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* Add optimizer and executor support for parallel index scans.Robert Haas2017-02-15
| | | | | | | | | | | | In combination with 569174f1be92be93f5366212cc46960d28a5c5cd, which taught the btree AM how to perform parallel index scans, this allows parallel index scan plans on btree indexes. This infrastructure should be general enough to support parallel index scans for other index AMs as well, if someone updates them to support parallel scans. Amit Kapila, reviewed and tested by Anastasia Lubennikova, Tushar Ahuja, and Haribabu Kommi, and me.
* Replace min_parallel_relation_size with two new GUCs.Robert Haas2017-02-15
| | | | | | | | | | | | | | | | | | | | | | | | | | When min_parallel_relation_size was added, the only supported type of parallel scan was a parallel sequential scan, but there are pending patches for parallel index scan, parallel index-only scan, and parallel bitmap heap scan. Those patches introduce two new types of complications: first, what's relevant is not really the total size of the relation but the portion of it that we will scan; and second, index pages and heap pages shouldn't necessarily be treated in exactly the same way. Typically, the number of index pages will be quite small, but that doesn't necessarily mean that a parallel index scan can't pay off. Therefore, we introduce min_parallel_table_scan_size, which works out a degree of parallelism for scans based on the number of table pages that will be scanned (and which is therefore equivalent to min_parallel_relation_size for parallel sequential scans) and also min_parallel_index_scan_size which can be used to work out a degree of parallelism based on the number of index pages that will be scanned. Amit Kapila and Robert Haas Discussion: http://postgr.es/m/CAA4eK1KowGSYYVpd2qPpaPPA5R90r++QwDFbrRECTE9H_HvpOg@mail.gmail.com Discussion: http://postgr.es/m/CAA4eK1+TnM4pXQbvn7OXqam+k_HZqb0ROZUMxOiL6DWJYCyYow@mail.gmail.com
* Fix wrong articles in pg_proc descriptions.Robert Haas2017-02-15
| | | | | | | This technically should involve a catversion bump, but that seems pedantic, so I skipped it. Report and patch by David Christensen.
* libpq: Make target_session_attrs=read-write consume empty result.Robert Haas2017-02-15
| | | | | | | Otherwise, the leftover empty result can cause problems in some situations. Michael Paquier and Ashutosh Bapat, per a report from Higuchi Daisuke
* pg_upgrade: Fix problems caused by renaming pg_resetxlog.Robert Haas2017-02-15
| | | | | | | | Commit 85c11324cabaddcfaf3347df78555b30d27c5b5a renamed pg_resetxlog to pg_resetwal, but didn't make pg_upgrade smart enough to cope with the situation. Michael Paquier, per a complaint from Jeff Janes
* Add CREATE COLLATION IF NOT EXISTS clausePeter Eisentraut2017-02-15
| | | | | | The core of the functionality was already implemented when pg_import_system_collations was added. This just exposes it as an option in the SQL command.
* btree: Support parallel index scans.Robert Haas2017-02-15
| | | | | | | | | | | | | This isn't exposed to the optimizer or the executor yet; we'll add support for those things in a separate patch. But this puts the basic mechanism in place: several processes can attach to a parallel btree index scan, and each one will get a subset of the tuples that would have been produced by a non-parallel scan. Each index page becomes the responsibility of a single worker, which then returns all of the TIDs on that page. Rahila Syed, Amit Kapila, Robert Haas, reviewed and tested by Anastasia Lubennikova, Tushar Ahuja, and Haribabu Kommi.
