summaryrefslogtreecommitdiff
path: root/src/backend/utils/cache
AgeCommit message (Collapse)Author
2021-10-23Fix CREATE INDEX CONCURRENTLY for the newest prepared transactions.Noah Misch
The purpose of commit 8a54e12a38d1545d249f1402f66c8cde2837d97c was to fix this, and it sufficed when the PREPARE TRANSACTION completed before the CIC looked for lock conflicts. Otherwise, things still broke. As before, in a cluster having used CIC while having enabled prepared transactions, queries that use the resulting index can silently fail to find rows. It may be necessary to reindex to recover from past occurrences; REINDEX CONCURRENTLY suffices. Fix this for future index builds by making CIC wait for arbitrarily-recent prepared transactions and for ordinary transactions that may yet PREPARE TRANSACTION. As part of that, have PREPARE TRANSACTION transfer locks to its dummy PGPROC before it calls ProcArrayClearTransaction(). Back-patch to 9.6 (all supported versions). Andrey Borodin, reviewed (in earlier versions) by Andres Freund. Discussion: https://postgr.es/m/01824242-AA92-4FE9-9BA7-AEBAFFEA3D0C@yandex-team.ru
2021-10-23Avoid race in RelationBuildDesc() affecting CREATE INDEX CONCURRENTLY.Noah Misch
CIC and REINDEX CONCURRENTLY assume backends see their catalog changes no later than each backend's next transaction start. That failed to hold when a backend absorbed a relevant invalidation in the middle of running RelationBuildDesc() on the CIC index. Queries that use the resulting index can silently fail to find rows. Fix this for future index builds by making RelationBuildDesc() loop until it finishes without accepting a relevant invalidation. It may be necessary to reindex to recover from past occurrences; REINDEX CONCURRENTLY suffices. Back-patch to 9.6 (all supported versions). Noah Misch and Andrey Borodin, reviewed (in earlier versions) by Andres Freund. Discussion: https://postgr.es/m/20210730022548.GA1940096@gust.leadboat.com
2021-07-10Fix assign_record_type_typmod().Jeff Davis
If an error occurred in the wrong place, it was possible to leave an unintialized entry in the hash table, leading to a crash. Fixed. Also, be more careful about the order of operations so that an allocation error doesn't leak memory in CacheMemoryContext or unnecessarily advance NextRecordTypmod. Backpatch through version 11. Earlier versions (prior to 35ea75632a5) do not exhibit the problem, because an uninitialized hash entry contains a valid empty list. Author: Sait Talha Nisanci <Sait.Nisanci@microsoft.com> Reviewed-by: Andres Freund Discussion: https://postgr.es/m/HE1PR8303MB009069D476225B9A9E194B8891779@HE1PR8303MB0090.EURPRD83.prod.outlook.com Backpatch-through: 11
2021-07-05Reduce overhead of cache-clobber testing in LookupOpclassInfo().Tom Lane
Commit 03ffc4d6d added logic to bypass all caching behavior in LookupOpclassInfo when CLOBBER_CACHE_ALWAYS is enabled. It doesn't look like I stopped to think much about what that would cost, but recent investigation shows that the cost is enormous: it roughly doubles the time needed for cache-clobber test runs. There does seem to be value in this behavior when trying to test the opclass-cache loading logic itself, but for other purposes the cost is excessive. Hence, let's back off to doing this only when debug_invalidate_system_caches_always is at least 3; or in older branches, when CLOBBER_CACHE_RECURSIVELY is defined. While here, clean up some other minor issues in LookupOpclassInfo. Re-order the code so we aren't left with broken cache entries (leading to later core dumps) in the unlikely case that we suffer OOM while trying to allocate space for a new entry. (That seems to be my oversight in 03ffc4d6d.) Also, in >= v13, stop allocating one array entry too many. That's evidently left over from sloppy reversion in 851b14b0c. Back-patch to all supported branches, mainly to reduce the runtime of cache-clobbering buildfarm animals. Discussion: https://postgr.es/m/1370856.1625428625@sss.pgh.pa.us
2021-06-24Another fix to relmapper race condition.Heikki Linnakangas
In previous commit, I missed that relmap_redo() was also not acquiring the RelationMappingLock. Thanks to Thomas Munro for pointing that out. Backpatch-through: 9.6, like previous commit. Discussion: https://www.postgresql.org/message-id/CA%2BhUKGLev%3DPpOSaL3WRZgOvgk217et%2BbxeJcRr4eR-NttP1F6Q%40mail.gmail.com
2021-06-24Prevent race condition while reading relmapper file.Heikki Linnakangas
Contrary to the comment here, POSIX does not guarantee atomicity of a read(), if another process calls write() concurrently. Or at least Linux does not. Add locking to load_relmap_file() to avoid the race condition. Fixes bug #17064. Thanks to Alexander Lakhin for the report and test case. Backpatch-through: 9.6, all supported versions. Discussion: https://www.postgresql.org/message-id/17064-bb0d7904ef72add3@postgresql.org
2021-06-18Don't set a fast default for anything but a plain tableAndrew Dunstan
The fast default code added in Release 11 omitted to check that the table a fast default was being added to was a plain table. Thus one could be added to a foreign table, which predicably blows up. Here we perform that check. In addition, on the back branches, since some of these might have escaped into the wild, if we encounter a missing value for an attribute of something other than a plain table we ignore it. Fixes bug #17056 Backpatch to release 11, Reviewed by: Andres Freund, Álvaro Herrera and Tom Lane
2021-05-29Fix race condition when sharing tuple descriptors.Thomas Munro
Parallel query processes that called BlessTupleDesc() for identical tuple descriptors at the same moment could crash. There was code to handle that rare case, but it dereferenced a bogus DSA pointer. Repair. Back-patch to 11, where commit cc5f8136 added support for sharing tuple descriptors in parallel queries. Reported-by: Eric Thinnes <e.thinnes@gmx.de> Discussion: https://postgr.es/m/99aaa2eb-e194-bf07-c29a-1a76b4f2bcf9%40gmx.de
