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2016-10-20Fix EXPLAIN so that it doesn't emit invalid XML in corner cases.Tom Lane
With track_io_timing = on, EXPLAIN (ANALYZE, BUFFERS) will emit fields named like "I/O Read Time". The slash makes that invalid as an XML element name, so that adding FORMAT XML would produce invalid XML. We already have code in there to translate spaces to dashes, so let's generalize that to convert anything that isn't a valid XML name character, viz letters, digits, hyphens, underscores, and periods. We could just reject slashes, which would run a bit faster. But the fact that this went unnoticed for so long doesn't give me a warm feeling that we'd notice the next creative violation, so let's make it a permanent fix. Reported by Markus Winand, though this isn't his initial patch proposal. Back-patch to 9.2 where track_io_timing was added. The problem is only latent in 9.1, so I don't feel a need to fix it there. Discussion: <E0BF6A45-68E8-45E6-918F-741FB332C6BB@winand.at>
2016-10-11Drop server support for FE/BE protocol version 1.0.Tom Lane
While this isn't a lot of code, it's been essentially untestable for a very long time, because libpq doesn't support anything older than protocol 2.0, and has not since release 6.3. There's no reason to believe any other client-side code still uses that protocol, either. Discussion: <2661.1475849167@sss.pgh.pa.us>
2016-10-10Remove some unnecessary #includes.Heikki Linnakangas
Amit Langote
2016-10-08Fix two bugs in merging of inherited CHECK constraints.Tom Lane
Historically, we've allowed users to add a CHECK constraint to a child table and then add an identical CHECK constraint to the parent. This results in "merging" the two constraints so that the pre-existing child constraint ends up with both conislocal = true and coninhcount > 0. However, if you tried to do it in the other order, you got a duplicate constraint error. This is problematic for pg_dump, which needs to issue separated ADD CONSTRAINT commands in some cases, but has no good way to ensure that the constraints will be added in the required order. And it's more than a bit arbitrary, too. The goal of complaining about duplicated ADD CONSTRAINT commands can be served if we reject the case of adding a constraint when the existing one already has conislocal = true; but if it has conislocal = false, let's just make the ADD CONSTRAINT set conislocal = true. In this way, either order of adding the constraints has the same end result. Another problem was that the code allowed creation of a parent constraint marked convalidated that is merged with a child constraint that is !convalidated. In this case, an inheritance scan of the parent table could emit some rows violating the constraint condition, which would be an unexpected result given the marking of the parent constraint as validated. Hence, forbid merging of constraints in this case. (Note: valid child and not-valid parent seems fine, so continue to allow that.) Per report from Benedikt Grundmann. Back-patch to 9.2 where we introduced possibly-not-valid check constraints. The second bug obviously doesn't apply before that, and I think the first doesn't either, because pg_dump only gets into this situation when dealing with not-valid constraints. Report: <CADbMkNPT-Jz5PRSQ4RbUASYAjocV_KHUWapR%2Bg8fNvhUAyRpxA%40mail.gmail.com> Discussion: <22108.1475874586@sss.pgh.pa.us>
2016-10-03Fix RLS with COPY (col1, col2) FROM tabStephen Frost
Attempting to COPY a subset of columns from a table with RLS enabled would fail due to an invalid query being constructed (using a single ColumnRef with the list of fields to exact in 'fields', but that's for the different levels of an indirection for a single column, not for specifying multiple columns). Correct by building a ColumnRef and then RestTarget for each column being requested and then adding those to the targetList for the select query. Include regression tests to hopefully catch if this is broken again in the future. Patch-By: Adam Brightwell Reviewed-By: Michael Paquier
2016-09-28Remove dead line of codePeter Eisentraut
2016-09-28Turn password_encryption GUC into an enum.Heikki Linnakangas
This makes the parameter easier to extend, to support other password-based authentication protocols than MD5. (SCRAM is being worked on.) The GUC still accepts on/off as aliases for "md5" and "plain", although we may want to remove those once we actually add support for another password hash type. Michael Paquier, reviewed by David Steele, with some further edits by me. Discussion: <CAB7nPqSMXU35g=W9X74HVeQp0uvgJxvYOuA4A-A3M+0wfEBv-w@mail.gmail.com>