* Fix typo in comment.Robert Haas2017-02-14
| | | | Higuchi Daisuke
* Allow parallel workers to execute subplans.Robert Haas2017-02-14
| | | | | | | | | | | | | | | This doesn't do anything to make Param nodes anything other than parallel-restricted, so this only helps with uncorrelated subplans, and it's not necessarily very cheap because each worker will run the subplan separately (just as a Hash Join will build a separate copy of the hash table in each participating process), but it's a first step toward supporting cases that are more likely to help in practice, and is occasionally useful on its own. Amit Kapila, reviewed and tested by Rafia Sabih, Dilip Kumar, and me. Discussion: http://postgr.es/m/CAA4eK1+e8Z45D2n+rnDMDYsVEb5iW7jqaCH_tvPMYau=1Rru9w@mail.gmail.com
* Split index xlog headers from other private index headers.Robert Haas2017-02-14
| | | | | | | | | | | | | The xlog-specific headers need to be included in both frontend code - specifically, pg_waldump - and the backend, but the remainder of the private headers for each index are only needed by the backend. By splitting the xlog stuff out into separate headers, pg_waldump pulls in fewer backend headers, which is a good thing. Patch by me, reviewed by Michael Paquier and Andres Freund, per a complaint from Dilip Kumar. Discussion: http://postgr.es/m/CA+TgmoZ=F=GkxV0YEv-A8tb+AEGy_Qa7GSiJ8deBKFATnzfEug@mail.gmail.com
* Minor fixes for WAL consistency checking.Robert Haas2017-02-14
| | | | | | Michael Paquier, reviewed and slightly revised by me. Discussion: http://postgr.es/m/CAB7nPqRzCQb=vdfHvMtP0HMLBHU6z1aGdo4GJsUP-HP8jx+Pkw@mail.gmail.com
* Don't disallow dropping NOT NULL for a list partition key.Robert Haas2017-02-14
| | | | | | | Range partitioning doesn't support nulls in the partitioning columns, but list partitioning does. Amit Langote, per a complaint from Amul Sul
* Remove duplicate code in planner.c.Tom Lane2017-02-14
| | | | | | | I noticed while hacking on join UNION transforms that planner.c's function get_base_rel_indexes() just duplicates the functionality of get_relids_in_jointree(). It doesn't even have the excuse of being older code :-(. Drop it and use the latter function instead.
* Replace reference to "xlog-method" with "wal-method" in error message.Fujii Masao2017-02-15
| | | | | Commit 62e8b38 renamed "--xlog-method" option for pg_basebackup to "--wal-method", but forgot to update the error message mentioning that option.
* Remove contrib/tsearch2.Robert Haas2017-02-13
| | | | | | | | | | | | This module was intended to ease migrations of applications that used the pre-8.3 version of text search to the in-core version introduced in that release. However, since all pre-8.3 releases of the database have been out of support for more than 5 years at this point, we expect that few people are depending on it at this point. If some people still need it, nothing prevents it from being maintained as a separate extension, outside of core. Discussion: http://postgr.es/m/CA+Tgmob5R8aDHiFRTQsSJbT1oreKg2FOSBrC=2f4tqEH3dOMAg@mail.gmail.com
* Ignore tablespace ACLs when ignoring schema ACLs.Noah Misch2017-02-12
| | | | | | | | | | | The ALTER TABLE ALTER TYPE implementation can issue DROP INDEX and CREATE INDEX to refit existing indexes for the new column type. Since this CREATE INDEX is an implementation detail of an index alteration, the ensuing DefineIndex() should skip ACL checks specific to index creation. It already skips the namespace ACL check. Make it skip the tablespace ACL check, too. Back-patch to 9.2 (all supported versions). Reviewed by Tom Lane.
* Add CREATE SEQUENCE AS <data type> clausePeter Eisentraut2017-02-10
| | | | | | | | | | | | | | | | | | | | | | | | This stores a data type, required to be an integer type, with the sequence. The sequences min and max values default to the range supported by the type, and they cannot be set to values exceeding that range. The internal implementation of the sequence is not affected. Change the serial types to create sequences of the appropriate type. This makes sure that the min and max values of the sequence for a serial column match the range of values supported by the table column. So the sequence can no longer overflow the table column. This also makes monitoring for sequence exhaustion/wraparound easier, which currently requires various contortions to cross-reference the sequences with the table columns they are used with. This commit also effectively reverts the pg_sequence column reordering in f3b421da5f4addc95812b9db05a24972b8fd9739, because the new seqtypid column allows us to fill the hole in the struct and create a more natural overall column ordering. Reviewed-by: Steve Singer <steve@ssinger.info> Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
* Rename command line options for ongoing xlog -> wal conversion.Robert Haas2017-02-09
| | | | | initdb and pg_basebackup now have a --waldir option rather --xlogdir, and pg_basebackup now has --wal-method rather than --xlog-method.
* Rename dtrace probes for ongoing xlog -> wal conversion.Robert Haas2017-02-09
| | | | xlog-switch becomes wal-switch, and xlog-insert becomes wal-insert.
* Rename user-facing tools with "xlog" in the name to say "wal".Robert Haas2017-02-09
| | | | | This means pg_receivexlog because pg_receivewal, pg_resetxlog becomes pg_resetwal, and pg_xlogdump becomes pg_waldump.