2021-03-18Don't run RelationInitTableAccessMethod in a long-lived context.Tom Lane
Some code paths in this function perform syscache lookups, which can lead to table accesses and possibly leakage of cruft into the caller's context. If said context is CacheMemoryContext, we eventually will have visible bloat. But fixing this is no harder than moving one memory context switch step. (The other callers don't have a problem.) Andres Freund and I independently found this via valgrind testing. Back-patch to v12 where this code was added. Discussion: https://postgr.es/m/20210317023101.anvejcfotwka6gaa@alap3.anarazel.de Discussion: https://postgr.es/m/3816764.1616104288@sss.pgh.pa.us
2021-03-18Don't leak rd_statlist when a relcache entry is dropped.Tom Lane
Although these lists are usually NIL, and even when not empty are unlikely to be large, constant relcache update traffic could eventually result in visible bloat of CacheMemoryContext. Found via valgrind testing. Back-patch to v10 where this field was added. Discussion: https://postgr.es/m/3816764.1616104288@sss.pgh.pa.us
2021-02-10Preserve pg_attribute.attstattarget across REINDEX CONCURRENTLYMichael Paquier
For an index, attstattarget can be updated using ALTER INDEX SET STATISTICS. This data was lost on the new index after REINDEX CONCURRENTLY. The update of this field is done when the old and new indexes are swapped to make the fix back-patchable. Another approach we could look after in the long-term is to change index_create() to pass the wanted values of attstattarget when creating the new relation, but, as this would cause an ABI breakage this can be done only on HEAD. Reported-by: Ronan Dunklau Author: Michael Paquier Reviewed-by: Ronan Dunklau, Tomas Vondra Discussion: https://postgr.es/m/16628084.uLZWGnKmhe@laptop-ronand Backpatch-through: 12
2020-12-28Fix inconsistent code with shared invalidations of snapshotsMichael Paquier
The code in charge of processing a single invalidation message has been using since 568d413 the structure for relation mapping messages. This had fortunately no consequence as both locate the database ID at the same location, but it could become a problem in the future if this area of the code changes. Author: Konstantin Knizhnik Discussion: https://postgr.es/m/8044c223-4d3a-2cdb-42bf-29940840ce94@postgrespro.ru Backpatch-through: 9.5
2020-12-18Avoid memcpy() with same source and destination during relmapper init.Tom Lane
A narrow reading of the C standard says that memcpy(x,x,n) is undefined, although it's hard to envision an implementation that would really misbehave. However, analysis tools such as valgrind might whine about this; accordingly, let's band-aid relmapper.c to not do it. See also 5b630501e, d3f4e8a8a, ad7b48ea0, and other similar fixes. Apparently, none of those folk tried valgrinding initdb? This has been like this for long enough that I'm surprised it hasn't been reported before. Back-patch, just in case anybody wants to use a back branch on a platform that complains about this; we back-patched those earlier fixes too. Discussion: https://postgr.es/m/161790.1608310142@sss.pgh.pa.us
2020-10-25Fix incorrect parameter name in a function header commentDavid Rowley
Author: Zhijie Hou Discussion: https://postgr.es/m/14cd74ea00204cc8a7ea5d738ac82cd1@G08CNEXMBPEKD05.g08.fujitsu.local Backpatch-through: 12, where the mistake was introduced
2020-04-06Preserve clustered index after rewrites with ALTER TABLEMichael Paquier
A table rewritten by ALTER TABLE would lose tracking of an index usable for CLUSTER. This setting is tracked by pg_index.indisclustered and is controlled by ALTER TABLE, so some extra work was needed to restore it properly. Note that ALTER TABLE only marks the index that can be used for clustering, and does not do the actual operation. Author: Amit Langote, Justin Pryzby Reviewed-by: Ibrar Ahmed, Michael Paquier Discussion: https://postgr.es/m/20200202161718.GI13621@telsasoft.com Backpatch-through: 9.5
2020-03-28Ensure snapshot is registered within ScanPgRelation().Andres Freund
In 9.4 I added support to use a historical snapshot in ScanPgRelation(), while adding logical decoding. Unfortunately a conflict with the concurrent removal of SnapshotNow was incorrectly resolved, leading to an unregistered snapshot being used. It is not correct to use an unregistered (or non-active) snapshot for anything non-trivial, because catalog invalidations can cause the snapshot to be invalidated. Luckily it seems unlikely to actively cause problems in practice, as ScanPgRelation() requires that we already have a lock on the relation, we only look for a single row, and we don't appear to rely on the result's tid to be correct. It however is clearly wrong and potential negative consequences would likely be hard to find. So it seems worth backpatching the fix, even without a concrete hazard. Discussion: https://postgr.es/m/20200229052459.wzhqnbhrriezg4v2@alap3.anarazel.de Backpatch: 9.5-
2020-03-22Revert "Skip WAL for new relfilenodes, under wal_level=minimal."Noah Misch
This reverts commit cb2fd7eac285b1b0a24eeb2b8ed4456b66c5a09f. Per numerous buildfarm members, it was incompatible with parallel query, and a test case assumed LP64. Back-patch to 9.5 (all supported versions). Discussion: https://postgr.es/m/20200321224920.GB1763544@rfd.leadboat.com
2020-03-21Skip WAL for new relfilenodes, under wal_level=minimal.Noah Misch
