We have a lot of code in which option names, which from the user's
viewpoint are logically keywords, are passed through the grammar as plain
identifiers, and then matched to string literals during command execution.
This approach avoids making words into lexer keywords unnecessarily. Some
places matched these strings using plain strcmp, some using pg_strcasecmp.
But the latter should be unnecessary since identifiers would have been
downcased on their way through the parser. Aside from any efficiency
concerns (probably not a big factor), the lack of consistency in this area
creates a hazard of subtle bugs due to different places coming to different
conclusions about whether two option names are the same or different.
Hence, standardize on using strcmp() to match any option names that are
expected to have been fed through the parser.
This does create a user-visible behavioral change, which is that while
formerly all of these would work:
alter table foo set (fillfactor = 50);
alter table foo set (FillFactor = 50);
alter table foo set ("fillfactor" = 50);
alter table foo set ("FillFactor" = 50);
now the last case will fail because that double-quoted identifier is
different from the others. However, none of our documentation says that
you can use a quoted identifier in such contexts at all, and we should
discourage doing so since it would break if we ever decide to parse such
constructs as true lexer keywords rather than poor man's substitutes.
So this shouldn't create a significant compatibility issue for users.
Daniel Gustafsson, reviewed by Michael Paquier, small changes by me
Discussion: https://postgr.es/m/29405B24-564E-476B-98C0-677A29805B84@yesql.se
This clause was superseded by SQL-standard syntax back in 7.3.
We've kept it around for backwards-compatibility purposes ever since;
but 15 years seems like long enough for that, especially seeing that
there are undocumented weirdnesses in how it interacts with the
SQL-standard syntax for specifying the same options.
Michael Paquier, per an observation by Daniel Gustafsson;
some small cosmetic adjustments to nearby code by me.
Discussion: https://postgr.es/m/20180115022748.GB1724@paquier.xyz
AclObjectKind was basically just another enumeration for object types,
and we already have a preferred one for that. It's only used in
aclcheck_error. By using ObjectType instead, we can also give some more
precise error messages, for example "index" instead of "relation".
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
There used to be a lot of different *Type and *Kind symbol groups to
address objects within different commands, most of which have been
replaced by ObjectType, starting with
b256f24264. But this conversion was never
done for the ACL commands until now.
This change ends up being just a plain replacement of the types and
symbols, without any code restructuring needed, except deleting some now
redundant code.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Stephen Frost <sfrost@snowman.net>
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
There are plans to extend the syntax for ANALYZE, so we need to break
the link between VacuumStmt and AnalyzeStmt. But apart from that, the
syntax above is undocumented and, if discovered by users, might give
the impression that the VERBOSE option for VACUUM differs from the
verbose option from ANALYZE, which it does not.
Nathan Bossart, reviewed by Michael Paquier and Masahiko Sawada
Discussion: http://postgr.es/m/D3FC73E2-9B1A-4DB4-8180-55F57D116B4E@amazon.com
Those cases currently crash and supporting them is more work then
originally thought, so we'll just prohibit these scenarios for now.
Author: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Reported-by: Мансур Галиев <gomer94@yandex.ru>
Bug: #14866
This adds a new object type "procedure" that is similar to a function
but does not have a return type and is invoked by the new CALL statement
instead of SELECT or similar. This implementation is aligned with the
SQL standard and compatible with or similar to other SQL implementations.
This commit adds new commands CALL, CREATE/ALTER/DROP PROCEDURE, as well
as ALTER/DROP ROUTINE that can refer to either a function or a
procedure (or an aggregate function, as an extension to SQL). There is
also support for procedures in various utility commands such as COMMENT
and GRANT, as well as support in pg_dump and psql. Support for defining
procedures is available in all the languages supplied by the core
distribution.
While this commit is mainly syntax sugar around existing functionality,
future features will rely on having procedures as a separate object
type.
Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Hash partitioning is useful when you want to partition a growing data
set evenly. This can be useful to keep table sizes reasonable, which
makes maintenance operations such as VACUUM faster, or to enable
partition-wise join.
At present, we still depend on constraint exclusion for partitioning
pruning, and the shape of the partition constraints for hash
partitioning is such that that doesn't work. Work is underway to fix
that, which should both improve performance and make partitioning
pruning work with hash partitioning.
Amul Sul, reviewed and tested by Dilip Kumar, Ashutosh Bapat, Yugo
Nagata, Rajkumar Raghuwanshi, Jesper Pedersen, and by me. A few
final tweaks also by me.