* Blind try to fix portability issue in commit 8f93bd851 et al.Tom Lane2017-02-09
| | | | | | | | | | | | | | | | | The S/390 members of the buildfarm are showing failures indicating that they're having trouble with the rint() calls I added yesterday. There's no good reason for that, and I wonder if it is a compiler bug similar to the one we worked around in d9476b838. Try to fix it using the same method as before, namely to store the result of rint() back into a "double" variable rather than immediately converting to int64. (This isn't entirely waving a dead chicken, since on machines with wider-than-double float registers, the extra store forces a width conversion. I don't know if S/390 is like that, but it seems worth trying.) In passing, merge duplicate ereport() calls in float8_timestamptz(). Per buildfarm.
* Remove all references to "xlog" from SQL-callable functions in pg_proc.Robert Haas2017-02-09
| | | | | | | | | | | | | | Commit f82ec32ac30ae7e3ec7c84067192535b2ff8ec0e renamed the pg_xlog directory to pg_wal. To make things consistent, and because "xlog" is terrible terminology for either "transaction log" or "write-ahead log" rename all SQL-callable functions that contain "xlog" in the name to instead contain "wal". (Note that this may pose an upgrade hazard for some users.) Similarly, rename the xlog_position argument of the functions that create slots to be called wal_position. Discussion: https://www.postgresql.org/message-id/CA+Tgmob=YmA=H3DbW1YuOXnFVgBheRmyDkWcD9M8f=5bGWYEoQ@mail.gmail.com
* simplehash: Additional tweaks to make specifying an allocator work.Robert Haas2017-02-09
| | | | | | | | | | | | | Even if we don't emit definitions for SH_ALLOCATE and SH_FREE, we still need prototypes. The user can't define them before including simplehash.h because SH_TYPE isn't available yet. For the allocator to be able to access private_data, it needs to become an argument to SH_CREATE. Previously we relied on callers to set that after returning from SH_CREATE, but SH_CREATE calls SH_ALLOCATE before returning. Dilip Kumar, reviewed by me.
* Fix race condition in ConditionVariablePrepareToSleep.Robert Haas2017-02-09
| | | | Thomas Munro
* pageinspect: Fix hash_bitmap_info not to read the underlying page.Robert Haas2017-02-09
| | | | | | | | | | | | It did that to verify that the page was an overflow page rather than anything else, but that means that checking the status of all the overflow bits requires reading the entire index. So don't do that. The new code validates that the page is not a primary bucket page or bitmap page by looking at the metapage, so that using this on large numbers of pages can be reasonably efficient. Ashutosh Sharma, per a complaint from me, and with further modifications by me.
* Allow index AMs to cache data across aminsert calls within a SQL command.Tom Lane2017-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | It's always been possible for index AMs to cache data across successive amgettuple calls within a single SQL command: the IndexScanDesc.opaque field is meant for precisely that. However, no comparable facility exists for amortizing setup work across successive aminsert calls. This patch adds such a feature and teaches GIN, GIST, and BRIN to use it to amortize catalog lookups they'd previously been doing on every call. (The other standard index AMs keep everything they need in the relcache, so there's little to improve there.) For GIN, the overall improvement in a statement that inserts many rows can be as much as 10%, though it seems a bit less for the other two. In addition, this makes a really significant difference in runtime for CLOBBER_CACHE_ALWAYS tests, since in those builds the repeated catalog lookups are vastly more expensive. The reason this has been hard up to now is that the aminsert function is not passed any useful place to cache per-statement data. What I chose to do is to add suitable fields to struct IndexInfo and pass that to aminsert. That's not widening the index AM API very much because IndexInfo is already within the ken of ambuild; in fact, by passing the same info to aminsert as to ambuild, this is really removing an inconsistency in the AM API. Discussion: https://postgr.es/m/27568.1486508680@sss.pgh.pa.us
* Add explicit ORDER BY to a few tests that exercise hash-join code.Andres Freund2017-02-08
| | | | | | | | | | A proposed patch, also by Thomas and in the same thread, would change the output order of these. Independent of the follow-up patches getting committed, nailing down the order in these specific tests at worst seems harmless. Author: Thomas Munro Discussion: https://postgr.es/m/CAEepm=1D4-tP7j7UAgT_j4ZX2j4Ehe1qgZQWFKBMb8F76UW5Rg@mail.gmail.com
* Fix roundoff problems in float8_timestamptz() and make_interval().Tom Lane2017-02-08