Until now, only selected bulk operations (e.g. COPY) did this. If a given relfilenode received both a WAL-skipping COPY and a WAL-logged operation (e.g. INSERT), recovery could lose tuples from the COPY. See src/backend/access/transam/README section "Skipping WAL for New RelFileNode" for the new coding rules. Maintainers of table access methods should examine that section. To maintain data durability, just before commit, we choose between an fsync of the relfilenode and copying its contents to WAL. A new GUC, wal_skip_threshold, guides that choice. If this change slows a workload that creates small, permanent relfilenodes under wal_level=minimal, try adjusting wal_skip_threshold. Users setting a timeout on COMMIT may need to adjust that timeout, and log_min_duration_statement analysis will reflect time consumption moving to COMMIT from commands like COPY. Internally, this requires a reliable determination of whether RollbackAndReleaseCurrentSubTransaction() would unlink a relation's current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the specification of rd_createSubid such that the field is zero when a new rel has an old rd_node. Make relcache.c retain entries for certain dropped relations until end of transaction. Back-patch to 9.5 (all supported versions). This introduces a new WAL record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC. As always, update standby systems before master systems. This changes sizeof(RelationData) and sizeof(IndexStmt), breaking binary compatibility for affected extensions. (The most recent commit to affect the same class of extensions was 089e4d405d0f3b94c74a2c6a54357a84a681754b.) Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert Haas. Heikki Linnakangas and Michael Paquier implemented earlier designs that materially clarified the problem. Reviewed, in earlier designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane, Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout. Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
2020-03-21Fix cosmetic blemishes involving rd_createSubid.Noah Misch
Remove an obsolete comment from AtEOXact_cleanup(). Restore formatting of a comment in struct RelationData, mangled by the pgindent run in commit 9af4159fce6654aa0e081b00d02bca40b978745c. Back-patch to 9.5 (all supported versions), because another fix stacks on this.
2020-03-13Preserve replica identity index across ALTER TABLE rewritePeter Eisentraut
If an index was explicitly set as replica identity index, this setting was lost when a table was rewritten by ALTER TABLE. Because this setting is part of pg_index but actually controlled by ALTER TABLE (not part of CREATE INDEX, say), we have to do some extra work to restore it. Based-on-patch-by: Quan Zongliang <quanzongliang@gmail.com> Reviewed-by: Euler Taveira <euler.taveira@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/flat/c70fcab2-4866-0d9f-1d01-e75e189db342@gmail.com
2020-03-10Prevent reindex of invalid indexes on TOAST tablesMichael Paquier
Such indexes can only be duplicated leftovers of a previously failed REINDEX CONCURRENTLY command, and a valid equivalent is guaranteed to exist. As toast indexes can only be dropped if invalid, reindexing these would lead to useless duplicated indexes that can't be dropped anymore, except if the parent relation is dropped. Thanks to Justin Pryzby for reminding that this problem was reported long ago during the review of the original patch of REINDEX CONCURRENTLY, but the issue was never addressed. Reported-by: Sergei Kornilov, Justin Pryzby Author: Julien Rouhaud Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/36712441546604286%40sas1-890ba5c2334a.qloud-c.yandex.net Discussion: https://postgr.es/m/20200216190835.GA21832@telsasoft.com Backpatch-through: 12
2020-01-31Fix CheckAttributeType's handling of collations for ranges.Tom Lane
Commit fc7695891 changed CheckAttributeType to recurse into ranges, but made it pass down the wrong collation (always InvalidOid, since ranges as such have no collation). This would result in guaranteed failure when considering a range type whose subtype is collatable. Embarrassingly, we lack any regression tests that would expose such a problem (but fortunately, somebody noticed before we shipped this bug in any release). Fix it to pass down the range's subtype collation property instead, and add some regression test cases to exercise collatable-subtype ranges a bit more. Back-patch to all supported branches, as the previous patch was. Report and patch by Julien Rouhaud, test cases tweaked by me Discussion: https://postgr.es/m/CAOBaU_aBWqNweiGUFX0guzBKkcfJ8mnnyyGC_KBQmO12Mj5f_A@mail.gmail.com
2019-12-01Fix misbehavior with expression indexes on ON COMMIT DELETE ROWS tables.Tom Lane
We implement ON COMMIT DELETE ROWS by truncating tables marked that way, which requires also truncating/rebuilding their indexes. But RelationTruncateIndexes asks the relcache for up-to-date copies of any index expressions, which may cause execution of eval_const_expressions on them, which can result in actual execution of subexpressions. This is a bad thing to have happening during ON COMMIT. Manuel Rigger reported that use of a SQL function resulted in crashes due to expectations that ActiveSnapshot would be set, which it isn't. The most obvious fix perhaps would be to push a snapshot during PreCommit_on_commit_actions, but I think that would just open the door to more problems: CommitTransaction explicitly expects that no user-defined code can be running at this point. Fortunately, since we know that no tuples exist to be indexed, there seems no need to use the real index expressions or predicates during RelationTruncateIndexes. We can set up dummy index expressions instead (we do need something that will expose the right data type, as there are places that build index tupdescs based on this), and just ignore predicates and exclusion constraints. In a green field it'd likely be better to reimplement ON COMMIT DELETE ROWS using the same "init fork" infrastructure used for unlogged relations. That seems impractical without catalog changes though, and even without that it'd be too big a change to back-patch. So for now do it like this. Per private report from Manuel Rigger. This has been broken forever, so back-patch to all supported branches.
