This adds the SQL standard feature that adds the SEARCH and CYCLE
clauses to recursive queries to be able to do produce breadth- or
depth-first search orders and detect cycles. These clauses can be
rewritten into queries using existing syntax, and that is what this
patch does in the rewriter.
Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/db80ceee-6f97-9b4a-8ee8-3ba0c58e5be2@2ndquadrant.com
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
While ereport() and elog() themselves are quite cheap when the
error message level is too low to be printed, some places need to do
substantial work before they can call those macros at all. To allow
optimizing away such setup work when nothing is to be printed, make
elog.c export a new function message_level_is_interesting(elevel)
that reports whether ereport/elog will do anything. Make use of that
in various places that had ad-hoc direct tests of log_min_messages etc.
Also teach ProcSleep to use it to avoid some work. (There may well
be other places that could usefully use this; I didn't search hard.)
Within elog.c, refactor a little bit to avoid having duplicate copies
of the policy-setting logic. When that code was written, we weren't
relying on the availability of inline functions; so it had some
duplications in the name of efficiency, which I got rid of.
Alvaro Herrera and Tom Lane
Discussion: https://postgr.es/m/129515.1606166429@sss.pgh.pa.us
Record the current version of dependent collations in pg_depend when
creating or rebuilding an index. When accessing the index later, warn
that the index may be corrupted if the current version doesn't match.
Thanks to Douglas Doole, Peter Eisentraut, Christoph Berg, Laurenz Albe,
Michael Paquier, Robert Haas, Tom Lane and others for very helpful
discussion.
Author: Thomas Munro <thomas.munro@gmail.com>
Author: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com> (earlier versions)
Discussion: https://postgr.es/m/CAEepm%3D0uEQCpfq_%2BLYFBdArCe4Ot98t1aR4eYiYTe%3DyavQygiQ%40mail.gmail.com
Provide a place for the version of referenced database objects to be
recorded. A follow-up commit will use this to record dependencies on
collation versions for indexes, but similar ideas for other kinds of
objects have also been mooted.
Author: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Discussion: https://postgr.es/m/CAEepm%3D0uEQCpfq_%2BLYFBdArCe4Ot98t1aR4eYiYTe%3DyavQygiQ%40mail.gmail.com
When using the following functions, users could see various types of
errors of the type "cache lookup failed for OID XXX" with elog(), that
can only be used for internal errors:
* pg_describe_object()
* pg_identify_object()
* pg_identify_object_as_address()
The set of APIs managing object addresses for all object types are made
smarter by gaining a new argument "missing_ok" that allows any caller to
control if an error is raised or not on an undefined object. The SQL
functions listed above are changed to handle the case where an object is
missing.
Regression tests are added for all object types for the cases where
these are undefined. Before this commit, these cases failed with cache
lookup errors, and now they basically return NULL (minus the name of the
object type requested).
Author: Michael Paquier
Reviewed-by: Aleksander Alekseev, Dmitry Dolgov, Daniel Gustafsson,
Álvaro Herrera, Kyotaro Horiguchi
Discussion: https://postgr.es/m/CAB7nPqSZxrSmdHK-rny7z8mi=EAFXJ5J-0RbzDw6aus=wB5azQ@mail.gmail.com
There are a number of Remove${Something}ById() functions that are
essentially identical in structure and only different in which catalog
they are working on. Refactor this to be one generic function. The
information about which oid column, index, etc. to use was already
available in ObjectProperty for most catalogs, in a few cases it was
easily added.
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/331d9661-1743-857f-1cbb-d5728bcd62cb%402ndquadrant.com
The additional pain from level 4 is excessive for the gain.
Also revert all the source annotation changes to their original
wordings, to avoid back-patching pain.
Discussion: https://postgr.es/m/31166.1589378554@sss.pgh.pa.us
Use it at level 4, a bit more restrictive than the default level, and
tweak our commanding comments to FALLTHROUGH.
(However, leave zic.c alone, since it's external code; to avoid the
warnings that would appear there, change CFLAGS for that file in the
Makefile.)