| | | | | | | | | | | | | | | | | | | | | | When converting a float value to integer microseconds, we should be careful to round the value to the nearest integer, typically with rint(); simply assigning to an int64 variable will truncate, causing apparently off-by-one values in cases that should work. Most places in the datetime code got this right, but not these two. float8_timestamptz() is new as of commit e511d878f (9.6). Previous versions effectively depended on interval_mul() to do roundoff correctly, which it does, so this fixes an accuracy regression in 9.6. The problem in make_interval() dates to its introduction in 9.4. Aside from being careful to round not truncate, let's incorporate the hours and minutes inputs into the result with exact integer arithmetic, rather than risk introducing roundoff error where there need not have been any. float8_timestamptz() problem reported by Erik Nordström, though this is not his proposed patch. make_interval() problem found by me. Discussion: https://postgr.es/m/CAHuQZDS76jTYk3LydPbKpNfw9KbACmD=49dC4BrzHcfPv6yA1A@mail.gmail.com
* Add WAL consistency checking facility.Robert Haas2017-02-08
| | | | | | | | | | | | | | When the new GUC wal_consistency_checking is set to a non-empty value, it triggers recording of additional full-page images, which are compared on the standby against the results of applying the WAL record (without regard to those full-page images). Allowable differences such as hints are masked out, and the resulting pages are compared; any difference results in a FATAL error on the standby. Kuntal Ghosh, based on earlier patches by Michael Paquier and Heikki Linnakangas. Extensively reviewed and revised by Michael Paquier and by me, with additional reviews and comments from Amit Kapila, Álvaro Herrera, Simon Riggs, and Peter Eisentraut.
* Fix relcache leaks in get_object_address_publication_rel()Peter Eisentraut2017-02-07
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* Revise the way the element allocator for a simplehash is specified.Robert Haas2017-02-07
| | | | | | | This method is more elegant and more efficient. Per a suggestion from Andres Freund, who also briefly reviewed the patch.
* Speed up "brin" regression test a little bit.Tom Lane2017-02-07
| | | | | | | | | | | In the large DO block, collect row TIDs into array variables instead of creating and dropping a pile of temporary tables. In a normal build, this reduces the brin test script's runtime from about 1.1 sec to 0.4 sec on my workstation. That's not all that exciting perhaps, but in a CLOBBER_CACHE_ALWAYS test build, the runtime drops from 20 min to 17 min, which is a little more useful. In combination with some other changes I plan to propose, this will help provide a noticeable reduction in cycle time for CLOBBER_CACHE_ALWAYS buildfarm critters.
* Avoid redefining simplehash_allocate/simplehash_free.Robert Haas2017-02-07
| | | | | | There's no generic guard against multiple inclusion in this file, for good reason. But these typedefs need one, as per a report from Jeff Janes.
* Allow the element allocator for a simplehash to be specified.Robert Haas2017-02-07
| | | | | | | | This is infrastructure for a pending patch to allow parallel bitmap heap scans. Dilip Kumar, reviewed (in earlier versions) by Andres Freund and (more recently) by me. Some further renaming by me, also.
* Fix compiler warning.Robert Haas2017-02-07
| | | | Mithun Cy, per a report by Erik Rijkers
* Cache hash index's metapage in rel->rd_amcache.Robert Haas2017-02-07
| | | | | | | | | | | | | | | | | | | | | | | This avoids a very significant amount of buffer manager traffic and contention when scanning hash indexes, because it's no longer necessary to lock and pin the metapage for every scan. We do need some way of figuring out when the cache is too stale to use any more, so that when we lock the primary bucket page to which the cached metapage points us, we can tell whether a split has occurred since we cached the metapage data. To do that, we use the hash_prevblkno field in the primary bucket page, which would otherwise always be set to InvalidBuffer. This patch contains code so that it will continue working (although less efficiently) with hash indexes built before this change, but perhaps we should consider bumping the hash version and ripping out the compatibility code. That decision can be made later, though. Mithun Cy, reviewed by Jesper Pedersen, Amit Kapila, and by me. Before committing, I made a number of cosmetic changes to the last posted version of the patch, adjusted _hash_getcachedmetap to be more careful about order of operation, and made some necessary updates to the pageinspect documentation and regression tests.
