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* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Post-feature-freeze pgindent run.Tom Lane2018-04-26
| | | | Discussion: https://postgr.es/m/15719.1523984266@sss.pgh.pa.us
* Rename TransactionChain functionsPeter Eisentraut2018-03-16
| | | | | | | | | We call this thing a "transaction block" everywhere except in a few functions, where it is mysteriously called a "transaction chain". In the SQL standard, a transaction chain is something different. So rename these functions to match the common terminology. Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
* Remove PortalGetQueryDesc()Peter Eisentraut2018-01-09
| | | | | | | | | After having gotten rid of PortalGetHeapMemory(), there seems little reason to keep one Portal access macro around that offers no actual abstraction and isn't consistently used anyway. Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
* Update portal-related memory context names and APIPeter Eisentraut2018-01-09
| | | | | | | | | | | | | Rename PortalMemory to TopPortalContext, to avoid confusion with PortalContext and align naming with similar top-level memory contexts. Rename PortalData's "heap" field to portalContext. The "heap" naming seems quite antiquated and confusing. Also get rid of the PortalGetHeapMemory() macro and access the field directly, which we do for other portal fields, so this abstraction doesn't buy anything. Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Remove unnecessary PG_TRY overhead for CurrentResourceOwner changes.Tom Lane2017-10-11
| | | | | | | | | | | | | | | | | | | resowner/README contained advice to use a PG_TRY block to restore the old CurrentResourceOwner value anywhere that that variable is transiently changed. That advice was only inconsistently followed, however, and on reflection it seems like unnecessary overhead. We don't bother with such a convention for transient CurrentMemoryContext changes, on the grounds that any (sub)transaction abort will start out by resetting CurrentMemoryContext to what it wants. But the same is true of CurrentResourceOwner, so there seems no need to treat it differently. Hence, remove PG_TRY blocks that exist only to restore CurrentResourceOwner before re-throwing the error. There are a couple of places that restore it along with some other actions, and I left those alone; the restore is probably unnecessary but no noticeable gain will result from removing it. Discussion: https://postgr.es/m/5236.1507583529@sss.pgh.pa.us
* Reduce excessive dereferencing of function pointersPeter Eisentraut2017-09-07
| | | | | | | | | | | | It is equivalent in ANSI C to write (*funcptr) () and funcptr(). These two styles have been applied inconsistently. After discussion, we'll use the more verbose style for plain function pointer variables, to make it clear that it's a variable, and the shorter style when the function pointer is in a struct (s.func() or s->func()), because then it's clear that it's not a plain function name, and otherwise the excessive punctuation makes some of those invocations hard to read. Discussion: https://www.postgresql.org/message-id/f52c16db-14ed-757d-4b48-7ef360b1631d@2ndquadrant.com
* Phase 2 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Improve castNode notation by introducing list-extraction-specific variants.Tom Lane2017-04-10
| | | | | | | | | | | | | | | | | This extends the castNode() notation introduced by commit 5bcab1114 to provide, in one step, extraction of a list cell's pointer and coercion to a concrete node type. For example, "lfirst_node(Foo, lc)" is the same as "castNode(Foo, lfirst(lc))". Almost half of the uses of castNode that have appeared so far include a list extraction call, so this is pretty widely useful, and it saves a few more keystrokes compared to the old way. As with the previous patch, back-patch the addition of these macros to pg_list.h, so that the notation will be available when back-patching. Patch by me, after an idea of Andrew Gierth's. Discussion: https://postgr.es/m/14197.1491841216@sss.pgh.pa.us
* Allow for parallel execution whenever ExecutorRun() is done only once.Robert Haas2017-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, it was unsafe to execute a plan in parallel if ExecutorRun() might be called with a non-zero row count. However, it's quite easy to fix things up so that we can support that case, provided that it is known that we will never call ExecutorRun() a second time for the same QueryDesc. Add infrastructure to signal this, and cross-checks to make sure that a caller who claims this is true doesn't later reneg. While that pattern never happens with queries received directly from a client -- there's no way to know whether multiple Execute messages will be sent unless the first one requests all the rows -- it's pretty common for queries originating from procedural languages, which often limit the result to a single tuple or to a user-specified number of tuples. This commit doesn't actually enable parallelism in any additional cases, because currently none of the places that would be able to benefit from this infrastructure pass CURSOR_OPT_PARALLEL_OK in the first place, but it makes it much more palatable to pass CURSOR_OPT_PARALLEL_OK in places where we currently don't, because it eliminates some cases where we'd end up having to run the parallel plan serially. Patch by me, based on some ideas from Rafia Sabih and corrected by Rafia Sabih based on feedback from Dilip Kumar and myself. Discussion: http://postgr.es/m/CA+TgmobXEhvHbJtWDuPZM9bVSLiTj-kShxQJ2uM5GPDze9fRYA@mail.gmail.com
* Use castNode() in a bunch of statement-list-related code.Tom Lane2017-01-26
| | | | | | | | | | | | | When I wrote commit ab1f0c822, I really missed the castNode() macro that Peter E. had proposed shortly before. This back-fills the uses I would have put it to. It's probably not all that significant, but there are more assertions here than there were before, and conceivably they will help catch any bugs associated with those representation changes. I left behind a number of usages like "(Query *) copyObject(query_var)". Those could have been converted as well, but Peter has proposed another notational improvement that would handle copyObject cases automatically, so I let that be for now.