Author: Julien Rouhaud <rjuju123@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20200412081825.qyo5vwwco3fv4gdo@nol
Discussion: https://postgr.es/m/flat/E1fDenm-0000C8-IJ@gemulon.postgresql.org
We were acquiring object locks then deleting objects one by one, instead
of acquiring all object locks first, ignoring those that did not exist,
and then deleting all objects together. The latter is the correct
protocol to use, and what this commits changes to code to do. Failing
to follow that leads to "cache lookup failed for relation XYZ" error
reports when DROP OWNED runs concurrently with other DDL -- for example,
a session termination that removes some temp tables.
Author: Álvaro Herrera
Reported-by: Mithun Chicklore Yogendra (Mithun CY)
Reviewed-by: Ahsan Hadi, Tom Lane
Discussion: https://postgr.es/m/CADq3xVZTbzK4ZLKq+dn_vB4QafXXbmMgDP3trY-GuLnib2Ai1w@mail.gmail.com
The need for this was removed by
8b9e9644dc.
A number of files now need to include utils/acl.h or
parser/parse_node.h explicitly where they previously got it indirectly
somehow.
Since parser/parse_node.h already includes nodes/parsenodes.h, the
latter is then removed where the former was added. Also, remove
nodes/pg_list.h from objectaddress.h, since that's included via
nodes/parsenodes.h.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/7601e258-26b2-8481-36d0-dc9dca6f28f1%402ndquadrant.com
The core idea of this patch is to make the parser generate join alias
Vars (that is, ones with varno pointing to a JOIN RTE) only when the
alias Var is actually different from any raw join input, that is a type
coercion and/or COALESCE is necessary to generate the join output value.
Otherwise just generate varno/varattno pointing to the relevant join
input column.
In effect, this means that the planner's flatten_join_alias_vars()
transformation is already done in the parser, for all cases except
(a) columns that are merged by JOIN USING and are transformed in the
process, and (b) whole-row join Vars. In principle that would allow
us to skip doing flatten_join_alias_vars() in many more queries than
we do now, but we don't have quite enough infrastructure to know that
we can do so --- in particular there's no cheap way to know whether
there are any whole-row join Vars. I'm not sure if it's worth the
trouble to add a Query-level flag for that, and in any case it seems
like fit material for a separate patch. But even without skipping the
work entirely, this should make flatten_join_alias_vars() faster,
particularly where there are nested joins that it previously had to
flatten recursively.
An essential part of this change is to replace Var nodes'
varnoold/varoattno fields with varnosyn/varattnosyn, which have
considerably more tightly-defined meanings than the old fields: when
they differ from varno/varattno, they identify the Var's position in
an aliased JOIN RTE, and the join alias is what ruleutils.c should
print for the Var. This is necessary because the varno change
destroyed ruleutils.c's ability to find the JOIN RTE from the Var's
varno.
Another way in which this change broke ruleutils.c is that it's no
longer feasible to determine, from a JOIN RTE's joinaliasvars list,
which join columns correspond to which columns of the join's immediate
input relations. (If those are sub-joins, the joinaliasvars entries
may point to columns of their base relations, not the sub-joins.)
But that was a horrid mess requiring a lot of fragile assumptions
already, so let's just bite the bullet and add some more JOIN RTE
fields to make it more straightforward to figure that out. I added
two integer-List fields containing the relevant column numbers from
the left and right input rels, plus a count of how many merged columns
there are.
This patch depends on the ParseNamespaceColumn infrastructure that
I added in commit 5815696bc. The biggest bit of code change is
restructuring transformFromClauseItem's handling of JOINs so that
the ParseNamespaceColumn data is propagated upward correctly.
Other than that and the ruleutils fixes, everything pretty much
just works, though some processing is now inessential. I grabbed
two pieces of low-hanging fruit in that line:
1. In find_expr_references, we don't need to recurse into join alias
Vars anymore. There aren't any except for references to merged USING
columns, which are more properly handled when we scan the join's RTE.
This change actually fixes an edge-case issue: we will now record a
dependency on any type-coercion function present in a USING column's
joinaliasvar, even if that join column has no references in the query
text. The odds of the missing dependency causing a problem seem quite
small: you'd have to posit somebody dropping an implicit cast between
two data types, without removing the types themselves, and then having
a stored rule containing a whole-row Var for a join whose USING merge
depends on that cast. So I don't feel a great need to change this in
the back branches. But in theory this way is more correct.
