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2021-10-03Fix checking of query type in plpgsql's RETURN QUERY command.Tom Lane
Prior to v14, we insisted that the query in RETURN QUERY be of a type that returns tuples. (For instance, INSERT RETURNING was allowed, but not plain INSERT.) That happened indirectly because we opened a cursor for the query, so spi.c checked SPI_is_cursor_plan(). As a consequence, the error message wasn't terribly on-point, but at least it was there. Commit 2f48ede08 lost this detail. Instead, plain RETURN QUERY insisted that the query be a SELECT (by checking for SPI_OK_SELECT) while RETURN QUERY EXECUTE failed to check the query type at all. Neither of these changes was intended. The only convenient place to check this in the EXECUTE case is inside _SPI_execute_plan, because we haven't done parse analysis until then. So we need to pass down a flag saying whether to enforce that the query returns tuples. Fortunately, we can squeeze another boolean into struct SPIExecuteOptions without an ABI break, since there's padding space there. (It's unlikely that any extensions would already be using this new struct, but preserving ABI in v14 seems like a smart idea anyway.) Within spi.c, it seemed like _SPI_execute_plan's parameter list was already ridiculously long, and I didn't want to make it longer. So I thought of passing SPIExecuteOptions down as-is, allowing that parameter list to become much shorter. This makes the patch a bit more invasive than it might otherwise be, but it's all internal to spi.c, so that seems fine. Per report from Marc Bachmann. Back-patch to v14 where the faulty code came in. Discussion: https://postgr.es/m/1F2F75F0-27DF-406F-848D-8B50C7EEF06A@gmail.com
2021-10-01Fix Portal snapshot tracking to handle subtransactions properly.Tom Lane
Commit 84f5c2908 forgot to consider the possibility that EnsurePortalSnapshotExists could run inside a subtransaction with lifespan shorter than the Portal's. In that case, the new active snapshot would be popped at the end of the subtransaction, leaving a dangling pointer in the Portal, with mayhem ensuing. To fix, make sure the ActiveSnapshot stack entry is marked with the same subtransaction nesting level as the associated Portal. It's certainly safe to do so since we won't be here at all unless the stack is empty; hence we can't create an out-of-order stack. Let's also apply this logic in the case where PortalRunUtility sets portalSnapshot, just to be sure that path can't cause similar problems. It's slightly less clear that that path can't create an out-of-order stack, so add an assertion guarding it. Report and patch by Bertrand Drouvot (with kibitzing by me). Back-patch to v11, like the previous commit. Discussion: https://postgr.es/m/ff82b8c5-77f4-3fe7-6028-fcf3303e82dd@amazon.com
2021-09-21Fix misevaluation of STABLE parameters in CALL within plpgsql.Tom Lane
Before commit 84f5c2908, a STABLE function in a plpgsql CALL statement's argument list would see an up-to-date snapshot, because exec_stmt_call would push a new snapshot. I got rid of that because the possibility of the snapshot disappearing within COMMIT made it too hard to manage a snapshot across the CALL statement. That's fine so far as the procedure itself goes, but I forgot to think about the possibility of STABLE functions within the CALL argument list. As things now stand, those'll be executed with the Portal's snapshot as ActiveSnapshot, keeping them from seeing updates more recent than Portal startup. (VOLATILE functions don't have a problem because they take their own snapshots; which indeed is also why the procedure itself doesn't have a problem. There are no STABLE procedures.) We can fix this by pushing a new snapshot transiently within ExecuteCallStmt itself. Popping the snapshot before we get into the procedure proper eliminates the management problem. The possibly-useless extra snapshot-grab is slightly annoying, but it's no worse than what happened before 84f5c2908. Per bug #17199 from Alexander Nawratil. Back-patch to v11, like the previous patch. Discussion: https://postgr.es/m/17199-1ab2561f0d94af92@postgresql.org
2021-09-13Fix EXIT out of outermost block in plpgsql.Tom Lane
Ordinarily, using EXIT this way would draw "control reached end of function without RETURN". However, if the function is one where we don't require an explicit RETURN (such as a DO block), that should not happen. It did anyway, because add_dummy_return() neglected to account for the case. Per report from Herwig Goemans. Back-patch to all supported branches. Discussion: https://postgr.es/m/868ae948-e3ca-c7ec-95a6-83cfc08ef750@gmail.com
2021-09-09Revoke PUBLIC CREATE from public schema, now owned by pg_database_owner.Noah Misch
This switches the default ACL to what the documentation has recommended since CVE-2018-1058. Upgrades will carry forward any old ownership and ACL. Sites that declined the 2018 recommendation should take a fresh look. Recipes for commissioning a new database cluster from scratch may need to create a schema, grant more privileges, etc. Out-of-tree test suites may require such updates. Reviewed by Peter Eisentraut. Discussion: https://postgr.es/m/20201031163518.GB4039133@rfd.leadboat.com
2021-08-21Improve error messages about misuse of SELECT INTO.Tom Lane