* Change representation of statement lists, and add statement location info.Tom Lane2017-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes several changes that improve the consistency of representation of lists of statements. It's always been the case that the output of parse analysis is a list of Query nodes, whatever the types of the individual statements in the list. This patch brings similar consistency to the outputs of raw parsing and planning steps: * The output of raw parsing is now always a list of RawStmt nodes; the statement-type-dependent nodes are one level down from that. * The output of pg_plan_queries() is now always a list of PlannedStmt nodes, even for utility statements. In the case of a utility statement, "planning" just consists of wrapping a CMD_UTILITY PlannedStmt around the utility node. This list representation is now used in Portal and CachedPlan plan lists, replacing the former convention of intermixing PlannedStmts with bare utility-statement nodes. Now, every list of statements has a consistent head-node type depending on how far along it is in processing. This allows changing many places that formerly used generic "Node *" pointers to use a more specific pointer type, thus reducing the number of IsA() tests and casts needed, as well as improving code clarity. Also, the post-parse-analysis representation of DECLARE CURSOR is changed so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained SELECT remains a child of the DeclareCursorStmt rather than getting flipped around to be the other way. It's now true for both Query and PlannedStmt that utilityStmt is non-null if and only if commandType is CMD_UTILITY. That allows simplifying a lot of places that were testing both fields. (I think some of those were just defensive programming, but in many places, it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.) Because PlannedStmt carries a canSetTag field, we're also able to get rid of some ad-hoc rules about how to reconstruct canSetTag for a bare utility statement; specifically, the assumption that a utility is canSetTag if and only if it's the only one in its list. While I see no near-term need for relaxing that restriction, it's nice to get rid of the ad-hocery. The API of ProcessUtility() is changed so that what it's passed is the wrapper PlannedStmt not just the bare utility statement. This will affect all users of ProcessUtility_hook, but the changes are pretty trivial; see the affected contrib modules for examples of the minimum change needed. (Most compilers should give pointer-type-mismatch warnings for uncorrected code.) There's also a change in the API of ExplainOneQuery_hook, to pass through cursorOptions instead of expecting hook functions to know what to pick. This is needed because of the DECLARE CURSOR changes, but really should have been done in 9.6; it's unlikely that any extant hook functions know about using CURSOR_OPT_PARALLEL_OK. Finally, teach gram.y to save statement boundary locations in RawStmt nodes, and pass those through to Query and PlannedStmt nodes. This allows more intelligent handling of cases where a source query string contains multiple statements. This patch doesn't actually do anything with the information, but a follow-on patch will. (Passing this information through cleanly is the true motivation for these changes; while I think this is all good cleanup, it's unlikely we'd have bothered without this end goal.) catversion bump because addition of location fields to struct Query affects stored rules. This patch is by me, but it owes a good deal to Fabien Coelho who did a lot of preliminary work on the problem, and also reviewed the patch. Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Fix TOAST access failure in RETURNING queries.Tom Lane2016-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Widen query numbers-of-tuples-processed counters to uint64.Tom Lane2016-03-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch widens SPI_processed, EState's es_processed field, PortalData's portalPos field, FuncCallContext's call_cntr and max_calls fields, ExecutorRun's count argument, PortalRunFetch's result, and the max number of rows in a SPITupleTable to uint64, and deals with (I hope) all the ensuing fallout. Some of these values were declared uint32 before, and others "long". I also removed PortalData's posOverflow field, since that logic seems pretty useless given that portalPos is now always 64 bits. The user-visible results are that command tags for SELECT etc will correctly report tuple counts larger than 4G, as will plpgsql's GET GET DIAGNOSTICS ... ROW_COUNT command. Queries processing more tuples than that are still not exactly the norm, but they're becoming more common. Most values associated with FETCH/MOVE distances, such as PortalRun's count argument and the count argument of most SPI functions that have one, remain declared as "long". It's not clear whether it would be worth promoting those to int64; but it would definitely be a large dollop of additional API churn on top of this, and it would only help 32-bit platforms which seem relatively less likely to see any benefit. Andreas Scherbaum, reviewed by Christian Ullrich, additional hacking by me
