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2018-12-14Make pg_statistic and related code account more honestly for collations.Tom Lane
When we first put in collations support, we basically punted on teaching pg_statistic, ANALYZE, and the planner selectivity functions about that. They've just used DEFAULT_COLLATION_OID independently of the actual collation of the data. It's time to improve that, so: * Add columns to pg_statistic that record the specific collation associated with each statistics slot. * Teach ANALYZE to use the column's actual collation when comparing values for statistical purposes, and record this in the appropriate slot. (Note that type-specific typanalyze functions are now expected to fill stats->stacoll with the appropriate collation, too.) * Teach assorted selectivity functions to use the actual collation of the stats they are looking at, instead of just assuming it's DEFAULT_COLLATION_OID. This should give noticeably better results in selectivity estimates for columns with nondefault collations, at least for query clauses that use that same collation (which would be the default behavior in most cases). It's still true that comparisons with explicit COLLATE clauses different from the stored data's collation won't be well-estimated, but that's no worse than before. Also, this patch does make the first step towards doing better with that, which is that it's now theoretically possible to collect stats for a collation other than the column's own collation. Patch by me; thanks to Peter Eisentraut for review. Discussion: https://postgr.es/m/14706.1544630227@sss.pgh.pa.us
2018-12-12Tweak pg_partition_tree for undefined relations and unsupported relkindsMichael Paquier
This fixes a crash which happened when calling the function directly with a relation OID referring to a non-existing object, and changes the behavior so as NULL is returned for unsupported relkinds instead of generating an error. This puts the new function in line with many other system functions, and eases actions like full scans of pg_class. Author: Michael Paquier Reviewed-by: Amit Langote, Stephen Frost Discussion: https://postgr.es/m/20181207010406.GO2407@paquier.xyz
2018-12-07Fix some errhint and errdetail strings missing a periodMichael Paquier
As per the error message style guide of the documentation, those should be full sentences. Author: Daniel Gustafsson Reviewed-by: Michael Paquier, Álvaro Herrera Discussion: https://1E8D49B4-16BC-4420-B4ED-58501D9E076B@yesql.se
2018-11-23Fix float-to-integer coercions to handle edge cases correctly.Tom Lane
ftoi4 and its sibling coercion functions did their overflow checks in a way that looked superficially plausible, but actually depended on an assumption that the MIN and MAX comparison constants can be represented exactly in the float4 or float8 domain. That fails in ftoi4, ftoi8, and dtoi8, resulting in a possibility that values near the MAX limit will be wrongly converted (to negative values) when they need to be rejected. Also, because we compared before rounding off the fractional part, the other three functions threw errors for values that really ought to get rounded to the min or max integer value. Fix by doing rint() first (requiring an assumption that it handles NaN and Inf correctly; but dtoi8 and ftoi8 were assuming that already), and by comparing to values that should coerce to float exactly, namely INTxx_MIN and -INTxx_MIN. Also remove some random cosmetic discrepancies between these six functions. Per bug #15519 from Victor Petrovykh. This should get back-patched, but first let's see what the buildfarm thinks of it --- I'm not too sure about portability of some of the regression test cases. Patch by me; thanks to Andrew Gierth for analysis and discussion. Discussion: https://postgr.es/m/15519-4fc785b483201ff1@postgresql.org
2018-11-23Clamp semijoin selectivity to be not more than inner-join selectivity.Tom Lane
We should never estimate the output of a semijoin to be more rows than we estimate for an inner join with the same input rels and join condition; it's obviously impossible for that to happen. However, given the relatively poor quality of our semijoin selectivity estimates --- particularly, but not only, in cases where we punt and return a default estimate --- we did often deliver such estimates. To improve matters, calculate both estimates inside eqjoinsel() and take the smaller one. The bulk of this patch is just mechanical refactoring to avoid repetitive information lookup when we call both eqjoinsel_semi and eqjoinsel_inner. The actual new behavior is just selec = Min(selec, inner_rel->rows * selec_inner); which looks a bit odd but is correct because of our different definitions for inner and semi join selectivity. There is one ensuing plan change in the regression tests, but it looks reasonable enough (and checking the actual row counts shows that the estimate moved closer to reality, not further away). Per bug #15160 from Alexey Ermakov. Although this is arguably a bug fix, I won't risk destabilizing plan choices in stable branches by back-patching. Tom Lane, reviewed by Melanie Plageman Discussion: https://postgr.es/m/152395805004.19366.3107109716821067806@wrigleys.postgresql.org
2018-11-23Add WL_EXIT_ON_PM_DEATH pseudo-event.Thomas Munro