2016-09-15Clarify policy on marking inherited constraints as valid.Robert Haas
Amit Langote and Robert Haas
2016-09-13Be pickier about converting between Name and Datum.Tom Lane
We were misapplying NameGetDatum() to plain C strings in some places. This worked, because it was just a pointer cast anyway, but it's a type cheat in some sense. Use CStringGetDatum instead, and modify the NameGetDatum macro so it won't compile if applied to something that's not a pointer to NameData. This should result in no changes to generated code, but it is logically cleaner. Mark Dilger, tweaked a bit by me Discussion: <EFD8AC94-4C1F-40C1-A5EA-304080089C1B@gmail.com>
2016-09-11Allow CREATE EXTENSION to follow extension update paths.Tom Lane
Previously, to update an extension you had to produce both a version-update script and a new base installation script. It's become more and more obvious that that's tedious, duplicative, and error-prone. This patch attempts to improve matters by allowing the new base installation script to be omitted. CREATE EXTENSION will install a requested version if it can find a base script and a chain of update scripts that will get there. As in the existing update logic, shorter chains are preferred if there's more than one possibility, with an arbitrary tie-break rule for chains of equal length. Also adjust the pg_available_extension_versions view to show such versions as installable. While at it, refactor the code so that CASCADE processing works for extensions requested during ApplyExtensionUpdates(). Without this, addition of a new requirement in an updated extension would require creating a new base script, even if there was no other reason to do that. (It would be easy at this point to add a CASCADE option to ALTER EXTENSION UPDATE, to allow the same thing to happen during a manually-commanded version update, but I have not done that here.) Tom Lane, reviewed by Andres Freund Discussion: <20160905005919.jz2m2yh3und2dsuy@alap3.anarazel.de>
2016-09-07Support renaming an existing value of an enum type.Tom Lane
Not much to be said about this patch: it does what it says on the tin. In passing, rename AlterEnumStmt.skipIfExists to skipIfNewValExists to clarify what it actually does. In the discussion of this patch we considered supporting other similar options, such as IF EXISTS on the type as a whole or IF NOT EXISTS on the target name. This patch doesn't actually add any such feature, but it might happen later. Dagfinn Ilmari Mannsåker, reviewed by Emre Hasegeli Discussion: <CAO=2mx6uvgPaPDf-rHqG8=1MZnGyVDMQeh8zS4euRyyg4D35OQ@mail.gmail.com>
2016-09-06Add a HINT for client-vs-server COPY failure cases.Tom Lane
Users often get confused between COPY and \copy and try to use client-side paths with COPY. The server then cannot find the file (if remote), or sees a permissions problem (if local), or some variant of that. Emit a hint about this in the most common cases. In future we might want to expand the set of errnos for which the hint gets printed, but be conservative for now. Craig Ringer, reviewed by Christoph Berg and Tom Lane Discussion: <CAMsr+YEqtD97qPEzQDqrCt5QiqPbWP_X4hmvy2pQzWC0GWiyPA@mail.gmail.com>
2016-09-06Add location field to DefElemPeter Eisentraut
Add a location field to the DefElem struct, used to parse many utility commands. Update various error messages to supply error position information. To propogate the error position information in a more systematic way, create a ParseState in standard_ProcessUtility() and pass that to interested functions implementing the utility commands. This seems better than passing the query string and then reassembling a parse state ad hoc, which violates the encapsulation of the ParseState type. Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
2016-09-06Fix VACUUM_TRUNCATE_LOCK_WAIT_INTERVALSimon Riggs
lazy_truncate_heap() was waiting for VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL, but in microseconds not milliseconds as originally intended. Found by code inspection. Simon Riggs
2016-09-05Cosmetic code cleanup in commands/extension.c.Tom Lane
Some of the comments added by the CREATE EXTENSION CASCADE patch were a bit sloppy, and I didn't care for redeclaring the same local variable inside a nested block either. No functional changes.
