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* tableam: Add and use scan APIs.Andres Freund2019-03-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Too allow table accesses to be not directly dependent on heap, several new abstractions are needed. Specifically: 1) Heap scans need to be generalized into table scans. Do this by introducing TableScanDesc, which will be the "base class" for individual AMs. This contains the AM independent fields from HeapScanDesc. The previous heap_{beginscan,rescan,endscan} et al. have been replaced with a table_ version. There's no direct replacement for heap_getnext(), as that returned a HeapTuple, which is undesirable for a other AMs. Instead there's table_scan_getnextslot(). But note that heap_getnext() lives on, it's still used widely to access catalog tables. This is achieved by new scan_begin, scan_end, scan_rescan, scan_getnextslot callbacks. 2) The portion of parallel scans that's shared between backends need to be able to do so without the user doing per-AM work. To achieve that new parallelscan_{estimate, initialize, reinitialize} callbacks are introduced, which operate on a new ParallelTableScanDesc, which again can be subclassed by AMs. As it is likely that several AMs are going to be block oriented, block oriented callbacks that can be shared between such AMs are provided and used by heap. table_block_parallelscan_{estimate, intiialize, reinitialize} as callbacks, and table_block_parallelscan_{nextpage, init} for use in AMs. These operate on a ParallelBlockTableScanDesc. 3) Index scans need to be able to access tables to return a tuple, and there needs to be state across individual accesses to the heap to store state like buffers. That's now handled by introducing a sort-of-scan IndexFetchTable, which again is intended to be subclassed by individual AMs (for heap IndexFetchHeap). The relevant callbacks for an AM are index_fetch_{end, begin, reset} to create the necessary state, and index_fetch_tuple to retrieve an indexed tuple. Note that index_fetch_tuple implementations need to be smarter than just blindly fetching the tuples for AMs that have optimizations similar to heap's HOT - the currently alive tuple in the update chain needs to be fetched if appropriate. Similar to table_scan_getnextslot(), it's undesirable to continue to return HeapTuples. Thus index_fetch_heap (might want to rename that later) now accepts a slot as an argument. Core code doesn't have a lot of call sites performing index scans without going through the systable_* API (in contrast to loads of heap_getnext calls and working directly with HeapTuples). Index scans now store the result of a search in IndexScanDesc->xs_heaptid, rather than xs_ctup->t_self. As the target is not generally a HeapTuple anymore that seems cleaner. To be able to sensible adapt code to use the above, two further callbacks have been introduced: a) slot_callbacks returns a TupleTableSlotOps* suitable for creating slots capable of holding a tuple of the AMs type. table_slot_callbacks() and table_slot_create() are based upon that, but have additional logic to deal with views, foreign tables, etc. While this change could have been done separately, nearly all the call sites that needed to be adapted for the rest of this commit also would have been needed to be adapted for table_slot_callbacks(), making separation not worthwhile. b) tuple_satisfies_snapshot checks whether the tuple in a slot is currently visible according to a snapshot. That's required as a few places now don't have a buffer + HeapTuple around, but a slot (which in heap's case internally has that information). Additionally a few infrastructure changes were needed: I) SysScanDesc, as used by systable_{beginscan, getnext} et al. now internally uses a slot to keep track of tuples. While systable_getnext() still returns HeapTuples, and will so for the foreseeable future, the index API (see 1) above) now only deals with slots. The remainder, and largest part, of this commit is then adjusting all scans in postgres to use the new APIs. Author: Andres Freund, Haribabu Kommi, Alvaro Herrera Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de https://postgr.es/m/20160812231527.GA690404@alvherre.pgsql
* 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
* 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
* Don't include heapam.h from others headers.Andres Freund2019-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | heapam.h previously was included in a number of widely used headers (e.g. execnodes.h, indirectly in executor.h, ...). That's problematic on its own, as heapam.h contains a lot of low-level details that don't need to be exposed that widely, but becomes more problematic with the upcoming introduction of pluggable table storage - it seems inappropriate for heapam.h to be included that widely afterwards. heapam.h was largely only included in other headers to get the HeapScanDesc typedef (which was defined in heapam.h, even though HeapScanDescData is defined in relscan.h). The better solution here seems to be to just use the underlying struct (forward declared where necessary). Similar for BulkInsertState. Another problem was that LockTupleMode was used in executor.h - parts of the file tried to cope without heapam.h, but due to the fact that it indirectly included it, several subsequent violations of that goal were not not noticed. We could just reuse the approach of declaring parameters as int, but it seems nicer to move LockTupleMode to lockoptions.h - that's not a perfect location, but also doesn't seem bad. As a number of files relied on implicitly included heapam.h, a significant number of files grew an explicit include. It's quite probably that a few external projects will need to do the same. Author: Andres Freund Reviewed-By: Alvaro Herrera Discussion: https://postgr.es/m/20190114000701.y4ttcb74jpskkcfb@alap3.anarazel.de
