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* Per-column collation supportPeter Eisentraut2011-02-08
| | | | | | | | This adds collation support for columns and domains, a COLLATE clause to override it per expression, and B-tree index support. Peter Eisentraut reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch
* Implement genuine serializable isolation level.Heikki Linnakangas2011-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Until now, our Serializable mode has in fact been what's called Snapshot Isolation, which allows some anomalies that could not occur in any serialized ordering of the transactions. This patch fixes that using a method called Serializable Snapshot Isolation, based on research papers by Michael J. Cahill (see README-SSI for full references). In Serializable Snapshot Isolation, transactions run like they do in Snapshot Isolation, but a predicate lock manager observes the reads and writes performed and aborts transactions if it detects that an anomaly might occur. This method produces some false positives, ie. it sometimes aborts transactions even though there is no anomaly. To track reads we implement predicate locking, see storage/lmgr/predicate.c. Whenever a tuple is read, a predicate lock is acquired on the tuple. Shared memory is finite, so when a transaction takes many tuple-level locks on a page, the locks are promoted to a single page-level lock, and further to a single relation level lock if necessary. To lock key values with no matching tuple, a sequential scan always takes a relation-level lock, and an index scan acquires a page-level lock that covers the search key, whether or not there are any matching keys at the moment. A predicate lock doesn't conflict with any regular locks or with another predicate locks in the normal sense. They're only used by the predicate lock manager to detect the danger of anomalies. Only serializable transactions participate in predicate locking, so there should be no extra overhead for for other transactions. Predicate locks can't be released at commit, but must be remembered until all the transactions that overlapped with it have completed. That means that we need to remember an unbounded amount of predicate locks, so we apply a lossy but conservative method of tracking locks for committed transactions. If we run short of shared memory, we overflow to a new "pg_serial" SLRU pool. We don't currently allow Serializable transactions in Hot Standby mode. That would be hard, because even read-only transactions can cause anomalies that wouldn't otherwise occur. Serializable isolation mode now means the new fully serializable level. Repeatable Read gives you the old Snapshot Isolation level that we have always had. Kevin Grittner and Dan Ports, reviewed by Jeff Davis, Heikki Linnakangas and Anssi Kääriäinen
* Fix wrong error reports in 'number of array dimensions exceeds theItagaki Takahiro2011-02-01
| | | | | | maximum allowed' messages, that have reported one-less dimensions. Alexey Klyukin
* Fix PlanRowMark/ExecRowMark structures to handle inheritance correctly.Tom Lane2011-01-12
| | | | | | | | | | | | | | | | | | In an inherited UPDATE/DELETE, each target table has its own subplan, because it might have a column set different from other targets. This means that the resjunk columns we add to support EvalPlanQual might be at different physical column numbers in each subplan. The EvalPlanQual rewrite I did for 9.0 failed to account for this, resulting in possible misbehavior or even crashes during concurrent updates to the same row, as seen in a recent report from Gordon Shannon. Revise the data structure so that we track resjunk column numbers separately for each subplan. I also chose to move responsibility for identifying the physical column numbers back to executor startup, instead of assuming that numbers derived during preprocess_targetlist would stay valid throughout subsequent massaging of the plan. That's a bit slower, so we might want to consider undoing it someday; but it would complicate the patch considerably and didn't seem justifiable in a bug fix that has to be back-patched to 9.0.
* Basic foreign table support.Robert Haas2011-01-01
| | | | | | | | | | | Foreign tables are a core component of SQL/MED. This commit does not provide a working SQL/MED infrastructure, because foreign tables cannot yet be queried. Support for foreign table scans will need to be added in a future patch. However, this patch creates the necessary system catalog structure, syntax support, and support for ancillary operations such as COMMENT and SECURITY LABEL. Shigeru Hanada, heavily revised by Robert Haas
* Stamp copyrights for year 2011.Bruce Momjian2011-01-01
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* Move symbols for ExecMergeJoin's state machine into nodeMergejoin.c.Tom Lane2010-12-30
| | | | | There's no reason for these values to be known anywhere else. After doing this, executor/execdefs.h is vestigial and can be removed.