Users of the WaitEventSet and WaitLatch() APIs can now choose between asking for WL_POSTMASTER_DEATH and then handling it explicitly, or asking for WL_EXIT_ON_PM_DEATH to trigger immediate exit on postmaster death. This reduces code duplication, since almost all callers want the latter. Repair all code that was previously ignoring postmaster death completely, or requesting the event but ignoring it, or requesting the event but then doing an unconditional PostmasterIsAlive() call every time through its event loop (which is an expensive syscall on platforms for which we don't have USE_POSTMASTER_DEATH_SIGNAL support). Assert that callers of WaitLatchXXX() under the postmaster remember to ask for either WL_POSTMASTER_DEATH or WL_EXIT_ON_PM_DEATH, to prevent future bugs. The only process that doesn't handle postmaster death is syslogger. It waits until all backends holding the write end of the syslog pipe (including the postmaster) have closed it by exiting, to be sure to capture any parting messages. By using the WaitEventSet API directly it avoids the new assertion, and as a by-product it may be slightly more efficient on platforms that have epoll(). Author: Thomas Munro Reviewed-by: Kyotaro Horiguchi, Heikki Linnakangas, Tom Lane Discussion: https://postgr.es/m/CAEepm%3D1TCviRykkUb69ppWLr_V697rzd1j3eZsRMmbXvETfqbQ%40mail.gmail.com, https://postgr.es/m/CAEepm=2LqHzizbe7muD7-2yHUbTOoF7Q+qkSD5Q41kuhttRTwA@mail.gmail.com
2018-11-22Fix another crash in json{b}_populate_recordset and json{b}_to_recordset.Tom Lane
populate_recordset_worker() failed to consider the possibility that the supplied JSON data contains no rows, so that update_cached_tupdesc never got called. This led to a null-pointer dereference since commit 9a5e8ed28; before that it led to a bogus "set-valued function called in context that cannot accept a set" error. Fix by forcing the update to happen. Per bug #15514. Back-patch to v11 as 9a5e8ed28 was. (If we were excited about the bogus error, we could perhaps go back further, but it'd take more work to figure out how to fix it in older branches. Given the lack of field complaints about that aspect, I'm not excited.) Discussion: https://postgr.es/m/15514-59d5b4c4065b178b@postgresql.org
2018-11-20Remove WITH OIDS support, change oid catalog column visibility.Andres Freund
Previously tables declared WITH OIDS, including a significant fraction of the catalog tables, stored the oid column not as a normal column, but as part of the tuple header. This special column was not shown by default, which was somewhat odd, as it's often (consider e.g. pg_class.oid) one of the more important parts of a row. Neither pg_dump nor COPY included the contents of the oid column by default. The fact that the oid column was not an ordinary column necessitated a significant amount of special case code to support oid columns. That already was painful for the existing, but upcoming work aiming to make table storage pluggable, would have required expanding and duplicating that "specialness" significantly. WITH OIDS has been deprecated since 2005 (commit ff02d0a05280e0). Remove it. Removing includes: - CREATE TABLE and ALTER TABLE syntax for declaring the table to be WITH OIDS has been removed (WITH (oids[ = true]) will error out) - pg_dump does not support dumping tables declared WITH OIDS and will issue a warning when dumping one (and ignore the oid column). - restoring an pg_dump archive with pg_restore will warn when restoring a table with oid contents (and ignore the oid column) - COPY will refuse to load binary dump that includes oids. - pg_upgrade will error out when encountering tables declared WITH OIDS, they have to be altered to remove the oid column first. - Functionality to access the oid of the last inserted row (like plpgsql's RESULT_OID, spi's SPI_lastoid, ...) has been removed. The syntax for declaring a table WITHOUT OIDS (or WITH (oids = false) for CREATE TABLE) is still supported. While that requires a bit of support code, it seems unnecessary to break applications / dumps that do not use oids, and are explicit about not using them. The biggest user of WITH OID columns was postgres' catalog. This commit changes all 'magic' oid columns to be columns that are normally declared and stored. To reduce unnecessary query breakage all the newly added columns are still named 'oid', even if a table's column naming scheme would indicate 'reloid' or such. This obviously requires adapting a lot code, mostly replacing oid access via HeapTupleGetOid() with access to the underlying Form_pg_*->oid column. The bootstrap process now assigns oids for all oid columns in genbki.pl that do not have an explicit value (starting at the largest oid previously used), only oids assigned later by oids will be above FirstBootstrapObjectId. As the oid column now is a normal column the special bootstrap syntax for oids has been removed. Oids are not automatically assigned during insertion anymore, all backend code explicitly assigns oids with GetNewOidWithIndex(). For the rare case that insertions into the catalog via SQL are called for the new pg_nextoid() function can be used (which only works on catalog tables). The fact that oid columns on system tables are now normal columns means that they will be included in the set of columns expanded by * (i.e. SELECT * FROM pg_class will now include the table's oid, previously it did not). It'd not technically be hard to hide oid column by default, but that'd mean confusing behavior would either have to be carried forward forever, or it'd cause breakage down the line. While it's not unlikely that further adjustments are needed, the scope/invasiveness of the patch makes it worthwhile to get merge this now. It's painful to maintain externally, too complicated to commit after the code code freeze, and a dependency of a number of other patches. Catversion bump, for obvious reasons. Author: Andres Freund, with contributions by John Naylor Discussion: https://postgr.es/m/20180930034810.ywp2c7awz7opzcfr@alap3.anarazel.de
2018-11-15Introduce notion of different types of slots (without implementing them).Andres Freund