Improve two places in plpgsql, and one in spi.c, where an error message would confusingly tell you that you couldn't use a SELECT query, when what you had written *was* a SELECT query. The actual problem is that you can't use SELECT ... INTO in these contexts, but the messages failed to make that apparent. Special-case SELECT INTO to make these errors more helpful. Also, fix the same spots in plpgsql, as well as several messages in exec_eval_expr(), to not quote the entire complained-of query or expression in the primary error message. That behavior very easily led to violating our message style guideline about keeping the primary error message short and single-line. Also, since the important part of the message was after the inserted text, it could make the real problem very hard to see. We can report the query or expression as the first line of errcontext instead. Per complaint from Roger Mason. Back-patch to v14, since (a) some of these messages are new in v14 and (b) v14's translatable strings are still somewhat in flux. The problem's older than that of course, but I'm hesitant to change the behavior further back. Discussion: https://postgr.es/m/1914708.1629474624@sss.pgh.pa.us
2021-07-20Fix corner-case uninitialized-variable issues in plpgsql.Tom Lane
If an error was raised during our initial attempt to check whether a successfully-compiled expression is "simple", subsequent calls of exec_stmt_execsql would suppose that stmt->mod_stmt was already computed when it had not been. This could lead to assertion failures in debug builds; in production builds the effect would typically be to act as if INTO STRICT had been specified even when it had not been. Of course that only matters if the subsequent attempt to execute the expression succeeds, so that the problem can only be reached by fixing a failure in some referenced, inline-able SQL function and then retrying the calling plpgsql function in the same session. (There might be even-more-obscure ways to change the expression's behavior without changing the plpgsql function, but that one seems like the only one people would be likely to hit in practice.) The most foolproof way to fix this would be to arrange for exec_prepare_plan to not set expr->plan until we've finished the subsidiary simple-expression check. But it seems hard to do that without creating reference-count leak issues. So settle for documenting the hazard in a comment and fixing exec_stmt_execsql to test separately for whether it's computed stmt->mod_stmt. (That adds a test-and-branch per execution, but hopefully that's negligible in context.) In v11 and up, also fix exec_stmt_call which had a variant of the same issue. Per bug #17113 from Alexander Lakhin. Back-patch to all supported branches. Discussion: https://postgr.es/m/17113-077605ce00e0e7ec@postgresql.org
2021-07-19Use l*_node() family of functions where appropriatePeter Eisentraut
Instead of castNode(…, lfoo(…)) Author: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> Discussion: https://www.postgresql.org/message-id/flat/87eecahraj.fsf@wibble.ilmari.org
2021-07-13Rename debug_invalidate_system_caches_always to debug_discard_caches.Tom Lane
The name introduced by commit 4656e3d66 was agreed to be unreasonably long. To match this change, rename initdb's recently-added --clobber-cache option to --discard-caches. Discussion: https://postgr.es/m/1374320.1625430433@sss.pgh.pa.us
2021-06-22Restore the portal-level snapshot for simple expressions, too.Tom Lane
Commits 84f5c2908 et al missed the need to cover plpgsql's "simple expression" code path. If the first thing we execute after a COMMIT/ROLLBACK is one of those, rather than a full-fledged SPI command, we must explicitly do EnsurePortalSnapshotExists() to make sure we have an outer snapshot. Note that it wouldn't be good enough to just push a snapshot for the duration of the expression execution: what comes back might be toasted, so we'd better have a snapshot protecting it. The test case demonstrating this fact cheats a bit by marking a SQL function immutable even though it fetches from a table. That's nothing that users haven't been seen to do, though. Per report from Jim Nasby. Back-patch to v11, like the previous fix. Discussion: https://postgr.es/m/378885e4-f85f-fc28-6c91-c4d1c080bf26@amazon.com
2021-06-21Translation updatesPeter Eisentraut
Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git Source-Git-Hash: 70796ae860c444c764bb591c885f22cac1c168ec
2021-06-10Reconsider the handling of procedure OUT parameters.Tom Lane
Commit 2453ea142 redefined pg_proc.proargtypes to include the types of OUT parameters, for procedures only. While that had some advantages for implementing the SQL-spec behavior of DROP PROCEDURE, it was pretty disastrous from a number of other perspectives. Notably, since the primary key of pg_proc is name + proargtypes, this made it possible to have multiple procedures with identical names + input arguments and differing output argument types. That would make it impossible to call any one of the procedures by writing just NULL (or "?", or any other data-type-free notation) for the output argument(s). The change also seems likely to cause grave confusion for client applications that examine pg_proc and expect the traditional definition of proargtypes. Hence, revert the definition of proargtypes to what it was, and undo a number of complications that had been added to support that. To support the SQL-spec behavior of DROP PROCEDURE, when there are no argmode markers in the command's parameter list, we perform the lookup both ways (that is, matching against both proargtypes and proallargtypes), succeeding if we get just one unique match. In principle this could result in ambiguous-function failures that would not happen when using only one of the two rules. However, overloading of procedure names is thought to be a pretty rare usage, so this shouldn't cause many problems in practice. Postgres-specific code such as pg_dump can defend against any possibility of such failures by being careful to specify argmodes for all procedure arguments. This also fixes a few other bugs in the area of CALL statements with named parameters, and improves the documentation a little. catversion bump forced because the representation of procedures with OUT arguments changes. Discussion: https://postgr.es/m/3742981.1621533210@sss.pgh.pa.us