2019-09-09Fix handling of non-key columns get_index_column_opclass()Alexander Korotkov
f2e40380 introduces support of non-key attributes in GiST indexes. Then if get_index_column_opclass() is asked by gistproperty() to get an opclass of non-key column, it returns garbage past oidvector value. This commit fixes that by making get_index_column_opclass() return InvalidOid in this case. Discussion: https://postgr.es/m/20190902231948.GA5343%40alvherre.pgsql Author: Nikita Glukhov, Alexander Korotkov Backpatch-through: 12
2019-08-28Avoid catalog lookups in RelationAllowsEarlyPruning().Thomas Munro
RelationAllowsEarlyPruning() performed a catalog scan, but is used in two contexts where that was a bad idea: 1. In heap_page_prune_opt(), which runs very frequently in some large scans. This caused major performance problems in a field report that was easy to reproduce. 2. In TestForOldSnapshot(), which runs while we hold a buffer content lock. It's not clear if this was guaranteed to be free of buffer deadlock risk. The check was introduced in commit 2cc41acd8 and defended against a real problem: 9.6's hash indexes have no page LSN and so we can't allow early pruning (ie the snapshot-too-old feature). We can remove the check from all later releases though: hash indexes are now logged, and there is no way to create UNLOGGED indexes on regular logged tables. If a future release allows such a combination, it might need to put a similar check in place, but it'll need some more thought. Back-patch to 10. Author: Thomas Munro Reviewed-by: Tom Lane, who spotted the second problem Discussion: https://postgr.es/m/CA%2BhUKGKT8oTkp5jw_U4p0S-7UG9zsvtw_M47Y285bER6a2gD%2Bg%40mail.gmail.com Discussion: https://postgr.es/m/CAA4eK1%2BWy%2BN4eE5zPm765h68LrkWc3Biu_8rzzi%2BOYX4j%2BiHRw%40mail.gmail.com
2019-08-15Fix plpgsql to re-look-up composite type names at need.Tom Lane
Commit 4b93f5799 rearranged things in plpgsql to make it cope better with composite types changing underneath it intra-session. However, I failed to consider the case of a composite type being dropped and recreated entirely. In my defense, the previous coding didn't consider that possibility at all either --- but it would accidentally work so long as you didn't change the type's field list, because the built-at-compile-time list of component variables would then still match the type's new definition. The new coding, however, occasionally tries to re-look-up the type by OID, and then fails to find the dropped type. To fix this, we need to save the TypeName struct, and then redo the type OID lookup from that. Of course that's expensive, so we don't want to do it every time we need the type OID. This can be fixed in the same way that 4b93f5799 dealt with changes to composite types' definitions: keep an eye on the type's typcache entry to see if its tupledesc has been invalidated. (Perhaps, at some point, this mechanism should be generalized so it can work for non-composite types too; but for now, plpgsql only tries to cope with intra-session redefinitions of composites.) I'm slightly hesitant to back-patch this into v11, because it changes the contents of struct PLpgSQL_type as well as the signature of plpgsql_build_datatype(), so in principle it could break code that is poking into the innards of plpgsql. However, the only popular extension of that ilk is pldebugger, and it doesn't seem to be affected. Since this is a regression for people who were relying on the old behavior, it seems worth taking the small risk of causing compatibility issues. Per bug #15913 from Daniel Fiori. Back-patch to v11 where 4b93f5799 came in. Discussion: https://postgr.es/m/15913-a7e112e16dedcffc@postgresql.org
2019-07-30Allow table AM's to use rd_amcache, too.Heikki Linnakangas
The rd_amcache allows an index AM to cache arbitrary information in a relcache entry. This commit moves the cleanup of rd_amcache so that it can also be used by table AMs. Nothing takes advantage of that yet, but I'm sure it'll come handy for anyone writing new table AMs. Backpatch to v12, where table AM interface was introduced. Reviewed-by: Julien Rouhaud
2019-07-01pgindent run prior to branching v12.Tom Lane
pgperltidy and reformat-dat-files too, though the latter didn't find anything to change.