Upcoming work intends to allow pluggable ways to introduce new ways of storing table data. Accessing those table access methods from the executor requires TupleTableSlots to be carry tuples in the native format of such storage methods; otherwise there'll be a significant conversion overhead. Different access methods will require different data to store tuples efficiently (just like virtual, minimal, heap already require fields in TupleTableSlot). To allow that without requiring additional pointer indirections, we want to have different structs (embedding TupleTableSlot) for different types of slots. Thus different types of slots are needed, which requires adapting creators of slots. The slot that most efficiently can represent a type of tuple in an executor node will often depend on the type of slot a child node uses. Therefore we need to track the type of slot is returned by nodes, so parent slots can create slots based on that. Relatedly, JIT compilation of tuple deforming needs to know which type of slot a certain expression refers to, so it can create an appropriate deforming function for the type of tuple in the slot. But not all nodes will only return one type of slot, e.g. an append node will potentially return different types of slots for each of its subplans. Therefore add function that allows to query the type of a node's result slot, and whether it'll always be the same type (whether it's fixed). This can be queried using ExecGetResultSlotOps(). The scan, result, inner, outer type of slots are automatically inferred from ExecInitScanTupleSlot(), ExecInitResultSlot(), left/right subtrees respectively. If that's not correct for a node, that can be overwritten using new fields in PlanState. This commit does not introduce the actually abstracted implementation of different kind of TupleTableSlots, that will be left for a followup commit. The different types of slots introduced will, for now, still use the same backing implementation. While this already partially invalidates the big comment in tuptable.h, it seems to make more sense to update it later, when the different TupleTableSlot implementations actually exist. Author: Ashutosh Bapat and Andres Freund, with changes by Amit Khandekar Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de
2018-11-15geo_ops.c: Clarify comments and function argumentsAlvaro Herrera
These functions were not crystal clear about what their respective APIs are. Make an effort to improve that. Emre's patch was correct AFAICT, but I (Álvaro) felt the need to improve a few comments a bit more. Any resulting errors are my own. Per complaint from Coverity, Ning Yu, and Tom Lane. Author: Emre Hasegeli, Álvaro Herrera Reviewed-by: Tomas Vondra, Álvaro Herrera Discussion: https://postgr.es/m/26769.1533090136@sss.pgh.pa.us
2018-11-14Add a timezone-specific variant of date_trunc().Tom Lane
date_trunc(field, timestamptz, zone_name) performs truncation using the named time zone as reference, rather than working in the session time zone as is the default behavior. It's equivalent to date_trunc(field, timestamptz at time zone zone_name) at time zone zone_name but it's faster, easier to type, and arguably easier to understand. Vik Fearing and Tom Lane Discussion: https://postgr.es/m/6249ffc4-2b22-4c1b-4e7d-7af84fedd7c6@2ndquadrant.com
2018-11-10Apply RI trigger skipping tests also for DELETEPeter Eisentraut
The tests added in cfa0f4255bb0f5550d37a01c4d8fe2966d20040c to skip firing an RI trigger if any old key value is NULL can also be applied for DELETE. This should give a performance gain in those cases, and it also saves a lot of duplicate code in the actual RI triggers. (That code was already dead code for the UPDATE cases.) Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
2018-11-10Remove dead foreign key optimization codePeter Eisentraut
The ri_KeysEqual() calls in the foreign-key trigger functions to optimize away some updates are useless because since adfeef55cbcc5dc72a772777f88c1be05a70dfee those triggers are not enqueued at all. (It's also not useful to keep these checks as some kind of backstop, since it's also semantically correct to just run the full check even with equal keys.) Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
2018-11-02Fix spelling errors and typos in commentsMagnus Hagander
Author: Daniel Gustafsson <daniel@yesql.se>
2018-10-30Add pg_partition_tree to display information about partitionsMichael Paquier
This new function is useful to display a full tree of partitions with a partitioned table given in output, and avoids the need of any complex WITH RECURSIVE query when looking at partition trees which are deep multiple levels. It returns a set of records, one for each partition, containing the partition's name, its immediate parent's name, a boolean value telling if the relation is a leaf in the tree and an integer telling its level in the partition tree with given table considered as root, beginning at zero for the root, and incrementing by one each time the scan goes one level down. Author: Amit Langote Reviewed-by: Jesper Pedersen, Michael Paquier, Robert Haas Discussion: https://postgr.es/m/8d00e51a-9a51-ad02-d53e-ba6bf50b2e52@lab.ntt.co.jp
2018-10-25Apply unconstify() in more placesPeter Eisentraut
Discussion: https://www.postgresql.org/message-id/08adbe4e-38f8-2c73-55f0-591392371687%402ndquadrant.com
2018-10-19Add missing quote_identifier calls for CREATE TRIGGER ... REFERENCING.Tom Lane
Mixed-case names for transition tables weren't dumped correctly. Oversight in commit 8c48375e5, per bug #15440 from Karl Czajkowski. In passing, I couldn't resist a bit of code beautification. Back-patch to v10 where this was introduced. Discussion: https://postgr.es/m/15440-02d1468e94d63d76@postgresql.org
2018-10-17Const-ify a few more large static tables.Tom Lane
Per research by Andres. Discussion: https://postgr.es/m/20181015200754.7y7zfuzsoux2c4ya@alap3.anarazel.de
2018-10-16Be smarter about age-counter overflow in formatting.c caches.Tom Lane
The previous code here simply threw away whatever it knew about cache entry ages whenever a counter overflow occurred. Since the counter is int width and will be bumped once per format function execution, overflows are not really so rare as to not be worth thinking about. Instead, let's deal with the situation by halving all the age values, essentially rescaling the age metric. In that way, we retain a pretty accurate (if not quite perfect) idea of which entries are oldest.