2. markRTEForSelectPriv and markTargetListOrigin don't need to recurse
into join alias Vars either, because the cases they care about don't
apply to alias Vars for USING columns that are semantically distinct
from the underlying columns. This removes the only case in which
markVarForSelectPriv could be called with NULL for the RTE, so adjust
the comments to describe that hack as being strictly internal to
markRTEForSelectPriv.
catversion bump required due to changes in stored rules.
Discussion: https://postgr.es/m/7115.1577986646@sss.pgh.pa.us
This follows multiple complains from Peter Geoghegan, Andres Freund and
Alvaro Herrera that this issue ought to be dug more before actually
happening, if it happens.
Discussion: https://postgr.es/m/20191226144606.GA5659@alvherre.pgsql
The following renaming is done so as source files related to index
access methods are more consistent with table access methods (the
original names used for index AMs ware too generic, and could be
confused as including features related to table AMs):
- amapi.h -> indexam.h.
- amapi.c -> indexamapi.c. Here we have an equivalent with
backend/access/table/tableamapi.c.
- amvalidate.c -> indexamvalidate.c.
- amvalidate.h -> indexamvalidate.h.
- genam.c -> indexgenam.c.
- genam.h -> indexgenam.h.
This has been discussed during the development of v12 when table AM was
worked on, but the renaming never happened.
Author: Michael Paquier
Reviewed-by: Fabien Coelho, Julien Rouhaud
Discussion: https://postgr.es/m/20191223053434.GF34339@paquier.xyz
The TableFunc node (i.e., XMLTABLE) includes type and collation OIDs
that might not be referenced anywhere else in the expression tree,
so they need to be accounted for when extracting dependencies.
Fortunately, the practical effects of this are limited, since
(a) it's somewhat unlikely that people would be extracting
columns of non-builtin types from an XML document, and (b)
in many scenarios, the query would contain other references
to such types, or functions depending on them. However, it's
not hard to construct examples wherein the existing code lets
one drop a type used in XMLTABLE and thereby break a view.
This is evidently an original oversight in the XMLTABLE patch,
so back-patch to v10 where that came in.
Discussion: https://postgr.es/m/18427.1573508501@sss.pgh.pa.us
query_tree_walker and query_tree_mutator were skipping the
windowClause of the query, without regard for the fact that the
startOffset and endOffset in a WindowClause node are expression trees
that need to be processed. This was an oversight in commit ec4be2ee6
from 2010 which added the expression fields; the main symptom is that
function parameters in window frame clauses don't work in inlined
functions.
Fix (as conservatively as possible since this needs to not break
existing out-of-tree callers) and add tests.
Backpatch all the way, since this has been broken since 9.0.
Per report from Alastair McKinley; fix by me with kibitzing and review
from Tom Lane.
Discussion: https://postgr.es/m/DB6PR0202MB2904E7FDDA9D81504D1E8C68E3800@DB6PR0202MB2904.eurprd02.prod.outlook.com
The logic in ATExecDropColumn that rejects dropping partition key
columns is quite an inadequate defense, because it doesn't execute
in cases where a column needs to be dropped due to cascade from
something that only the column, not the whole partitioned table,
depends on. That leaves us with a badly broken partitioned table;
even an attempt to load its relcache entry will fail.
We really need to have explicit pg_depend entries that show that the
column can't be dropped without dropping the whole table. Hence,
add those entries. In v12 and HEAD, bump catversion to ensure that
partitioned tables will have such entries. We can't do that in
released branches of course, so in v10 and v11 this patch affords
protection only to partitioned tables created after the patch is
installed. Given the lack of field complaints (this bug was found
by fuzz-testing not by end users), that's probably good enough.
In passing, fix ATExecDropColumn and ATPrepAlterColumnType
messages to be more specific about which partition key column
they're complaining about.
Per report from Manuel Rigger. Back-patch to v10 where partitioned
tables were added.
Discussion: https://postgr.es/m/CA+u7OA4JKCPFrdrAbOs7XBiCyD61XJxeNav4LefkSmBLQ-Vobg@mail.gmail.com
Discussion: https://postgr.es/m/31920.1562526703@sss.pgh.pa.us
This adds the CONCURRENTLY option to the REINDEX command. A REINDEX
CONCURRENTLY on a specific index creates a new index (like CREATE
INDEX CONCURRENTLY), then renames the old index away and the new index
in place and adjusts the dependencies, and then drops the old
index (like DROP INDEX CONCURRENTLY). The REINDEX command also has
the capability to run its other variants (TABLE, DATABASE) with the
CONCURRENTLY option (but not SYSTEM).