2019-07-01Fix many typos and inconsistenciesMichael Paquier
Author: Alexander Lakhin Discussion: https://postgr.es/m/af27d1b3-a128-9d62-46e0-88f424397f44@gmail.com
2019-06-16Rework the pg_statistic_ext catalogTomas Vondra
Since extended statistic got introduced in PostgreSQL 10, there was a single catalog pg_statistic_ext storing both the definitions and built statistic. That's however problematic when a user is supposed to have access only to the definitions, but not to user data. Consider for example pg_dump on a database with RLS enabled - if the pg_statistic_ext catalog respects RLS (which it should, if it contains user data), pg_dump would not see any records and the result would not define any extended statistics. That would be a surprising behavior. Until now this was not a pressing issue, because the existing types of extended statistic (functional dependencies and ndistinct coefficients) do not include any user data directly. This changed with introduction of MCV lists, which do include most common combinations of values. The easiest way to fix this is to split the pg_statistic_ext catalog into two - one for definitions, one for the built statistic values. The new catalog is called pg_statistic_ext_data, and we're maintaining a 1:1 relationship with the old catalog - either there are matching records in both catalogs, or neither of them. Bumped CATVERSION due to changing system catalog definitions. Author: Dean Rasheed, with improvements by me Reviewed-by: Dean Rasheed, John Naylor Discussion: https://postgr.es/m/CAEZATCUhT9rt7Ui%3DVdx4N%3D%3DVV5XOK5dsXfnGgVOz_JhAicB%3DZA%40mail.gmail.com
2019-06-14Fix typos and inconsistencies in code commentsMichael Paquier
Author: Alexander Lakhin Discussion: https://postgr.es/m/dec6aae8-2d63-639f-4d50-20e229fb83e3@gmail.com
2019-06-10Don't access catalogs to validate GUCs when not connected to a DB.Andres Freund
Vignesh found this bug in the check function for default_table_access_method's check hook, but that was just copied from older GUCs. Investigation by Michael and me then found the bug in further places. When not connected to a database (e.g. in a walsender connection), we cannot perform (most) GUC checks that need database access. Even when only shared tables are needed, unless they're nailed (c.f. RelationCacheInitializePhase2()), they cannot be accessed without pg_class etc. being present. Fix by extending the existing IsTransactionState() checks to also check for MyDatabaseOid. Reported-By: Vignesh C, Michael Paquier, Andres Freund Author: Vignesh C, Andres Freund Discussion: https://postgr.es/m/CALDaNm1KXK9gbZfY-p_peRFm_XrBh1OwQO1Kk6Gig0c0fVZ2uw%40mail.gmail.com Backpatch: 9.4-
2019-05-22Phase 2 pgindent run for v12.Tom Lane
Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22Initial pgindent run for v12.Tom Lane
This is still using the 2.0 version of pg_bsd_indent. I thought it would be good to commit this separately, so as to document the differences between 2.0 and 2.1 behavior. Discussion: https://postgr.es/m/16296.1558103386@sss.pgh.pa.us
2019-05-08Clean up the behavior and API of catalog.c's is-catalog-relation tests.Tom Lane
The right way for IsCatalogRelation/Class to behave is to return true for OIDs less than FirstBootstrapObjectId (not FirstNormalObjectId), without any of the ad-hoc fooling around with schema membership. The previous code was wrong because (1) it claimed that information_schema tables were not catalog relations but their toast tables were, which is silly; and (2) if you dropped and recreated information_schema, which is a supported operation, the behavior changed. That's even sillier. With this definition, "catalog relations" are exactly the ones traceable to the postgres.bki data, which seems like what we want. With this simplification, we don't actually need access to the pg_class tuple to identify a catalog relation; we only need its OID. Hence, replace IsCatalogClass with "IsCatalogRelationOid(oid)". But keep IsCatalogRelation as a convenience function. This allows fixing some arguably-wrong semantics in contrib/sepgsql and ReindexRelationConcurrently, which were using an IsSystemNamespace test where what they really should be using is IsCatalogRelationOid. The previous coding failed to protect toast tables of system catalogs, and also was not on board with the general principle that user-created tables do not become catalogs just by virtue of being renamed into pg_catalog. We can also get rid of a messy hack in ReindexMultipleTables. While we're at it, also rename IsSystemNamespace to IsCatalogNamespace, because the previous name invited confusion with the more expansive semantics used by IsSystemRelation/Class. Also improve the comments in catalog.c. There are a few remaining places in replication-related code that are special-casing OIDs below FirstNormalObjectId. I'm inclined to think those are wrong too, and if there should be any special case it should just extend to FirstBootstrapObjectId. But first we need to debate whether a FOR ALL TABLES publication should include information_schema. Discussion: https://postgr.es/m/21697.1557092753@sss.pgh.pa.us Discussion: https://postgr.es/m/15150.1557257111@sss.pgh.pa.us
2019-05-03Remove RelationSetIndexList().Tom Lane
In the wake of commit f912d7dec, RelationSetIndexList isn't used any more. It was always a horrid wart, so getting rid of it is very nice. We can also convert rd_indexvalid back to a plain boolean. Discussion: https://postgr.es/m/28926.1556664156@sss.pgh.pa.us
2019-05-02Fix reindexing of pg_class indexes some more.Tom Lane