Discussion: http://postgr.es/m/CAAJ_b96fhpJAP=ALbETmeLk1Uni_GFZD938zgenhF49qgDTjaQ@mail.gmail.com
The lower case spellings are C and C++ standard and are used in most
parts of the PostgreSQL sources. The upper case spellings are only used
in some files/modules. So standardize on the standard spellings.
The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so
those are left as is when using those APIs.
In code comments, we use the lower-case spelling for the C concepts and
keep the upper-case spelling for the SQL concepts.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
The update path of an INSERT ... ON CONFLICT DO UPDATE requires SELECT
permission on the columns of the arbiter index, but it failed to check
for that in the case of an arbiter specified by constraint name.
In addition, for a table with row level security enabled, it failed to
check updated rows against the table's SELECT policies when the update
path was taken (regardless of how the arbiter index was specified).
Backpatch to 9.5 where ON CONFLICT DO UPDATE and RLS were introduced.
Security: CVE-2017-15099
Commit d5b760ecb wasn't quite right, on second thought: if the
caller didn't ask for column names then it would happily emit
more Vars than if the caller did ask for column names. This
is surely not a good idea. Advance the aliasp_item whether or
not we're preparing a colnames list.
expandRTE() supposed that an RTE_SUBQUERY subquery must have exactly
as many non-junk tlist items as the RTE has column aliases for it.
This was true at the time the code was written, and is still true so
far as parse analysis is concerned --- but when the function is used
during planning, the subquery might have appeared through insertion
of a view that now has more columns than it did when the outer query
was parsed. This results in a core dump if, for instance, we have
to expand a whole-row Var that references the subquery.
To avoid crashing, we can either stop expanding the RTE when we run
out of aliases, or invent new aliases for the added columns. While
the latter might be more useful, the former is consistent with what
expandRTE() does for composite-returning functions in the RTE_FUNCTION
case, so it seems like we'd better do it that way.
Per bug #14876 from Samuel Horwitz. This has been busted since commit
ff1ea2173 allowed views to acquire more columns, so back-patch to all
supported branches.
Discussion: https://postgr.es/m/20171026184035.1471.82810@wrigleys.postgresql.org
This is the last major omission in our domains feature: you can now
make a domain over anything that's not a pseudotype.
The major complication from an implementation standpoint is that places
that might be creating tuples of a domain type now need to be prepared
to apply domain_check(). It seems better that unprepared code fail
with an error like "<type> is not composite" than that it silently fail
to apply domain constraints. Therefore, relevant infrastructure like
get_func_result_type() and lookup_rowtype_tupdesc() has been adjusted
to treat domain-over-composite as a distinct case that unprepared code
won't recognize, rather than just transparently treating it the same
as plain composite. This isn't a 100% solution to the possibility of
overlooked domain checks, but it catches most places.
In passing, improve typcache.c's support for domains (it can now cache
the identity of a domain's base type), and rewrite the argument handling
logic in jsonfuncs.c's populate_record[set]_worker to reduce duplicative
per-call lookups.
I believe this is code-complete so far as the core and contrib code go.
The PLs need varying amounts of work, which will be tackled in followup
patches.
Discussion: https://postgr.es/m/4206.1499798337@sss.pgh.pa.us
setTargetTable threw an error if the proposed target RangeVar's relname
matched any visible CTE or ENR. This breaks backwards compatibility in
the CTE case, since pre-v10 we never looked for a CTE here at all, so that
CTE names did not mask regular tables. It does seem like a good idea to
throw an error for the ENR case, though, thus causing ENRs to mask tables
for this purpose; ENRs are new in v10 so we're not breaking existing code,
and we may someday want to allow them to be the targets of DML.
To fix that, replace use of getRTEForSpecialRelationTypes, which was
overkill anyway, with use of scanNameSpaceForENR.
A second problem was that the check neglected to verify null schemaname,
so that a CTE or ENR could incorrectly be thought to match a qualified
RangeVar. That happened because getRTEForSpecialRelationTypes relied
on its caller to have checked for null schemaname. Even though the one
remaining caller got it right, this is obviously bug-prone, so move
the check inside getRTEForSpecialRelationTypes.
Also, revert commit 18ce3a4ab's extremely poorly thought out decision to
add a NULL return case to parserOpenTable --- without either documenting
that or adjusting any of the callers to check for it. The current bug
seems to have arisen in part due to working around that bad idea.
In passing, remove the one-line shim functions transformCTEReference and
transformENRReference --- they don't seem to be adding any clarity or
functionality.
Per report from Hugo Mercier (via Julien Rouhaud). Back-patch to v10
where the bug was introduced.
