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* Show sort ordering options in EXPLAIN output.Tom Lane2015-01-16
| | | | | | | | | | | | Up to now, EXPLAIN has contented itself with printing the sort expressions in a Sort or Merge Append plan node. This patch improves that by annotating the sort keys with COLLATE, DESC, USING, and/or NULLS FIRST/LAST whenever nondefault sort ordering options are used. The output is now a reasonably close approximation of an ORDER BY clause equivalent to the plan's ordering. Marius Timmer, Lukas Kreft, and Arne Scheffer; reviewed by Mike Blackwell. Some additional hacking by me.
* Rearrange explain.c's API so callers need not embed sizeof(ExplainState).Tom Lane2015-01-15
| | | | | | | | | | The folly of the previous arrangement was just demonstrated: there's no convenient way to add fields to ExplainState without breaking ABI, even if callers have no need to touch those fields. Since we might well need to do that again someday in back branches, let's change things so that only explain.c has to have sizeof(ExplainState) compiled into it. This costs one extra palloc() per EXPLAIN operation, which is surely pretty negligible.
* Improve performance of EXPLAIN with large range tables.Tom Lane2015-01-15
| | | | | | | | | | | | | | | | | | | | | | | | | As of 9.3, ruleutils.c goes to some lengths to ensure that table and column aliases used in its output are unique. Of course this takes more time than was required before, which in itself isn't fatal. However, EXPLAIN was set up so that recalculation of the unique aliases was repeated for each subexpression printed in a plan. That results in O(N^2) time and memory consumption for large plan trees, which did not happen in older branches. Fortunately, the expensive work is the same across a whole plan tree, so there is no need to repeat it; we can do most of the initialization just once per query and re-use it for each subexpression. This buys back most (not all) of the performance loss since 9.2. We need an extra ExplainState field to hold the precalculated deparse context. That's no problem in HEAD, but in the back branches, expanding sizeof(ExplainState) seems risky because third-party extensions might have local variables of that struct type. So, in 9.4 and 9.3, introduce an auxiliary struct to keep sizeof(ExplainState) the same. We should refactor the APIs to avoid such local variables in future, but that's material for a separate HEAD-only commit. Per gripe from Alexey Bashtanov. Back-patch to 9.3 where the issue was introduced.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Remove odd blank line in comment.Fujii Masao2014-12-18
| | | | Etsuro Fujita
* Add missing case for CustomScan.Tom Lane2014-11-20
| | | | | | | Per KaiGai Kohei. In passing improve formatting of some code added in commit 30d7ae3c, because otherwise pgindent will make a mess of it.
* Introduce custom path and scan providers.Robert Haas2014-11-07
| | | | | | | | | | | This allows extension modules to define their own methods for scanning a relation, and get the core code to use them. It's unclear as yet how much use this capability will find, but we won't find out if we never commit it. KaiGai Kohei, reviewed at various times and in various levels of detail by Shigeru Hanada, Tom Lane, Andres Freund, Álvaro Herrera, and myself.
* Print planning time only in EXPLAIN ANALYZE, not plain EXPLAIN.Tom Lane2014-10-15
| | | | | | | | | | | | We've gotten enough push-back on that change to make it clear that it wasn't an especially good idea to do it like that. Revert plain EXPLAIN to its previous behavior, but keep the extra output in EXPLAIN ANALYZE. Per discussion. Internally, I set this up as a separate flag ExplainState.summary that controls printing of planning time and execution time. For now it's just copied from the ANALYZE option, but we could consider exposing it to users.
* Increase number of hash join buckets for underestimate.Kevin Grittner2014-10-13
| | | | | | | | | | | | | | | | | | | | | | | | | | If we expect batching at the very beginning, we size nbuckets for "full work_mem" (see how many tuples we can get into work_mem, while not breaking NTUP_PER_BUCKET threshold). If we expect to be fine without batching, we start with the 'right' nbuckets and track the optimal nbuckets as we go (without actually resizing the hash table). Once we hit work_mem (considering the optimal nbuckets value), we keep the value. At the end of the first batch, we check whether (nbuckets != nbuckets_optimal) and resize the hash table if needed. Also, we keep this value for all batches (it's OK because it assumes full work_mem, and it makes the batchno evaluation trivial). So the resize happens only once. There could be cases where it would improve performance to allow the NTUP_PER_BUCKET threshold to be exceeded to keep everything in one batch rather than spilling to a second batch, but attempts to generate such a case have so far been unsuccessful; that issue may be addressed with a follow-on patch after further investigation. Tomas Vondra with minor format and comment cleanup by me Reviewed by Robert Haas, Heikki Linnakangas, and Kevin Grittner
* Split builtins.h to a new header ruleutils.hAlvaro Herrera2014-10-08
| | | | | | | The new header contains many prototypes for functions in ruleutils.c that are not exposed to the SQL level. Reviewed by Andres Freund and Michael Paquier.
