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path: root/src/backend/commands/tablecmds.c
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2019-07-23Check that partitions are not in use when dropping constraintsAlvaro Herrera
If the user creates a deferred constraint in a partition, and in a transaction they cause the constraint's trigger execution to be deferred until commit time *and* drop the constraint, then when commit time comes the queued trigger will fail to run because the trigger object will have been dropped. This is explained because when a constraint gets dropped in a partitioned table, the recursion to drop the ones in partitions is done by the dependency mechanism, not by ALTER TABLE traversing the recursion tree as in all other cases. In the non-partitioned case, this problem is avoided by checking that the table is not "in use" by alter-table; other alter-table subcommands that recurse to partitions do that check for each partition. But the dependency mechanism doesn't have a way to do that. Fix the problem by applying the same check to all partitions during ALTER TABLE's "prep" phase, which correctly raises the necessary error. Reported-by: Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com> Discussion: https://postgr.es/m/CAKcux6nZiO9-eEpr1ZD84bT1mBoVmeZkfont8iSpcmYrjhGWgA@mail.gmail.com
2019-07-22Install dependencies to prevent dropping partition key columns.Tom Lane
The logic in ATExecDropColumn that rejects dropping partition key columns is quite an inadequate defense, because it doesn't execute in cases where a column needs to be dropped due to cascade from something that only the column, not the whole partitioned table, depends on. That leaves us with a badly broken partitioned table; even an attempt to load its relcache entry will fail. We really need to have explicit pg_depend entries that show that the column can't be dropped without dropping the whole table. Hence, add those entries. In v12 and HEAD, bump catversion to ensure that partitioned tables will have such entries. We can't do that in released branches of course, so in v10 and v11 this patch affords protection only to partitioned tables created after the patch is installed. Given the lack of field complaints (this bug was found by fuzz-testing not by end users), that's probably good enough. In passing, fix ATExecDropColumn and ATPrepAlterColumnType messages to be more specific about which partition key column they're complaining about. Per report from Manuel Rigger. Back-patch to v10 where partitioned tables were added. Discussion: https://postgr.es/m/CA+u7OA4JKCPFrdrAbOs7XBiCyD61XJxeNav4LefkSmBLQ-Vobg@mail.gmail.com Discussion: https://postgr.es/m/31920.1562526703@sss.pgh.pa.us
2019-07-16Fix thinko in construction of old_conpfeqop list.Tom Lane
This should lappend the OIDs, not lcons them; the existing code produced a list in reversed order. This is harmless for single-key FKs or FKs where all the key columns are of the same type, which probably explains how it went unnoticed. But if those conditions are not met, ATAddForeignKeyConstraint would make the wrong decision about whether an existing FK needs to be revalidated. I think it would almost always err in the safe direction by revalidating a constraint that didn't need it. You could imagine scenarios where the pfeqop check was fooled by swapping the types of two FK columns in one ALTER TABLE, but that case would probably be rejected by other tests, so it might be impossible to get to the worst-case scenario where an FK should be revalidated and isn't. (And even then, it's likely to be fine, unless there are weird inconsistencies in the equality behavior of the replacement types.) However, this is a performance bug at least. Noted while poking around to see whether lcons calls could be converted to lappend. This bug is old, dating to commit cb3a7c2b9, so back-patch to all supported branches.
2019-07-09Propagate trigger arguments to partitionsAlvaro Herrera
We were creating the cloned triggers with an empty list of arguments, losing the ones that had been specified by the user when creating the trigger in the partitioned table. Repair. This was forgotten in commit 86f575948c77. Author: Patrick McHardy Reviewed-by: Tomas Vondra Discussion: https://postgr.es/m/20190709130027.amr2cavjvo7rdvac@access1.trash.net Discussion: https://postgr.es/m/15752-123bc90287986de4@postgresql.org
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.