* Support RIGHT and FULL OUTER JOIN in hash joins.Tom Lane2010-12-30
| | | | | | | | | | | | | | | | | | | | | | This is advantageous first because it allows us to hash the smaller table regardless of the outer-join type, and second because hash join can be more flexible than merge join in dealing with arbitrary join quals in a FULL join. For merge join all the join quals have to be mergejoinable, but hash join will work so long as there's at least one hashjoinable qual --- the others can be any condition. (This is true essentially because we don't keep per-inner-tuple match flags in merge join, while hash join can do so.) To do this, we need a has-it-been-matched flag for each tuple in the hashtable, not just one for the current outer tuple. The key idea that makes this practical is that we can store the match flag in the tuple's infomask, since there are lots of bits there that are of no interest for a MinimalTuple. So we aren't increasing the size of the hashtable at all for the feature. To write this without turning the hash code into even more of a pile of spaghetti than it already was, I rewrote ExecHashJoin in a state-machine style, similar to ExecMergeJoin. Other than that decision, it was pretty straightforward.
* Fix typos.Robert Haas2010-12-21
| | | | Andreas Karlsson
* Generalize concept of temporary relations to "relation persistence".Robert Haas2010-12-13
| | | | | | | | | | | | | | | This commit replaces pg_class.relistemp with pg_class.relpersistence; and also modifies the RangeVar node type to carry relpersistence rather than istemp. It also removes removes rd_istemp from RelationData and instead performs the correct computation based on relpersistence. For clarity, we add three new macros: RelationNeedsWAL(), RelationUsesLocalBuffers(), and RelationUsesTempNamespace(), so that we can clarify the purpose of each check that previous depended on rd_istemp. This is intended as infrastructure for the upcoming unlogged tables patch, as well as for future possible work on global temporary tables.
* Create core infrastructure for KNNGIST.Tom Lane2010-12-02
| | | | | | | | | | | | | | | | | | | This is a heavily revised version of builtin_knngist_core-0.9. The ordering operators are no longer mixed in with actual quals, which would have confused not only humans but significant parts of the planner. Instead, ordering operators are carried separately throughout planning and execution. Since the API for ambeginscan and amrescan functions had to be changed anyway, this commit takes the opportunity to rationalize that a bit. RelationGetIndexScan no longer forces a premature index_rescan call; instead, callers of index_beginscan must call index_rescan too. Aside from making the AM-side initialization logic a bit less peculiar, this has the advantage that we do not make a useless extra am_rescan call when there are runtime key values. AMs formerly could not assume that the key values passed to amrescan were actually valid; now they can. Teodor Sigaev and Tom Lane
* Prevent inlining a SQL function with multiple OUT parameters.Tom Lane2010-12-01
| | | | | | | | | | | | | There were corner cases in which the planner would attempt to inline such a function, which would result in a failure at runtime due to loss of information about exactly what the result record type is. Fix by disabling inlining when the function's recorded result type is RECORD. There might be some sub-cases where inlining could still be allowed, but this is a simple and backpatchable fix, so leave refinements for another day. Per bug #5777 from Nate Carson. Back-patch to all supported branches. 8.1 happens to avoid a core-dump here, but it still does the wrong thing.
* Dept of second thoughts: don't try to push LIMIT below a SRF.Tom Lane2010-11-18
| | | | | | | | If we have Limit->Result->Sort, the Result might be projecting a tlist that contains a set-returning function. If so, it's possible for the SRF to sometimes return zero rows, which means we could need to fetch more than N rows from the Sort in order to satisfy LIMIT N. So top-N sorting cannot be used in this scenario.
* Further fallout from the MergeAppend patch.Tom Lane2010-11-18
| | | | | | | | | | | | | | Fix things so that top-N sorting can be used in child Sort nodes of a MergeAppend node, when there is a LIMIT and no intervening joins or grouping. Actually doing this on the executor side isn't too bad, but it's a bit messier to get the planner to cost it properly. Per gripe from Robert Haas. In passing, fix an oversight in the original top-N-sorting patch: query_planner should not assume that a LIMIT can be used to make an explicit sort cheaper when there will be grouping or aggregation in between. Possibly this should be back-patched, but I'm not sure the mistake is serious enough to be a real problem in practice.
* Avoid using a local FunctionCallInfoData struct in ExecMakeFunctionResultTom Lane2010-11-01
| | | | | | | | | | | | | | and related routines. We already had a redundant FunctionCallInfoData struct in FuncExprState, but were using that copy only in set-returning-function cases, to avoid keeping function evaluation state in the expression tree for the benefit of plpgsql's "simple expression" logic. But of course that didn't work anyway. Given the recent fixes in plpgsql there is no need to have two separate behaviors here. Getting rid of the local FunctionCallInfoData structs should make things a little faster (because we don't need to do InitFunctionCallInfoData each time), and it also makes for a noticeable reduction in stack space consumption during recursive calls.