2016-09-05Relax transactional restrictions on ALTER TYPE ... ADD VALUE.Tom Lane
To prevent possibly breaking indexes on enum columns, we must keep uncommitted enum values from getting stored in tables, unless we can be sure that any such column is new in the current transaction. Formerly, we enforced this by disallowing ALTER TYPE ... ADD VALUE from being executed at all in a transaction block, unless the target enum type had been created in the current transaction. This patch removes that restriction, and instead insists that an uncommitted enum value can't be referenced unless it belongs to an enum type created in the same transaction as the value. Per discussion, this should be a bit less onerous. It does require each function that could possibly return a new enum value to SQL operations to check this restriction, but there aren't so many of those that this seems unmaintainable. Andrew Dunstan and Tom Lane Discussion: <4075.1459088427@sss.pgh.pa.us>
2016-09-02Move code shared between libpq and backend from backend/libpq/ to common/.Heikki Linnakangas
When building libpq, ip.c and md5.c were symlinked or copied from src/backend/libpq into src/interfaces/libpq, but now that we have a directory specifically for routines that are shared between the server and client binaries, src/common/, move them there. Some routines in ip.c were only used in the backend. Keep those in src/backend/libpq, but rename to ifaddr.c to avoid confusion with the file that's now in common. Fix the comment in src/common/Makefile to reflect how libpq actually links those files. There are two more files that libpq symlinks directly from src/backend: encnames.c and wchar.c. I don't feel compelled to move those right now, though. Patch by Michael Paquier, with some changes by me. Discussion: <69938195-9c76-8523-0af8-eb718ea5b36e@iki.fi>
2016-08-27Add macros to make AllocSetContextCreate() calls simpler and safer.Tom Lane
I found that half a dozen (nearly 5%) of our AllocSetContextCreate calls had typos in the context-sizing parameters. While none of these led to especially significant problems, they did create minor inefficiencies, and it's now clear that expecting people to copy-and-paste those calls accurately is not a great idea. Let's reduce the risk of future errors by introducing single macros that encapsulate the common use-cases. Three such macros are enough to cover all but two special-purpose contexts; those two calls can be left as-is, I think. While this patch doesn't in itself improve matters for third-party extensions, it doesn't break anything for them either, and they can gradually adopt the simplified notation over time. In passing, change TopMemoryContext to use the default allocation parameters. Formerly it could only be extended 8K at a time. That was probably reasonable when this code was written; but nowadays we create many more contexts than we did then, so that it's not unusual to have a couple hundred K in TopMemoryContext, even without considering various dubious code that sticks other things there. There seems no good reason not to let it use growing blocks like most other contexts. Back-patch to 9.6, mostly because that's still close enough to HEAD that it's easy to do so, and keeping the branches in sync can be expected to avoid some future back-patching pain. The bugs fixed by these changes don't seem to be significant enough to justify fixing them further back. Discussion: <21072.1472321324@sss.pgh.pa.us>
2016-08-15Final pgindent + perltidy run for 9.6.Tom Lane
2016-08-13Add SQL-accessible functions for inspecting index AM properties.Tom Lane
Per discussion, we should provide such functions to replace the lost ability to discover AM properties by inspecting pg_am (cf commit 65c5fcd35). The added functionality is also meant to displace any code that was looking directly at pg_index.indoption, since we'd rather not believe that the bit meanings in that field are part of any client API contract. As future-proofing, define the SQL API to not assume that properties that are currently AM-wide or index-wide will remain so unless they logically must be; instead, expose them only when inquiring about a specific index or even specific index column. Also provide the ability for an index AM to override the behavior. In passing, document pg_am.amtype, overlooked in commit 473b93287. Andrew Gierth, with kibitzing by me and others Discussion: <87mvl5on7n.fsf@news-spur.riddles.org.uk>
2016-08-12Fix inappropriate printing of never-measured times in EXPLAIN.Tom Lane