2019-06-28Fix for dropped columns in a partitioned table's default partitionAlvaro Herrera
We forgot to map column numbers to/from the default partition for various operations, leading to valid cases failing with spurious errors, such as ERROR: attribute N of type some_partition has been dropped It was also possible that the search for conflicting rows in the default partition when attaching another partition would fail to detect some. Secondarily, it was also possible that such a search should be skipped (because the constraint was implied) but wasn't. Fix all this by mapping column numbers when necessary. Reported by: Daniel Wilches Author: Amit Langote Discussion: https://postgr.es/m/15873-8c61945d6b3ef87c@postgresql.org
2019-06-26Fix partitioned index creation with foreign partitionsAlvaro Herrera
When a partitioned tables contains foreign tables as partitions, it is not possible to implement unique or primary key indexes -- but when regular indexes are created, there is no reason to do anything other than ignoring such partitions. We were raising errors upon encountering the foreign partitions, which is unfriendly and doesn't protect against any actual problems. Relax this restriction so that index creation is allowed on partitioned tables containing foreign partitions, becoming a no-op on them. (We may later want to redefine this so that the FDW is told to create the indexes on the foreign side.) This applies to CREATE INDEX, as well as ALTER TABLE / ATTACH PARTITION and CREATE TABLE / PARTITION OF. Backpatch to 11, where indexes on partitioned tables were introduced. Discussion: https://postgr.es/m/15724-d5a58fa9472eef4f@postgresql.org Author: Álvaro Herrera Reviewed-by: Amit Langote
2019-06-24Purely-cosmetic adjustments in tablecmds.c.Tom Lane
Move ATExecAlterColumnGenericOptions away from where it was unthinkingly dropped, in the middle of a lot of ALTER COLUMN TYPE code. I don't have any high principles about where to put it instead, so let's just put it after ALTER COLUMN TYPE and before ALTER OWNER, matching existing decisions about how to order related code stanzas. Also add the minimal function header comment that the original author was too cool to bother with. Along the way, upgrade header comments for nearby ALTER COLUMN TYPE functions. Discussion: https://postgr.es/m/14787.1561403130@sss.pgh.pa.us
2019-06-24Further fix ALTER COLUMN TYPE's handling of indexes and index constraints.Tom Lane
This patch reverts all the code changes of commit e76de8861, which turns out to have been seriously misguided. We can't wait till later to compute the definition string for an index; we must capture that before applying the data type change for any column it depends on, else ruleutils.c will deliverr wrong/misleading results. (This fine point was documented nowhere, of course.) I'd also managed to forget that ATExecAlterColumnType executes once per ALTER COLUMN TYPE clause, not once per statement; which resulted in the code being basically completely broken for any case in which multiple ALTER COLUMN TYPE clauses are applied to a table having non-constraint indexes that must be rebuilt. Through very bad luck, none of the existing test cases nor the ones added by e76de8861 caught that, but of course it was soon found in the field. The previous patch also had an implicit assumption that if a constraint's index had a dependency on a table column, so would the constraint --- but that isn't actually true, so it didn't fix such cases. Instead of trying to delete unneeded index dependencies later, do the is-there-a-constraint lookup immediately on seeing an index dependency, and switch to remembering the constraint if so. In the unusual case of multiple column dependencies for a constraint index, this will result in duplicate constraint lookups, but that's not that horrible compared to all the other work that happens here. Besides, such cases did not work at all before, so it's hard to argue that they're performance-critical for anyone. Per bug #15865 from Keith Fiske. As before, back-patch to all supported branches. Discussion: https://postgr.es/m/15865-17940eacc8f8b081@postgresql.org
2019-06-12Fix ALTER COLUMN TYPE failure with a partial exclusion constraint.Tom Lane