2021-06-08Force NO SCROLL for plpgsql's implicit cursors.Tom Lane
Further thought about bug #17050 suggests that it's a good idea to use CURSOR_OPT_NO_SCROLL for the implicit cursor opened by a plpgsql FOR-over-query loop. This ensures that, if somebody commits inside the loop, PersistHoldablePortal won't try to rewind and re-read the cursor. While we'd have selected NO_SCROLL anyway if FOR UPDATE/SHARE appears in the query, there are other hazards with volatile functions; and in any case, it's silly to expend effort storing rows that we know for certain won't be needed. (While here, improve the comment in exec_run_select, which was a bit confused about the rationale for when we can use parallel mode. Cursor operations aren't a hazard for nameless portals.) This wasn't an issue until v11, which introduced the possibility of persisting such cursors. Hence, back-patch to v11. Per bug #17050 from Алексей Булгаков. Discussion: https://postgr.es/m/17050-f77aa827dc85247c@postgresql.org
2021-06-08Avoid misbehavior when persisting a non-stable cursor.Tom Lane
PersistHoldablePortal has long assumed that it should store the entire output of the query-to-be-persisted, which requires rewinding and re-reading the output. This is problematic if the query is not stable: we might get different row contents, or even a different number of rows, which'd confuse the cursor state mightily. In the case where the cursor is NO SCROLL, this is very easy to solve: just store the remaining query output, without any rewinding, and tweak the portal's cursor state to match. Aside from removing the semantic problem, this could be significantly more efficient than storing the whole output. If the cursor is scrollable, there's not much we can do, but it was already the case that scrolling a volatile query's result was pretty unsafe. We can just document more clearly that getting correct results from that is not guaranteed. There are already prohibitions in place on using SCROLL with FOR UPDATE/SHARE, which is one way for a SELECT query to have non-stable results. We could imagine prohibiting SCROLL when the query contains volatile functions, but that would be expensive to enforce. Moreover, it could break applications that work just fine, if they have functions that are in fact stable but the user neglected to mark them so. So settle for documenting the hazard. While this problem has existed in some guise for a long time, it got a lot worse in v11, which introduced the possibility of persisting plpgsql cursors (perhaps implicit ones) even when they violate the rules for what can be marked WITH HOLD. Hence, I've chosen to back-patch to v11 but not further. Per bug #17050 from Алексей Булгаков. Discussion: https://postgr.es/m/17050-f77aa827dc85247c@postgresql.org
2021-06-05Fix subtransaction test for Python 3.10Peter Eisentraut
Starting with Python 3.10, the stacktrace looks differently: - PL/Python function "subtransaction_exit_subtransaction_in_with", line 3, in <module> - s.__exit__(None, None, None) + PL/Python function "subtransaction_exit_subtransaction_in_with", line 2, in <module> + with plpy.subtransaction() as s: Using try/except specifically makes the error look always the same. (See https://github.com/python/cpython/pull/25719 for the discussion of this change in Python.) Author: Honza Horak <hhorak@redhat.com> Discussion: https://www.postgresql.org/message-id/flat/853083.1620749597%40sss.pgh.pa.us RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1959080
2021-05-22Remove plpgsql's special-case code paths for SET/RESET.Tom Lane
In the wake of 84f5c2908, it's no longer necessary for plpgsql to handle SET/RESET specially. The point of that was just to avoid taking a new transaction snapshot prematurely, which the regular code path through _SPI_execute_plan() now does just fine (in fact better, since it now does the right thing for LOCK too). Hence, rip out a few lines of code, going back to the old way of treating SET/RESET as a generic SQL command. This essentially reverts all but the test cases from b981275b6. Discussion: https://postgr.es/m/15990-eee2ac466b11293d@postgresql.org
2021-05-21Restore the portal-level snapshot after procedure COMMIT/ROLLBACK.Tom Lane