* Prevent bitmap heap scans from showing unnecessary block info in EXPLAIN ↵Fujii Masao2014-07-14
| | | | | | | | | | | | | | ANALYZE. EXPLAIN ANALYZE shows the information of the numbers of exact/lossy blocks which bitmap heap scan processes. But, previously, when those numbers were both zero, it displayed only the prefix "Heap Blocks:" in TEXT output format. This is strange and would confuse the users. So this commit suppresses such unnecessary information. Backpatch to 9.4 where EXPLAIN ANALYZE was changed so that such information was displayed. Etsuro Fujita
* Prevent auto_explain from changing the output of a user's EXPLAIN.Tom Lane2014-05-20
| | | | | | | | | | | | | | | | | | Commit af7914c6627bcf0b0ca614e9ce95d3f8056602bf, which introduced the EXPLAIN (TIMING) option, for some reason coded explain.c to look at planstate->instrument->need_timer rather than es->timing to decide whether to print timing info. However, the former flag might get set as a result of contrib/auto_explain wanting timing information. We certainly don't want activation of auto_explain to change user-visible statement behavior, so fix that. Also fix an independent bug introduced in the same patch: in the code path for a never-executed node with a machine-friendly output format, if timing was selected, it would fail to print the Actual Rows and Actual Loops items. Per bug #10404 from Tomonari Katsumata. Back-patch to 9.2 where the faulty code was introduced.
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Rename EXPLAIN ANALYZE's "total runtime" output to "execution time".Tom Lane2014-04-16
| | | | | | | | | | | | | Now that EXPLAIN also outputs a "planning time" measurement, the use of "total" here seems rather confusing: it sounds like it might include the planning time which of course it doesn't. Majority opinion was that "execution time" is a better label, so we'll call it that. This should be noted as a backwards incompatibility for tools that examine EXPLAIN ANALYZE output. In passing, I failed to resist the temptation to do a little editing on the materialized-view example affected by this change.
* Include planning time in EXPLAIN ANALYZE output.Robert Haas2014-01-29
| | | | | | | | This doesn't work for prepared queries, but it's not too easy to get the information in that case and there's some debate as to exactly what the right thing to measure is, so just do this for now. Andreas Karlsson, with slight doc changes by me.
* Expose a routine to print triggers during EXPLAIN ANALYZEAlvaro Herrera2014-01-20
| | | | | | This is so that auto_explain can use it. Kyotaro HORIGUCHI
* Make bitmap heap scans show exact/lossy block info in EXPLAIN ANALYZE.Robert Haas2014-01-13
| | | | Etsuro Fujita
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Improve EXPLAIN to print the grouping columns in Agg and Group nodes.Tom Lane2013-12-12
| | | | Per request from Kevin Grittner.
* Support multi-argument UNNEST(), and TABLE() syntax for multiple functions.Tom Lane2013-11-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the ability to write TABLE( function1(), function2(), ...) as a single FROM-clause entry. The result is the concatenation of the first row from each function, followed by the second row from each function, etc; with NULLs inserted if any function produces fewer rows than others. This is believed to be a much more useful behavior than what Postgres currently does with multiple SRFs in a SELECT list. This syntax also provides a reasonable way to combine use of column definition lists with WITH ORDINALITY: put the column definition list inside TABLE(), where it's clear that it doesn't control the ordinality column as well. Also implement SQL-compliant multiple-argument UNNEST(), by turning UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)). The SQL standard specifies TABLE() with only a single function, not multiple functions, and it seems to require an implicit UNNEST() which is not what this patch does. There may be something wrong with that reading of the spec, though, because if it's right then the spec's TABLE() is just a pointless alternative spelling of UNNEST(). After further review of that, we might choose to adopt a different syntax for what this patch does, but in any case this functionality seems clearly worthwhile. Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and significantly revised by me
* Use appendStringInfoString instead of appendStringInfo where possible.Robert Haas2013-10-31
| | | | | | | This shaves a few cycles, and generally seems like good programming practice. David Rowley
* pgindent run for release 9.3Bruce Momjian2013-05-29
| | | | | This is the first run of the Perl-based pgindent script. Also update pgindent instructions.