The reindexdb command gets the --concurrently option.
Author: Michael Paquier, Andreas Karlsson, Peter Eisentraut
Reviewed-by: Andres Freund, Fujii Masao, Jim Nasby, Sergei Kornilov
Discussion: https://www.postgresql.org/message-id/flat/60052986-956b-4478-45ed-8bd119e9b9cf%402ndquadrant.com#74948a1044c56c5e817a5050f554ddee
This finishes a task we left undone in commit f1ad067fc, by extending
the delete-in-descending-OID-order rule to deletions triggered by
DROP OWNED BY. We've coped with machine-dependent deletion orders
one time too many, and the new issues caused by Peter G's recent
nbtree hacking seem like the last straw.
Discussion: https://postgr.es/m/E1h6eep-0001Mw-Vd@gemulon.postgresql.org
The original setup for dependencies of partitioned objects had
serious problems:
1. It did not verify that a drop cascading to a partition-child object
also cascaded to at least one of the object's partition parents. Now,
normally a child object would share all its dependencies with one or
another parent (e.g. a child index's opclass dependencies would be shared
with the parent index), so that this oversight is usually harmless.
But if some dependency failed to fit this pattern, the child could be
dropped while all its parents remain, creating a logically broken
situation. (It's easy to construct artificial cases that break it,
such as attaching an unrelated extension dependency to the child object
and then dropping the extension. I'm not sure if any less-artificial
cases exist.)
2. Management of partition dependencies during ATTACH/DETACH PARTITION
was complicated and buggy; for example, after detaching a partition
table it was possible to create cases where a formerly-child index
should be dropped and was not, because the correct set of dependencies
had not been reconstructed.
Less seriously, because multiple partition relationships were
represented identically in pg_depend, there was an order-of-traversal
dependency on which partition parent was cited in error messages.
We also had some pre-existing order-of-traversal hazards for error
messages related to internal and extension dependencies. This is
cosmetic to users but causes testing problems.
To fix#1, add a check at the end of the partition tree traversal
to ensure that at least one partition parent got deleted. To fix#2,
establish a new policy that partition dependencies are in addition to,
not instead of, a child object's usual dependencies; in this way
ATTACH/DETACH PARTITION need not cope with adding or removing the
usual dependencies.
To fix the cosmetic problem, distinguish between primary and secondary
partition dependency entries in pg_depend, by giving them different
deptypes. (They behave identically except for having different
priorities for being cited in error messages.) This means that the
former 'I' dependency type is replaced with new 'P' and 'S' types.
This also fixes a longstanding bug that after handling an internal
dependency by recursing to the owning object, findDependentObjects
did not verify that the current target was now scheduled for deletion,
and did not apply the current recursion level's objflags to it.
Perhaps that should be back-patched; but in the back branches it
would only matter if some concurrent transaction had removed the
internal-linkage pg_depend entry before the recursive call found it,
or the recursive call somehow failed to find it, both of which seem
unlikely.
Catversion bump because the contents of pg_depend change for
partitioning relationships.
Patch HEAD only. It's annoying that we're not fixing #2 in v11,
but there seems no practical way to do so given that the problem
is exactly a poor choice of what entries to put in pg_depend.
We can't really fix that while staying compatible with what's
in pg_depend in existing v11 installations.
Discussion: https://postgr.es/m/CAH2-Wzkypv1R+teZrr71U23J578NnTBt2X8+Y=Odr4pOdW1rXg@mail.gmail.com
Most of these had been obsoleted by 568d4138c / the SnapshotNow
removal.
This is is preparation for moving most of tqual.[ch] into either
snapmgr.h or heapam.h, which in turn is in preparation for pluggable
table AMs.
Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
Historically, the notices output by DROP CASCADE tended to come out
in uncertain order, and in some cases you might get different claims
about which object depends on which other one. This is because we
just traversed the dependency tree in the order in which pg_depend
entries are seen, and nbtree has never promised anything about the
order of equal-keyed index entries. We've put up with that for years,
hacking regression tests when necessary to prevent them from emitting
unstable output. However, it's a problem for pending work that will
change nbtree's behavior for equal keys, as that causes unexpected
changes in the regression test results.