* Support MergeAppend plans, to allow sorted output from append relations.Tom Lane2010-10-14
| | | | | | | | | This patch eliminates the former need to sort the output of an Append scan when an ordered scan of an inheritance tree is wanted. This should be particularly useful for fast-start cases such as queries with LIMIT. Original patch by Greg Stark, with further hacking by Hans-Jurgen Schonig, Robert Haas, and Tom Lane.
* Support triggers on views.Tom Lane2010-10-10
| | | | | | | | | | | | | | | This patch adds the SQL-standard concept of an INSTEAD OF trigger, which is fired instead of performing a physical insert/update/delete. The trigger function is passed the entire old and/or new rows of the view, and must figure out what to do to the underlying tables to implement the update. So this feature can be used to implement updatable views using trigger programming style rather than rule hacking. In passing, this patch corrects the names of some columns in the information_schema.triggers view. It seems the SQL committee renamed them somewhere between SQL:99 and SQL:2003. Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
* Remove cvs keywords from all files.Magnus Hagander2010-09-20
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* SERIALIZABLE transactions are actually implemented beneath the covers withJoe Conway2010-09-11
| | | | | | | | | | | transaction snapshots, i.e. a snapshot registered at the beginning of a transaction. Change variable naming and comments to reflect this reality in preparation for a future, truly serializable mode, e.g. Serializable Snapshot Isolation (SSI). For the moment transaction snapshots are still used to implement SERIALIZABLE, but hopefully not for too much longer. Patch by Kevin Grittner and Dan Ports with review and some minor wording changes by me.
* Fix ExecMakeTableFunctionResult to verify that all rows returned by a SRFTom Lane2010-08-26
| | | | | | | | | | | returning "record" actually do have the same rowtype. This is needed because the parser can't realistically enforce that they will all have the same typmod, as seen in a recent example from David Wheeler. Back-patch to 8.0, which is as far back as we have the notion of RECORD subtypes being distinguished by typmod. Wheeler's example depends on 8.4-and-up features, but I suspect there may be ways to provoke similar failures before 8.4.
* Reset the per-output-tuple exprcontext each time through the main loop inTom Lane2010-08-18
| | | | | | | | | | ExecModifyTable(). This avoids memory leakage when trigger functions leave junk behind in that context (as they more or less must). Problem and solution identified by Dean Rasheed. I'm a bit concerned about the longevity of this solution --- once a plan can have multiple ModifyTable nodes, we are very possibly going to have to do something different. But it should hold up for 9.0.
* Standardize get_whatever_oid functions for object types withRobert Haas2010-08-05
| | | | | | | | | | | | | unqualified names. - Add a missing_ok parameter to get_tablespace_oid. - Avoid duplicating get_tablespace_od guts in objectNamesToOids. - Add a missing_ok parameter to get_database_oid. - Replace get_roleid and get_role_checked with get_role_oid. - Add get_namespace_oid, get_language_oid, get_am_oid. - Refactor existing code to use new interfaces. Thanks to KaiGai Kohei for the review.
* Fix oversight in new EvalPlanQual logic: the second loop over the ExecRowMarkTom Lane2010-07-28
| | | | | | list in ExecLockRows() forgot to allow for the possibility that some of the rowmarks are for child tables that aren't relevant to the current row. Per report from Kenichiro Tanaka.
* Fix potential failure when hashing the output of a subplan that producesTom Lane2010-07-28
| | | | | | | | | | | | | | | a pass-by-reference datatype with a nontrivial projection step. We were using the same memory context for the projection operation as for the temporary context used by the hashtable routines in execGrouping.c. However, the hashtable routines feel free to reset their temp context at any time, which'd lead to destroying input data that was still needed. Report and diagnosis by Tao Ma. Back-patch to 8.1, where the problem was introduced by the changes that allowed us to work with "virtual" tuples instead of materializing intermediate tuple values everywhere. The earlier code looks quite similar, but it doesn't suffer the problem because the data gets copied into another context as a result of having to materialize ExecProject's output tuple.
* CREATE TABLE IF NOT EXISTS.Robert Haas2010-07-25
| | | | Reviewed by Bernd Helmle.