ATExecAlterColumnType failed to consider the possibility that an index that needs to be rebuilt might be a child of a constraint that needs to be rebuilt. We missed this so far because usually a constraint index doesn't have a direct dependency on its table, just on the constraint object. But if there's a WHERE clause, then dependency analysis of the WHERE clause results in direct dependencies on the column(s) mentioned in WHERE. This led to trying to drop and rebuild both the constraint and its underlying index. In v11/HEAD, we successfully drop both the index and the constraint, and then try to rebuild both, and of course the second rebuild hits a duplicate-index-name problem. Before v11, it fails with obscure messages about a missing relation OID, due to trying to drop the index twice. This is essentially the same kind of problem noted in commit 20bef2c31: the possible dependency linkages are broader than what ATExecAlterColumnType was designed for. It was probably OK when written, but it's certainly been broken since the introduction of partial exclusion constraints. Fix by adding an explicit check for whether any of the indexes-to-be-rebuilt belong to any of the constraints-to-be-rebuilt, and ignoring any that do. In passing, fix a latent bug introduced by commit 8b08f7d48: in get_constraint_index() we must "continue" not "break" when rejecting a relation of a wrong relkind. This is harmless today because we don't expect that code path to be taken anyway; but if there ever were any relations to be ignored, the existing coding would have an extremely undesirable dependency on the order of pg_depend entries. Also adjust a couple of obsolete comments. Per bug #15835 from Yaroslav Schekin. Back-patch to all supported branches. Discussion: https://postgr.es/m/15835-32d9b7a76c06a7a9@postgresql.org
2019-06-08Fix assorted inconsistencies.Amit Kapila
There were a number of issues in the recent commits which include typos, code and comments mismatch, leftover function declarations. Fix them. Reported-by: Alexander Lakhin Author: Alexander Lakhin, Amit Kapila and Amit Langote Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/ef0c0232-0c1d-3a35-63d4-0ebd06e31387@gmail.com
2019-06-07Fix default_tablespace usage for partitioned tablesAlvaro Herrera
In commit 87259588d0ab I (Álvaro) tried to rationalize the determination of tablespace to use for partitioned tables, but failed to handle the default_tablespace case. Repair and add proper tests. Author: Amit Langote, Rushabh Lathia Reported-by: Rushabh Lathia Reviewed-by: Amit Langote, Álvaro Herrera Discussion: https://postgr.es/m/CAGPqQf0cYjm1=rjxk_6gU0SjUS70=yFUAdCJLwWzh9bhNJnyVg@mail.gmail.com
2019-06-05Rework code using list_delete_cell() in MergeAttributesMichael Paquier
When merging two attributes, we are sure that at least one remains. However, when deleting one element in the attribute list we may finish with an empty list returned as NIL by list_delete_cell(), but the code failed to track that, which is not project-like. Adjust the call so as we check for an empty list, and make use of it in an assertion. This has been introduced by e7b3349, when adding support for CREATE TABLE OF. Author: Mark Dilger Reviewed-by: Álvaro Herrera, Michael Paquier Discussion: https://postgr.es/m/CAE-h2TpPDqSWgOvfvSziOaMngMPwW+QZcmPpY8hQ_KOJ2+3hXQ@mail.gmail.com
2019-06-03Fix unsafe memory management in CloneRowTriggersToPartition().Tom Lane
It's not really supported to call systable_getnext() in a different memory context than systable_beginscan() was called in, and it's *definitely* not safe to do so and then reset that context between calls. I'm not very clear on how this code survived CLOBBER_CACHE_ALWAYS testing ... but Alexander Lakhin found a case that would crash it pretty reliably. Per bug #15828. Fix, and backpatch to v11 where this code came in. Discussion: https://postgr.es/m/15828-f6ddd7df4852f473@postgresql.org
2019-05-26Fix typos.Amit Kapila
Reported-by: Alexander Lakhin Author: Alexander Lakhin Reviewed-by: Amit Kapila and Tom Lane Discussion: https://postgr.es/m/7208de98-add8-8537-91c0-f8b089e2928c@gmail.com
2019-05-23tableam: Rename wrapper functions to match callback names.Andres Freund
Some of the wrapper functions didn't match the callback names. Many of them due to staying "consistent" with historic naming of the wrapped functionality. We decided that for most cases it's more important to be for tableam to be consistent going forward, than with the past. The one exception is beginscan/endscan/... because it'd have looked odd to have systable_beginscan/endscan/... with a different naming scheme, and changing the systable_* APIs would have caused way too much churn (including breaking a lot of external users). Author: Ashwin Agrawal, with some small additions by Andres Freund Reviewed-By: Andres Freund Discussion: https://postgr.es/m/CALfoeiugyrXZfX7n0ORCa4L-m834dzmaE8eFdbNR6PMpetU4Ww@mail.gmail.com
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
2019-05-16More message style fixesAlvaro Herrera
Discussion: https://postgr.es/m/20190515183005.GA26486@alvherre.pgsql
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
2019-05-08Fix error messagesAlvaro Herrera
Some messages related to foreign servers were reporting the server name without quotes, or not at all; our style is to have all names be quoted, and the server name already appears quoted in a few other messages, so just add quotes and make them all consistent. Remove an extra "s" in other messages (typos introduced by myself in f56f8f8da6af).