EXPLAIN (ANALYZE, TIMING OFF) would print an elapsed time of zero for a trigger function, because no measurement has been taken but it printed the field anyway. This isn't what EXPLAIN does elsewhere, so suppress it. In the same vein, EXPLAIN (ANALYZE, BUFFERS) with non-text output format would print buffer I/O timing numbers even when no measurement has been taken because track_io_timing is off. That seems not per policy, either, so change it. Back-patch to 9.2 where these features were introduced. Maksim Milyutin Discussion: <081c0540-ecaa-bd29-3fd2-6358f3b359a9@postgrespro.ru>
2016-08-07Fix misestimation of n_distinct for a nearly-unique column with many nulls.Tom Lane
If ANALYZE found no repeated non-null entries in its sample, it set the column's stadistinct value to -1.0, intending to indicate that the entries are all distinct. But what this value actually means is that the number of distinct values is 100% of the table's rowcount, and thus it was overestimating the number of distinct values by however many nulls there are. This could lead to very poor selectivity estimates, as for example in a recent report from Andreas Joseph Krogh. We should discount the stadistinct value by whatever we've estimated the nulls fraction to be. (That is what will happen if we choose to use a negative stadistinct for a column that does have repeated entries, so this code path was just inconsistent.) In addition to fixing the stadistinct entries stored by several different ANALYZE code paths, adjust the logic where get_variable_numdistinct() forces an "all distinct" estimate on the basis of finding a relevant unique index. Unique indexes don't reject nulls, so there's no reason to assume that the null fraction doesn't apply. Back-patch to all supported branches. Back-patching is a bit of a judgment call, but this problem seems to affect only a few users (else we'd have identified it long ago), and it's bad enough when it does happen that destabilizing plan choices in a worse direction seems unlikely. Patch by me, with documentation wording suggested by Dean Rasheed Report: <VisenaEmail.26.df42f82acae38a58.156463942b8@tc7-visena> Discussion: <16143.1470350371@sss.pgh.pa.us>
2016-08-07Fix TOAST access failure in RETURNING queries.Tom Lane
Discussion of commit 3e2f3c2e4 exposed a problem that is of longer standing: since we don't detoast data while sticking it into a portal's holdStore for PORTAL_ONE_RETURNING and PORTAL_UTIL_SELECT queries, and we release the query's snapshot as soon as we're done loading the holdStore, later readout of the holdStore can do TOAST fetches against data that can no longer be seen by any of the session's live snapshots. This means that a concurrent VACUUM could remove the TOAST data before we can fetch it. Commit 3e2f3c2e4 exposed the problem by showing that sometimes we had *no* live snapshots while fetching TOAST data, but we'd be at risk anyway. I believe this code was all right when written, because our management of a session's exposed xmin was such that the TOAST references were safe until end of transaction. But that's no longer true now that we can advance or clear our PGXACT.xmin intra-transaction. To fix, copy the query's snapshot during FillPortalStore() and save it in the Portal; release it only when the portal is dropped. This essentially implements a policy that we must hold a relevant snapshot whenever we access potentially-toasted data. We had already come to that conclusion in other places, cf commits 08e261cbc94ce9a7 and ec543db77b6b72f2. I'd have liked to add a regression test case for this, but I didn't see a way to make one that's not unreasonably bloated; it seems to require returning a toasted value to the client, and those will be big. In passing, improve PortalRunUtility() so that it positively verifies that its ending PopActiveSnapshot() call will pop the expected snapshot, removing a rather shaky assumption about which utility commands might do their own PopActiveSnapshot(). There's no known bug here, but now that we're actively referencing the snapshot it's almost free to make this code a bit more bulletproof. We might want to consider back-patching something like this into older branches, but it would be prudent to let it prove itself more in HEAD beforehand. Discussion: <87vazemeda.fsf@credativ.de>
2016-07-25Message style improvementsPeter Eisentraut
2016-07-19Add comment & docs about no vacuum truncation with sto.Kevin Grittner
Omission noted by Andres Freund.