Hence, adjust findDependentObjects to sort the results of each
indexscan before processing them. The sort is on descending OID of
the dependent objects, hence more or less reverse creation order.
While this rule could still result in bogus regression test failures
if an OID wraparound occurred mid-test, that seems unlikely to happen
in any plausible development or packaging-test scenario.
This is enough to ensure output stability for ordinary DROP CASCADE
commands, but not for DROP OWNED BY, because that has a different
code path with the same problem. We might later choose to sort in
the DROP OWNED BY code as well, but this patch doesn't do so.
I've also not done anything about reverting the existing hacks to
suppress unstable DROP CASCADE output in specific regression tests.
It might be worth undoing those, but it seems like a distinct question.
The first indexscan loop in findDependentObjects is not touched,
meaning there is a hazard of unstable error reports from that too.
However, said hazard is not the fault of that code: it was designed
on the assumption that there could be at most one "owning" object
to complain about, and that assumption does not seem unreasonable.
The recent patch that added the possibility of multiple
DEPENDENCY_INTERNAL_AUTO links broke that assumption, but we should
fix that situation not band-aid around it. That's a matter for
another patch, though.
Discussion: https://postgr.es/m/12244.1547854440@sss.pgh.pa.us
A cascaded drop might find independent reasons to drop both a table
and some column of the table (for instance, a schema drop might include
dropping a data type used in some table in the schema). Depending on
the order of visitation of pg_depend entries, we might report the
table column and the whole table as separate objects-to-be-dropped,
or we might only report the table. This is confusing and leads to
unstable regression test output, so fix it to report only the table
regardless of visitation order.
Per gripe from Peter Geoghegan. This is just cosmetic from a user's
standpoint, and we haven't actually seen regression test problems in
practice (yet), so I'll refrain from back-patching.
Discussion: https://postgr.es/m/15908.1547762076@sss.pgh.pa.us
This is the genam.h equivalent of 4c850ecec6 (which removed
heapam.h from a lot of other headers). There's still a few header
includes of genam.h, but not from central headers anymore.
As a few headers are not indirectly included anymore, execnodes.h and
relscan.h need a few additional includes. Some of the depended on
types were replacable by using the underlying structs, but e.g. for
Snapshot in execnodes.h that'd have gotten more invasive than
reasonable in this commit.
Like the aforementioned commit 4c850ecec6, this requires adding new
genam.h includes to a number of backend files, which likely is also
required in a few external projects.
Author: Andres Freund
Discussion: https://postgr.es/m/20190114000701.y4ttcb74jpskkcfb@alap3.anarazel.de
heapam.h previously was included in a number of widely used
headers (e.g. execnodes.h, indirectly in executor.h, ...). That's
problematic on its own, as heapam.h contains a lot of low-level
details that don't need to be exposed that widely, but becomes more
problematic with the upcoming introduction of pluggable table storage
- it seems inappropriate for heapam.h to be included that widely
afterwards.
heapam.h was largely only included in other headers to get the
HeapScanDesc typedef (which was defined in heapam.h, even though
HeapScanDescData is defined in relscan.h). The better solution here
seems to be to just use the underlying struct (forward declared where
necessary). Similar for BulkInsertState.
Another problem was that LockTupleMode was used in executor.h - parts
of the file tried to cope without heapam.h, but due to the fact that
it indirectly included it, several subsequent violations of that goal
were not not noticed. We could just reuse the approach of declaring
parameters as int, but it seems nicer to move LockTupleMode to
lockoptions.h - that's not a perfect location, but also doesn't seem
bad.
As a number of files relied on implicitly included heapam.h, a
significant number of files grew an explicit include. It's quite
probably that a few external projects will need to do the same.
Author: Andres Freund
Reviewed-By: Alvaro Herrera
Discussion: https://postgr.es/m/20190114000701.y4ttcb74jpskkcfb@alap3.anarazel.de
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
Traditionally, include/catalog/pg_foo.h contains extern declarations
for functions in backend/catalog/pg_foo.c, in addition to its function
as the authoritative definition of the pg_foo catalog's rowtype.
In some cases, we'd been forced to split out those extern declarations
into separate pg_foo_fn.h headers so that the catalog definitions
could be #include'd by frontend code. That problem is gone as of
commit 9c0a0de4c, so let's undo the splits to make things less
confusing.