Commits 3dbb317d3 et al failed under CLOBBER_CACHE_ALWAYS testing. Investigation showed that to reindex pg_class_oid_index, we must suppress accesses to the index (via SetReindexProcessing) before we call RelationSetNewRelfilenode, or at least before we do CommandCounterIncrement therein; otherwise, relcache reloads happening within the CCI may try to fetch pg_class rows using the index's new relfilenode value, which is as yet an empty file. Of course, the point of 3dbb317d3 was that that ordering didn't work either, because then RelationSetNewRelfilenode's own update of the index's pg_class row cannot access the index, should it need to. There are various ways we might have got around that, but Andres Freund came up with a brilliant solution: for a mapped index, we can really just skip the pg_class update altogether. The only fields it was actually changing were relpages etc, but it was just setting them to zeroes which is useless make-work. (Correct new values will be installed at the end of index build.) All pg_class indexes are mapped and probably always will be, so this eliminates the problem by removing work rather than adding it, always a pleasant outcome. Having taught RelationSetNewRelfilenode to do it that way, we can revert the code reordering in reindex_index. (But I left the moved setup code where it was; there seems no reason why it has to run without use of the old index. If you're trying to fix a busted pg_class index, you'll have had to disable system index use altogether to get this far.) Moreover, this means we don't need RelationSetIndexList at all, because reindex_relation's hacking to make "REINDEX TABLE pg_class" work is likewise now unnecessary. We'll leave that code in place in the back branches, but a follow-on patch will remove it in HEAD. In passing, do some minor cleanup for commit 5c1560606 (in HEAD only), notably removing a duplicate newrnode assignment. Patch by me, using a core idea due to Andres Freund. Back-patch to all supported branches, as 3dbb317d3 was. Discussion: https://postgr.es/m/28926.1556664156@sss.pgh.pa.us
2019-04-29Fix several recently introduced issues around handling new relation forks.Andres Freund
Most of these stem from d25f519107 "tableam: relation creation, VACUUM FULL/CLUSTER, SET TABLESPACE.". 1) To pass data to the relation_set_new_filenode() RelationSetNewRelfilenode() was made to update RelationData.rd_rel directly. That's not OK however, as it makes the relcache entries temporarily inconsistent. Which among other scenarios is a problem if a REINDEX targets an index on pg_class - the CatalogTupleUpdate() in RelationSetNewRelfilenode(). Presumably that was introduced because other places in the code do so - while those aren't "good practice" they don't appear to be actively buggy (e.g. because system tables may not be targeted). I (Andres) should have caught this while reviewing and signficantly evolving the code in that commit, mea culpa. Fix that by instead passing in the new RelFileNode as separate argument to relation_set_new_filenode() and rely on the relcache to update the catalog entry. Also revert that the RelationMapUpdateMap() call was changed to immediate, and undo some other more unnecessary changes. 2) Document that the relation_set_new_filenode cannot rely on the whole relcache entry to be valid. It might be worthwhile to refactor the code to never have to rely on that, but given the way heap_create() is currently coded, that'd be a large change. 3) ATExecSetTableSpace() shouldn't do FlushRelationBuffers() itself. A table AM might not use shared buffers at all. Move to index_copy_data() and heapam_relation_copy_data(). 4) heapam_relation_set_new_filenode() previously sometimes accessed rel->rd_rel->relpersistence rather than the `persistence` argument. Code movement mistake. 5) Previously heapam_relation_set_new_filenode() re-opened the smgr relation to create the init for, if necesary. Instead have RelationCreateStorage() return the SMgrRelation and use it to create the init fork. 6) Add a note about the danger of modifying the relcache directly to ATExecSetTableSpace() - it's currently not a bug because there's a check ERRORing for catalog tables. Regression tests and assertion improvements that together trigger the bug described in 1) will be added in a later commit, as there is a related bug on all branches. Reported-By: Michael Paquier Diagnosed-By: Tom Lane and Andres Freund Author: Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/20190418011430.GA19133@paquier.xyz
2019-04-18Fix handling of temp and unlogged tables in FOR ALL TABLES publicationsPeter Eisentraut
If a FOR ALL TABLES publication exists, temporary and unlogged tables are ignored for publishing changes. But CheckCmdReplicaIdentity() would still check in that case that such a table has a replica identity set before accepting updates. To fix, have GetRelationPublicationActions() return that such a table publishes no actions. Discussion: https://www.postgresql.org/message-id/f3f151f7-c4dd-1646-b998-f60bd6217dd3@2ndquadrant.com
2019-04-13Prevent memory leaks associated with relcache rd_partcheck structures.Tom Lane
The original coding of generate_partition_qual() just copied the list of predicate expressions into the global CacheMemoryContext, making it effectively impossible to clean up when the owning relcache entry is destroyed --- the relevant code in RelationDestroyRelation() only managed to free the topmost List header :-(. This resulted in a session-lifespan memory leak whenever a table partition's relcache entry is rebuilt. Fortunately, that's not normally a large data structure, and rebuilds shouldn't occur all that often in production situations; but this is still a bug worth fixing back to v10 where the code was introduced. To fix, put the cached expression tree into its own small memory context, as we do with other complicated substructures of relcache entries. Also, deal more honestly with the case that a partition has an empty partcheck list; while that probably isn't a case that's very interesting for production use, it's legal. In passing, clarify comments about how partitioning-related relcache data structures are managed, and add some Asserts that we're not leaking old copies when we overwrite these data fields. Amit Langote and Tom Lane Discussion: https://postgr.es/m/7961.1552498252@sss.pgh.pa.us
2019-04-05Fix compiler warningPeter Eisentraut
Rewrite get_attgenerated() to avoid compiler warning if the compiler does not recognize that elog(ERROR) does not return. Reported-by: David Rowley <david.rowley@2ndquadrant.com>
2019-03-30Generated columnsPeter Eisentraut