2016-07-18Clear all-frozen visibilitymap status when locking tuples.Andres Freund
Since a892234 & fd31cd265 the visibilitymap's freeze bit is used to avoid vacuuming the whole relation in anti-wraparound vacuums. Doing so correctly relies on not adding xids to the heap without also unsetting the visibilitymap flag. Tuple locking related code has not done so. To allow selectively resetting all-frozen - to avoid pessimizing heap_lock_tuple - allow to selectively reset the all-frozen with visibilitymap_clear(). To avoid having to use visibilitymap_get_status (e.g. via VM_ALL_FROZEN) inside a critical section, have visibilitymap_clear() return whether any bits have been reset. There's a remaining issue (denoted by XXX): After the PageIsAllVisible() check in heap_lock_tuple() and heap_lock_updated_tuple_rec() the page status could theoretically change. Practically that currently seems impossible, because updaters will hold a page level pin already. Due to the next beta coming up, it seems better to get the required WAL magic bump done before resolving this issue. The added flags field fields to xl_heap_lock and xl_heap_lock_updated require bumping the WAL magic. Since there's already been a catversion bump since the last beta, that's not an issue. Reviewed-By: Robert Haas, Amit Kapila and Andres Freund Author: Masahiko Sawada, heavily revised by Andres Freund Discussion: CAEepm=3fWAbWryVW9swHyLTY4sXVf0xbLvXqOwUoDiNCx9mBjQ@mail.gmail.com Backpatch: -
2016-07-11Print a given subplan only once in EXPLAIN.Tom Lane
We have, for a very long time, allowed the same subplan (same member of the PlannedStmt.subplans list) to be referenced by more than one SubPlan node; this avoids problems for cases such as subplans within an IndexScan's indxqual and indxqualorig fields. However, EXPLAIN had not gotten the memo and would print each reference as though it were an independent identical subplan. To fix, track plan_ids of subplans we've printed and don't print the same plan_id twice. Per report from Pavel Stehule. BTW: the particular case of IndexScan didn't cause visible duplication in a plain EXPLAIN, only EXPLAIN ANALYZE, because in the former case we short-circuit executor startup before the indxqual field is processed by ExecInitExpr. That seems like it could easily lead to other EXPLAIN problems in future, but it's not clear how to avoid it without breaking the "EXPLAIN a plan using hypothetical indexes" use-case. For now I've left that issue alone. Although this is a longstanding bug, it's purely cosmetic (no great harm is done by the repeat printout) and we haven't had field complaints before. So I'm hesitant to back-patch it, especially since there is some small risk of ABI problems due to the need to add a new field to ExplainState. In passing, rearrange order of fields in ExplainState to be less random, and update some obsolete comments about when/where to initialize them. Report: <CAFj8pRAimq+NK-menjt+3J4-LFoodDD8Or6=Lc_stcFD+eD4DA@mail.gmail.com>
2016-06-30Fix several mistakes around parallel workers and client_encoding.Robert Haas
Previously, workers sent data to the leader using the client encoding. That mostly worked, but the leader the converted the data back to the server encoding. Since not all encoding conversions are reversible, that could provoke failures. Fix by using the database encoding for all communication between worker and leader. Also, while temporary changes to GUC settings, as from the SET clause of a function, are in general OK for parallel query, changing client_encoding this way inside of a parallel worker is not OK. Previously, that would have confused the leader; with these changes, it would not confuse the leader, but it wouldn't do anything either. So refuse such changes in parallel workers. Also, the previous code naively assumed that when it received a NotifyResonse from the worker, it could pass that directly back to the user. But now that worker-to-leader communication always uses the database encoding, that's clearly no longer correct - though, actually, the old way was always broken for V2 clients. So disassemble and reconstitute the message instead. Issues reported by Peter Eisentraut. Patch by me, reviewed by Peter Eisentraut.