COMMIT/ROLLBACK necessarily destroys all snapshots within the session. The original implementation of intra-procedure transactions just cavalierly did that, ignoring the fact that this left us executing in a rather different environment than normal. In particular, it turns out that handling of toasted datums depends rather critically on there being an outer ActiveSnapshot: otherwise, when SPI or the core executor pop whatever snapshot they used and return, it's unsafe to dereference any toasted datums that may appear in the query result. It's possible to demonstrate "no known snapshots" and "missing chunk number N for toast value" errors as a result of this oversight. Historically this outer snapshot has been held by the Portal code, and that seems like a good plan to preserve. So add infrastructure to pquery.c to allow re-establishing the Portal-owned snapshot if it's not there anymore, and add enough bookkeeping support that we can tell whether it is or not. We can't, however, just re-establish the Portal snapshot as part of COMMIT/ROLLBACK. As in normal transaction start, acquiring the first snapshot should wait until after SET and LOCK commands. Hence, teach spi.c about doing this at the right time. (Note that this patch doesn't fix the problem for any PLs that try to run intra-procedure transactions without using SPI to execute SQL commands.) This makes SPI's no_snapshots parameter rather a misnomer, so in HEAD, rename that to allow_nonatomic. replication/logical/worker.c also needs some fixes, because it wasn't careful to hold a snapshot open around AFTER trigger execution. That code doesn't use a Portal, which I suspect someday we're gonna have to fix. But for now, just rearrange the order of operations. This includes back-patching the recent addition of finish_estate() to centralize the cleanup logic there. This also back-patches commit 2ecfeda3e into v13, to improve the test coverage for worker.c (it was that test that exposed that worker.c's snapshot management is wrong). Per bug #15990 from Andreas Wicht. Back-patch to v11 where intra-procedure COMMIT was added. Discussion: https://postgr.es/m/15990-eee2ac466b11293d@postgresql.org
2021-05-20Avoid detoasting failure after COMMIT inside a plpgsql FOR loop.Tom Lane
exec_for_query() normally tries to prefetch a few rows at a time from the query being iterated over, so as to reduce executor entry/exit overhead. Unfortunately this is unsafe if we have COMMIT or ROLLBACK within the loop, because there might be TOAST references in the data that we prefetched but haven't yet examined. Immediately after the COMMIT/ROLLBACK, we have no snapshots in the session, meaning that VACUUM is at liberty to remove recently-deleted TOAST rows. This was originally reported as a case triggering the "no known snapshots" error in init_toast_snapshot(), but even if you miss hitting that, you can get "missing toast chunk", as illustrated by the added isolation test case. To fix, just disable prefetching in non-atomic contexts. Maybe there will be performance complaints prompting us to work harder later, but it's not clear at the moment that this really costs much, and I doubt we'd want to back-patch any complicated fix. In passing, adjust that error message in init_toast_snapshot() to be a little clearer about the likely cause of the problem. Patch by me, based on earlier investigation by Konstantin Knizhnik. Per bug #15990 from Andreas Wicht. Back-patch to v11 where intra-procedure COMMIT was added. Discussion: https://postgr.es/m/15990-eee2ac466b11293d@postgresql.org
2021-05-17Translation updatesPeter Eisentraut
Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git Source-Git-Hash: 9bbd9c3714d0c76daaa806588b1fbf744aa60496
2021-05-10Translation updatesPeter Eisentraut
Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git Source-Git-Hash: 1c361d3ac016b61715d99f2055dee050397e3f13
2021-05-07Remove extraneous newlines added by perl copyright patchAndrew Dunstan
2021-05-07Add a copyright notice to perl files lacking one.Andrew Dunstan
2021-04-13Redesign the caching done by get_cached_rowtype().Tom Lane
Previously, get_cached_rowtype() cached a pointer to a reference-counted tuple descriptor from the typcache, relying on the ExprContextCallback mechanism to release the tupdesc refcount when the expression tree using the tupdesc was destroyed. This worked fine when it was designed, but the introduction of within-DO-block COMMITs broke it. The refcount is logged in a transaction-lifespan resource owner, but plpgsql won't destroy simple expressions made within the DO block (before its first commit) until the DO block is exited. That results in a warning about a leaked tupdesc refcount when the COMMIT destroys the original resource owner, and then an error about the active resource owner not holding a matching refcount when the expression is destroyed. To fix, get rid of the need to have a shutdown callback at all, by instead caching a pointer to the relevant typcache entry. Those survive for the life of the backend, so we needn't worry about the pointer becoming stale. (For registered RECORD types, we can still cache a pointer to the tupdesc, knowing that it won't change for the life of the backend.) This mechanism has been in use in plpgsql and expandedrecord.c since commit 4b93f5799, and seems to work well. This change requires modifying the ExprEvalStep structs used by the relevant expression step types, which is slightly worrisome for back-patching. However, there seems no good reason for extensions to be familiar with the details of these particular sub-structs. Per report from Rohit Bhogate. Back-patch to v11 where within-DO-block COMMITs became a thing. Discussion: https://postgr.es/m/CAAV6ZkQRCVBh8qAY+SZiHnz+U+FqAGBBDaDTjF2yiKa2nJSLKg@mail.gmail.com
2021-04-12Port regress-python3-mangle.mk to Solaris "sed".Noah Misch
It doesn't support "\(foo\)*" like a POSIX "sed" implementation does; see the Autoconf manual. Back-patch to 9.6 (all supported versions).