This is an SQL-standard feature that allows creating columns that are computed from expressions rather than assigned, similar to a view or materialized view but on a column basis. This implements one kind of generated column: stored (computed on write). Another kind, virtual (computed on read), is planned for the future, and some room is left for it. Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/b151f851-4019-bdb1-699e-ebab07d2f40a@2ndquadrant.com
2019-03-28tableam: relation creation, VACUUM FULL/CLUSTER, SET TABLESPACE.Andres Freund
This moves the responsibility for: - creating the storage necessary for a relation, including creating a new relfilenode for a relation with existing storage - non-transactional truncation of a relation - VACUUM FULL / CLUSTER's rewrite of a table below tableam. This is fairly straight forward, with a bit of complexity smattered in to move the computation of xid / multixid horizons below the AM, as they don't make sense for every table AM. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-03-22Collations with nondeterministic comparisonPeter Eisentraut
This adds a flag "deterministic" to collations. If that is false, such a collation disables various optimizations that assume that strings are equal only if they are byte-wise equal. That then allows use cases such as case-insensitive or accent-insensitive comparisons or handling of strings with different Unicode normal forms. This functionality is only supported with the ICU provider. At least glibc doesn't appear to have any locales that work in a nondeterministic way, so it's not worth supporting this for the libc provider. The term "deterministic comparison" in this context is from Unicode Technical Standard #10 (https://unicode.org/reports/tr10/#Deterministic_Comparison). This patch makes changes in three areas: - CREATE COLLATION DDL changes and system catalog changes to support this new flag. - Many executor nodes and auxiliary code are extended to track collations. Previously, this code would just throw away collation information, because the eventually-called user-defined functions didn't use it since they only cared about equality, which didn't need collation information. - String data type functions that do equality comparisons and hashing are changed to take the (non-)deterministic flag into account. For comparison, this just means skipping various shortcuts and tie breakers that use byte-wise comparison. For hashing, we first need to convert the input string to a canonical "sort key" using the ICU analogue of strxfrm(). Reviewed-by: Daniel Verite <daniel@manitou-mail.org> Reviewed-by: Peter Geoghegan <pg@bowt.ie> Discussion: https://www.postgresql.org/message-id/flat/1ccc668f-4cbc-0bef-af67-450b47cdfee7@2ndquadrant.com
2019-03-15Further reduce memory footprint of CLOBBER_CACHE_ALWAYS testing.Tom Lane
Some buildfarm members using CLOBBER_CACHE_ALWAYS have been having OOM problems of late. Commit 2455ab488 addressed this problem by recovering space transiently used within RelationBuildPartitionDesc, but it turns out that leaves quite a lot on the table, because other subroutines of RelationBuildDesc also leak memory like mad. Let's move the temp-context management into RelationBuildDesc so that leakage from the other subroutines is also recovered. I examined this issue by arranging for postgres.c to dump the size of MessageContext just before resetting it in each command cycle, and then running the update.sql regression test (which is one of the two that are seeing buildfarm OOMs) with and without CLOBBER_CACHE_ALWAYS. Before 2455ab488, the peak space usage with CCA was as much as 250MB. That patch got it down to ~80MB, but with this patch it's about 0.5MB, and indeed the space usage now seems nearly indistinguishable from a non-CCA build. RelationBuildDesc's traditional behavior of not worrying about leaking transient data is of many years' standing, so I'm pretty hesitant to change that without more evidence that it'd be useful in a normal build. (So far as I can see, non-CCA memory consumption is about the same with or without this change, whuch if anything suggests that it isn't useful.) Hence, configure the patch so that we recover space only when CLOBBER_CACHE_ALWAYS or CLOBBER_CACHE_RECURSIVELY is defined. However, that choice can be overridden at compile time, in case somebody would like to do some performance testing and try to develop evidence for changing that decision. It's possible that we ought to back-patch this change, but in the absence of back-branch OOM problems in the buildfarm, I'm not in a hurry to do that. Discussion: https://postgr.es/m/CA+TgmoY3bRmGB6-DUnoVy5fJoreiBJ43rwMrQRCdPXuKt4Ykaw@mail.gmail.com
2019-03-11Fix typos in commit 8586bf7ed8.Amit Kapila
Author: Amit Kapila Discussion: https://postgr.es/m/CAA4eK1KNv1Mg2krf4E9ssWFnE=8A9mZ1VbVywXBZTFSzb+wP2g@mail.gmail.com
2019-03-11Move hash_any prototype from access/hash.h to utils/hashutils.hAlvaro Herrera
... as well as its implementation from backend/access/hash/hashfunc.c to backend/utils/hash/hashfn.c. access/hash is the place for the hash index AM, not really appropriate for generic facilities, which is what hash_any is; having things the old way meant that anything using hash_any had to include the AM's include file, pointlessly polluting its namespace with unrelated, unnecessary cruft. Also move the HTEqual strategy number to access/stratnum.h from access/hash.h. To avoid breaking third-party extension code, add an #include "utils/hashutils.h" to access/hash.h. (An easily removed line by committers who enjoy their asbestos suits to protect them from angry extension authors.) Discussion: https://postgr.es/m/201901251935.ser5e4h6djt2@alvherre.pgsql
2019-03-09Tighten use of OpenTransientFile and CloseTransientFileMichael Paquier