2018-10-16Avoid statically allocating formatting.c's format string caches.Tom Lane
This eliminates circa 120KB of static data from Postgres' memory footprint. In some usage patterns that space will get allocated anyway, but in many processes it never will be allocated. We can improve matters further by allocating only as many cache entries as we actually use, rather than allocating the whole array on first use. However, to avoid wasting lots of space due to palloc's habit of rounding requests up to power-of-2 sizes, tweak the maximum cacheable format string length to make the struct sizes be powers of 2 or just less. The sizes I chose make the maximums a little bit less than they were before, but I doubt it matters much. While at it, rearrange struct FormatNode to avoid wasting quite so much padding space. This change actually halves the size of that struct on 64-bit machines. Discussion: https://postgr.es/m/20181015200754.7y7zfuzsoux2c4ya@alap3.anarazel.de
2018-10-16Correct constness of system attributes in heap.c & prerequisites.Andres Freund
This allows the compiler / linker to mark affected pages as read-only. There's a fair number of pre-requisite changes, to allow the const properly be propagated. Most of consts were already required for correctness anyway, just not represented on the type-level. Arguably we could be more aggressive in using consts in related code, but.. This requires using a few of the types underlying typedefs that removes pointers (e.g. const NameData *) as declaring the typedefed type constant doesn't have the same meaning (it makes the variable const, not what it points to). Discussion: https://postgr.es/m/20181015200754.7y7zfuzsoux2c4ya@alap3.anarazel.de
2018-10-16Avoid statically allocating gmtsub()'s timezone workspace.Tom Lane
localtime.c's "struct state" is a rather large object, ~23KB. We were statically allocating one for gmtsub() to use to represent the GMT timezone, even though that function is not at all heavily used and is never reached in most backends. Let's malloc it on-demand, instead. This does pose the question of how to handle a malloc failure, but there's already a well-defined error report convention here, ie set errno and return NULL. We have but one caller of pg_gmtime in HEAD, and two in back branches, neither of which were troubling to check for error. Make them do so. The possible errors are sufficiently unlikely (out-of-range timestamp, and now malloc failure) that I think elog() is adequate. Back-patch to all supported branches to keep our copies of the IANA timezone code in sync. This particular change is in a stanza that already differs from upstream, so it's a wash for maintenance purposes --- but only as long as we keep the branches the same. Discussion: https://postgr.es/m/20181015200754.7y7zfuzsoux2c4ya@alap3.anarazel.de
2018-10-15Correct constness of a few variables.Andres Freund
This allows the compiler / linker to mark affected pages as read-only. There's other cases, but they're a bit more invasive, and should go through some review. These are easy. They were found with objdump -j .data -t src/backend/postgres|awk '{print $4, $5, $6}'|sort -r|less Discussion: https://postgr.es/m/20181015200754.7y7zfuzsoux2c4ya@alap3.anarazel.de
2018-10-11Remove deprecated abstime, reltime, tinterval datatypes.Andres Freund
These types have been deprecated for a *long* time. Catversion bump, for obvious reasons. Author: Andres Freund Discussion: https://postgr.es/m/20181009192237.34wjp3nmw7oynmmr@alap3.anarazel.de https://postgr.es/m/20171213080506.cwjkpcz3bkk6yz2u@alap3.anarazel.de https://postgr.es/m/25615.1513115237@sss.pgh.pa.us
2018-10-11Move timeofday() implementation out of nabstime.c.Andres Freund
nabstime.c is about to be removed, but timeofday() isn't related to the rest of the functionality therein, and some find it useful. Move to timestamp.c. Discussion: https://postgr.es/m/20181009192237.34wjp3nmw7oynmmr@alap3.anarazel.de https://postgr.es/m/20180928223240.kgwc4czzzekrpsid%40alap3.anarazel.de
2018-10-09Add pg_ls_archive_statusdir functionMichael Paquier
This function lists the contents of the WAL archive status directory, and is intended to be used by monitoring tools. Unlike pg_ls_dir(), access to it can be granted to non-superusers so that those monitoring tools can observe the principle of least privilege. Access is also given by default to members of pg_monitor. Author: Christoph Moench-Tegeder Reviewed-by: Aya Iwata Discussion: https://postgr.es/m/20180930205920.GA64534@elch.exwg.net
2018-10-09Relax transactional restrictions on ALTER TYPE ... ADD VALUE (redux).Thomas Munro