2021-02-02Remove extra increment of plpgsql's statement counter for FOR loops.Tom Lane
This left gaps in the internal statement numbering, which is not terribly harmful (else we'd have noticed sooner), but it's not great either. Oversight in bbd5c207b; backpatch to v12 where that came in. Pavel Stehule Discussion: https://postgr.es/m/CAFj8pRDXyQaJmpotNTQVc-t-WxdWZC35V2PnmwOaV1-taidFWA@mail.gmail.com
2021-01-26Rethink recently-added SPI interfaces.Tom Lane
SPI_execute_with_receiver and SPI_cursor_parse_open_with_paramlist are new in v14 (cf. commit 2f48ede08). Before they can get out the door, let's change their APIs to follow the practice recently established by SPI_prepare_extended etc: shove all optional arguments into a struct that callers are supposed to pre-zero. The hope is to allow future addition of more options without either API breakage or a continuing proliferation of new SPI entry points. With that in mind, choose slightly more generic names for them: SPI_execute_extended and SPI_cursor_parse_open respectively. Discussion: https://postgr.es/m/CAFj8pRCLPdDAETvR7Po7gC5y_ibkn_-bOzbeJb39WHms01194Q@mail.gmail.com
2021-01-26Suppress compiler warnings from commit ee895a655.Tom Lane
For obscure reasons, some buildfarm members are now generating complaints about plpgsql_call_handler's "retval" variable possibly being used uninitialized. It seems no less safe than it was before that commit, but these complaints are (mostly?) new. I trust that initializing the variable where it's declared will be enough to shut that up. I also notice that some compilers are warning about setjmp clobber of the same variable, which is maybe a bit more defensible. Mark it volatile to silence that. Also, rearrange the logic to give procedure_resowner a single point of initialization, in hopes of silencing some setjmp-clobber warnings about that. (Marking it volatile would serve too, but its sibling variables are depending on single assignment, so let's stick with that method.) Discussion: https://postgr.es/m/E1l4F1z-0000cN-Lx@gemulon.postgresql.org
2021-01-25Improve performance of repeated CALLs within plpgsql procedures.Tom Lane
This patch essentially is cleaning up technical debt left behind by the original implementation of plpgsql procedures, particularly commit d92bc83c4. That patch (or more precisely, follow-on patches fixing its worst bugs) forced us to re-plan CALL and DO statements each time through, if we're in a non-atomic context. That wasn't for any fundamental reason, but just because use of a saved plan requires having a ResourceOwner to hold a reference count for the plan, and we had no suitable resowner at hand, nor would the available APIs support using one if we did. While it's not that expensive to create a "plan" for CALL/DO, the cycles do add up in repeated executions. This patch therefore makes the following API changes: * GetCachedPlan/ReleaseCachedPlan are modified to let the caller specify which resowner to use to pin the plan, rather than forcing use of CurrentResourceOwner. * spi.c gains a "SPI_execute_plan_extended" entry point that lets callers say which resowner to use to pin the plan. This borrows the idea of an options struct from the recently added SPI_prepare_extended, hopefully allowing future options to be added without more API breaks. This supersedes SPI_execute_plan_with_paramlist (which I've marked deprecated) as well as SPI_execute_plan_with_receiver (which is new in v14, so I just took it out altogether). * I also took the opportunity to remove the crude hack of letting plpgsql reach into SPI private data structures to mark SPI plans as "no_snapshot". It's better to treat that as an option of SPI_prepare_extended. Now, when running a non-atomic procedure or DO block that contains any CALL or DO commands, plpgsql creates a ResourceOwner that will be used to pin the plans of the CALL/DO commands. (In an atomic context, we just use CurrentResourceOwner, as before.) Having done this, we can just save CALL/DO plans normally, whether or not they are used across transaction boundaries. This seems to be good for something like 2X speedup of a CALL of a trivial procedure with a few simple argument expressions. By restricting the creation of an extra ResourceOwner like this, there's essentially zero penalty in cases that can't benefit. Pavel Stehule, with some further hacking by me Discussion: https://postgr.es/m/CAFj8pRCLPdDAETvR7Po7gC5y_ibkn_-bOzbeJb39WHms01194Q@mail.gmail.com
2021-01-08Fix plpgsql tests for debug_invalidate_system_caches_always.Tom Lane
Commit c9d529848 resulted in having a couple more places where the error context stack for a failure varies depending on debug_invalidate_system_caches_always (nee CLOBBER_CACHE_ALWAYS). This is not very surprising, since we have to re-parse cached plans if the plan cache is clobbered. Stabilize the expected test output by hiding the context stack in these places, as we've done elsewhere in this test script. (Another idea worth considering, now that we have debug_invalidate_system_caches_always, is to force it to zero for these test cases. That seems like it'd risk reducing the coverage of cache-clobber testing, which might or might not be worth being able to verify that we get the expected error output in normal cases. For the moment I just stuck with the existing technique.) In passing, update comments that referred to CLOBBER_CACHE_ALWAYS. Per buildfarm member hyrax.