2019-05-05Fix style violations in syscache lookups.Tom Lane
Project style is to check the success of SearchSysCacheN and friends by applying HeapTupleIsValid to the result. A tiny minority of calls creatively did it differently. Bring them into line with the rest. This is just cosmetic, since HeapTupleIsValid is indeed just a null check at the moment ... but that may not be true forever, and in any case it puts a mental burden on readers who may wonder why these call sites are not like the rest. Back-patch to v11 just to keep the branches in sync. (The bulk of these errors seem to have originated in v11 or v12, though a few are old.) Per searching to see if anyplace else had made the same error repaired in 62148c352.
2019-04-30Message style fixesAlvaro Herrera
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
2019-04-26Apply stopgap fix for bug #15672.Tom Lane
Fix DefineIndex so that it doesn't attempt to pass down a to-be-reused index relfilenode to a child index creation, and fix TryReuseIndex to not think that reuse is sensible for a partitioned index. In v11, this fixes a problem where ALTER TABLE on a partitioned table could assign the same relfilenode to several different child indexes, causing very nasty catalog corruption --- in fact, attempting to DROP the partitioned table then leads not only to a database crash, but to inability to restart because the same crash will recur during WAL replay. Either of these two changes would be enough to prevent the failure, but since neither action could possibly be sane, let's put in both changes for future-proofing. In HEAD, no such bug manifests, but that's just an accidental consequence of having changed the pg_class representation of partitioned indexes to have relfilenode = 0. Both of these changes still seem like smart future-proofing. This is only a stop-gap because the code for ALTER TABLE on a partitioned table with a no-op type change still leaves a great deal to be desired. As the added regression tests show, it gets things wrong for comments on child indexes/constraints, and it is regenerating child indexes it doesn't have to. However, fixing those problems will take more work which may not get back-patched into v11. We need a fix for the corruption problem now. Per bug #15672 from Jianing Yang. Patch by me, regression test cases based on work by Amit Langote, who also did a lot of the investigative work. Discussion: https://postgr.es/m/15672-b9fa7db32698269f@postgresql.org
2019-04-25Fix partitioned index attachmentAlvaro Herrera
When an existing index in a partition is attached to a new index on its parent, we forgot to set the "relispartition" flag correctly, which meant that it was not possible to find the index in various operations, such as adding a foreign key constraint that references that partitioned table. One of four places that was assigning the parent index was forgetting to do that, so fix by shifting responsibility of updating the flag to the routine that changes the parent. Author: Amit Langote, Álvaro Herrera Reported-by: Hubert "depesz" Lubaczewski Discussion: https://postgr.es/m/CA+HiwqHMsRtRYRWYTWavKJ8x14AFsv7bmAV46mYwnfD3vy8goQ@mail.gmail.com
2019-04-25Fix tablespace inheritance for partitioned relsAlvaro Herrera
Commit ca4103025dfe left a few loose ends. The most important one (broken pg_dump output) is already fixed by virtue of commit 3b23552ad8bb, but some things remained: * When ALTER TABLE rewrites tables, the indexes must remain in the tablespace they were originally in. This didn't work because index recreation during ALTER TABLE runs manufactured SQL (yuck), which runs afoul of default_tablespace in competition with the parent relation tablespace. To fix, reset default_tablespace to the empty string temporarily, and add the TABLESPACE clause as appropriate. * Setting a partitioned rel's tablespace to the database default is confusing; if it worked, it would direct the partitions to that tablespace regardless of default_tablespace. But in reality it does not work, and making it work is a larger project. Therefore, throw an error when this condition is detected, to alert the unwary. Add some docs and tests, too. Author: Álvaro Herrera Discussion: https://postgr.es/m/CAKJS1f_1c260nOt_vBJ067AZ3JXptXVRohDVMLEBmudX1YEx-A@mail.gmail.com
2019-04-23Avoid order-of-execution problems with ALTER TABLE ADD PRIMARY KEY.Tom Lane
