410165236.rwyrny7ihi4ddxw4%40awork3.anarazel.de
* Revert: Custom reloptions for table AMAlexander Korotkov2024-04-11
| | | | | | This commit reverts 9bd99f4c26 and 422041542f per review by Andres Freund. Discussion: https://postgr.es/m/20240410165236.rwyrny7ihi4ddxw4%40awork3.anarazel.de
* Provide a way block-level table AMs could re-use acquire_sample_rows()Alexander Korotkov2024-04-08
| | | | | | | | | | While keeping API the same, this commit provides a way for block-level table AMs to re-use existing acquire_sample_rows() by providing custom callbacks for getting the next block and the next tuple. Reported-by: Andres Freund Discussion: https://postgr.es/m/20240407214001.jgpg5q3yv33ve6y3%40awork3.anarazel.de Reviewed-by: Pavel Borisov
* Custom reloptions for table AMAlexander Korotkov2024-04-08
| | | | | | | | | | | | | | | | | | Let table AM define custom reloptions for its tables. This allows specifying AM-specific parameters by the WITH clause when creating a table. The reloptions, which could be used outside of table AM, are now extracted into the CommonRdOptions data structure. These options could be by decision of table AM directly specified by a user or calculated in some way. The new test module test_tam_options evaluates the ability to set up custom reloptions and calculate fields of CommonRdOptions on their base. The code may use some parts from prior work by Hao Wu. Discussion: https://postgr.es/m/CAPpHfdurb9ycV8udYqM%3Do0sPS66PJ4RCBM1g-bBpvzUfogY0EA%40mail.gmail.com Discussion: https://postgr.es/m/AMUA1wBBBxfc3tKRLLdU64rb.1.1683276279979.Hmail.wuhao%40hashdata.cn Reviewed-by: Reviewed-by: Pavel Borisov, Matthias van de Meent, Jess Davis
* Use streaming I/O in ANALYZE.Thomas Munro2024-04-08
| | | | | | | | | | | | | | The ANALYZE command prefetches and reads sample blocks chosen by a BlockSampler algorithm. Instead of calling [Prefetch|Read]Buffer() for each block, ANALYZE now uses the streaming API introduced in b5a9b18cd0. Author: Nazir Bilal Yavuz <byavuz81@gmail.com> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Jakub Wartak <jakub.wartak@enterprisedb.com> Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Reviewed-by: Thomas Munro <thomas.munro@gmail.com> Discussion: https://postgr.es/m/flat/CAN55FZ0UhXqk9v3y-zW_fp4-WCp43V8y0A72xPmLkOM%2B6M%2BmJg%40mail.gmail.com
* BitmapHeapScan: Push skip_fetch optimization into table AMTomas Vondra2024-04-07
| | | | | | | | | | | | | | | | | | | | | Commit 7c70996ebf0949b142 introduced an optimization to allow bitmap scans to operate like index-only scans by not fetching a block from the heap if none of the underlying data is needed and the block is marked all visible in the visibility map. With the introduction of table AMs, a FIXME was added to this code indicating that the skip_fetch logic should be pushed into the table AM-specific code, as not all table AMs may use a visibility map in the same way. This commit resolves this FIXME for the current block. The layering violation is still present in BitmapHeapScans's prefetching code, which uses the visibility map to decide whether or not to prefetch a block. However, this can be addressed independently. Author: Melanie Plageman Reviewed-by: Andres Freund, Heikki Linnakangas, Tomas Vondra, Mark Dilger Discussion: https://postgr.es/m/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com
* Secondary refactor of heap scanning functionsDavid Rowley2024-04-04
| | | | | | | | Similar to 44086b097, refactor heap scanning functions to be more suitable for the read stream API. Author: Melanie Plageman Discussion: https://postgr.es/m/CAAKRu_YtXJiYKQvb5JsA2SkwrsizYLugs4sSOZh3EAjKUg=gEQ@mail.gmail.com
* Preliminary refactor of heap scanning functionsDavid Rowley2024-04-04