Thomas Munro, with minor editing by me
Discussion: https://postgr.es/m/CAOBaU_YdPVH+PTtiKSSLOiiW3mVDYsnNUekK+XPbHXiP=wrFLA@mail.gmail.com
Flex generates a lot of functions that are not actually used. In order
to avoid coverage figures being ruined by that, mark up the part of the
.l files where the generated code appears by lcov exclusion markers.
That way, lcov will typically only reported on coverage for the .l file,
which is under our control, but not for the .c file.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Not much to say about this; does what it says on the tin.
However, formerly, if there was a column list then the ANALYZE action was
implied; now it must be specified, or you get an error. This is because
it would otherwise be a bit unclear what the user meant if some tables
have column lists and some don't.
Nathan Bossart, reviewed by Michael Paquier and Masahiko Sawada, with some
editorialization by me
Discussion: https://postgr.es/m/E061A8E3-5E3D-494D-94F0-E8A9B312BBFC@amazon.com
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
It is equivalent in ANSI C to write (*funcptr) () and funcptr(). These
two styles have been applied inconsistently. After discussion, we'll
use the more verbose style for plain function pointer variables, to make
it clear that it's a variable, and the shorter style when the function
pointer is in a struct (s.func() or s->func()), because then it's clear
that it's not a plain function name, and otherwise the excessive
punctuation makes some of those invocations hard to read.
Discussion: https://www.postgresql.org/message-id/f52c16db-14ed-757d-4b48-7ef360b1631d@2ndquadrant.com
Index columns are referenced by ordinal number rather than name, e.g.
CREATE INDEX coord_idx ON measured (x, y, (z + t));
ALTER INDEX coord_idx ALTER COLUMN 3 SET STATISTICS 1000;
Incompatibility note for release notes:
\d+ for indexes now also displays Stats Target
Authors: Alexander Korotkov, with contribution by Adrien NAYRAT
Review: Adrien NAYRAT, Simon Riggs
Wordsmith: Simon Riggs
The NAMEDTUPLESTORE patch piggybacked on the infrastructure for
TABLEFUNC/VALUES/CTE RTEs, none of which can ever have dropped columns,
so the possibility was ignored most places. Fix that, including adding a
specification to parsenodes.h about what it's supposed to look like.
In passing, clean up assorted comments that hadn't been maintained
properly by said patch.
Per bug #14799 from Philippe Beaudoin. Back-patch to v10.
Discussion: https://postgr.es/m/20170906120005.25630.84360@wrigleys.postgresql.org
This is a mechanical change in preparation for a later commit that
will change the layout of TupleDesc. Introducing a macro to abstract
the details of where attributes are stored will allow us to change
that in separate step and revise it in future.
Author: Thomas Munro, editorialized by Andres Freund
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAEepm=0ZtQ-SpsgCyzzYpsXS6e=kZWqk3g5Ygn3MDV7A8dabUA@mail.gmail.com
ALTER USER ... SET did not support all the syntax variants of ALTER ROLE
... SET. Fix that, and to avoid further deviations of this kind, unify
many the grammar rules for ROLE/USER/GROUP commands.
Reported-by: Pavel Golub <pavel@microolap.com>
Otherwise, partitioned tables with RETURNING expressions or subject
to a WITH CHECK OPTION do not work properly.
Amit Langote, reviewed by Amit Khandekar and Etsuro Fujita. A few
comment changes by me.
Discussion: http://postgr.es/m/9a39df80-871e-6212-0684-f93c83be4097@lab.ntt.co.jp
This doesn't have a significant impact except that now SECURITY LABEL ON
DOMAIN rejects types that are not domains.
Reported-by: 高增琦 <pgf00a@gmail.com>
Previously, UNBOUNDED meant no lower bound when used in the FROM list,
and no upper bound when used in the TO list, which was OK for
single-column range partitioning, but problematic with multiple
columns. For example, an upper bound of (10.0, UNBOUNDED) would not be
collocated with a lower bound of (10.0, UNBOUNDED), thus making it
difficult or impossible to define contiguous multi-column range
partitions in some cases.
Fix this by using MINVALUE and MAXVALUE instead of UNBOUNDED to
represent a partition column that is unbounded below or above
respectively. This syntax removes any ambiguity, and ensures that if
one partition's lower bound equals another partition's upper bound,
then the partitions are contiguous.
Also drop the constraint prohibiting finite values after an unbounded
column, and just document the fact that any values after MINVALUE or
MAXVALUE are ignored. Previously it was necessary to repeat UNBOUNDED
multiple times, which was needlessly verbose.
Note: Forces a post-PG 10 beta2 initdb.