* Avoid permission failure in pg_sequences.last_valuePeter Eisentraut2017-02-06
| | | | | | | | | | Before, reading pg_sequences.last_value would fail unless the user had appropriate sequence permissions, which would make the pg_sequences view cumbersome to use. Instead, return null instead of the real value when there are no permissions. From: Michael Paquier <michael.paquier@gmail.com> Reported-by: Shinoda, Noriyoshi <noriyoshi.shinoda@hpe.com>
* Avoid returning stale attribute bitmaps in RelationGetIndexAttrBitmap().Tom Lane2017-02-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem with the original coding here is that we might receive (and clear) a relcache invalidation signal for the target relation down inside one of the index_open calls we're doing. Since the target is open, we would not drop the relcache entry, just reset its rd_indexvalid and rd_indexlist fields. But RelationGetIndexAttrBitmap() kept going, and would eventually cache and return potentially-obsolete attribute bitmaps. The case where this matters is where the inval signal was from a CREATE INDEX CONCURRENTLY telling us about a new index on a formerly-unindexed column. (In all other cases, the lock we hold on the target rel should prevent any concurrent change in index state.) Even just returning the stale attribute bitmap is not such a problem, because it shouldn't matter during the transaction in which we receive the signal. What hurts is caching the stale data, because it can survive into later transactions, breaking CREATE INDEX CONCURRENTLY's expectation that later transactions will not create new broken HOT chains. The upshot is that there's a window for building corrupted indexes during CREATE INDEX CONCURRENTLY. This patch fixes the problem by rechecking that the set of index OIDs is still the same at the end of RelationGetIndexAttrBitmap() as it was at the start. If not, we loop back and try again. That's a little more than is strictly necessary to fix the bug --- in principle, we could return the stale data but not cache it --- but it seems like a bad idea on general principles for relcache to return data it knows is stale. There might be more hazards of the same ilk, or there might be a better way to fix this one, but this patch definitely improves matters and seems unlikely to make anything worse. So let's push it into today's releases even as we continue to study the problem. Pavan Deolasee and myself Discussion: https://postgr.es/m/CABOikdM2MUq9cyZJi1KyLmmkCereyGp5JQ4fuwKoyKEde_mzkQ@mail.gmail.com
* Update comment in relcache.c.Tom Lane2017-02-06
| | | | | | Commit 665d1fad9 introduced rd_pkindex, and made RelationGetIndexList responsible for updating it, but didn't bother to fix RelationGetIndexList's header comment to say so.
* Add missing newline to error messagesPeter Eisentraut2017-02-06
| | | | Also improve the message style a bit while we're here.
* Fix typo in variable name.Heikki Linnakangas2017-02-06
| | | | Masahiko Sawada
* Fix typos in comments.Heikki Linnakangas2017-02-06
| | | | | | | | | Backpatch to all supported versions, where applicable, to make backpatching of future fixes go more smoothly. Josh Soref Discussion: https://www.postgresql.org/message-id/CACZqfqCf+5qRztLPgmmosr-B0Ye4srWzzw_mo4c_8_B_mtjmJQ@mail.gmail.com
* Remove redundant comment.Robert Haas2017-02-03
| | | | Rafia Sabih
* Improve grammar of message about two-phase state files.Robert Haas2017-02-03
| | | | | | | | | | When there's only one two-phase state file, there's also only one long-running prepared transaction. Adjust the message text accordingly. Nikhil Sontakke Discussion: http://postgr.es/m/CAMGcDxcmR_DWZXXndGoPzVQx=B17A5=RviEA1qNaF=FWLy5Whw@mail.gmail.com
* Be sure to release LogicalRepLauncherLock in DROP SUBSCRIPTION command.Fujii Masao2017-02-04
| | | | | | | | Previously DROP SUBSCRIPTION command forgot to release the lock at all. Original patches by Kyotaro Horiguchi and Michael Paquier, but I didn't use them. Discussion: http://postgr.es/m/20170201.173623.66249355.horiguchi.kyotaro@lab.ntt.co.jp
* Clean up psql's behavior for a few more control variables.Tom Lane2017-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify FETCH_COUNT to always have a defined value, like other control variables, mainly so it will always appear in "\set" output. Add hooks to force HISTSIZE to be defined and require it to have an integer value. (I don't see any point in allowing it to be set to non-integral values.) Add hooks to force IGNOREEOF to be defined and require it to have an integer value. Unlike the other cases, here we're trying to be bug-compatible with a rather bogus externally-defined behavior, so I think we need to continue to allow "\set IGNOREEOF whatever". Fix it so that the substitution hook silently replace non-numeric values with "10", so that the stored value always reflects what we're really doing. Add a dummy assign hook for