* Centralize DML permissions-checking logic.Robert Haas2010-07-22
| | | | | | | | | | | | Remove bespoke code in DoCopy and RI_Initial_Check, which now instead fabricate call ExecCheckRTPerms with a manufactured RangeTblEntry. This is intended to make it feasible for an enhanced security provider to actually make use of ExecutorCheckPerms_hook, but also has the advantage that RI_Initial_Check can allow use of the fast-path when column-level but not table-level permissions are present. KaiGai Kohei. Reviewed (in an earlier version) by Stephen Frost, and by me. Some further changes to the comments by me.
* Remove a sanity check in the exclusion-constraint code that prevented usersTom Lane2010-07-16
| | | | | | | | | | | from defining non-self-conflicting constraints. Jeff Davis Note: I (tgl) objected to removing this check in 9.0 on the grounds that it was an important sanity check in new, poorly tested code. However, it should be all right to remove it for 9.1, since we'll get field testing from the 9.0 branch.
* Make NestLoop plan nodes pass outer-relation variables into their innerTom Lane2010-07-12
| | | | | | | | | | | | relation using the general PARAM_EXEC executor parameter mechanism, rather than the ad-hoc kluge of passing the outer tuple down through ExecReScan. The previous method was hard to understand and could never be extended to handle parameters coming from multiple join levels. This patch doesn't change the set of possible plans nor have any significant performance effect, but it's necessary infrastructure for future generalization of the concept of an inner indexscan plan. ExecReScan's second parameter is now unused, so it's removed.
* Add a hook in ExecCheckRTPerms().Robert Haas2010-07-09
| | | | | | | | | | | This hook allows a loadable module to gain control when table permissions are checked. It is expected to be used by an eventual SE-PostgreSQL implementation, but there are other possible applications as well. A sample contrib module can be found in the archives at: http://archives.postgresql.org/pgsql-hackers/2010-05/msg01095.php Robert Haas and Stephen Frost
* pgindent run for 9.0, second runBruce Momjian2010-07-06
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* Add C comment that we will have to remove an exclusion constraint checkBruce Momjian2010-05-29
| | | | | | if we ever implement '<>' index opclasses. Jeff Davis
* Rejigger mergejoin logic so that a tuple with a null in the first merge columnTom Lane2010-05-28
| | | | | | | | | | | | | | | | | | | is treated like end-of-input, if nulls sort last in that column and we are not doing outer-join filling for that input. In such a case, the tuple cannot join to anything from the other input (because we assume mergejoinable operators are strict), and neither can any tuple following it in the sort order. If we're not interested in doing outer-join filling we can just pretend the tuple and its successors aren't there at all. This can save a great deal of time in situations where there are many nulls in the join column, as in a recent example from Scott Marlowe. Also, since the planner tends to not count nulls in its mergejoin scan selectivity estimates, this is an important fix to make the runtime behavior more like the estimate. I regard this as an omission in the patch I wrote years ago to teach mergejoin that tuples containing nulls aren't joinable, so I'm back-patching it. But only to 8.3 --- in older versions, we didn't have a solid notion of whether nulls sort high or low, so attempting to apply this optimization could break things.
* Introduce wal_level GUC to explicitly control if information needed forHeikki Linnakangas2010-04-28
| | | | | | | | | | | | | | | | | | | | | | archival or hot standby should be WAL-logged, instead of deducing that from other options like archive_mode. This replaces recovery_connections GUC in the primary, where it now has no effect, but it's still used in the standby to enable/disable hot standby. Remove the WAL-logging of "unlogged operations", like creating an index without WAL-logging and fsyncing it at the end. Instead, we keep a copy of the wal_mode setting and the settings that affect how much shared memory a hot standby server needs to track master transactions (max_connections, max_prepared_xacts, max_locks_per_xact) in pg_control. Whenever the settings change, at server restart, write a WAL record noting the new settings and update pg_control. This allows us to notice the change in those settings in the standby at the right moment, they used to be included in checkpoint records, but that meant that a changed value was not reflected in the standby until the first checkpoint after the change. Bump PG_CONTROL_VERSION and XLOG_PAGE_MAGIC. Whack XLOG_PAGE_MAGIC back to the sequence it used to follow, before hot standby and subsequent patches changed it to 0x9003.