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Fix subtransaction cleanup after an outer-subtransaction portal fails.Tom Lane2015-09-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Formerly, we treated only portals created in the current subtransaction as having failed during subtransaction abort. However, if the error occurred while running a portal created in an outer subtransaction (ie, a cursor declared before the last savepoint), that has to be considered broken too. To allow reliable detection of which ones those are, add a bookkeeping field to struct Portal that tracks the innermost subtransaction in which each portal has actually been executed. (Without this, we'd end up failing portals containing functions that had called the subtransaction, thereby breaking plpgsql exception blocks completely.) In addition, when we fail an outer-subtransaction Portal, transfer its resources into the subtransaction's resource owner, so that they're released early in cleanup of the subxact. This fixes a problem reported by Jim Nasby in which a function executed in an outer-subtransaction cursor could cause an Assert failure or crash by referencing a relation created within the inner subtransaction. The proximate cause of the Assert failure is that AtEOSubXact_RelationCache assumed it could blow away a relcache entry without first checking that the entry had zero refcount. That was a bad idea on its own terms, so add such a check there, and to the similar coding in AtEOXact_RelationCache. This provides an independent safety measure in case there are still ways to provoke the situation despite the Portal-level changes. This has been broken since subtransactions were invented, so back-patch to all supported branches. Tom Lane and Michael Paquier
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* 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.
* Improve some O(N^2) behavior in window function evaluation.Tom Lane2014-04-13
| | | | | | | | | | | | | | | | | | | Repositioning the tuplestore seek pointer in window_gettupleslot() turns out to be a very significant expense when the window frame is sizable and the frame end can move. To fix, introduce a tuplestore function for skipping an arbitrary number of tuples in one call, parallel to the one we introduced for tuplesort objects in commit 8d65da1f. This reduces the cost of window_gettupleslot() to O(1) if the tuplestore has not spilled to disk. As in the previous commit, I didn't try to do any real optimization of tuplestore_skiptuples for the case where the tuplestore has spilled to disk. There is probably no practical way to get the cost to less than O(N) anyway, but perhaps someone can think of something later. Also fix PersistHoldablePortal() to make use of this API now that we have it. Based on a suggestion by Dean Rasheed, though this turns out not to look much like his patch.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Only install a portal's ResourceOwner if it actually has one.Tom Lane2013-06-13
| | | | | | | | | | | | | | | | | | | | | In most scenarios a portal without a ResourceOwner is dead and not subject to any further execution, but a portal for a cursor WITH HOLD remains in existence with no ResourceOwner after the creating transaction is over. In this situation, if we attempt to "execute" the portal directly to fetch data from it, we were setting CurrentResourceOwner to NULL, leading to a segfault if the datatype output code did anything that required a resource owner (such as trying to fetch system catalog entries that weren't already cached). The case appears to be impossible to provoke with stock libpq, but psqlODBC at least is able to cause it when working with held cursors. Simplest fix is to just skip the assignment to CurrentResourceOwner, so that any resources used by the data output operations will be managed by the transaction-level resource owner instead. For consistency I changed all the places that install a portal's resowner as current, even though some of them are probably not reachable with a held cursor's portal. Per report from Joshua Berry (with thanks to Hiroshi Inoue for developing a self-contained test case). Back-patch to all supported versions.
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Revert patch for taking fewer snapshots.Tom Lane2012-11-26
| | | | | | | | | | | | | This reverts commit d573e239f03506920938bf0be56c868d9c3416da, "Take fewer snapshots". While that seemed like a good idea at the time, it caused execution to use a snapshot that had been acquired before locking any of the tables mentioned in the query. This created user-visible anomalies that were not present in any prior release of Postgres, as reported by Tomas Vondra. While this whole area could do with a redesign (since there are related cases that have anomalies anyway), it doesn't seem likely that any future patch would be reasonably back-patchable; and we don't want 9.2 to exhibit a behavior that's subtly unlike either past or future releases. Hence, revert to prior code while we rethink the problem.