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Add support for nearest-neighbor (KNN) searches to SP-GiSTAlexander Korotkov2018-09-19
| | | | | | | | | | | | | Currently, KNN searches were supported only by GiST. SP-GiST also capable to support them. This commit implements that support. SP-GiST scan stack is replaced with queue, which serves as stack if no ordering is specified. KNN support is provided for three SP-GIST opclasses: quad_point_ops, kd_point_ops and poly_ops (catversion is bumped). Some common parts between GiST and SP-GiST KNNs are extracted into separate functions. Discussion: https://postgr.es/m/570825e8-47d0-4732-2bf6-88d67d2d51c8%40postgrespro.ru Author: Nikita Glukhov, Alexander Korotkov based on GSoC work by Vlad Sterzhanov Review: Andrey Borodin, Alexander Korotkov
* Further cleanup of client dependencies on src/include/catalog headers.Tom Lane2018-04-09
| | | | | | | | | | | | | | | | | In commit 9c0a0de4c, I'd failed to notice that catalog/catalog.h should also be considered a frontend-unsafe header, because it includes (and needs) the full form of pg_class.h, not to mention relcache.h. However, various frontend code was depending on it to get TABLESPACE_VERSION_DIRECTORY, so refactoring of some sort is called for. The cleanest answer seems to be to move TABLESPACE_VERSION_DIRECTORY, as well as the OIDCHARS symbol, to common/relpath.h. Do that, and mop up inclusions as necessary. (I found that quite a few current users of catalog/catalog.h don't seem to need it at all anymore, apparently as a result of the refactorings that created common/relpath.[hc]. And initdb.c needed it only as a route to pg_class_d.h.) Discussion: https://postgr.es/m/6629.1523294509@sss.pgh.pa.us
* Local partitioned indexesAlvaro Herrera2018-01-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | When CREATE INDEX is run on a partitioned table, create catalog entries for an index on the partitioned table (which is just a placeholder since the table proper has no data of its own), and recurse to create actual indexes on the existing partitions; create them in future partitions also. As a convenience gadget, if the new index definition matches some existing index in partitions, these are picked up and used instead of creating new ones. Whichever way these indexes come about, they become attached to the index on the parent table and are dropped alongside it, and cannot be dropped on isolation unless they are detached first. To support pg_dump'ing these indexes, add commands CREATE INDEX ON ONLY <table> (which creates the index on the parent partitioned table, without recursing) and ALTER INDEX ATTACH PARTITION (which is used after the indexes have been created individually on each partition, to attach them to the parent index). These reconstruct prior database state exactly. Reviewed-by: (in alphabetical order) Peter Eisentraut, Robert Haas, Amit Langote, Jesper Pedersen, Simon Riggs, David Rowley Discussion: https://postgr.es/m/20171113170646.gzweigyrgg6pwsg4@alvherre.pgsql
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Change TRUE/FALSE to true/falsePeter Eisentraut2017-11-08
| | | | | | | | | | | | | | The lower case spellings are C and C++ standard and are used in most parts of the PostgreSQL sources. The upper case spellings are only used in some files/modules. So standardize on the standard spellings. The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so those are left as is when using those APIs. In code comments, we use the lower-case spelling for the C concepts and keep the upper-case spelling for the SQL concepts. Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
* Phase 3 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Phase 2 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Allow index AMs to return either HeapTuple or IndexTuple format during IOS.Tom Lane2017-02-27
| | | | | | | | | | | | | | | | | | | | | | Previously, only IndexTuple format was supported for the output data of an index-only scan. This is fine for btree, which is just returning a verbatim index tuple anyway. It's not so fine for SP-GiST, which can return reconstructed data that's much larger than a page. To fix, extend the index AM API so that index-only scan data can be returned in either HeapTuple or IndexTuple format. There's other ways we could have done it, but this way avoids an API break for index AMs that aren't concerned with the issue, and it costs little except a couple more fields in IndexScanDescs. I changed both GiST and SP-GiST to use the HeapTuple method. I'm not very clear on whether GiST can reconstruct data that's too large for an IndexTuple, but that seems possible, and it's not much of a code change to fix. Per a complaint from Vik Fearing. Reviewed by Jason Li. Discussion: https://postgr.es/m/49527f79-530d-0bfe-3dad-d183596afa92@2ndquadrant.fr