* Message tuningPeter Eisentraut2010-03-21
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* Modify error context callback functions to not assume that they can fetchTom Lane2010-03-19
| | | | | | | | | | | | | | | | | | catalog entries via SearchSysCache and related operations. Although, at the time that these callbacks are called by elog.c, we have not officially aborted the current transaction, it still seems rather risky to initiate any new catalog fetches. In all these cases the needed information is readily available in the caller and so it's just a matter of a bit of extra notation to pass it to the callback. Per crash report from Dennis Koegel. I've concluded that the real fix for his problem is to clear the error context stack at entry to proc_exit, but it still seems like a good idea to make the callbacks a bit less fragile for other cases. Backpatch to 8.4. We could go further back, but the patch doesn't apply cleanly. In the absence of proof that this fixes something and isn't just paranoia, I'm not going to expend the effort.
* pgindent run for 9.0Bruce Momjian2010-02-26
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* Clean up handling of XactReadOnly and RecoveryInProgress checks.Tom Lane2010-02-20
| | | | | | | | | | | | | | | | | | Add some checks that seem logically necessary, in particular let's make real sure that HS slave sessions cannot create temp tables. (If they did they would think that temp tables belonging to the master's session with the same BackendId were theirs. We *must* not allow myTempNamespace to become set in a slave session.) Change setval() and nextval() so that they are only allowed on temp sequences in a read-only transaction. This seems consistent with what we allow for table modifications in read-only transactions. Since an HS slave can't have a temp sequence, this also provides a nicer cure for the setval PANIC reported by Erik Rijkers. Make the error messages more uniform, and have them mention the specific command being complained of. This seems worth the trifling amount of extra code, since people are likely to see such messages a lot more than before.
* Fix ExecEvalArrayRef to pass down the old value of the array element or sliceTom Lane2010-02-18
| | | | | | | | | | | | | being assigned to, in case the expression to be assigned is a FieldStore that would need to modify that value. The need for this was foreseen some time ago, but not implemented then because we did not have arrays of composites. Now we do, but the point evidently got overlooked in that patch. Net result is that updating a field of an array element doesn't work right, as illustrated if you try the new regression test on an unpatched backend. Noted while experimenting with EXPLAIN VERBOSE, which has also got some issues in this area. Backpatch to 8.3, where arrays of composites were introduced.
* Wrap calls to SearchSysCache and related functions using macros.Robert Haas2010-02-14
| | | | | | | | | | | | The purpose of this change is to eliminate the need for every caller of SearchSysCache, SearchSysCacheCopy, SearchSysCacheExists, GetSysCacheOid, and SearchSysCacheList to know the maximum number of allowable keys for a syscache entry (currently 4). This will make it far easier to increase the maximum number of keys in a future release should we choose to do so, and it makes the code shorter, too. Design and review by Tom Lane.
* Extend the set of frame options supported for window functions.Tom Lane2010-02-12
| | | | | | | | | This patch allows the frame to start from CURRENT ROW (in either RANGE or ROWS mode), and it also adds support for ROWS n PRECEDING and ROWS n FOLLOWING start and end points. (RANGE value PRECEDING/FOLLOWING isn't there yet --- the grammar works, but that's all.) Hitoshi Harada, reviewed by Pavel Stehule
* Fix up rickety handling of relation-truncation interlocks.Tom Lane2010-02-09
| | | | | | | | | | | | | | | | | | | | Move rd_targblock, rd_fsm_nblocks, and rd_vm_nblocks from relcache to the smgr relation entries, so that they will get reset to InvalidBlockNumber whenever an smgr-level flush happens. Because we now send smgr invalidation messages immediately (not at end of transaction) when a relation truncation occurs, this ensures that other backends will reset their values before they next access the relation. We no longer need the unreliable assumption that a VACUUM that's doing a truncation will hold its AccessExclusive lock until commit --- in fact, we can intentionally release that lock as soon as we've completed the truncation. This patch therefore reverts (most of) Alvaro's patch of 2009-11-10, as well as my marginal hacking on it yesterday. We can also get rid of assorted no-longer-needed relcache flushes, which are far more expensive than an smgr flush because they kill a lot more state. In passing this patch fixes smgr_redo's failure to perform visibility-map truncation, and cleans up some rather dubious assumptions in freespace.c and visibilitymap.c about when rd_fsm_nblocks and rd_vm_nblocks can be out of date.
* Create an official API function for C functions to use to check if they areTom Lane2010-02-08
| | | | | | | | | | being called as aggregates, and to get the aggregate transition state memory context if needed. Use it instead of poking directly into AggState and WindowAggState in places that shouldn't know so much. We should have done this in 8.4, probably, but better late than never. Revised version of a patch by Hitoshi Harada.