Up to now, DefineIndex() was responsible for adding attnotnull constraints to the columns of a primary key, in any case where it hadn't been convenient for transformIndexConstraint() to mark those columns as is_not_null. It (or rather its minion index_check_primary_key) did this by executing an ALTER TABLE SET NOT NULL command for the target table. The trouble with this solution is that if we're creating the index due to ALTER TABLE ADD PRIMARY KEY, and the outer ALTER TABLE has additional sub-commands, the inner ALTER TABLE's operations executed at the wrong time with respect to the outer ALTER TABLE's operations. In particular, the inner ALTER would perform a validation scan at a point where the table's storage might be inconsistent with its catalog entries. (This is on the hairy edge of being a security problem, but AFAICS it isn't one because the inner scan would only be interested in the tuples' null bitmaps.) This can result in unexpected failures, such as the one seen in bug #15580 from Allison Kaptur. To fix, let's remove the attempt to do SET NOT NULL from DefineIndex(), reducing index_check_primary_key's role to verifying that the columns are already not null. (It shouldn't ever see such a case, but it seems wise to keep the check for safety.) Instead, make transformIndexConstraint() generate ALTER TABLE SET NOT NULL subcommands to be executed ahead of the ADD PRIMARY KEY operation in every case where it can't force the column to be created already-not-null. This requires only minor surgery in parse_utilcmd.c, and it makes for a much more satisfying spec for transformIndexConstraint(): it's no longer having to take it on faith that someone else will handle addition of NOT NULL constraints. To make that work, we have to move the execution of AT_SetNotNull into an ALTER pass that executes ahead of AT_PASS_ADD_INDEX. I moved it to AT_PASS_COL_ATTRS, and put that after AT_PASS_ADD_COL to avoid failure when the column is being added in the same command. This incidentally fixes a bug in the only previous usage of AT_PASS_COL_ATTRS, for AT_SetIdentity: it didn't work either for a newly-added column. Playing around with this exposed a separate bug in ALTER TABLE ONLY ... ADD PRIMARY KEY for partitioned tables. The intent of the ONLY modifier in that context is to prevent doing anything that would require holding lock for a long time --- but the implied SET NOT NULL would recurse to the child partitions, and do an expensive validation scan for any child where the column(s) were not already NOT NULL. To fix that, invent a new ALTER subcommand AT_CheckNotNull that just insists that a child column be already NOT NULL, and apply that, not AT_SetNotNull, when recursing to children in this scenario. This results in a slightly laxer definition of ALTER TABLE ONLY ... SET NOT NULL for partitioned tables, too: that command will now work as long as all children are already NOT NULL, whereas before it just threw up its hands if there were any partitions. In passing, clean up the API of generateClonedIndexStmt(): remove a useless argument, ensure that the output argument is not left undefined, update the header comment. A small side effect of this change is that no-such-column errors in ALTER TABLE ADD PRIMARY KEY now produce a different message that includes the table name, because they are now detected by the SET NOT NULL step which has historically worded its error that way. That seems fine to me, so I didn't make any effort to avoid the wording change. The basic bug #15580 is of very long standing, and these other bugs aren't new in v12 either. However, this is a pretty significant change in the way ALTER TABLE ADD PRIMARY KEY works. On balance it seems best not to back-patch, at least not till we get some more confidence that this patch has no new bugs. Patch by me, but thanks to Jie Zhang for a preliminary version. Discussion: https://postgr.es/m/15580-d1a6de5a3d65da51@postgresql.org Discussion: https://postgr.es/m/1396E95157071C4EBBA51892C5368521017F2E6E63@G08CNEXMBPEKD02.g08.fujitsu.local
2019-04-07Reset memory context once per tuple in validateForeignKeyConstraint.Andres Freund
When using tableam ExecFetchSlotHeapTuple() might return a separately allocated tuple. We could use the shouldFree argument to explicitly free it, but it seems more robust to to protect Also add a CHECK_FOR_INTERRUPTS() after each tuple. It's likely that each AM has (heap does) a CFI somewhere in the relevant path, but it seems more robust to have one in validateForeignKeyConstraint() itself. Note that this only affects the cases that couldn't be optimized to be verified with a query. Author: Andres Freund Reviewed-By: Tom Lane (in an earlier version) Discussion: https://postgr.es/m/19030.1554574075@sss.pgh.pa.us https://postgr.es/m/CAKJS1f_SHKcPYMsi39An5aUjhAcEMZb6Cx1Sj1QWEWSiKJkBVQ@mail.gmail.com https://postgr.es/m/20180711185628.mrvl46bjgk2uxoki@alap3.anarazel.de