* 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
* Run a portal's cleanup hook immediately when pushing it to FAILED state.Tom Lane2012-02-15
| | | | | | | | | | | | | | | | This extends the changes of commit 6252c4f9e201f619e5eebda12fa867acd4e4200e so that we run the cleanup hook earlier for failure cases as well as success cases. As before, the point is to avoid an assertion failure from an Assert I added in commit a874fe7b4c890d1fe3455215a83ca777867beadd, which was meant to check that no user-written code can be called during portal cleanup. This fixes a case reported by Pavan Deolasee in which the Assert could be triggered during backend exit (see the new regression test case), and also prevents the possibility that the cleanup hook is run after portions of the portal's state have already been recycled. That doesn't really matter in current usage, but it foreseeably could matter in the future. Back-patch to 9.1 where the Assert in question was added.
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Take fewer snapshots.Robert Haas2011-12-21
| | | | | | | | | | | | | | | | | | | When a PORTAL_ONE_SELECT query is executed, we can opportunistically reuse the parse/plan shot for the execution phase. This cuts down the number of snapshots per simple query from 2 to 1 for the simple protocol, and 3 to 2 for the extended protocol. Since we are only reusing a snapshot taken early in the processing of the same protocol message, the change shouldn't be user-visible, except that the remote possibility of the planning and execution snapshots being different is eliminated. Note that this change does not make it safe to assume that the parse/plan snapshot will certainly be reused; that will currently only happen if PortalStart() decides to use the PORTAL_ONE_SELECT strategy. It might be worth trying to provide some stronger guarantees here in the future, but for now we don't. Patch by me; review by Dimitri Fontaine.
* pgindent run before PG 9.1 beta 1.Bruce Momjian2011-04-10
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* 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.
* Stamp copyrights for year 2011.Bruce Momjian2011-01-01
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* Remove cvs keywords from all files.Magnus Hagander2010-09-20
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* Update copyright for the year 2010.Bruce Momjian2010-01-02
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* Fix snapshot management, take two.Alvaro Herrera2009-10-07
| | | | | | | | | | | | | | | | | | | | Partially revert the previous patch I installed and replace it with a more general fix: any time a snapshot is pushed as Active, we need to ensure that it will not be modified in the future. This means that if the same snapshot is used as CurrentSnapshot, it needs to be copied separately. This affects serializable transactions only, because CurrentSnapshot has already been copied by RegisterSnapshot and so PushActiveSnapshot does not think it needs another copy. However, CommandCounterIncrement would modify CurrentSnapshot, whereas ActiveSnapshots must not have their command counters incremented. I say "partially" because the regression test I added for the previous bug has been kept. (This restores 8.3 behavior, because before snapmgr.c existed, any snapshot set as Active was copied.) Per bug report from Stuart Bishop in 6bc73d4c0910042358k3d1adff3qa36f8df75198ecea@mail.gmail.com
* Ensure that a cursor has an immutable snapshot throughout its lifespan.Alvaro Herrera2009-10-02
| | | | | | | | | The old coding was using a regular snapshot, referenced elsewhere, that was subject to having its command counter updated. Fix by creating a private copy of the snapshot exclusively for the cursor. Backpatch to 8.4, which is when the bug was introduced during the snapshot management rewrite.
* 8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef listBruce Momjian2009-06-11
| | | | provided by Andrew.
* Update copyright for 2009.Bruce Momjian2009-01-01
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* Ensure that the contents of a holdable cursor don't depend on out-of-lineTom Lane2008-12-01
| | | | | | | | | | | toasted values, since those could get dropped once the cursor's transaction is over. Per bug #4553 from Andrew Gierth. Back-patch as far as 8.1. The bug actually exists back to 7.4 when holdable cursors were introduced, but this patch won't work before 8.1 without significant adjustments. Given the lack of field complaints, it doesn't seem worth the work (and risk of introducing new bugs) to try to make a patch for the older branches.