* Clarify documentation of EXPLAIN (TIMING OFF) option.Tom Lane2013-05-19
| | | | | | | Clarify that this option doesn't suppress measurement of the statement's total runtime. Greg Smith
* Clean up the mess around EXPLAIN and materialized views.Tom Lane2013-04-12
| | | | | | | | | | | | | | | | | | | | | | | | | Revert the matview-related changes in explain.c's API, as per recent complaint from Robert Haas. The reason for these appears to have been principally some ill-considered choices around having intorel_startup do what ought to be parse-time checking, plus a poor arrangement for passing it the view parsetree it needs to store into pg_rewrite when creating a materialized view. Do the latter by having parse analysis stick a copy into the IntoClause, instead of doing it at runtime. (On the whole, I seriously question the choice to represent CREATE MATERIALIZED VIEW as a variant of SELECT INTO/CREATE TABLE AS, because that means injecting even more complexity into what was already a horrid legacy kluge. However, I didn't go so far as to rethink that choice ... yet.) I also moved several error checks into matview parse analysis, and made the check for external Params in a matview more accurate. In passing, clean things up a bit more around interpretOidsOption(), and fix things so that we can use that to force no-oids for views, sequences, etc, thereby eliminating the need to cons up "oids = false" options when creating them. catversion bump due to change in IntoClause. (I wonder though if we really need readfuncs/outfuncs support for IntoClause anymore.)
* Adjust ExplainOneQuery_hook_type to take a DestReceiver argument.Robert Haas2013-04-09
| | | | | | | | The materialized views patch adjusted ExplainOneQuery to take an additional DestReceiver argument, but failed to add a matching argument to the definition of ExplainOneQuery_hook. This is a problem for users of the hook that want to call ExplainOnePlan. Fix by adding the missing argument.
* Support writable foreign tables.Tom Lane2013-03-10
| | | | | | | | | | | This patch adds the core-system infrastructure needed to support updates on foreign tables, and extends contrib/postgres_fdw to allow updates against remote Postgres servers. There's still a great deal of room for improvement in optimization of remote updates, but at least there's basic functionality there now. KaiGai Kohei, reviewed by Alexander Korotkov and Laurenz Albe, and rather heavily revised by Tom Lane.
* Add a materialized view relations.Kevin Grittner2013-03-03
| | | | | | | | | | | | | | | | | | | | | | A materialized view has a rule just like a view and a heap and other physical properties like a table. The rule is only used to populate the table, references in queries refer to the materialized data. This is a minimal implementation, but should still be useful in many cases. Currently data is only populated "on demand" by the CREATE MATERIALIZED VIEW and REFRESH MATERIALIZED VIEW statements. It is expected that future releases will add incremental updates with various timings, and that a more refined concept of defining what is "fresh" data will be developed. At some point it may even be possible to have queries use a materialized in place of references to underlying tables, but that requires the other above-mentioned features to be working first. Much of the documentation work by Robert Haas. Review by Noah Misch, Thom Brown, Robert Haas, Marko Tiikkaja Security review by KaiGai Kohei, with a decision on how best to implement sepgsql still pending.
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Fix ruleutils to cope with conflicts from adding/dropping/renaming columns.Tom Lane2012-12-31
| | | | | | | | | | | | | | | | | In commit 11e131854f8231a21613f834c40fe9d046926387, we improved the rule/view dumping code so that it would produce valid query representations even if some of the tables involved in a query had been renamed since the query was parsed. This patch extends that idea to fix problems that occur when individual columns are renamed, or added or dropped. As before, the core of the fix is to assign unique new aliases when a name conflict has been created. This is complicated by the JOIN USING feature, which requires the same column alias to be used in both input relations, but we can handle that with a sufficiently complex approach to assigning aliases. A fortiori, this patch takes care of situations where the query didn't have unique column names to begin with, such as in a recent complaint from Bryan Nuse. (Because of expansion of "SELECT *", re-parsing a dumped query can require column name uniqueness even though the original text did not.)
* Improve ruleutils.c's heuristics for dealing with rangetable aliases.Tom Lane2012-09-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous scheme had bugs in some corner cases involving tables that had been renamed since a view was made. This could result in dumped views that failed to reload or reloaded incorrectly, as seen in bug #7553 from Lloyd Albin, as well as in some pgsql-hackers discussion back in January. Also, its behavior for printing EXPLAIN plans was sometimes confusing because of willingness to use the same alias for multiple RTEs (it was Ashutosh Bapat's complaint about that aspect that started the January thread). To fix, ensure that each RTE in the query has a unique unqualified alias, by modifying the alias if necessary (we add "_" and digits as needed to create a non-conflicting name). Then we can just print its variables with that alias, avoiding the confusing and bug-prone scheme of sometimes schema-qualifying variable names. In EXPLAIN, it proves to be expedient to take the further step of only assigning such aliases to RTEs that are actually referenced in the query, since the planner has a habit of generating extra RTEs with the same alias in situations such as inheritance-tree expansion. Although this fixes a bug of very long standing, I'm hesitant to back-patch such a noticeable behavioral change. My experiments while creating a regression test convinced me that actually incorrect output (as opposed to confusing output) occurs only in very narrow cases, which is backed up by the lack of previous complaints from the field. So we may be better off living with it in released branches; and in any case it'd be smart to let this ripen awhile in HEAD before we consider back-patching it.