2019-04-06Fix failures in validateForeignKeyConstraint's slow path.Tom Lane
The foreign-key-checking loop in ATRewriteTables failed to ignore relations without storage (e.g., partitioned tables), unlike the initial loop. This accidentally worked as long as RI_Initial_Check succeeded, which it does in most practical cases (including all the ones exercised in the existing regression tests :-(). However, if that failed, as for instance when there are permissions issues, then we entered the slow fire-the-trigger-on-each-tuple path. And that would try to read from the referencing relation, and fail if it lacks storage. A second problem, recently introduced in HEAD, was that this loop had been broken by sloppy refactoring for the tableam API changes. Repair both issues, and add a regression test case so we have some coverage on this code path. Back-patch as needed to v11. (It looks like this code could do with additional bulletproofing, but let's get a working test case in place first.) Hadi Moshayedi, Tom Lane, Andres Freund Discussion: https://postgr.es/m/CAK=1=WrnNmBbe5D9sm3t0a6dnAq3cdbF1vXY816j1wsMqzC8bw@mail.gmail.com Discussion: https://postgr.es/m/19030.1554574075@sss.pgh.pa.us Discussion: https://postgr.es/m/20190325180405.jytoehuzkeozggxx%40alap3.anarazel.de
2019-04-04Harden tableam against nonexistant / wrong kind of AMs.Andres Freund
Previously it was allowed to set default_table_access_method to an empty string. That makes sense for default_tablespace, where that was copied from, as it signals falling back to the database's default tablespace. As there is no equivalent for table AMs, forbid that. Also make sure to throw a usable error when creating a table using an index AM, by using get_am_type_oid() to implement get_table_am_oid() instead of a separate copy. Previously we'd error out only later, in GetTableAmRoutine(). Thirdly remove GetTableAmRoutineByAmId() - it was only used in an earlier version of 8586bf7ed8. Add tests for the above (some for index AMs as well).
2019-04-03Copy name when cloning FKs recurses to partitionsAlvaro Herrera
We were passing a string owned by a syscache entry, which was released before recursing. Fix by pstrdup'ing the string. Per buildfarm member prion.
2019-04-03Support foreign keys that reference partitioned tablesAlvaro Herrera
Previously, while primary keys could be made on partitioned tables, it was not possible to define foreign keys that reference those primary keys. Now it is possible to do that. Author: Álvaro Herrera Reviewed-by: Amit Langote, Jesper Pedersen Discussion: https://postgr.es/m/20181102234158.735b3fevta63msbj@alvherre.pgsql
2019-04-01tableam: Add table_finish_bulk_insert().Andres Freund
This replaces the previous calls of heap_sync() in places using bulk-insert. By passing in the flags used for bulk-insert the AM can decide (first at insert time and then during the finish call) which of the optimizations apply to it, and what operations are necessary to finish a bulk insert operation. Also change HEAP_INSERT_* flags to TABLE_INSERT, and rename hi_options to ti_options. These changes are made even in copy.c, which hasn't yet been converted to tableam. There's no harm in doing so. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
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
2019-03-29REINDEX CONCURRENTLYPeter Eisentraut
This adds the CONCURRENTLY option to the REINDEX command. A REINDEX CONCURRENTLY on a specific index creates a new index (like CREATE INDEX CONCURRENTLY), then renames the old index away and the new index in place and adjusts the dependencies, and then drops the old index (like DROP INDEX CONCURRENTLY). The REINDEX command also has the capability to run its other variants (TABLE, DATABASE) with the CONCURRENTLY option (but not SYSTEM). The reindexdb command gets the --concurrently option. Author: Michael Paquier, Andreas Karlsson, Peter Eisentraut Reviewed-by: Andres Freund, Fujii Masao, Jim Nasby, Sergei Kornilov Discussion: https://www.postgresql.org/message-id/flat/60052986-956b-4478-45ed-8bd119e9b9cf%402ndquadrant.com#74948a1044c56c5e817a5050f554ddee
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