| | | | | | | | | | | | | | | | | | | | | | | | To allow the use of the read stream API added in b5a9b18cd for sequential scans on heap tables, here we make some adjustments to make that change less invasive and perhaps make the code easier to follow in the process. Here heapgetpage() gets broken into two functions: 1) The part which reads the block has now been moved into a function named heapfetchbuf(). 2) The part which performed pruning and populated the scan's rs_vistuples[] array is now moved into a new function named heap_prepare_pagescan(). The functionality provided by heap_prepare_pagescan() was only ever required by SO_ALLOW_PAGEMODE scans, so the branching that was previously done in heapgetpage() is no longer needed as we simply just don't call heap_prepare_pagescan() from heapgettup() in the refactored code. Author: Melanie Plageman Discussion: https://postgr.es/m/CAAKRu_YtXJiYKQvb5JsA2SkwrsizYLugs4sSOZh3EAjKUg=gEQ@mail.gmail.com
* Combine freezing and pruning steps in VACUUMHeikki Linnakangas2024-04-03
| | | | | | | | | | | | | | | | | | | | | | | | Execute both freezing and pruning of tuples in the same heap_page_prune() function, now called heap_page_prune_and_freeze(), and emit a single WAL record containing all changes. That reduces the overall amount of WAL generated. This moves the freezing logic from vacuumlazy.c to the heap_page_prune_and_freeze() function. The main difference in the coding is that in vacuumlazy.c, we looked at the tuples after the pruning had already happened, but in heap_page_prune_and_freeze() we operate on the tuples before pruning. The heap_prepare_freeze_tuple() function is now invoked after we have determined that a tuple is not going to be pruned away. VACUUM no longer needs to loop through the items on the page after pruning. heap_page_prune_and_freeze() does all the work. It now returns the list of dead offsets, including existing LP_DEAD items, to the caller. Similarly it's now responsible for tracking 'all_visible', 'all_frozen', and 'hastup' on the caller's behalf. Author: Melanie Plageman <melanieplageman@gmail.com> Discussion: https://www.postgresql.org/message-id/20240330055710.kqg6ii2cdojsxgje@liskov
* Revert "Custom reloptions for table AM"Alexander Korotkov2024-04-02
| | | | | | | | This reverts commit c95c25f9af4bc77f2f66a587735c50da08c12b37 due to multiple design issues spotted after commit. Reported-by: Jeff Davis Discussion: https://postgr.es/m/11550b536211d5748bb2865ed6cb3502ff073bf7.camel%40j-davis.com
* Let table AM insertion methods control index insertionAlexander Korotkov2024-03-30
| | | | | | | | | | | | Previously, the executor did index insert unconditionally after calling table AM interface methods tuple_insert() and multi_insert(). This commit introduces the new parameter insert_indexes for these two methods. Setting '*insert_indexes' to true saves the current logic. Setting it to false indicates that table AM cares about index inserts itself and doesn't want the caller to do that. Discussion: https://postgr.es/m/CAPpHfdurb9ycV8udYqM%3Do0sPS66PJ4RCBM1g-bBpvzUfogY0EA%40mail.gmail.com Reviewed-by: Pavel Borisov, Matthias van de Meent, Mark Dilger
* Custom reloptions for table AMAlexander Korotkov2024-03-30
| | | | | | | | | | | Let table AM define custom reloptions for its tables. This allows to specify AM-specific parameters by WITH clause when creating a table. The code may use some parts from prior work by Hao Wu. Discussion: https://postgr.es/m/CAPpHfdurb9ycV8udYqM%3Do0sPS66PJ4RCBM1g-bBpvzUfogY0EA%40mail.gmail.com Discussion: https://postgr.es/m/AMUA1wBBBxfc3tKRLLdU64rb.1.1683276279979.Hmail.wuhao%40hashdata.cn Reviewed-by: Reviewed-by: Pavel Borisov, Matthias van de Meent
* Generalize relation analyze in table AM interfaceAlexander Korotkov2024-03-30
| | | | | | | | | | | | | | | Currently, there is just one algorithm for sampling tuples from a table written in acquire_sample_rows(). Custom table AM can just redefine the way to get the next block/tuple by implementing scan_analyze_next_block() and scan_analyze_next_tuple() API functions. This approach doesn't seem general enough. For instance, it's unclear how to sample this way index-organized tables. This commit allows table AM to encapsulate the whole sampling algorithm (currently implemented in acquire_sample_rows()) into the relation_analyze() API function. Discussion: https://postgr.es/m/CAPpHfdurb9ycV8udYqM%3Do0sPS66PJ4RCBM1g-bBpvzUfogY0EA%40mail.gmail.com Reviewed-by: Pavel Borisov, Matthias van de Meent