2021-01-04Rethink the "read/write parameter" mechanism in pl/pgsql.Tom Lane
Performance issues with the preceding patch to re-implement array element assignment within pl/pgsql led me to realize that the read/write parameter mechanism is misdesigned. Instead of requiring the assignment source expression to be such that *all* its references to the target variable could be passed as R/W, we really want to identify *one* reference to the target variable to be passed as R/W, allowing any other ones to be passed read/only as they would be by default. As long as the R/W reference is a direct argument to the top-level (hence last to be executed) function in the expression, there is no harm in R/O references being passed to other lower parts of the expression. Nor is there any use-case for more than one argument of the top-level function being R/W. Hence, rewrite that logic to identify one single Param that references the target variable, and make only that Param pass a read/write reference, not any other Params referencing the target variable. Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
2021-01-04Remove PLPGSQL_DTYPE_ARRAYELEM datum type within pl/pgsql.Tom Lane
In the wake of the previous commit, we don't really need this anymore, since array assignment is primarily handled by the core code. The only way that that code could still be reached is that a GET DIAGNOSTICS target variable could be an array element. But that doesn't seem like a particularly essential feature. I'd added it in commit 55caaaeba, but just because it was easy not because anyone had actually asked for it. Hence, revert that patch and then remove the now-unreachable stuff. (If we really had to, we could probably reimplement GET DIAGNOSTICS using the new assignment machinery; but the cost/benefit ratio looks very poor, and it'd likely be a bit slower.) Note that PLPGSQL_DTYPE_RECFIELD remains. It's possible that we could get rid of that too, but maintaining the existing behaviors for RECORD-type variables seems like it might be difficult. Since there's not any functional limitation in those code paths as there was in the ARRAYELEM code, I've not pursued the idea. Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
2021-01-04Re-implement pl/pgsql's expression and assignment parsing.Tom Lane
Invent new RawParseModes that allow the core grammar to handle pl/pgsql expressions and assignments directly, and thereby get rid of a lot of hackery in pl/pgsql's parser. This moves a good deal of knowledge about pl/pgsql into the core code: notably, we have to invent a CoercionContext that matches pl/pgsql's (rather dubious) historical behavior for assignment coercions. That's getting away from the original idea of pl/pgsql as an arm's-length extension of the core, but really we crossed that bridge a long time ago. The main advantage of doing this is that we can now use the core parser to generate FieldStore and/or SubscriptingRef nodes to handle assignments to pl/pgsql variables that are records or arrays. That fixes a number of cases that had never been implemented in pl/pgsql assignment, such as nested records and array slicing, and it allows pl/pgsql assignment to support the datatype-specific subscripting behaviors introduced in commit c7aba7c14. There are cosmetic benefits too: when a syntax error occurs in a pl/pgsql expression, the error report no longer includes the confusing "SELECT" keyword that used to get prefixed to the expression text. Also, there seem to be some small speed gains. Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
2021-01-04Add the ability for the core grammar to have more than one parse target.Tom Lane
This patch essentially allows gram.y to implement a family of related syntax trees, rather than necessarily always parsing a list of SQL statements. raw_parser() gains a new argument, enum RawParseMode, to say what to do. As proof of concept, add a mode that just parses a TypeName without any other decoration, and use that to greatly simplify typeStringToTypeName(). In addition, invent a new SPI entry point SPI_prepare_extended() to allow SPI users (particularly plpgsql) to get at this new functionality. In hopes of making this the last variant of SPI_prepare(), set up its additional arguments as a struct rather than direct arguments, and promise that future additions to the struct can default to zero. SPI_prepare_cursor() and SPI_prepare_params() can perhaps go away at some point. Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
2021-01-02Update copyright for 2021Bruce Momjian
Backpatch-through: 9.5
2020-12-28Further fix thinko in plpgsql memory leak fix.Tom Lane
There's a second call of get_eval_mcontext() that should also be get_stmt_mcontext(). This is actually dead code, since no interesting allocations happen before switching back to the original context, but we should keep it in sync with the other call to forestall possible future bugs. Discussion: https://postgr.es/m/f075f7be-c654-9aa8-3ffc-e9214622f02a@enterprisedb.com
2020-12-28Fix thinko in plpgsql memory leak fix.Tom Lane
Commit a6b1f5365 intended to place the transient "target" list of a CALL statement in the function's statement-lifespan context, but I fat-fingered that and used get_eval_mcontext() instead of get_stmt_mcontext(). The eval_mcontext belongs to the "simple expression" infrastructure, which is destroyed at transaction end. The net effect is that a CALL in a procedure to another procedure that has OUT or INOUT parameters would fail if the called procedure did a COMMIT. Per report from Peter Eisentraut. Back-patch to v11, like the prior patch. Discussion: https://postgr.es/m/f075f7be-c654-9aa8-3ffc-e9214622f02a@enterprisedb.com