* Allow index AMs to cache data across aminsert calls within a SQL command.Tom Lane2017-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | It's always been possible for index AMs to cache data across successive amgettuple calls within a single SQL command: the IndexScanDesc.opaque field is meant for precisely that. However, no comparable facility exists for amortizing setup work across successive aminsert calls. This patch adds such a feature and teaches GIN, GIST, and BRIN to use it to amortize catalog lookups they'd previously been doing on every call. (The other standard index AMs keep everything they need in the relcache, so there's little to improve there.) For GIN, the overall improvement in a statement that inserts many rows can be as much as 10%, though it seems a bit less for the other two. In addition, this makes a really significant difference in runtime for CLOBBER_CACHE_ALWAYS tests, since in those builds the repeated catalog lookups are vastly more expensive. The reason this has been hard up to now is that the aminsert function is not passed any useful place to cache per-statement data. What I chose to do is to add suitable fields to struct IndexInfo and pass that to aminsert. That's not widening the index AM API very much because IndexInfo is already within the ken of ambuild; in fact, by passing the same info to aminsert as to ambuild, this is really removing an inconsistency in the AM API. Discussion: https://postgr.es/m/27568.1486508680@sss.pgh.pa.us
* Extend index AM API for parallel index scans.Robert Haas2017-01-24
| | | | | | | This patch doesn't actually make any index AM parallel-aware, but it provides the necessary functions at the AM layer to do so. Rahila Syed, Amit Kapila, Robert Haas
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Restructure index access method API to hide most of it at the C level.Tom Lane2016-01-17
| | | | | | | | | | | | | | | | | | | | | | | | This patch reduces pg_am to just two columns, a name and a handler function. All the data formerly obtained from pg_am is now provided in a C struct returned by the handler function. This is similar to the designs we've adopted for FDWs and tablesample methods. There are multiple advantages. For one, the index AM's support functions are now simple C functions, making them faster to call and much less error-prone, since the C compiler can now check function signatures. For another, this will make it far more practical to define index access methods in installable extensions. A disadvantage is that SQL-level code can no longer see attributes of index AMs; in particular, some of the crosschecks in the opr_sanity regression test are no longer possible from SQL. We've addressed that by adding a facility for the index AM to perform such checks instead. (Much more could be done in that line, but for now we're content if the amvalidate functions more or less replace what opr_sanity used to do.) We might also want to expose some sort of reporting functionality, but this patch doesn't do that. Alexander Korotkov, reviewed by Petr Jelínek, and rather heavily editorialized on by me.
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Add support for index-only scans in GiST.Heikki Linnakangas2015-03-26
| | | | | | | | | | | | | | This adds a new GiST opclass method, 'fetch', which is used to reconstruct the original Datum from the value stored in the index. Also, the 'canreturn' index AM interface function gains a new 'attno' argument. That makes it possible to use index-only scans on a multi-column index where some of the opclasses support index-only scans but some do not. This patch adds support in the box and point opclasses. Other opclasses can added later as follow-on patches (btree_gist would be particularly interesting). Anastasia Lubennikova, with additional fixes and modifications by me.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Introduce logical decoding.Robert Haas2014-03-03
| | | | | | | | | | | | | | | | | | | | | | This feature, building on previous commits, allows the write-ahead log stream to be decoded into a series of logical changes; that is, inserts, updates, and deletes and the transactions which contain them. It is capable of handling decoding even across changes to the schema of the effected tables. The output format is controlled by a so-called "output plugin"; an example is included. To make use of this in a real replication system, the output plugin will need to be modified to produce output in the format appropriate to that system, and to perform filtering. Currently, information can be extracted from the logical decoding system only via SQL; future commits will add the ability to stream changes via walsender. Andres Freund, with review and other contributions from many other people, including Álvaro Herrera, Abhijit Menon-Sen, Peter Gheogegan, Kevin Grittner, Robert Haas, Heikki Linnakangas, Fujii Masao, Abhijit Menon-Sen, Michael Paquier, Simon Riggs, Craig Ringer, and Steve Singer.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Remove some unused and seldom used fields from RelationAmInfo.Heikki Linnakangas2013-04-16
| | | | | | | This saves some memory from each index relcache entry. At least on a 64-bit machine, it saves just enough to shrink a typical relcache entry's memory usage from 2k to 1k. That's nice if you have a lot of backends and a lot of indexes.