* Allow locking updated tuples in tuple_update() and tuple_delete()Alexander Korotkov2024-03-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, in read committed transaction isolation mode (default), we have the following sequence of actions when tuple_update()/tuple_delete() finds the tuple updated by the concurrent transaction. 1. Attempt to update/delete tuple with tuple_update()/tuple_delete(), which returns TM_Updated. 2. Lock tuple with tuple_lock(). 3. Re-evaluate plan qual (recheck if we still need to update/delete and calculate the new tuple for update). 4. Second attempt to update/delete tuple with tuple_update()/tuple_delete(). This attempt should be successful, since the tuple was previously locked. This commit eliminates step 2 by taking the lock during the first tuple_update()/tuple_delete() call. The heap table access method saves some effort by checking the updated tuple once instead of twice. Future undo-based table access methods, which will start from the latest row version, can immediately place a lock there. Also, this commit makes tuple_update()/tuple_delete() optionally save the old tuple into the dedicated slot. That saves efforts on re-fetching tuples in certain cases. The code in nodeModifyTable.c is simplified by removing the nested switch/case. Discussion: https://postgr.es/m/CAPpHfdua-YFw3XTprfutzGp28xXLigFtzNbuFY8yPhqeq6X5kg%40mail.gmail.com Reviewed-by: Aleksander Alekseev, Pavel Borisov, Vignesh C, Mason Sharp Reviewed-by: Andres Freund, Chris Travers
* Allow table AM tuple_insert() method to return the different slotAlexander Korotkov2024-03-21
| | | | | | | | | | | This allows table AM to return a native tuple slot even if VirtualTupleTableSlot is given as an input. Native tuple slots have knowledge about system attributes, which could be accessed in the future. table_multi_insert() method already can modify the input 'slots' array. Discussion: https://postgr.es/m/CAPpHfdurb9ycV8udYqM%3Do0sPS66PJ4RCBM1g-bBpvzUfogY0EA%40mail.gmail.com Reviewed-by: Matthias van de Meent, Mark Dilger, Pavel Borisov Reviewed-by: Nikita Malakhov, Japin Li
* Allow table AM to store complex data structures in rd_amcacheAlexander Korotkov2024-03-21
| | | | | | | | | | | The new table AM method free_rd_amcache is responsible for freeing all the memory related to rd_amcache and setting free_rd_amcache to NULL. If the new method is not specified, we still assume rd_amcache to be a single chunk of memory, which could be just pfree'd. Discussion: https://postgr.es/m/CAPpHfdurb9ycV8udYqM%3Do0sPS66PJ4RCBM1g-bBpvzUfogY0EA%40mail.gmail.com Reviewed-by: Matthias van de Meent, Mark Dilger, Pavel Borisov Reviewed-by: Nikita Malakhov, Japin Li
* Remove unnecessary smgropen() callsHeikki Linnakangas2024-02-12
| | | | | | | | Now that RelationCreateStorage() returns the SmgrRelation (since commit 5c1560606dc), use that. Author: Japin Li Discussion: https://www.postgresql.org/message-id/ME3P282MB316600FA62F6605477F26F6AB6742@ME3P282MB3166.AUSP282.PROD.OUTLOOK.COM
* Update copyright for 2024Bruce Momjian2024-01-03
| | | | | | | | Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
* Remove unnecessary smgrimmedsync() when creating unlogged table.Heikki Linnakangas2023-09-15
| | | | | | | | | | | | | | This became safe after commit 4b4798e138. The smgrcreate() call will now register the segment for syncing at the next checkpoint, so we don't need to sync it here. If a checkpoint happens before the creation is WAL-logged, the records will be replayed when starting recovery from the checkpoint. If a checkpoint happens after the WAL logging, the checkpoint will fsync() it. In the passing, clarify a comment in smgrDoPendingSyncs(). Discussion: https://www.postgresql.org/message-id/6e5bbc08-cdfc-b2b3-9e23-1a914b9850a9%40iki.fi Reviewed-by: Robert Haas