HISTFILE, just so it's always in variables.c's list. We can't require it to be defined always, because that would break the interaction with the PSQL_HISTORY environment variable, so there isn't any change in visible behavior here. Remove tab-complete.c's private list of known variable names, since that's really a maintenance nuisance. Given the preceding changes, there are no control variables it won't show anyway. This does mean that if for some reason you've unset one of the status variables (DBNAME, HOST, etc), that variable would not appear in tab completion for \set. But I think that's fine, for at least two reasons: we shouldn't be encouraging people to use those variables as regular variables, and if someone does do so anyway, why shouldn't it act just like a regular variable? Remove ugly and no-longer-used-anywhere GetVariableNum(). In general, future additions of integer-valued control variables should follow the paradigm of adding an assign hook using ParseVariableNum(), so there's no reason to expect we'd need this again later. Discussion: https://postgr.es/m/17516.1485973973@sss.pgh.pa.us
* Avoid improbable null pointer dereference in pgpassfileWarning().Tom Lane2017-02-02
| | | | | | | | | | Coverity complained that we might pass a null pointer to strcmp() if PQresultErrorField were to return NULL. That shouldn't be possible, since the server is supposed to always provide some SQLSTATE or other in an error message. But we usually defend against such hazards, and it only takes a little more code to do so here. There's no good reason to think this is a live bug, so no back-patch.
* Fix placement of initPlans when forcibly materializing a subplan.Tom Lane2017-02-02
| | | | | | | | | | | | | | | | | | | | If we forcibly place a Material node atop a finished subplan, we need to move any initPlans attached to the subplan up to the Material node, in order to keep SS_finalize_plan() happy. I'd figured this out in commit 7b67a0a49 for the case of materializing a cursor plan, but out of an abundance of caution, I put the initPlan movement hack at the call site for that case, rather than inside materialize_finished_plan(). That was the wrong thing, because it turns out to also be necessary for the only other caller of materialize_finished_plan(), ie subselect.c. We lacked any test cases that exposed the mistake, but bug#14524 from Wei Congrui shows that it's possible to get an initPlan reference into the top tlist in that case too, and then SS_finalize_plan() complains. Hence, move the hack into materialize_finished_plan(). In HEAD, also relocate some recently-added tests in subselect.sql, which I'd unthinkingly dropped into the middle of a sequence of related tests. Report: https://postgr.es/m/20170202060020.1400.89021@wrigleys.postgresql.org
* Fix mishandling of tSRFs at different nesting levels.Tom Lane2017-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Given a targetlist like "srf(x), f(srf(x))", split_pathtarget_at_srfs() decided that it needed two levels of ProjectSet nodes, failing to notice that the two SRF calls are textually equal(). Because of that, setrefs.c would convert the upper ProjectSet's tlist to "Var1, f(Var1)" (where Var1 represents a reference to the srf(x) output of the lower ProjectSet). This triggered an assertion in nodeProjectSet.c complaining that it found no SRFs to evaluate, as reported by Erik Rijkers. What we want in such a case is to evaluate srf(x) only once and use a plain Result node to compute "Var1, f(Var1)"; that gives results similar to what previous versions produced, whereas allowing srf(x) to be evaluated again in an upper ProjectSet would square the number of rows emitted. Furthermore, even if the SRF calls aren't textually identical, we want them to be evaluated in lockstep, because that's what happened in the old implementation. But split_pathtarget_at_srfs() got this completely wrong, using two levels of ProjectSet for a case like "srf(x), f(srf(y))". Hence, rewrite split_pathtarget_at_srfs() from the ground up so that it groups SRFs according to the depth of nesting of SRFs in their arguments. This is pretty much how we envisioned that working originally, but I blew it when it came to implementation. In passing, optimize the case of target == input_target, which I noticed is not only possible but quite common. Discussion: https://postgr.es/m/dcbd2853c05d22088766553d60dc78c6@xs4all.nl
* Increase upper bound for bgwriter_lru_maxpages.Robert Haas2017-02-02
| | | | | | | | | | | There is no particularly good reason to limit this value to 1000, so increase the limit to INT_MAX / 2, the same limit we use for shared_buffers. It's not clear how much practical effect larger settings will have, but there seems no harm in letting people try it. Jim Nasby, less a comment change I stripped out. Discussion: http://postgr.es/m/f6e58a22-030b-eb8a-5457-f62fb08d701c@BlueTreble.com