2016-06-29Fix some infelicities in EXPLAIN output for parallel query plans.Tom Lane
In non-text output formats, parallelized aggregates were reporting "Partial" or "Finalize" as a field named "Operation", which might be all right in the absence of any context --- but other plan node types use that field to report SQL-visible semantics, such as Select/Insert/Update/Delete. So that naming choice didn't seem good to me. I changed it to "Partial Mode". Also, the field did not appear at all for a non-parallelized Agg plan node, which is contrary to expectation in non-text formats. We're notionally producing objects that conform to a schema, so the set of fields for a given node type and EXPLAIN mode should be well-defined. I set it up to fill in "Simple" in such cases. Other fields that were added for parallel query, namely "Parallel Aware" and Gather's "Single Copy", had not gotten the word on that point either. Make them appear always in non-text output. Also, the latter two fields were nominally producing boolean output, but were getting it wrong, because bool values shouldn't be quoted in JSON or YAML. Somehow we'd not needed an ExplainPropertyBool formatting subroutine before 9.6; but now we do, so invent it. Discussion: <16002.1466972724@sss.pgh.pa.us>
2016-06-27Fix CREATE MATVIEW/CREATE TABLE AS ... WITH NO DATA to not plan the query.Tom Lane
Previously, these commands always planned the given query and went through executor startup before deciding not to actually run the query if WITH NO DATA is specified. This behavior is problematic for pg_dump because it may cause errors to be raised that we would rather not see before a REFRESH MATERIALIZED VIEW command is issued. See for example bug #13907 from Marian Krucina. This change is not sufficient to fix that particular bug, because we also need to tweak pg_dump to issue the REFRESH later, but it's a necessary step on the way. A user-visible side effect of doing things this way is that the returned command tag for WITH NO DATA cases will now be "CREATE MATERIALIZED VIEW" or "CREATE TABLE AS", not "SELECT 0". We could preserve the old behavior but it would take more code, and arguably that was just an implementation artifact not intended behavior anyhow. In 9.5 and HEAD, also get rid of the static variable CreateAsReladdr, which was trouble waiting to happen; there is not any prohibition on nested CREATE commands. Back-patch to 9.3 where CREATE MATERIALIZED VIEW was introduced. Michael Paquier and Tom Lane Report: <20160202161407.2778.24659@wrigleys.postgresql.org>
2016-06-26Rethink node-level representation of partial-aggregation modes.Tom Lane
The original coding had three separate booleans representing partial aggregation behavior, which was confusing, unreadable, and error-prone, not least because the booleans weren't always listed in the same order. It was also inadequate for the allegedly-desirable future extension to support intermediate partial aggregation, because we'd need separate markers for serialization and deserialization in such a case. Merge these bools into an enum "AggSplit" to provide symbolic names for the supported operating modes (and document what those are). By assigning the values of the enum constants carefully, we can treat AggSplit values as options bitmasks so that tests of what to do aren't noticeably more expensive than before. While at it, get rid of Aggref.aggoutputtype. That's not needed since commit 59a3795c2 got rid of setrefs.c's special-purpose Aggref comparison code, and it likewise seemed more confusing than helpful. Assorted comment cleanup as well (there's still more that I want to do in that line). catversion bump for change in Aggref node contents. Should be the last one for partial-aggregation changes. Discussion: <29309.1466699160@sss.pgh.pa.us>
2016-06-22Fix type-safety problem with parallel aggregate serial/deserialization.Tom Lane
The original specification for this called for the deserialization function to have signature "deserialize(serialtype) returns transtype", which is a security violation if transtype is INTERNAL (which it always would be in practice) and serialtype is not (which ditto). The patch blithely overrode the opr_sanity check for that, which was sloppy-enough work in itself, but the indisputable reason this cannot be allowed to stand is that CREATE FUNCTION will reject such a signature and thus it'd be impossible for extensions to create parallelizable aggregates. The minimum fix to make the signature type-safe is to add a second, dummy argument of type INTERNAL. But to lock it down a bit more and make misuse of INTERNAL-accepting functions less likely, let's get rid of the ability to specify a "serialtype" for an aggregate and just say that the only useful serialtype is BYTEA --- which, in practice, is the only interesting value anyway, due to the usefulness of the send/recv infrastructure for this purpose. That means we only have to allow "serialize(internal) returns bytea" and "deserialize(bytea, internal) returns internal" as the signatures for these support functions. In passing fix bogus signature of int4_avg_combine, which I found thanks to adding an opr_sanity check on combinefunc signatures. catversion bump due to removing pg_aggregate.aggserialtype and adjusting signatures of assorted built-in functions. David Rowley and Tom Lane Discussion: <27247.1466185504@sss.pgh.pa.us>
2016-06-17Add VACUUM (DISABLE_PAGE_SKIPPING) for emergencies.Robert Haas
If you really want to vacuum every single page in the relation, regardless of apparent visibility status or anything else, you can use this option. In previous releases, this behavior could be achieved using VACUUM (FREEZE), but because we can now recognize all-frozen pages as not needing to be frozen again, that no longer works. There should be no need for routine use of this option, but maybe bugs or disaster recovery will necessitate its use. Patch by me, reviewed by Andres Freund.