* Fix race in SSI interaction with bitmap heap scan.Thomas Munro2023-07-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When performing a bitmap heap scan, we don't want to miss concurrent writes that occurred after we observed the heap's rs_nblocks, but before we took predicate locks on index pages. Therefore, we can't skip fetching any heap tuples that are referenced by the index, because we need to test them all with CheckForSerializableConflictOut(). The old optimization that would ignore any references to blocks >= rs_nblocks gets in the way of that requirement, because it means that concurrent writes in that window are ignored. Removing that optimization shouldn't affect correctness at any isolation level, because any new tuples shouldn't be visible to an MVCC snapshot. There also shouldn't be any error-causing references to heap blocks past the end, because we should have held at least an AccessShareLock on the table before the index scan. It can't get smaller while our transaction is running. For now, though, we'll keep the optimization at lower levels to avoid making unnecessary changes in a bug fix. Back-patch to all supported releases. In release 11, the code is in a different place but not fundamentally different. Fixes one aspect of bug #17949. Reported-by: Artem Anisimov <artem.anisimov.255@gmail.com> Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/17949-a0f17035294a55e2%40postgresql.org
* nbtree: Allocate new pages in separate function.Peter Geoghegan2023-06-10
| | | | | | | | | | | | | | | | | | | | | | | | Split nbtree's _bt_getbuf function is two: code that read locks or write locks existing pages remains in _bt_getbuf, while code that deals with allocating new pages is moved to a new, dedicated function called _bt_allocbuf. This simplifies most _bt_getbuf callers, since it is no longer necessary for them to pass a heaprel argument. Many of the changes to nbtree from commit 61b313e4 can be reverted. This minimizes the divergence between HEAD/PostgreSQL 16 and earlier release branches. _bt_allocbuf replaces the previous nbtree idiom of passing P_NEW to _bt_getbuf. There are only 3 affected call sites, all of which continue to pass a heaprel for recovery conflict purposes. Note that nbtree's use of P_NEW was superficial; nbtree never actually relied on the P_NEW code paths in bufmgr.c, so this change is strictly mechanical. GiST already took the same approach; it has a dedicated function for allocating new pages called gistNewBuffer(). That factor allowed commit 61b313e4 to make much more targeted changes to GiST. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/CAH2-Wz=8Z9qY58bjm_7TAHgtW6RzZ5Ke62q5emdCEy9BAzwhmg@mail.gmail.com
* Pre-beta mechanical code beautification.Tom Lane2023-05-19
| | | | | | | | | | | | | | | Run pgindent, pgperltidy, and reformat-dat-files. This set of diffs is a bit larger than typical. We've updated to pg_bsd_indent 2.1.2, which properly indents variable declarations that have multi-line initialization expressions (the continuation lines are now indented one tab stop). We've also updated to perltidy version 20230309 and changed some of its settings, which reduces its desire to add whitespace to lines to make assignments etc. line up. Going forward, that should make for fewer random-seeming changes to existing code. Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
* Fix typos in commentsMichael Paquier2023-05-02
| | | | | | | | | The changes done in this commit impact comments with no direct user-visible changes, with fixes for incorrect function, variable or structure names. Author: Alexander Lakhin Discussion: https://postgr.es/m/e8c38840-596a-83d6-bd8d-cebc51111572@gmail.com
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