2019-03-26Fix partitioned index creation bug with dropped columnsAlvaro Herrera
ALTER INDEX .. ATTACH PARTITION fails if the partitioned table where the index is defined contains more dropped columns than its partition, with this message: ERROR: incorrect attribute map The cause was that one caller of CompareIndexInfo was passing the number of attributes of the partition rather than the parent, which confused the length check. Repair. This can cause pg_upgrade to fail when used on such a database. Leave some more objects around after regression tests, so that the case is detected by pg_upgrade test suite. Remove some spurious empty lines noticed while looking for other cases of the same problem. Discussion: https://postgr.es/m/20190326213924.GA2322@alvherre.pgsql
2019-03-20Add index_get_partition convenience functionAlvaro Herrera
This new function simplifies some existing coding, as well as supports future patches. Discussion: https://postgr.es/m/201901222145.t6wws6t6vrcu@alvherre.pgsql Reviewed-by: Amit Langote, Jesper Pedersen
2019-03-13Include all columns in default names for foreign key constraintsPeter Eisentraut
When creating a name for a foreign key constraint when none is specified, use all column names instead of only the first one, similar to how it is already done for index names. Author: Paul Martinez <hellopfm@gmail.com> Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/flat/CAF+2_SFjky6XRfLNRXpkG97W6PRbOO_mjAxqXzAAimU=c7w7_A@mail.gmail.com
2019-03-13Allow ALTER TABLE .. SET NOT NULL to skip provably unnecessary scans.Robert Haas
If existing CHECK or NOT NULL constraints preclude the presence of nulls, we need not look to see whether any are present. Sergei Kornilov, reviewed by Stephen Frost, Ildar Musin, David Rowley, and by me. Discussion: http://postgr.es/m/81911511895540@web58j.yandex.ru
2019-03-11tableam: Add and use scan APIs.Andres Freund
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
2019-03-08Avoid some table rewrites for ALTER TABLE .. SET DATA TYPE timestamp.Noah Misch
When the timezone is UTC, timestamptz and timestamp are binary coercible in both directions. See b8a18ad4850ea5ad7884aa6ab731fd392e73b4ad and c22ecc6562aac895f0f0529707d7bdb460fd2a49 for the previous attempt in this problem space. Skip the table rewrite; for now, continue to needlessly rewrite any index on an affected column. Reviewed by Simon Riggs and Tom Lane. Discussion: https://postgr.es/m/20190226061450.GA1665944@rfd.leadboat.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
2019-02-26Use slots in trigger infrastructure, except for the actual invocation.Andres Freund
In preparation for abstracting table storage, convert trigger.c to track tuples in slots. Which also happens to make code calling triggers simpler. As the calling interface for triggers themselves is not changed in this patch, HeapTuples still are extracted from the slot at that time. But that's handled solely inside trigger.c, not visible to callers. It's quite likely that we'll want to revise the external trigger interface, but that's a separate large project. As part of this work the slots used for old/new/return tuples are moved from EState into ResultRelInfo, as different updated tables might need different slots. The slots are now also now created on-demand, which is good both from an efficiency POV, but also makes the modifying code simpler. Author: Andres Freund, Amit Khandekar and Ashutosh Bapat Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-02-26Store table oid and tuple's tid in tuple slots directly.Andres Freund
After the introduction of tuple table slots all table AMs need to support returning the table oid of the tuple stored in a slot created by said AM. It does not make sense to re-implement that in every AM, therefore move handling of table OIDs into the TupleTableSlot structure itself. It's possible that we, at a later date, might want to get rid of HeapTupleData.t_tableOid entirely, but doing so before the abstractions for table AMs are integrated turns out to be too hard, so delay that for now. Similarly, every AM needs to support the concept of a tuple identifier (tid / item pointer) for its tuples. It's quite possible that we'll generalize the exact form of a tid at a future point (to allow for things like index organized tables), but for now many parts of the code know about tids, so there's not much point in abstracting tids away. Therefore also move into slot (rather than providing API to set/get the tid associated with the tuple in a slot). Once table AM includes insert/updating/deleting tuples, the responsibility to set the correct tid after such an action will move into that. After that change, code doing such modifications, should not have to deal with HeapTuples directly anymore. Author: Andres Freund, Haribabu Kommi and Ashutosh Bapat Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-02-21Move code for managing PartitionDescs into a new file, partdesc.cRobert Haas