* Run pgindent on 9.2 source tree in preparation for first 9.3Bruce Momjian2012-06-10
| | | | commit-fest.
* Rename I/O timing statistics columns to blk_read_time and blk_write_time.Tom Lane2012-04-29
| | | | | This seems more consistent with the pre-existing choices for names of other statistics columns. Rename assorted internal identifiers to match.
* New GUC, track_iotiming, to track I/O timings.Robert Haas2012-03-27
| | | | | | | | Currently, the only way to see the numbers this gathers is via EXPLAIN (ANALYZE, BUFFERS), but the plan is to add visibility through the stats collector and pg_stat_statements in subsequent patches. Ants Aasma, reviewed by Greg Smith, with some further changes by me.
* Restructure SELECT INTO's parsetree representation into CreateTableAsStmt.Tom Lane2012-03-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | Making this operation look like a utility statement seems generally a good idea, and particularly so in light of the desire to provide command triggers for utility statements. The original choice of representing it as SELECT with an IntoClause appendage had metastasized into rather a lot of places, unfortunately, so that this patch is a great deal more complicated than one might at first expect. In particular, keeping EXPLAIN working for SELECT INTO and CREATE TABLE AS subcommands required restructuring some EXPLAIN-related APIs. Add-on code that calls ExplainOnePlan or ExplainOneUtility, or uses ExplainOneQuery_hook, will need adjustment. Also, the cases PREPARE ... SELECT INTO and CREATE RULE ... SELECT INTO, which formerly were accepted though undocumented, are no longer accepted. The PREPARE case can be replaced with use of CREATE TABLE AS EXECUTE. The CREATE RULE case doesn't seem to have much real-world use (since the rule would work only once before failing with "table already exists"), so we'll not bother with that one. Both SELECT INTO and CREATE TABLE AS still return a command tag of "SELECT nnnn". There was some discussion of returning "CREATE TABLE nnnn", but for the moment backwards compatibility wins the day. Andres Freund and Tom Lane
* Make EXPLAIN (BUFFERS) track blocks dirtied, as well as those written.Robert Haas2012-02-22
| | | | | | Also expose the new counters through pg_stat_statements. Patch by me. Review by Fujii Masao and Greg Smith.
* Add TIMING option to EXPLAIN, to allow eliminating of timing overhead.Robert Haas2012-02-07
| | | | | | | | Sometimes it may be useful to get actual row counts out of EXPLAIN (ANALYZE) without paying the cost of timing every node entry/exit. With this patch, you can say EXPLAIN (ANALYZE, TIMING OFF) to get that. Tomas Vondra, reviewed by Eric Theise, with minor doc changes by me.
* Add array_to_json and row_to_json functions.Andrew Dunstan2012-02-03
| | | | | | | Also move the escape_json function from explain.c to json.c where it seems to belong. Andrew Dunstan, Reviewd by Abhijit Menon-Sen.
* Built-in JSON data type.Robert Haas2012-01-31
| | | | | | | | | | Like the XML data type, we simply store JSON data as text, after checking that it is valid. More complex operations such as canonicalization and comparison may come later, but this is enough for not. There are a few open issues here, such as whether we should attempt to detect UTF-8 surrogate pairs represented as \uXXXX\uYYYY, but this gets the basic framework in place.
* Instrument index-only scans to count heap fetches performed.Robert Haas2012-01-25
| | | | Patch by me; review by Tom Lane, Jeff Davis, and Peter Geoghegan.
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Rearrange the implementation of index-only scans.Tom Lane2011-10-11
| | | | | | | | | | | | | | | | | | | | | | This commit changes index-only scans so that data is read directly from the index tuple without first generating a faux heap tuple. The only immediate benefit is that indexes on system columns (such as OID) can be used in index-only scans, but this is necessary infrastructure if we are ever to support index-only scans on expression indexes. The executor is now ready for that, though the planner still needs substantial work to recognize the possibility. To do this, Vars in index-only plan nodes have to refer to index columns not heap columns. I introduced a new special varno, INDEX_VAR, to mark such Vars to avoid confusion. (In passing, this commit renames the two existing special varnos to OUTER_VAR and INNER_VAR.) This allows ruleutils.c to handle them with logic similar to what we use for subplan reference Vars. Since index-only scans are now fundamentally different from regular indexscans so far as their expression subtrees are concerned, I also chose to change them to have their own plan node type (and hence, their own executor source file).