* Clean up the API for DestReceiver objects by eliminating the assumptionTom Lane2008-11-30
| | | | | | | | | | | | that a Portal is a useful and sufficient additional argument for CreateDestReceiver --- it just isn't, in most cases. Instead formalize the approach of passing any needed parameters to the receiver separately. One unexpected benefit of this change is that we can declare typedef Portal in a less surprising location. This patch is just code rearrangement and doesn't change any functionality. I'll tackle the HOLD-cursor-vs-toast problem in a follow-on patch.
* Adjust things so that the query_string of a cached plan and the sourceText ofTom Lane2008-07-18
| | | | | | | | | | | | | | | | | | | | | | | | a portal are never NULL, but reliably provide the source text of the query. It turns out that there was only one place that was really taking a short-cut, which was the 'EXECUTE' utility statement. That doesn't seem like a sufficiently critical performance hotspot to justify not offering a guarantee of validity of the portal source text. Fix it to copy the source text over from the cached plan. Add Asserts in the places that set up cached plans and portals to reject null source strings, and simplify a bunch of places that formerly needed to guard against nulls. There may be a few places that cons up statements for execution without having any source text at all; I found one such in ConvertTriggerToFK(). It seems sufficient to inject a phony source string in such a case, for instance ProcessUtility((Node *) atstmt, "(generated ALTER TABLE ADD FOREIGN KEY command)", NULL, false, None_Receiver, NULL); We should take a second look at the usage of debug_query_string, particularly the recently added current_query() SQL function. ITAGAKI Takahiro and Tom Lane
* Improve snapshot manager by keeping explicit track of snapshots.Alvaro Herrera2008-05-12
| | | | | | | | | | | | | There are two ways to track a snapshot: there's the "registered" list, which is used for arbitrary long-lived snapshots; and there's the "active stack", which is used for the snapshot that is considered "active" at any time. This also allows users of snapshots to stop worrying about snapshot memory allocation and freeing, and about using PG_TRY blocks around ActiveSnapshot assignment. This is all done automatically now. As a consequence, this allows us to reset MyProc->xmin when there are no more snapshots registered in the current backend, reducing the impact that long-running transactions have on VACUUM.
* Revert my bad decision of about a year ago to make PortalDefineQueryTom Lane2008-04-02
| | | | | | | | | | | | | | responsible for copying the query string into the new Portal. Such copying is unnecessary in the common code path through exec_simple_query, and in this case it can be enormously expensive because the string might contain a large number of individual commands; we were copying the entire, long string for each command, resulting in O(N^2) behavior for N commands. (This is the cause of bug #4079.) A second problem with it is that PortalDefineQuery really can't risk error, because if it elog's before having set up the Portal, we will leak the plancache refcount that the caller is trying to hand off to the portal. So go back to the design in which the caller is responsible for making sure everything is copied into the portal if necessary.
* Rename snapmgmt.c/h to snapmgr.c/h, for consistency with other files.Alvaro Herrera2008-03-26
| | | | Per complaint from Tom Lane.
* Separate snapshot management code from tuple visibility code, create aAlvaro Herrera2008-03-26
| | | | | | | | | | | | | snapmgmt.c file for the former. The header files have also been reorganized in three parts: the most basic snapshot definitions are now in a new file snapshot.h, and the also new snapmgmt.h keeps the definitions for snapmgmt.c. tqual.h has been reduced to the bare minimum. This patch is just a first step towards managing live snapshots within a transaction; there is no functionality change. Per my proposal to pgsql-patches on 20080318191940.GB27458@alvh.no-ip.org and subsequent discussion.
* Add a couple of missing FreeQueryDesc calls. Noticed while testing aAlvaro Herrera2008-03-20
| | | | framework to keep track of snapshots in use.
* Update copyrights in source tree to 2008.Bruce Momjian2008-01-01
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* Re-run pgindent with updated list of typedefs. (Updated README shouldBruce Momjian2007-11-15
| | | | avoid this problem in the future.)
* pgindent run for 8.3.Bruce Momjian2007-11-15
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* Disallow scrolling of FOR UPDATE/FOR SHARE cursors, so as to avoid problemsTom Lane2007-10-24
| | | | | | | | | | | in corner cases such as re-fetching a just-deleted row. We may be able to relax this someday, but let's find out how many people really care before we invest a lot of work in it. Per report from Heikki and subsequent discussion. While in the neighborhood, make the combination of INSENSITIVE and FOR UPDATE throw an error, since they are semantically incompatible. (Up to now we've accepted but just ignored the INSENSITIVE option of DECLARE CURSOR.)
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