* Remove old-style VACUUM FULL (which was known for a little while asTom Lane2010-02-08
| | | | | | | | | | | | | | | | | VACUUM FULL INPLACE), along with a boatload of subsidiary code and complexity. Per discussion, the use case for this method of vacuuming is no longer large enough to justify maintaining it; not to mention that we don't wish to invest the work that would be needed to make it play nicely with Hot Standby. Aside from the code directly related to old-style VACUUM FULL, this commit removes support for certain WAL record types that could only be generated within VACUUM FULL, redirect-pointer removal in heap_page_prune, and nontransactional generation of cache invalidation sinval messages (the last being the sticking point for Hot Standby). We still have to retain all code that copes with finding HEAP_MOVED_OFF and HEAP_MOVED_IN flag bits on existing tuples. This can't be removed as long as we want to support in-place update from pre-9.0 databases.
* Create a "relation mapping" infrastructure to support changing the relfilenodesTom Lane2010-02-07
| | | | | | | | | | | | | | | | | | | | | | | of shared or nailed system catalogs. This has two key benefits: * The new CLUSTER-based VACUUM FULL can be applied safely to all catalogs. * We no longer have to use an unsafe reindex-in-place approach for reindexing shared catalogs. CLUSTER on nailed catalogs now works too, although I left it disabled on shared catalogs because the resulting pg_index.indisclustered update would only be visible in one database. Since reindexing shared system catalogs is now fully transactional and crash-safe, the former special cases in REINDEX behavior have been removed; shared catalogs are treated the same as non-shared. This commit does not do anything about the recently-discussed problem of deadlocks between VACUUM FULL/CLUSTER on a system catalog and other concurrent queries; will address that in a separate patch. As a stopgap, parallel_schedule has been tweaked to run vacuum.sql by itself, to avoid such failures during the regression tests.
* Move the responsibility of writing a "unlogged WAL operation" record fromHeikki Linnakangas2010-02-03
| | | | | | heap_sync() to the callers, because heap_sync() is sometimes called even if the operation itself is WAL-logged. This eliminates the bogus unlogged records from CLUSTER that Simon Riggs reported, patch by Fujii Masao.
* Augment EXPLAIN output with more details on Hash nodes.Robert Haas2010-02-01
| | | | | | We show the number of buckets, the number of batches (and also the original number if it has changed), and the peak space used by the hash table. Minor executor changes to track peak space used.
* Fix memory leak created by deferrable-index-constraints patches.Tom Lane2010-01-31
| | | | | | | | | We need to free the OID list returned by ExecInsertIndexTuples to avoid a query-lifespan memory leak. When many rows require rechecking, this can be a significant leak --- it's even more than the space used for the queued trigger events. Dean Rasheed
* Type table featurePeter Eisentraut2010-01-28
| | | | This adds the CREATE TABLE name OF type command, per SQL standard.
* Introduce Streaming Replication.Heikki Linnakangas2010-01-15
| | | | | | | | | | | | | | | | | | | | This includes two new kinds of postmaster processes, walsenders and walreceiver. Walreceiver is responsible for connecting to the primary server and streaming WAL to disk, while walsender runs in the primary server and streams WAL from disk to the client. Documentation still needs work, but the basics are there. We will probably pull the replication section to a new chapter later on, as well as the sections describing file-based replication. But let's do that as a separate patch, so that it's easier to see what has been added/changed. This patch also adds a new section to the chapter about FE/BE protocol, documenting the protocol used by walsender/walreceivxer. Bump catalog version because of two new functions, pg_last_xlog_receive_location() and pg_last_xlog_replay_location(), for monitoring the progress of replication. Fujii Masao, with additional hacking by me
* Improve ExecEvalVar's handling of whole-row variables in cases where theTom Lane2010-01-11
| | | | | | | | | | | | | | | | | rowtype contains dropped columns. Sometimes the input tuple will be formed from a select targetlist in which dropped columns are filled with a NULL of an arbitrary type (the planner typically uses INT4, since it can't tell what type the dropped column really was). So we need to relax the rowtype compatibility check to not insist on physical compatibility if the actual column value is NULL. In principle we might need to do this for functions returning composite types, too (see tupledesc_match()). In practice there doesn't seem to be a bug there, probably because the function will be using the same cached rowtype descriptor as the caller. Fixing that code path would require significant rearrangement, so I left it alone for now. Per complaint from Filip Rembialkowski.