2020-12-20Multirange datatypesAlexander Korotkov
Multiranges are basically sorted arrays of non-overlapping ranges with set-theoretic operations defined over them. Since v14, each range type automatically gets a corresponding multirange datatype. There are both manual and automatic mechanisms for naming multirange types. Once can specify multirange type name using multirange_type_name attribute in CREATE TYPE.  Otherwise, a multirange type name is generated automatically. If the range type name contains "range" then we change that to "multirange". Otherwise, we add "_multirange" to the end. Implementation of multiranges comes with a space-efficient internal representation format, which evades extra paddings and duplicated storage of oids.  Altogether this format allows fetching a particular range by its index in O(n). Statistic gathering and selectivity estimation are implemented for multiranges. For this purpose, stored multirange is approximated as union range without gaps. This field will likely need improvements in the future. Catversion is bumped. Discussion: https://postgr.es/m/CALNJ-vSUpQ_Y%3DjXvTxt1VYFztaBSsWVXeF1y6gTYQ4bOiWDLgQ%40mail.gmail.com Discussion: https://postgr.es/m/a0b8026459d1e6167933be2104a6174e7d40d0ab.camel%40j-davis.com#fe7218c83b08068bfffb0c5293eceda0 Author: Paul Jungwirth, revised by me Reviewed-by: David Fetter, Corey Huinker, Jeff Davis, Pavel Stehule Reviewed-by: Alvaro Herrera, Tom Lane, Isaac Morland, David G. Johnston Reviewed-by: Zhihong Yu, Alexander Korotkov
2020-12-15Improve hash_create()'s API for some added robustness.Tom Lane
Invent a new flag bit HASH_STRINGS to specify C-string hashing, which was formerly the default; and add assertions insisting that exactly one of the bits HASH_STRINGS, HASH_BLOBS, and HASH_FUNCTION be set. This is in hopes of preventing recurrences of the type of oversight fixed in commit a1b8aa1e4 (i.e., mistakenly omitting HASH_BLOBS). Also, when HASH_STRINGS is specified, insist that the keysize be more than 8 bytes. This is a heuristic, but it should catch accidental use of HASH_STRINGS for integer or pointer keys. (Nearly all existing use-cases set the keysize to NAMEDATALEN or more, so there's little reason to think this restriction should be problematic.) Tweak hash_create() to insist that the HASH_ELEM flag be set, and remove the defaults it had for keysize and entrysize. Since those defaults were undocumented and basically useless, no callers omitted HASH_ELEM anyway. Also, remove memset's zeroing the HASHCTL parameter struct from those callers that had one. This has never been really necessary, and while it wasn't a bad coding convention it was confusing that some callers did it and some did not. We might as well save a few cycles by standardizing on "not". Also improve the documentation for hash_create(). In passing, improve reinit.c's usage of a hash table by storing the key as a binary Oid rather than a string; and, since that's a temporary hash table, allocate it in CurrentMemoryContext for neatness. Discussion: https://postgr.es/m/590625.1607878171@sss.pgh.pa.us
2020-12-09Support subscripting of arbitrary types, not only arrays.Tom Lane
This patch generalizes the subscripting infrastructure so that any data type can be subscripted, if it provides a handler function to define what that means. Traditional variable-length (varlena) arrays all use array_subscript_handler(), while the existing fixed-length types that support subscripting use raw_array_subscript_handler(). It's expected that other types that want to use subscripting notation will define their own handlers. (This patch provides no such new features, though; it only lays the foundation for them.) To do this, move the parser's semantic processing of subscripts (including coercion to whatever data type is required) into a method callback supplied by the handler. On the execution side, replace the ExecEvalSubscriptingRef* layer of functions with direct calls to callback-supplied execution routines. (Thus, essentially no new run-time overhead should be caused by this patch. Indeed, there is room to remove some overhead by supplying specialized execution routines. This patch does a little bit in that line, but more could be done.) Additional work is required here and there to remove formerly hard-wired assumptions about the result type, collation, etc of a SubscriptingRef expression node; and to remove assumptions that the subscript values must be integers. One useful side-effect of this is that we now have a less squishy mechanism for identifying whether a data type is a "true" array: instead of wiring in weird rules about typlen, we can look to see if pg_type.typsubscript == F_ARRAY_SUBSCRIPT_HANDLER. For this to be bulletproof, we have to forbid user-defined types from using that handler directly; but there seems no good reason for them to do so. This patch also removes assumptions that the number of subscripts is limited to MAXDIM (6), or indeed has any hard-wired limit. That limit still applies to types handled by array_subscript_handler or raw_array_subscript_handler, but to discourage other dependencies on this constant, I've moved it from c.h to utils/array.h. Dmitry Dolgov, reviewed at various times by Tom Lane, Arthur Zakirov, Peter Eisentraut, Pavel Stehule Discussion: https://postgr.es/m/CA+q6zcVDuGBv=M0FqBYX8DPebS3F_0KQ6OVFobGJPM507_SZ_w@mail.gmail.com Discussion: https://postgr.es/m/CA+q6zcVovR+XY4mfk-7oNk-rF91gH0PebnNfuUjuuDsyHjOcVA@mail.gmail.com
2020-10-29Don't use custom OID symbols in pg_type.dat, either.Tom Lane