2016-06-15Fix lazy_scan_heap so that it won't mark pages all-frozen too soon.Robert Haas
Commit a892234f830e832110f63fc0a2afce2fb21d1584 added a new bit per page to the visibility map fork indicating whether the page is all-frozen, but incorrectly assumed that if lazy_scan_heap chose to freeze a tuple then that tuple would not need to later be frozen again. This turns out to be false, because xmin and xmax (and conceivably xvac, if dealing with tuples from very old releases) could be frozen at separate times. Thanks to Andres Freund for help in uncovering and tracking down this issue.
2016-06-09pgindent run for 9.6Robert Haas
2016-06-07Message style and wording fixesPeter Eisentraut
2016-06-06Don't reset changes_since_analyze after a selective-columns ANALYZE.Tom Lane
If we ANALYZE only selected columns of a table, we should not postpone auto-analyze because of that; other columns may well still need stats updates. As committed, the counter is left alone if a column list is given, whether or not it includes all analyzable columns of the table. Per complaint from Tomasz Ostrowski. It's been like this a long time, so back-patch to all supported branches. Report: <ef99c1bd-ff60-5f32-2733-c7b504eb960c@ato.waw.pl>
2016-06-06Stop the executor if no more tuples can be sent from worker to leader.Robert Haas
If a Gather node has read as many tuples as it needs (for example, due to Limit) it may detach the queue connecting it to the worker before reading all of the worker's tuples. Rather than let the worker continue to generate and send all of the results, have it stop after sending the next tuple. More could be done here to stop the worker even quicker, but this is about as well as we can hope to do for 9.6. This is in response to a problem report from Andreas Seltenreich. Commit 44339b892a04e94bbb472235882dc6f7023bdc65 should be actually be sufficient to fix that example even without this change, but it seems better to do this, too, since we might otherwise waste quite a large amount of effort in one or more workers. Discussion: CAA4eK1KOKGqmz9bGu+Z42qhRwMbm4R5rfnqsLCNqFs9j14jzEA@mail.gmail.com Amit Kapila
2016-06-03Fix comment to be more accurate.Robert Haas
Now that we skip vacuuming all-frozen pages, this comment needs updating. Masahiko Sawada
2016-06-03Fix various common mispellings.Greg Stark
Mostly these are just comments but there are a few in documentation and a handful in code and tests. Hopefully this doesn't cause too much unnecessary pain for backpatching. I relented from some of the most common like "thru" for that reason. The rest don't seem numerous enough to cause problems. Thanks to Kevin Lyda's tool https://pypi.python.org/pypi/misspellings
2016-06-03Cosmetic improvements to freeze map code.Robert Haas
Per post-commit review comments from Andres Freund, improve variable names, comments, and in one place, slightly improve the code structure. Masahiko Sawada
2016-05-27Fix DROP ACCESS METHOD IF EXISTS.Tom Lane
The IF EXISTS option was documented, and implemented in the grammar, but it didn't actually work for lack of support in does_not_exist_skipping(). Per bug #14160. Report and patch by Kouhei Sutou Report: <20160527070433.19424.81712@wrigleys.postgresql.org>
2016-05-24Fetch XIDs atomically during vac_truncate_clog().Tom Lane
Because vac_update_datfrozenxid() updates datfrozenxid and datminmxid in-place, it's unsafe to assume that successive reads of those values will give consistent results. Fetch each one just once to ensure sane behavior in the minimum calculation. Noted while reviewing Alexander Korotkov's patch in the same area. Discussion: <8564.1464116473@sss.pgh.pa.us>
2016-05-24Avoid consuming an XID during vac_truncate_clog().Tom Lane