* Support index-only scans using the visibility map to avoid heap fetches.Tom Lane2011-10-07
| | | | | | | | | | | | | When a btree index contains all columns required by the query, and the visibility map shows that all tuples on a target heap page are visible-to-all, we don't need to fetch that heap page. This patch depends on the previous patches that made the visibility map reliable. There's a fair amount left to do here, notably trying to figure out a less chintzy way of estimating the cost of an index-only scan, but the core functionality seems ready to commit. Robert Haas and Ibrar Ahmed, with some previous work by Heikki Linnakangas.
* Make EXPLAIN ANALYZE report the numbers of rows rejected by filter steps.Tom Lane2011-09-22
| | | | | | | | | | | | | | | This provides information about the numbers of tuples that were visited but not returned by table scans, as well as the numbers of join tuples that were considered and discarded within a join plan node. There is still some discussion going on about the best way to report counts for outer-join situations, but I think most of what's in the patch would not change if we revise that, so I'm going to go ahead and commit it as-is. Documentation changes to follow (they weren't in the submitted patch either). Marko Tiikkaja, reviewed by Marc Cousin, somewhat revised by Tom
* Remove unnecessary #include references, per pgrminclude script.Bruce Momjian2011-09-01
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* Move Trigger and TriggerDesc structs out of rel.h into a new reltrigger.hAlvaro Herrera2011-07-04
| | | | | This lets us stop including rel.h into execnodes.h, which is a widely used header.
* Clean up most -Wunused-but-set-variable warnings from gcc 4.6Peter Eisentraut2011-04-11
| | | | | | This warning is new in gcc 4.6 and part of -Wall. This patch cleans up most of the noise, but there are some still warnings that are trickier to remove.
* pgindent run before PG 9.1 beta 1.Bruce Momjian2011-04-10
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* Include the target table in EXPLAIN output for ModifyTable nodes.Tom Lane2011-03-01
| | | | | | | | | | Per discussion, this seems important for plans involving writable CTEs, since there can now be more than one ModifyTable node in the plan. To retain the same formatting as for target tables of scan nodes, we show only one target table, which will be the parent table in case of an UPDATE or DELETE on an inheritance tree. Individual child tables can be determined by inspecting the child plan trees if needed.
* Rearrange snapshot handling to make rule expansion more consistent.Tom Lane2011-02-28
| | | | | | | | | | | | | | | | | | | | | With this patch, portals, SQL functions, and SPI all agree that there should be only a CommandCounterIncrement between the queries that are generated from a single SQL command by rule expansion. Fetching a whole new snapshot now happens only between original queries. This is equivalent to the existing behavior of EXPLAIN ANALYZE, and it was judged to be the best choice since it eliminates one source of concurrency hazards for rules. The patch should also make things marginally faster by reducing the number of snapshot push/pop operations. The patch removes pg_parse_and_rewrite(), which is no longer used anywhere. There was considerable discussion about more aggressive refactoring of the query-processing functions exported by postgres.c, but for the moment nothing more has been done there. I also took the opportunity to refactor snapmgr.c's API slightly: the former PushUpdatedSnapshot() has been split into two functions. Marko Tiikkaja, reviewed by Steve Singer and Tom Lane
* Refactor the executor's API to support data-modifying CTEs better.Tom Lane2011-02-27
| | | | | | | | | | | | | | | | | | | | | | The originally committed patch for modifying CTEs didn't interact well with EXPLAIN, as noted by myself, and also had corner-case problems with triggers, as noted by Dean Rasheed. Those problems show it is really not practical for ExecutorEnd to call any user-defined code; so split the cleanup duties out into a new function ExecutorFinish, which must be called between the last ExecutorRun call and ExecutorEnd. Some Asserts have been added to these functions to help verify correct usage. It is no longer necessary for callers of the executor to call AfterTriggerBeginQuery/AfterTriggerEndQuery for themselves, as this is now done by ExecutorStart/ExecutorFinish respectively. If you really need to suppress that and do it for yourself, pass EXEC_FLAG_SKIP_TRIGGERS to ExecutorStart. Also, refactor portal commit processing to allow for the possibility that PortalDrop will invoke user-defined code. I think this is not actually necessary just yet, since the portal-execution-strategy logic forces any non-pure-SELECT query to be run to completion before we will consider committing. But it seems like good future-proofing.
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