Originally committed as 15bc038f (plus some follow-ups), this was reverted in 28e07270 due to a problem discovered in parallel workers. This new version corrects that problem by sending the list of uncommitted enum values to parallel workers. Here follows the original commit message describing the change: To prevent possibly breaking indexes on enum columns, we must keep uncommitted enum values from getting stored in tables, unless we can be sure that any such column is new in the current transaction. Formerly, we enforced this by disallowing ALTER TYPE ... ADD VALUE from being executed at all in a transaction block, unless the target enum type had been created in the current transaction. This patch removes that restriction, and instead insists that an uncommitted enum value can't be referenced unless it belongs to an enum type created in the same transaction as the value. Per discussion, this should be a bit less onerous. It does require each function that could possibly return a new enum value to SQL operations to check this restriction, but there aren't so many of those that this seems unmaintainable. Author: Andrew Dunstan and Tom Lane, with parallel query fix by Thomas Munro Reviewed-by: Tom Lane Discussion: https://postgr.es/m/CAEepm%3D0Ei7g6PaNTbcmAh9tCRahQrk%3Dr5ZWLD-jr7hXweYX3yg%40mail.gmail.com Discussion: https://postgr.es/m/4075.1459088427%40sss.pgh.pa.us
2018-10-08Improve snprintf.c's handling of NaN, Infinity, and minus zero.Tom Lane
Up to now, float4out/float8out handled NaN and Infinity cases explicitly, and invoked psprintf only for ordinary float values. This was done because platform implementations of snprintf produce varying representations of these special cases. But now that we use snprintf.c always, it's better to give it the responsibility to produce a uniform representation of these cases, so that we have uniformity across the board not only in float4out/float8out. Hence, move that work into fmtfloat(). Also, teach fmtfloat() to recognize IEEE minus zero and handle it correctly. The previous coding worked only accidentally, and would fail for e.g. "%+f" format (it'd print "+-0.00000"). Now that we're using snprintf.c everywhere, it's not acceptable for it to do weird things in corner cases. (This incidentally avoids a portability problem we've seen on some really ancient platforms, that native sprintf does the wrong thing with minus zero.) Also, introduce a new entry point in snprintf.c to allow float[48]out to bypass the work of interpreting a well-known format spec, as well as bypassing the overhead of the psprintf layer. I modeled this API loosely on strfromd(). In my testing, this brings float[48]out back to approximately the same speed they had when using native snprintf, fixing one of the main performance issues caused by using snprintf.c. (There is some talk of more aggressive work to improve the speed of floating-point output conversion, but these changes seem to provide a better starting point for such work anyway.) Getting rid of the previous ad-hoc hack for Infinity/NaN in fmtfloat() allows removing <ctype.h> from snprintf.c's #includes. I also removed a few other #includes that I think are historical, though the buildfarm may expose that as wrong. Discussion: https://postgr.es/m/13178.1538794717@sss.pgh.pa.us
2018-10-06Don't use is_infinite() where isinf() will do.Tom Lane
Places that aren't testing for sign should not use the more expensive function; it's just wasteful, not to mention being a cognitive load for readers who may know what isinf() is but not is_infinite(). As things stand, we actually don't need is_infinite() anyplace except float4out/float8out, which means it could potentially go away altogether after the changes I proposed in <13178.1538794717@sss.pgh.pa.us>.
2018-10-06Improve the accuracy of floating point statistical aggregates.Dean Rasheed
When computing statistical aggregates like variance, the common schoolbook algorithm which computes the sum of the squares of the values and subtracts the square of the mean can lead to a large loss of precision when using floating point arithmetic, because the difference between the two terms is often very small relative to the terms themselves. To avoid this, re-work these aggregates to use the Youngs-Cramer algorithm, which is a proven, numerically stable algorithm that directly aggregates the sum of the squares of the differences of the values from the mean in a single pass over the data. While at it, improve the test coverage to test the aggregate combine functions used during parallel aggregation. Per report and suggested algorithm from Erich Schubert. Patch by me, reviewed by Madeleine Thompson. Discussion: https://postgr.es/m/153313051300.1397.9594490737341194671@wrigleys.postgresql.org
2018-10-05Add pg_ls_tmpdir functionMichael Paquier
This lists the contents of a temporary directory associated to a given tablespace, useful to get information about on-disk consumption caused by temporary files used by a session query. By default, pg_default is scanned, and a tablespace can be specified as argument. This function is intended to be used by monitoring tools, and, unlike pg_ls_dir(), access to them can be granted to non-superusers so that those monitoring tools can observe the principle of least privilege. Access is also given by default to members of pg_monitor. Author: Nathan Bossart Reviewed-by: Laurenz Albe Discussion: https://postgr.es/m/92F458A2-6459-44B8-A7F2-2ADD3225046A@amazon.com
2018-10-04Refactor user-facing SQL functions signalling backendsMichael Paquier