Report by Amul Sul, original patch by Amit Langote with some
additional hacking by me.
Discussion: https://postgr.es/m/CAAJ_b947mowpLdxL3jo3YLKngRjrq9+Ej4ymduQTfYR+8=YAYQ@mail.gmail.com
check_agg_arguments_walker threw an error upon seeing a SRF or window
function, but that is too aggressive: if the function is within a
sub-select then it's perfectly fine. I broke the SRF case in commit
0436f6bde by copying the logic for window functions ... but that was
broken too, and had been since commit eaccfded9.
Repair both cases in HEAD, and the window function case back to 9.3.
9.2 gets this right.
I misplaced the IF NOT EXISTS clause in commit 7b504eb282, before the
word STATISTICS. Put it where it belongs.
Patch written independently by Amit Langote and myself. I adopted his
submitted test case with a slight edit also.
Reported-by: Bruno Wolff III
Discussion: https://postgr.es/m/20170621004237.GB8337@wolff.to
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
The new indent version includes numerous fixes thanks to Piotr Stefaniak.
The main changes visible in this commit are:
* Nicer formatting of function-pointer declarations.
* No longer unexpectedly removes spaces in expressions using casts,
sizeof, or offsetof.
* No longer wants to add a space in "struct structname *varname", as
well as some similar cases for const- or volatile-qualified pointers.
* Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely.
* Fixes bug where comments following declarations were sometimes placed
with no space separating them from the code.
* Fixes some odd decisions for comments following case labels.
* Fixes some cases where comments following code were indented to less
than the expected column 33.
On the less good side, it now tends to put more whitespace around typedef
names that are not listed in typedefs.list. This might encourage us to
put more effort into typedef name collection; it's not really a bug in
indent itself.
There are more changes coming after this round, having to do with comment
indentation and alignment of lines appearing within parentheses. I wanted
to limit the size of the diffs to something that could be reviewed without
one's eyes completely glazing over, so it seemed better to split up the
changes as much as practical.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
When we reimplemented SRFs in commit 69f4b9c85, our initial choice was
to allow the behavior to vary from historical practice in cases where a
SRF call appeared within a conditional-execution construct (currently,
only CASE or COALESCE). But that was controversial to begin with, and
subsequent discussion has resulted in a consensus that it's better to
throw an error instead of executing the query differently from before,
so long as we can provide a reasonably clear error message and a way to
rewrite the query.
Hence, add a parser mechanism to allow detection of such cases during
parse analysis. The mechanism just requires storing, in the ParseState,
a pointer to the set-returning FuncExpr or OpExpr most recently emitted
by parse analysis. Then the parsing functions for CASE and COALESCE can
detect the presence of a SRF in their arguments by noting whether this
pointer changes while analyzing their arguments. Furthermore, if it does,
it provides a suitable error cursor location for the complaint. (This
means that if there's more than one SRF in the arguments, the error will
point at the last one to be analyzed not the first. While connoisseurs of
parsing behavior might find that odd, it's unlikely the average user would
ever notice.)
While at it, we can also provide more specific error messages than before
about some pre-existing restrictions, such as no-SRFs-within-aggregates.
Also, reject at parse time cases where a NULLIF or IS DISTINCT FROM
construct would need to return a set. We've never supported that, but the
restriction is depended on in more subtle ways now, so it seems wise to
detect it at the start.
Also, provide some documentation about how to rewrite a SRF-within-CASE
query using a custom wrapper SRF.
It turns out that the information_schema.user_mapping_options view
contained an instance of exactly the behavior we're now forbidding; but
rewriting it makes it more clear and safer too.
initdb forced because of user_mapping_options change.
Patch by me, with error message suggestions from Alvaro Herrera and
Andres Freund, pursuant to a complaint from Regina Obe.
Discussion: https://postgr.es/m/000001d2d5de$d8d66170$8a832450$@pcorp.us
generateSerialExtraStmts() was sloppy about handling the case where
SEQUENCE NAME is given with a not-schema-qualified name. It was generating
a CreateSeqStmt with an unqualified sequence name, and an AlterSeqStmt
whose "owned_by" DefElem contained a T_String Value with a null string
pointer in the schema-name position. The generated nextval() argument was
also underqualified. This accidentally failed to fail at runtime, but only
so long as the current default creation namespace at runtime is the right
namespace. That's bogus; the parse-time transformation is supposed to be
inserting the right schema name in all cases, so as to avoid any possible
skew in that selection. I'm not sure this could fail in pg_dump's usage,
but it's still wrong; we have had real bugs in this area before adopting
the policy that parse_utilcmd.c should generate only fully-qualified
auxiliary commands. A slightly lesser problem, which is what led me to
notice this in the first place, is that pprint() dumped core on the
AlterSeqStmt because of the bogus T_String.