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Run pgindent on 9.2 source tree in preparation for first 9.3Bruce Momjian2012-06-10
| | | | commit-fest.
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Replace simple constant pg_am.amcanreturn with an AM support function.Tom Lane2011-12-18
| | | | | | | | | The need for this was debated when we put in the index-only-scan feature, but at the time we had no near-term expectation of having AMs that could support such scans for only some indexes; so we kept it simple. However, the SP-GiST AM forces the issue, so let's fix it. This patch only installs the new API; no behavior actually changes.
* Improve index-only scans to avoid repeated access to the index page.Tom Lane2011-10-09
| | | | | | | | | | | | We copy all the matched tuples off the page during _bt_readpage, instead of expensively re-locking the page during each subsequent tuple fetch. This costs a bit more local storage, but not more than 2*BLCKSZ worth, and the reduction in LWLock traffic is certainly worth that. What's more, this lets us get rid of the API wart in the original patch that said an index AM could randomly decline to supply an index tuple despite having asserted pg_am.amcanreturn. That will be important for future improvements in the index-only-scan feature, since the executor will now be able to rely on having the index data available.
* Support index-only scans using the visibility map to avoid heap fetches.Tom Lane2011-10-07
| | | | | | | | | | | | | When a btree index contains all columns required by the query, and the visibility map shows that all tuples on a target heap page are visible-to-all, we don't need to fetch that heap page. This patch depends on the previous patches that made the visibility map reliable. There's a fair amount left to do here, notably trying to figure out a less chintzy way of estimating the cost of an index-only scan, but the core functionality seems ready to commit. Robert Haas and Ibrar Ahmed, with some previous work by Heikki Linnakangas.
* Remove unnecessary #include references, per pgrminclude script.Bruce Momjian2011-09-01
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* Avoid having two copies of the HOT-chain search logic.Robert Haas2011-06-27
| | | | | | | | | | | | | It's been like this since HOT was originally introduced, but the logic is complex enough that this is a recipe for bugs, as we've already found out with SSI. So refactor heap_hot_search_buffer() so that it can satisfy the needs of index_getnext(), and make index_getnext() use that rather than duplicating the logic. This change was originally proposed by Heikki Linnakangas as part of a larger refactoring oriented towards allowing index-only scans. I extracted and adjusted this part, since it seems to have independent merit. Review by Jeff Davis.
* Make non-MVCC snapshots exempt from predicate locking. Scans with non-MVCCHeikki Linnakangas2011-06-15
| | | | | | | | snapshots, like in REINDEX, are basically non-transactional operations. The DDL operation itself might participate in SSI, but there's separate functions for that. Kevin Grittner and Dan Ports, with some changes by me.
* Pgindent run before 9.1 beta2.Bruce Momjian2011-06-09
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* The row-version chaining in Serializable Snapshot Isolation was still wrong.Heikki Linnakangas2011-05-30
| | | | | | | | | | On further analysis, it turns out that it is not needed to duplicate predicate locks to the new row version at update, the lock on the version that the transaction saw as visible is enough. However, there was a different bug in the code that checks for dangerous structures when a new rw-conflict happens. Fix that bug, and remove all the row-version chaining related code. Kevin Grittner & Dan Ports, with some comment editorialization by me.
* Add an Assert that indexam.c isn't used on an index awaiting reindexing.Tom Lane2011-04-16
| | | | | | | This might have caught the recent embarrassment over trying to modify pg_index while its indexes were being rebuilt. Noah Misch
* Pass collations to functions in FunctionCallInfoData, not FmgrInfo.Tom Lane2011-04-12
| | | | | | | | | | | Since collation is effectively an argument, not a property of the function, FmgrInfo is really the wrong place for it; and this becomes critical in cases where a cached FmgrInfo is used for varying purposes that might need different collation settings. Fix by passing it in FunctionCallInfoData instead. In particular this allows a clean fix for bug #5970 (record_cmp not working). This requires touching a bit more code than the original method, but nobody ever thought that collations would not be an invasive patch...
* pgindent run before PG 9.1 beta 1.Bruce Momjian2011-04-10
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* Revise collation derivation method and expression-tree representation.Tom Lane2011-03-19
| | | | | | | | | | | | | | | | | | | All expression nodes now have an explicit output-collation field, unless they are known to only return a noncollatable data type (such as boolean or record). Also, nodes that can invoke collation-aware functions store a separate field that is the collation value to pass to the function. This avoids confusion that arises when a function has collatable inputs and noncollatable output type, or vice versa. Also, replace the parser's on-the-fly collation assignment method with a post-pass over the completed expression tree. This allows us to use a more complex (and hopefully more nearly spec-compliant) assignment rule without paying for it in extra storage in every expression node. Fix assorted bugs in the planner's handling of collations by making collation one of the defining properties of an EquivalenceClass and by converting CollateExprs into discardable RelabelType nodes during expression preprocessing.