Discussion: https://postgr.es/m/23690.1523031777@sss.pgh.pa.us
This patch adds the ability to use "RANGE offset PRECEDING/FOLLOWING"
frame boundaries in window functions. We'd punted on that back in the
original patch to add window functions, because it was not clear how to
do it in a reasonably data-type-extensible fashion. That problem is
resolved here by adding the ability for btree operator classes to provide
an "in_range" support function that defines how to add or subtract the
RANGE offset value. Factoring it this way also allows the operator class
to avoid overflow problems near the ends of the datatype's range, if it
wishes to expend effort on that. (In the committed patch, the integer
opclasses handle that issue, but it did not seem worth the trouble to
avoid overflow failures for datetime types.)
The patch includes in_range support for the integer_ops opfamily
(int2/int4/int8) as well as the standard datetime types. Support for
other numeric types has been requested, but that seems like suitable
material for a follow-on patch.
In addition, the patch adds GROUPS mode which counts the offset in
ORDER-BY peer groups rather than rows, and it adds the frame_exclusion
options specified by SQL:2011. As far as I can see, we are now fully
up to spec on window framing options.
Existing behaviors remain unchanged, except that I changed the errcode
for a couple of existing error reports to meet the SQL spec's expectation
that negative "offset" values should be reported as SQLSTATE 22013.
Internally and in relevant parts of the documentation, we now consistently
use the terminology "offset PRECEDING/FOLLOWING" rather than "value
PRECEDING/FOLLOWING", since the term "value" is confusingly vague.
Oliver Ford, reviewed and whacked around some by me
Discussion: https://postgr.es/m/CAGMVOdu9sivPAxbNN0X+q19Sfv9edEPv=HibOJhB14TJv_RCQg@mail.gmail.com
When CREATE INDEX is run on a partitioned table, create catalog entries
for an index on the partitioned table (which is just a placeholder since
the table proper has no data of its own), and recurse to create actual
indexes on the existing partitions; create them in future partitions
also.
As a convenience gadget, if the new index definition matches some
existing index in partitions, these are picked up and used instead of
creating new ones. Whichever way these indexes come about, they become
attached to the index on the parent table and are dropped alongside it,
and cannot be dropped on isolation unless they are detached first.
To support pg_dump'ing these indexes, add commands
CREATE INDEX ON ONLY <table>
(which creates the index on the parent partitioned table, without
recursing) and
ALTER INDEX ATTACH PARTITION
(which is used after the indexes have been created individually on each
partition, to attach them to the parent index). These reconstruct prior
database state exactly.
Reviewed-by: (in alphabetical order) Peter Eisentraut, Robert Haas, Amit
Langote, Jesper Pedersen, Simon Riggs, David Rowley
Discussion: https://postgr.es/m/20171113170646.gzweigyrgg6pwsg4@alvherre.pgsql
On closer investigation, commits f3ea3e3e8 et al were a few bricks
shy of a load. What we need is not so much to lock down the result
type of a FieldSelect, as to lock down the existence of the column
it's trying to extract. Otherwise, we can break it by dropping that
column. The dependency on the result type is then held indirectly
through the column, and doesn't need to be recorded explicitly.
Out of paranoia, I left in the code to record a dependency on the
result type, but it's used only if we can't identify the pg_class OID
for the column. That shouldn't ever happen right now, AFAICS, but
it seems possible that in future the input node could be marked as
being of type RECORD rather than some specific composite type.
Likewise for FieldStore.
Like the previous patch, back-patch to all supported branches.
Discussion: https://postgr.es/m/22571.1509064146@sss.pgh.pa.us
find_expr_references() neglected to record a dependency on the result type
of a FieldSelect node, allowing a DROP TYPE to break a view or rule that
contains such an expression. I think we'd omitted this case intentionally,
reasoning that there would always be a related dependency ensuring that the
DROP would cascade to the view. But at least with nested field selection
expressions, that's not true, as shown in bug #14867 from Mansur Galiev.
Add the dependency, and for good measure a dependency on the node's exposed
collation.
Likewise add a dependency on the result type of a FieldStore. I think here
the reasoning was that it'd only appear within an assignment to a field,
and the dependency on the field's column would be enough ... but having
seen this example, I think that's wrong for nested-composites cases.