This moves the system administration functions for signalling backends from backend/utils/adt/misc.c into a separate file dedicated to backend signalling. No new functionality is introduced in this commit. Author: Daniel Gustafsson Reviewed-by: Michael Paquier, Álvaro Herrera Discussion: https://postgr.es/m/C2C7C3EC-CC5F-44B6-9C78-637C88BD7D14@yesql.se
2018-10-03MAXALIGN the target address where we store flattened value.Amit Kapila
The API (EOH_flatten_into) that flattens the expanded value representation expects the target address to be maxaligned. All it's usage adhere to that principle except when serializing datums for parallel query. Fix that usage. Diagnosed-by: Tom Lane Author: Tom Lane and Amit Kapila Backpatch-through: 9.6 Discussion: https://postgr.es/m/11629.1536550032@sss.pgh.pa.us
2018-10-02Fix corner-case failures in has_foo_privilege() family of functions.Tom Lane
The variants of these functions that take numeric inputs (OIDs or column numbers) are supposed to return NULL rather than failing on bad input; this rule reduces problems with snapshot skew when queries apply the functions to all rows of a catalog. has_column_privilege() had careless handling of the case where the table OID didn't exist. You might get something like this: select has_column_privilege(9999,'nosuchcol','select'); ERROR: column "nosuchcol" of relation "(null)" does not exist or you might get a crash, depending on the platform's printf's response to a null string pointer. In addition, while applying the column-number variant to a dropped column returned NULL as desired, applying the column-name variant did not: select has_column_privilege('mytable','........pg.dropped.2........','select'); ERROR: column "........pg.dropped.2........" of relation "mytable" does not exist It seems better to make this case return NULL as well. Also, the OID-accepting variants of has_foreign_data_wrapper_privilege, has_server_privilege, and has_tablespace_privilege didn't follow the principle of returning NULL for nonexistent OIDs. Superusers got TRUE, everybody else got an error. Per investigation of Jaime Casanova's report of a new crash in HEAD. These behaviors have been like this for a long time, so back-patch to all supported branches. Patch by me; thanks to Stephen Frost for discussion and review Discussion: https://postgr.es/m/CAJGNTeP=-6Gyqq5TN9OvYEydi7Fv1oGyYj650LGTnW44oAzYCg@mail.gmail.com
2018-09-30Create an RTE field to record the query's lock mode for each relation.Tom Lane
Add RangeTblEntry.rellockmode, which records the appropriate lock mode for each RTE_RELATION rangetable entry (either AccessShareLock, RowShareLock, or RowExclusiveLock depending on the RTE's role in the query). This patch creates the field and makes all creators of RTE nodes fill it in reasonably, but for the moment nothing much is done with it. The plan is to replace assorted post-parser logic that re-determines the right lockmode to use with simple uses of rte->rellockmode. For now, just add Asserts in each of those places that the rellockmode matches what they are computing today. (In some cases the match isn't perfect, so the Asserts are weaker than you might expect; but this seems OK, as per discussion.) This passes check-world for me, but it seems worth pushing in this state to see if the buildfarm finds any problems in cases I failed to test. catversion bump due to change of stored rules. Amit Langote, reviewed by David Rowley and Jesper Pedersen, and whacked around a bit more by me Discussion: https://postgr.es/m/468c85d9-540e-66a2-1dde-fec2b741e688@lab.ntt.co.jp
2018-09-26Fix problems in handling the line data typeTomas Vondra
According to the source history, the internal format of line data type has changed, but various functions working with it did were not updated and thus were producing wrong results. This patch addresses various such issues, in particular: * Reject invalid specification A=B=0 on receive * Reject same points on line_construct_pp() * Fix perpendicular operator when negative values are involved * Avoid division by zero on perpendicular operator * Fix intersection and distance operators when neither A nor B are 1 * Return NULL for closest point when objects are parallel * Check whether closest point of line segments is the intersection point * Fix closest point of line segments being on the wrong segment Aside from handling those issues, the patch also aims to make operators more symmetric and less sen to precision loss. The EPSILON interferes with even minor changes, but the least we can do is applying it to both sides of the operators equally. Author: Emre Hasegeli Reviewed-by: Tomas Vondra Discussion: https://www.postgresql.org/message-id/CAE2gYzxF7-5djV6-cEvqQu-fNsnt%3DEqbOURx7ZDg%2BVv6ZMTWbg%40mail.gmail.com
2018-09-25Split ExecStoreTuple into ExecStoreHeapTuple and ExecStoreBufferHeapTuple.Andres Freund