This is similar in spirit to the existing partbounds.c file in the same directory, except that there's a lot less code in the new file created by this commit. Pending work in this area proposes to add a bunch more code related to PartitionDescs, though, and this will give us a good place to put it. Discussion: http://postgr.es/m/CA+TgmoZUwPf_uanjF==gTGBMJrn8uCq52XYvAEorNkLrUdoawg@mail.gmail.com
2019-02-11Redesign the partition dependency mechanism.Tom Lane
The original setup for dependencies of partitioned objects had serious problems: 1. It did not verify that a drop cascading to a partition-child object also cascaded to at least one of the object's partition parents. Now, normally a child object would share all its dependencies with one or another parent (e.g. a child index's opclass dependencies would be shared with the parent index), so that this oversight is usually harmless. But if some dependency failed to fit this pattern, the child could be dropped while all its parents remain, creating a logically broken situation. (It's easy to construct artificial cases that break it, such as attaching an unrelated extension dependency to the child object and then dropping the extension. I'm not sure if any less-artificial cases exist.) 2. Management of partition dependencies during ATTACH/DETACH PARTITION was complicated and buggy; for example, after detaching a partition table it was possible to create cases where a formerly-child index should be dropped and was not, because the correct set of dependencies had not been reconstructed. Less seriously, because multiple partition relationships were represented identically in pg_depend, there was an order-of-traversal dependency on which partition parent was cited in error messages. We also had some pre-existing order-of-traversal hazards for error messages related to internal and extension dependencies. This is cosmetic to users but causes testing problems. To fix #1, add a check at the end of the partition tree traversal to ensure that at least one partition parent got deleted. To fix #2, establish a new policy that partition dependencies are in addition to, not instead of, a child object's usual dependencies; in this way ATTACH/DETACH PARTITION need not cope with adding or removing the usual dependencies. To fix the cosmetic problem, distinguish between primary and secondary partition dependency entries in pg_depend, by giving them different deptypes. (They behave identically except for having different priorities for being cited in error messages.) This means that the former 'I' dependency type is replaced with new 'P' and 'S' types. This also fixes a longstanding bug that after handling an internal dependency by recursing to the owning object, findDependentObjects did not verify that the current target was now scheduled for deletion, and did not apply the current recursion level's objflags to it. Perhaps that should be back-patched; but in the back branches it would only matter if some concurrent transaction had removed the internal-linkage pg_depend entry before the recursive call found it, or the recursive call somehow failed to find it, both of which seem unlikely. Catversion bump because the contents of pg_depend change for partitioning relationships. Patch HEAD only. It's annoying that we're not fixing #2 in v11, but there seems no practical way to do so given that the problem is exactly a poor choice of what entries to put in pg_depend. We can't really fix that while staying compatible with what's in pg_depend in existing v11 installations. Discussion: https://postgr.es/m/CAH2-Wzkypv1R+teZrr71U23J578NnTBt2X8+Y=Odr4pOdW1rXg@mail.gmail.com
2019-02-10Fix trigger drop procedureAlvaro Herrera
After commit 123cc697a8eb, we remove redundant FK action triggers during partition ATTACH by merely deleting the catalog tuple, but that's wrong: it should use performDeletion() instead. Repair, and make the comments more explicit. Per code review from Tom Lane. Discussion: https://postgr.es/m/18885.1549642539@sss.pgh.pa.us