Looking at nearby code, I notice we're not recording a dependency on the
exposed collation of CoerceViaIO, which seems inconsistent with our choices
for related node types. Maybe that's OK but I'm feeling suspicious of this
code today, so let's add that; it certainly can't hurt.
This patch does not do anything to protect already-existing views, only
views created after it's installed. But seeing that the issue has been
there a very long time and nobody noticed till now, that's probably good
enough.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/20171023150118.1477.19174@wrigleys.postgresql.org
Allowing arrays with a domain type as their element type was left un-done
in the original domain patch, but not for any very good reason. This
omission leads to such surprising results as array_agg() not working on
a domain column, because the parser can't identify a suitable output type
for the polymorphic aggregate.
In order to fix this, first clean up the APIs of coerce_to_domain() and
some internal functions in parse_coerce.c so that we consistently pass
around a CoercionContext along with CoercionForm. Previously, we sometimes
passed an "isExplicit" boolean flag instead, which is strictly less
information; and coerce_to_domain() didn't even get that, but instead had
to reverse-engineer isExplicit from CoercionForm. That's contrary to the
documentation in primnodes.h that says that CoercionForm only affects
display and not semantics. I don't think this change fixes any live bugs,
but it makes things more consistent. The main reason for doing it though
is that now build_coercion_expression() receives ccontext, which it needs
in order to be able to recursively invoke coerce_to_target_type().
Next, reimplement ArrayCoerceExpr so that the node does not directly know
any details of what has to be done to the individual array elements while
performing the array coercion. Instead, the per-element processing is
represented by a sub-expression whose input is a source array element and
whose output is a target array element. This simplifies life in
parse_coerce.c, because it can build that sub-expression by a recursive
invocation of coerce_to_target_type(). The executor now handles the
per-element processing as a compiled expression instead of hard-wired code.
The main advantage of this is that we can use a single ArrayCoerceExpr to
handle as many as three successive steps per element: base type conversion,
typmod coercion, and domain constraint checking. The old code used two
stacked ArrayCoerceExprs to handle type + typmod coercion, which was pretty
inefficient, and adding yet another array deconstruction to do domain
constraint checking seemed very unappetizing.
In the case where we just need a single, very simple coercion function,
doing this straightforwardly leads to a noticeable increase in the
per-array-element runtime cost. Hence, add an additional shortcut evalfunc
in execExprInterp.c that skips unnecessary overhead for that specific form
of expression. The runtime speed of simple cases is within 1% or so of
where it was before, while cases that previously required two levels of
array processing are significantly faster.
Finally, create an implicit array type for every domain type, as we do for
base types, enums, etc. Everything except the array-coercion case seems
to just work without further effort.
Tom Lane, reviewed by Andrew Dunstan
Discussion: https://postgr.es/m/9852.1499791473@sss.pgh.pa.us
Add missing infrastructure for this node type, notably in ruleutils.c where
its lack could demonstrably cause EXPLAIN to fail. Add outfuncs/readfuncs
support. (outfuncs support is useful today for debugging purposes. The
readfuncs support may never be needed, since at present it would only
matter for parallel query and NextValueExpr should never appear in a
parallelizable query; but it seems like a bad idea to have a primnode type
that isn't fully supported here.) Teach planner infrastructure that
NextValueExpr is a volatile, parallel-unsafe, non-leaky expression node
with cost cpu_operator_cost. Given its limited scope of usage, there
*might* be no live bug today from the lack of that knowledge, but it's
certainly going to bite us on the rear someday. Teach pg_stat_statements
about the new node type, too.
While at it, also teach cost_qual_eval() that MinMaxExpr, SQLValueFunction,
XmlExpr, and CoerceToDomain should be charged as cpu_operator_cost.
Failing to do this for SQLValueFunction was an oversight in my commit
0bb51aa96. The others are longer-standing oversights, but no time like the
present to fix them. (In principle, CoerceToDomain could have cost much
higher than this, but it doesn't presently seem worth trying to examine the
domain's constraints here.)
Modify execExprInterp.c to execute NextValueExpr as an out-of-line
function; it seems quite unlikely to me that it's worth insisting that
it be inlined in all expression eval methods. Besides, providing the
out-of-line function doesn't stop anyone from inlining if they want to.
Adjust some places where NextValueExpr support had been inserted with the
aid of a dartboard rather than keeping it in the same order as elsewhere.