vac_truncate_clog() uses its own transaction ID as the comparison point in a sanity check that no database's datfrozenxid has already wrapped around "into the future". That was probably fine when written, but in a lazy vacuum we won't have assigned an XID, so calling GetCurrentTransactionId() causes an XID to be assigned when otherwise one would not be. Most of the time that's not a big problem ... but if we are hard up against the wraparound limit, consuming XIDs during antiwraparound vacuums is a very bad thing. Instead, use ReadNewTransactionId(), which not only avoids this problem but is in itself a better comparison point to test whether wraparound has already occurred. Report and patch by Alexander Korotkov. Back-patch to all versions. Report: <CAPpHfdspOkmiQsxh-UZw2chM6dRMwXAJGEmmbmqYR=yvM7-s6A@mail.gmail.com>
2016-05-06Remove various special checks around default rolesStephen Frost
Default roles really should be like regular roles, for the most part. This removes a number of checks that were trying to make default roles extra special by not allowing them to be used as regular roles. We still prevent users from creating roles in the "pg_" namespace or from altering roles which exist in that namespace via ALTER ROLE, as we can't preserve such changes, but otherwise the roles are very much like regular roles. Based on discussion with Robert and Tom.
2016-04-20Revert no-op changes to BufferGetPage()Kevin Grittner
The reverted changes were intended to force a choice of whether any newly-added BufferGetPage() calls needed to be accompanied by a test of the snapshot age, to support the "snapshot too old" feature. Such an accompanying test is needed in about 7% of the cases, where the page is being used as part of a scan rather than positioning for other purposes (such as DML or vacuuming). The additional effort required for back-patching, and the doubt whether the intended benefit would really be there, have indicated it is best just to rely on developers to do the right thing based on comments and existing usage, as we do with many other conventions. This change should have little or no effect on generated executable code. Motivated by the back-patching pain of Tom Lane and Robert Haas
2016-04-16Disallow creation of indexes on system columns (except for OID).Tom Lane
Although OID acts pretty much like user data, the other system columns do not, so an index on one would likely misbehave. And it's pretty hard to see a use-case for one, anyway. Let's just forbid the case rather than worry about whether it should be supported. David Rowley
2016-04-15Fix possible crash in ALTER TABLE ... REPLICA IDENTITY USING INDEX.Tom Lane
Careless coding added by commit 07cacba983ef79be could result in a crash or a bizarre error message if someone tried to select an index on the OID column as the replica identity index for a table. Back-patch to 9.4 where the feature was introduced. Discussion: CAKJS1f8TQYgTRDyF1_u9PVCKWRWz+DkieH=U7954HeHVPJKaKg@mail.gmail.com David Rowley
2016-04-15Tweak EXPLAIN for parallel query to show workers launched.Robert Haas
The previous display was sort of confusing, because it didn't distinguish between the number of workers that we planned to launch and the number that actually got launched. This has already confused several people, so display both numbers and label them clearly. Julien Rouhaud, reviewed by me.
2016-04-13Fix broken dependency-mongering for index operator classes/families.Tom Lane
For a long time, opclasscmds.c explained that "we do not create a dependency link to the AM [for an opclass or opfamily], because we don't currently support DROP ACCESS METHOD". Commit 473b93287040b200 invented DROP ACCESS METHOD, but it batted only 1 for 2 on adding the dependency links, and 0 for 2 on updating the comments about the topic. In passing, undo the same commit's entirely inappropriate decision to blow away an existing index as a side-effect of create_am.sql.