On the same reasoning as in commit 36b931214, forbid using custom oid_symbol macros in pg_type as well as pg_proc, so that we always rely on the predictable macro names generated by genbki.pl. We do continue to grant grandfather status to the names CASHOID and LSNOID, although those are now considered deprecated aliases for the preferred names MONEYOID and PG_LSNOID. This is because there's likely to be client-side code using the old names, and this bout of neatnik-ism doesn't quite seem worth breaking client code. There might be a case for grandfathering EVTTRIGGEROID, too, since externally-maintained PLs may reference that symbol. But renaming such references to EVENT_TRIGGEROID doesn't seem like a particularly heavy lift --- we make far more significant backend API changes in every major release. For now I didn't add that, but we could reconsider if there's pushback. The other names changed here seem pretty unlikely to have any outside uses. Again, we could add alias macros if there are complaints, but for now I didn't. As before, no need for a catversion bump. John Naylor Discussion: https://postgr.es/m/CAFBsxsHpCbjfoddNGpnnnY5pHwckWfiYkMYSF74PmP1su0+ZOw@mail.gmail.com
2020-10-15Fixup some appendStringInfo and appendPQExpBuffer callsDavid Rowley
A number of places were using appendStringInfo() when they could have been using appendStringInfoString() instead. While there's no functionality change there, it's just more efficient to use appendStringInfoString() when no formatting is required. Likewise for some appendStringInfoString() calls which were just appending a single char. We can just use appendStringInfoChar() for that. Additionally, many places were using appendPQExpBuffer() when they could have used appendPQExpBufferStr(). Change those too. Patch by Zhijie Hou, but further searching by me found significantly more places that deserved the same treatment. Author: Zhijie Hou, David Rowley Discussion: https://postgr.es/m/cb172cf4361e4c7ba7167429070979d4@G08CNEXMBPEKD05.g08.fujitsu.local
2020-10-09plperl.h should #undef fstat along with stat and lstat.Tom Lane
Needed now that commit bed90759f caused win32_port.h to provide a #define for that too. Per buildfarm.
2020-10-05Support for OUT parameters in proceduresPeter Eisentraut
Unlike for functions, OUT parameters for procedures are part of the signature. Therefore, they have to be listed in pg_proc.proargtypes as well as mentioned in ALTER PROCEDURE and DROP PROCEDURE. Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com> Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/2b8490fe-51af-e671-c504-47359dc453c5@2ndquadrant.com
2020-10-02Tidy up error reporting when converting PL/Python arrays.Heikki Linnakangas
Use PLy_elog() only when a call to a Python C API function failed, and ereport() for other errors. Add an error code to the "wrong length of inner sequence" ereport(). Reviewed-by: Daniel Gustafsson Discussion: https://www.postgresql.org/message-id/B8B72889-D6D7-48FF-B782-D670A6CA4D37%40yesql.se
2020-10-01Fix incorrect assertion on number of array dimensions.Heikki Linnakangas
This has been wrong ever since the support for multi-dimensional arrays as PL/python function arguments and return values was introduced in commit 94aceed317. Backpatch-through: 10 Discussion: https://www.postgresql.org/message-id/61647b8e-961c-0362-d5d3-c8a18f4a7ec6%40iki.fi
2020-09-29Fix memory leak in plpgsql's CALL processing.Tom Lane
When executing a CALL or DO in a non-atomic context (i.e., not inside a function or query), plpgsql creates a new plan each time through, as a rather hacky solution to some resource management issues. But it failed to free this plan until exit of the current procedure or DO block, resulting in serious memory bloat in procedures that called other procedures many times. Fix by remembering to free the plan, and by being more honest about restoring the previous state (otherwise, recursive procedure calls have a problem). There was also a smaller leak associated with recalculation of the "target" list of output variables. Fix that by using the statement- lifespan context to hold non-permanent values. Back-patch to v11 where procedures were introduced. Pavel Stehule and Tom Lane Discussion: https://postgr.es/m/CAFj8pRDiiU1dqym+_P4_GuTWm76knJu7z9opWayBJTC0nQGUUA@mail.gmail.com
2020-09-21Fix a few more generator scripts to produce pgindent-clean output.Tom Lane
This completes the project of making all our derived files be pgindent-clean (or else explicitly excluded from indentation), so that no surprises result when running pgindent in a built-out development tree. Discussion: https://postgr.es/m/79ed5348-be7a-b647-dd40-742207186a22@2ndquadrant.com
2020-09-21Standardize order of use strict and use warnings in Perl codePeter Eisentraut
The standard order in PostgreSQL and other code is use strict first, but some code was uselessly inconsistent about this.
2020-09-16Improve formatting of create_help.pl and plperl_opmask.pl output.Tom Lane
Adjust the whitespace in the emitted files so that it matches what pgindent would do. This makes the generated files look like they match project style, and avoids confusion if someone does run pgindent on the generated files. Also, add probes.h to pgindent's exclusion list, because it can confuse pgindent, plus there's not much point in processing it. Daniel Gustafsson, additional fixes by me Discussion: https://postgr.es/m/79ed5348-be7a-b647-dd40-742207186a22@2ndquadrant.com
2020-09-02Remove unused parameterPeter Eisentraut
unused since 39bd3fd1db6f3aa3764d4a1bebcd71c4e9c00281 Discussion: https://www.postgresql.org/message-id/flat/511bb100-f829-ba21-2f10-9f952ec06ead%402ndquadrant.com