Discussion: https://postgr.es/m/23862.1499981661@sss.pgh.pa.us
Don't move parenthesized lines to the left, even if that means they
flow past the right margin.
By default, BSD indent lines up statement continuation lines that are
within parentheses so that they start just to the right of the preceding
left parenthesis. However, traditionally, if that resulted in the
continuation line extending to the right of the desired right margin,
then indent would push it left just far enough to not overrun the margin,
if it could do so without making the continuation line start to the left of
the current statement indent. That makes for a weird mix of indentations
unless one has been completely rigid about never violating the 80-column
limit.
This behavior has been pretty universally panned by Postgres developers.
Hence, disable it with indent's new -lpl switch, so that parenthesized
lines are always lined up with the preceding left paren.
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
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 e3860ffa4d 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
Remove default cases from assorted switches over ObjectClass and some
related enum types, so that we'll get compiler warnings when someone
adds a new enum value without accounting for it in all these places.
In passing, re-order some switch cases as needed to match the declaration
of enum ObjectClass. OK, that's just neatnik-ism, but I dislike code
that looks like it was assembled with the help of a dartboard.
Discussion: https://postgr.es/m/20170512221010.nglatgt5azzdxjlj@alvherre.pgsql
This is the SQL standard-conforming variant of PostgreSQL's serial
columns. It fixes a few usability issues that serial columns have:
- CREATE TABLE / LIKE copies default but refers to same sequence
- cannot add/drop serialness with ALTER TABLE
- dropping default does not drop sequence
- need to grant separate privileges to sequence
- other slight weirdnesses because serial is some kind of special macro
Reviewed-by: Vitaly Burovoy <vitaly.burovoy@gmail.com>
Add support for explicitly declared statistic objects (CREATE
STATISTICS), allowing collection of statistics on more complex
combinations that individual table columns. Companion commands DROP
STATISTICS and ALTER STATISTICS ... OWNER TO / SET SCHEMA / RENAME are
added too. All this DDL has been designed so that more statistic types
can be added later on, such as multivariate most-common-values and
multivariate histograms between columns of a single table, leaving room
for permitting columns on multiple tables, too, as well as expressions.
This commit only adds support for collection of n-distinct coefficient
on user-specified sets of columns in a single table. This is useful to
estimate number of distinct groups in GROUP BY and DISTINCT clauses;
estimation errors there can cause over-allocation of memory in hashed
aggregates, for instance, so it's a worthwhile problem to solve. A new
special pseudo-type pg_ndistinct is used.
(num-distinct estimation was deemed sufficiently useful by itself that
this is worthwhile even if no further statistic types are added
immediately; so much so that another version of essentially the same
functionality was submitted by Kyotaro Horiguchi:
https://postgr.es/m/20150828.173334.114731693.horiguchi.kyotaro@lab.ntt.co.jp
though this commit does not use that code.)
Author: Tomas Vondra. Some code rework by Álvaro.
Reviewed-by: Dean Rasheed, David Rowley, Kyotaro Horiguchi, Jeff Janes,
Ideriha Takeshi
Discussion: https://postgr.es/m/543AFA15.4080608@fuzzy.czhttps://postgr.es/m/20170320190220.ixlaueanxegqd5gr@alvherre.pgsql
This extends the work done in commit 2f5c9d9c9 to provide a more nearly
complete abstraction layer hiding the details of index updating for catalog
changes. That commit only invented abstractions for catalog inserts and
updates, leaving nearby code for catalog deletes still calling the
heap-level routines directly. That seems rather ugly from here, and it
does little to help if we ever want to shift to a storage system in which
indexing work is needed at delete time.
Hence, create a wrapper function CatalogTupleDelete(), and replace calls
of simple_heap_delete() on catalog tuples with it. There are now very
few direct calls of [simple_]heap_delete remaining in the tree.
Discussion: https://postgr.es/m/462.1485902736@sss.pgh.pa.us
This avoids additional translatable strings for each distinct type, as
well as making our quoting style around type names more consistent
(namely, that we don't quote type names). This continues what started
as f402b99501.
Discussion: https://postgr.es/m/20160401170642.GA57509@alvherre.pgsql
Peter Eisentraut
Bruce Momjian
Tom Lane
Thomas Munro
Michael Paquier
Alvaro Herrera
Andrew Gierth
Andres Freund
Peter Eisentraut