* Fix incorrect access to pg_index.indcollation.Tom Lane2011-03-06
| | | | | | | | | Since this field is after a variable-length field, it can't simply be accessed via the C struct for pg_index. Fortunately, the relcache already did the dirty work of pulling the information out to where it can be accessed easily, so this is a one-line fix. Andres Freund
* Per-column collation supportPeter Eisentraut2011-02-08
| | | | | | | | This adds collation support for columns and domains, a COLLATE clause to override it per expression, and B-tree index support. Peter Eisentraut reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch
* Implement genuine serializable isolation level.Heikki Linnakangas2011-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Until now, our Serializable mode has in fact been what's called Snapshot Isolation, which allows some anomalies that could not occur in any serialized ordering of the transactions. This patch fixes that using a method called Serializable Snapshot Isolation, based on research papers by Michael J. Cahill (see README-SSI for full references). In Serializable Snapshot Isolation, transactions run like they do in Snapshot Isolation, but a predicate lock manager observes the reads and writes performed and aborts transactions if it detects that an anomaly might occur. This method produces some false positives, ie. it sometimes aborts transactions even though there is no anomaly. To track reads we implement predicate locking, see storage/lmgr/predicate.c. Whenever a tuple is read, a predicate lock is acquired on the tuple. Shared memory is finite, so when a transaction takes many tuple-level locks on a page, the locks are promoted to a single page-level lock, and further to a single relation level lock if necessary. To lock key values with no matching tuple, a sequential scan always takes a relation-level lock, and an index scan acquires a page-level lock that covers the search key, whether or not there are any matching keys at the moment. A predicate lock doesn't conflict with any regular locks or with another predicate locks in the normal sense. They're only used by the predicate lock manager to detect the danger of anomalies. Only serializable transactions participate in predicate locking, so there should be no extra overhead for for other transactions. Predicate locks can't be released at commit, but must be remembered until all the transactions that overlapped with it have completed. That means that we need to remember an unbounded amount of predicate locks, so we apply a lossy but conservative method of tracking locks for committed transactions. If we run short of shared memory, we overflow to a new "pg_serial" SLRU pool. We don't currently allow Serializable transactions in Hot Standby mode. That would be hard, because even read-only transactions can cause anomalies that wouldn't otherwise occur. Serializable isolation mode now means the new fully serializable level. Repeatable Read gives you the old Snapshot Isolation level that we have always had. Kevin Grittner and Dan Ports, reviewed by Jeff Davis, Heikki Linnakangas and Anssi Kääriäinen
* Stamp copyrights for year 2011.Bruce Momjian2011-01-01
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* Create core infrastructure for KNNGIST.Tom Lane2010-12-02
| | | | | | | | | | | | | | | | | | | This is a heavily revised version of builtin_knngist_core-0.9. The ordering operators are no longer mixed in with actual quals, which would have confused not only humans but significant parts of the planner. Instead, ordering operators are carried separately throughout planning and execution. Since the API for ambeginscan and amrescan functions had to be changed anyway, this commit takes the opportunity to rationalize that a bit. RelationGetIndexScan no longer forces a premature index_rescan call; instead, callers of index_beginscan must call index_rescan too. Aside from making the AM-side initialization logic a bit less peculiar, this has the advantage that we do not make a useless extra am_rescan call when there are runtime key values. AMs formerly could not assume that the key values passed to amrescan were actually valid; now they can. Teodor Sigaev and Tom Lane
* Remove cvs keywords from all files.Magnus Hagander2010-09-20
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* pgindent run for 9.0Bruce Momjian2010-02-26
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* Update copyright for the year 2010.Bruce Momjian2010-01-02
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* Allow read only connections during recovery, known as Hot Standby.Simon Riggs2009-12-19
| | | | | | | | | | | | Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
* Support deferrable uniqueness constraints.Tom Lane2009-07-29
| | | | | | | | | | The current implementation fires an AFTER ROW trigger for each tuple that looks like it might be non-unique according to the index contents at the time of insertion. This works well as long as there aren't many conflicts, but won't scale to massive unique-key reassignments. Improving that case is a TODO item. Dean Rasheed
* 8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef listBruce Momjian2009-06-11
| | | | provided by Andrew.