Upcoming changes introduce further types of tuple table slots, in preparation of making table storage pluggable. New storage methods will have different representation of tuples, therefore the slot accessor should refer explicitly to heap tuples. Instead of just renaming the functions, split it into one function that accepts heap tuples not residing in buffers, and one accepting ones in buffers. Previously one function was used for both, but that was a bit awkward already, and splitting will allow us to represent slot types for tuples in buffers and normal memory separately. This is split out from the patch introducing abstract slots, as this largely consists out of mechanical changes. Author: Ashutosh Bapat Reviewed-By: Andres Freund Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
2018-09-24Fix over-allocation of space for array_out()'s result string.Tom Lane
array_out overestimated the space needed for its output, possibly by a very substantial amount if the array is multi-dimensional, because of wrong order of operations in the loop that counts the number of curly-brace pairs needed. While the output string is normally short-lived, this could still cause problems in extreme cases. An additional minor error was that it counted one more delimiter than is actually needed. Repair those errors, add an Assert that the space is now correctly calculated, and make some minor improvements in the comments. I also failed to resist the temptation to get rid of an integer modulus operation per array element; a simple comparison is sufficient. This bug dates clear back to Berkeley days, so back-patch to all supported versions. Keiichi Hirobe, minor additional work by me Discussion: https://postgr.es/m/CAH=EFxE9W0tRvQkixR2XJRRCToUYUEDkJZk6tnADXugPBRdcdg@mail.gmail.com
2018-09-24Document aclitem functions and operatorsJoe Conway
aclitem functions and operators have been heretofore undocumented. Fix that. While at it, ensure the non-operator aclitem functions have pg_description strings. Does not seem worthwhile to back-patch. Author: Fabien Coelho, with pg_description from John Naylor, and significant refactoring and editorialization by me. Reviewed by: Tom Lane Discussion: https://postgr.es/m/flat/alpine.DEB.2.21.1808010825490.18204%40lancre
2018-09-20Fix handling of format string text characters in to_timestamp()/to_date()Alexander Korotkov
cf984672 introduced improvement of handling of spaces and separators in to_timestamp()/to_date() functions. In particular, now we're skipping spaces both before and after fields. That may cause format string text character to consume part of field in the situations, when it didn't happen before cf984672. This commit cause format string text character consume input string characters only when since previous field (or string beginning) number of skipped input string characters is not greater than number of corresponding format string characters (that is we didn't skip any extra characters in input string).
2018-09-19Add support for nearest-neighbor (KNN) searches to SP-GiSTAlexander Korotkov
Currently, KNN searches were supported only by GiST. SP-GiST also capable to support them. This commit implements that support. SP-GiST scan stack is replaced with queue, which serves as stack if no ordering is specified. KNN support is provided for three SP-GIST opclasses: quad_point_ops, kd_point_ops and poly_ops (catversion is bumped). Some common parts between GiST and SP-GiST KNNs are extracted into separate functions. Discussion: https://postgr.es/m/570825e8-47d0-4732-2bf6-88d67d2d51c8%40postgrespro.ru Author: Nikita Glukhov, Alexander Korotkov based on GSoC work by Vlad Sterzhanov Review: Andrey Borodin, Alexander Korotkov
2018-09-17Fix parsetree representation of XMLTABLE(XMLNAMESPACES(DEFAULT ...)).Tom Lane
The original coding for XMLTABLE thought it could represent a default namespace by a T_String Value node with a null string pointer. That's not okay, though; in particular outfuncs.c/readfuncs.c are not on board with such a representation, meaning you'll get a null pointer crash if you try to store a view or rule containing this construct. To fix, change the parsetree representation so that we have a NULL list element, instead of a bogus Value node. This isn't really a functional limitation since default XML namespaces aren't yet implemented in the executor; you'd just get "DEFAULT namespace is not supported" anyway. But crashes are not nice, so back-patch to v10 where this syntax was added. Ordinarily we'd consider a parsetree representation change to be un-backpatchable; but since existing releases would crash on the way to storing such constructs, there can't be any existing views/rules to be incompatible with. Per report from Andrey Lepikhov. Discussion: https://postgr.es/m/3690074f-abd2-56a9-144a-aa5545d7a291@postgrespro.ru
2018-09-12Repair bug in regexp split performance improvements.Andrew Gierth
Commit c8ea87e4b introduced a temporary conversion buffer for substrings extracted during regexp splits. Unfortunately the code that sized it was failing to ignore the effects of ignored degenerate regexp matches, so for regexp_split_* calls it could under-size the buffer in such cases. Fix, and add some regression test cases (though those will only catch the bug if run in a multibyte encoding). Backpatch to 9.3 as the faulty code was. Thanks to the PostGIS project, Regina Obe and Paul Ramsey for the report (via IRC) and assistance in analysis. Patch by me.