This fixes two sets of issues related to the use of transient files in the backend: 1) OpenTransientFile() has been used in some code paths with read-write flags while read-only is sufficient, so switch those calls to be read-only where necessary. These have been reported by Joe Conway. 2) When opening transient files, it is up to the caller to close the file descriptors opened. In error code paths, CloseTransientFile() gets called to clean up things before issuing an error. However in normal exit paths, a lot of callers of CloseTransientFile() never actually reported errors, which could leave a file descriptor open without knowing about it. This is an issue I complained about a couple of times, but never had the courage to write and submit a patch, so here we go. Note that one frontend code path is impacted by this commit so as an error is issued when fetching control file data, making backend and frontend to be treated consistently. Reported-by: Joe Conway, Michael Paquier Author: Michael Paquier Reviewed-by: Álvaro Herrera, Georgios Kokolatos, Joe Conway Discussion: https://postgr.es/m/20190301023338.GD1348@paquier.xyz Discussion: https://postgr.es/m/c49b69ec-e2f7-ff33-4f17-0eaa4f2cef27@joeconway.com
2019-03-07Allow ATTACH PARTITION with only ShareUpdateExclusiveLock.Robert Haas
We still require AccessExclusiveLock on the partition itself, because otherwise an insert that violates the newly-imposed partition constraint could be in progress at the same time that we're changing that constraint; only the lock level on the parent relation is weakened. To make this safe, we have to cope with (at least) three separate problems. First, relevant DDL might commit while we're in the process of building a PartitionDesc. If so, find_inheritance_children() might see a new partition while the RELOID system cache still has the old partition bound cached, and even before invalidation messages have been queued. To fix that, if we see that the pg_class tuple seems to be missing or to have a null relpartbound, refetch the value directly from the table. We can't get the wrong value, because DETACH PARTITION still requires AccessExclusiveLock throughout; if we ever want to change that, this will need more thought. In testing, I found it quite difficult to hit even the null-relpartbound case; the race condition is extremely tight, but the theoretical risk is there. Second, successive calls to RelationGetPartitionDesc might not return the same answer. The query planner will get confused if lookup up the PartitionDesc for a particular relation does not return a consistent answer for the entire duration of query planning. Likewise, query execution will get confused if the same relation seems to have a different PartitionDesc at different times. Invent a new PartitionDirectory concept and use it to ensure consistency. This ensures that a single invocation of either the planner or the executor sees the same view of the PartitionDesc from beginning to end, but it does not guarantee that the planner and the executor see the same view. Since this allows pointers to old PartitionDesc entries to survive even after a relcache rebuild, also postpone removing the old PartitionDesc entry until we're certain no one is using it. For the most part, it seems to be OK for the planner and executor to have different views of the PartitionDesc, because the executor will just ignore any concurrently added partitions which were unknown at plan time; those partitions won't be part of the inheritance expansion, but invalidation messages will trigger replanning at some point. Normally, this happens by the time the very next command is executed, but if the next command acquires no locks and executes a prepared query, it can manage not to notice until a new transaction is started. We might want to tighten that up, but it's material for a separate patch. There would still be a small window where a query that started just after an ATTACH PARTITION command committed might fail to notice its results -- but only if the command starts before the commit has been acknowledged to the user. All in all, the warts here around serializability seem small enough to be worth accepting for the considerable advantage of being able to add partitions without a full table lock. Although in general the consequences of new partitions showing up between planning and execution are limited to the query not noticing the new partitions, run-time partition pruning will get confused in that case, so that's the third problem that this patch fixes. Run-time partition pruning assumes that indexes into the PartitionDesc are stable between planning and execution. So, add code so that if new partitions are added between plan time and execution time, the indexes stored in the subplan_map[] and subpart_map[] arrays within the plan's PartitionedRelPruneInfo get adjusted accordingly. There does not seem to be a simple way to generalize this scheme to cope with partitions that are removed, mostly because they could then get added back again with different bounds, but it works OK for added partitions. This code does not try to ensure that every backend participating in a parallel query sees the same view of the PartitionDesc. That currently doesn't matter, because we never pass PartitionDesc indexes between backends. Each backend will ignore the concurrently added partitions which it notices, and it doesn't matter if different backends are ignoring different sets of concurrently added partitions. If in the future that matters, for example because we allow writes in parallel query and want all participants to do tuple routing to the same set of partitions, the PartitionDirectory concept could be improved to share PartitionDescs across backends. There is a draft patch to serialize and restore PartitionDescs on the thread where this patch was discussed, which may be a useful place to start. Patch by me. Thanks to Alvaro Herrera, David Rowley, Simon Riggs, Amit Langote, and Michael Paquier for discussion, and to Alvaro Herrera for some review. Discussion: http://postgr.es/m/CA+Tgmobt2upbSocvvDej3yzokd7AkiT+PvgFH+a9-5VV1oJNSQ@mail.gmail.com Discussion: http://postgr.es/m/CA+TgmoZE0r9-cyA-aY6f8WFEROaDLLL7Vf81kZ8MtFCkxpeQSw@mail.gmail.com Discussion: http://postgr.es/m/CA+TgmoY13KQZF-=HNTrt9UYWYx3_oYOQpu9ioNT49jGgiDpUEA@mail.gmail.com
2019-03-06tableam: introduce table AM infrastructure.Andres Freund
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