2018-09-11Remove ruleutils.c's special case for BIT [VARYING] literals.Tom Lane
Up to now, get_const_expr() insisted on prefixing BIT and VARBIT literals with 'B'. That's not really necessary, because we always append explicit-cast syntax to identify the constant's type. Moreover, it's subtly wrong for VARBIT, because the parser will interpret B'...' as '...'::"bit"; see make_const() which explicitly assigns type BITOID for a T_BitString literal. So what had been a simple VARBIT literal is reconstructed as ('...'::"bit")::varbit, which is not the same thing, at least not before constant folding. This results in odd differences after dump/restore, as complained of by the patch submitter, and it could result in actual failures in partitioning or inheritance DDL operations (see commit 542320c2b, which repaired similar misbehaviors for some other data types). Fixing it is pretty easy: just remove the special case and let the default code path handle these types. We could have kept the special case for BIT only, but there seems little point in that. Like the previous patch, I judge that back-patching this into stable branches wouldn't be a good idea. However, it seems not quite too late for v11, so let's fix it there. Paul Guo, reviewed by Davy Machado and John Naylor, minor adjustments by me Discussion: https://postgr.es/m/CABQrizdTra=2JEqA6+Ms1D1k1Kqw+aiBBhC9TreuZRX2JzxLAA@mail.gmail.com
2018-09-09Improve behavior of to_timestamp()/to_date() functionsAlexander Korotkov
to_timestamp()/to_date() functions were introduced mainly for Oracle compatibility, and became very popular among PostgreSQL users. However, some behavior of to_timestamp()/to_date() functions are both incompatible with Oracle and confusing for our users. This behavior is related to handling of spaces and separators in non FX (fixed format) mode. This commit reworks this behavior making less confusing, better documented and more compatible with Oracle. Nevertheless, there are still following incompatibilities with Oracle. 1) We don't insist that there are no format string patterns unmatched to input string. 2) In FX mode we don't insist space and separators in format string to exactly match input string. 3) When format string patterns are divided by mix of spaces and separators, we don't distinguish them, while Oracle takes into account only last group of spaces/separators. Discussion: https://postgr.es/m/1873520224.1784572.1465833145330.JavaMail.yahoo%40mail.yahoo.com Author: Artur Zakirov, Alexander Korotkov, Liudmila Mantrova Review: Amul Sul, Robert Haas, Tom Lane, Dmitry Dolgov, David G. Johnston
2018-09-08Remove duplicated words split across lines in commentsMichael Paquier
This has been detected using some interesting tricks with sed, and the method used is mentioned in details in the discussion below. Author: Justin Pryzby Discussion: https://postgr.es/m/20180908013109.GB15350@telsasoft.com
2018-09-03Remove pg_constraint.conincludingAlvaro Herrera
This column was added in commit 8224de4f42cc ("Indexes with INCLUDE columns and their support in B-tree") to ease writing the ruleutils.c supporting code for that feature, but it turns out to be unnecessary -- we can do the same thing with just one more syscache lookup. Even the documentation for the new column being removed in this commit is awkward. Discussion: https://postgr.es/m/20180902165018.33otxftp3olgtu4t@alvherre.pgsql
2018-08-28Avoid quadratic slowdown in regexp match/split functions.Andrew Gierth
regexp_matches, regexp_split_to_table and regexp_split_to_array all work by compiling a list of match positions as character offsets (NOT byte positions) in the source string. Formerly, they then used text_substr to extract the matched text; but in a multi-byte encoding, that counts the characters in the string, and the characters needed to reach the starting byte position, on every call. Accordingly, the performance degraded as the product of the input string length and the number of match positions, such that splitting a string of a few hundred kbytes could take many minutes. Repair by keeping the wide-character copy of the input string available (only in the case where encoding_max_length is not 1) after performing the match operation, and extracting substrings from that instead. This reduces the complexity to being linear in the number of result bytes, discounting the actual regexp match itself (which is not affected by this patch). In passing, remove cleanup using retail pfree() which was obsoleted by commit ff428cded (Feb 2008) which made cleanup of SRF multi-call contexts automatic. Also increase (to ~134 million) the maximum number of matches and provide an error message when it is reached. Backpatch all the way because this has been wrong forever. Analysis and patch by me; review by Kaiting Chen. Discussion: https://postgr.es/m/87pnyn55qh.fsf@news-spur.riddles.org.uk see also https://postgr.es/m/87lg996g4r.fsf@news-spur.riddles.org.uk
2018-08-27Fix typos.Thomas Munro
Author: David Rowley Discussion: https://postgr.es/m/CAKJS1f8du35u5DprpykWvgNEScxapbWYJdHq%2Bz06Wj3Y2KFPbw%40mail.gmail.com
2018-08-16Use the built-in float datatypes to implement geometric typesTomas Vondra
This patch makes the geometric operators and functions use the exported function of the float4/float8 datatypes. The main reason of doing so is to check for underflow and overflow, and to handle NaNs consciously. The float datatypes consider NaNs values to be equal and greater than all non-NaN values. This change considers NaNs equal only for equality operators. The placement operators, contains, overlaps, left/right of etc. continue to return false when NaNs are involved. We don't need to worry about them being considered greater than any-NaN because there aren't any basic comparison operators like less/greater than for the geometric datatypes. The changes may be summarised as: * Check for underflow, overflow and division by zero * Consider NaN values to be equal * Return NULL when the distance is NaN for all closest point operators * Favour not-NaN over NaN where it makes sense The patch also replaces all occurrences of "double" as "float8". They are the same, but were used inconsistently in the same file. Author: Emre Hasegeli Reviewed-by: Kyotaro Horiguchi, Tomas Vondra Discussion: https://www.postgresql.org/message-id/CAE2gYzxF7-5djV6-cEvqQu-fNsnt%3DEqbOURx7ZDg%2BVv6ZMTWbg%40mail.gmail.com