Noted while poking into the open problem with ALTER SEQUENCE breaking
pg_upgrade.
There was a grammar ambiguity between SET PUBLICATION name REFRESH and
SET PUBLICATION SKIP REFRESH, because SKIP is not a reserved word. To
resolve that, fold the refresh choice into the WITH options. Refreshing
is the default now.
Reported-by: tushar <tushar.ahuja@enterprisedb.com>
The NumericOnly grammar production accepted ICONST, + ICONST, - ICONST,
FCONST, and - FCONST, but for some reason not + FCONST. This led to
strange inconsistencies like
regression=# set random_page_cost = +4;
SET
regression=# set random_page_cost = 4000000000;
SET
regression=# set random_page_cost = +4000000000;
ERROR: syntax error at or near "4000000000"
(because 4000000000 is too large to be an ICONST). While there's
no actual functional reason to need to write a "+", if we allow
it for integers it seems like we should allow it for numerics too.
It's been like that forever, so back-patch to all supported branches.
Discussion: https://postgr.es/m/30908.1496006184@sss.pgh.pa.us
Fix failure to check that we got a plain Const from const-simplification of
a coercion request. This is the cause of bug #14666 from Tian Bing: there
is an int4 to money cast, but it's only stable not immutable (because of
dependence on lc_monetary), resulting in a FuncExpr that the code was
miserably unequipped to deal with, or indeed even to notice that it was
failing to deal with. Add test cases around this coercion behavior.
In view of the above, sprinkle the code liberally with castNode() macros,
in hope of catching the next such bug a bit sooner. Also, change some
functions that were randomly declared to take Node* to take more specific
pointer types. And change some struct fields that were declared Node*
but could be given more specific types, allowing removal of assorted
explicit casts.
Place PARTITION_MAX_KEYS check a bit closer to the code it's protecting.
Likewise check only-one-key-for-list-partitioning restriction in a less
random place.
Avoid not-per-project-style usages like !strcmp(...).
Fix assorted failures to avoid scribbling on the input of parse
transformation. I'm not sure how necessary this is, but it's entirely
silly for these functions to be expending cycles to avoid that and not
getting it right.
Add guards against partitioning on system columns.
Put backend/nodes/ support code into an order that matches handling
of these node types elsewhere.
Annotate the fact that somebody added location fields to PartitionBoundSpec
and PartitionRangeDatum but forgot to handle them in
outfuncs.c/readfuncs.c. This is fairly harmless for production purposes
(since readfuncs.c would just substitute -1 anyway) but it's still bogus.
It's not worth forcing a post-beta1 initdb just to fix this, but if we
have another reason to force initdb before 10.0, we should go back and
clean this up.
Contrariwise, somebody added location fields to PartitionElem and
PartitionSpec but forgot to teach exprLocation() about them.
Consolidate duplicative code in transformPartitionBound().
Improve a couple of error messages.
Improve assorted commentary.
Re-pgindent the files touched by this patch; this affects a few comment
blocks that must have been added quite recently.
Report: https://postgr.es/m/20170524024550.29935.14396@wrigleys.postgresql.org
Previously, we had the WITH clause in the middle of the command, where
you'd specify both generic options as well as statistic types. Few
people liked this, so this commit changes it to remove the WITH keyword
from that clause and makes it accept statistic types only. (We
currently don't have any generic options, but if we invent in the
future, we will gain a new WITH clause, probably at the end of the
command).
Also, the column list is now specified without parens, which makes the
whole command look more similar to a SELECT command. This change will
let us expand the command to supporting expressions (not just columns
names) as well as multiple tables and their join conditions.
Tom added lots of code comments and fixed some parts of the CREATE
STATISTICS reference page, too; more changes in this area are
forthcoming. He also fixed a potential problem in the alter_generic
regression test, reducing verbosity on a cascaded drop to avoid
dependency on message ordering, as we do in other tests.
Tom also closed a security bug: we documented that table ownership was
required in order to create a statistics object on it, but didn't
actually implement it.
Implement tab-completion for statistics objects. This can stand some
more improvement.
Authors: Alvaro Herrera, with lots of cleanup by Tom Lane
Discussion: https://postgr.es/m/20170420212426.ltvgyhnefvhixm6i@alvherre.pgsql
For CREATE/ALTER PUBLICATION/SUBSCRIPTION, use similar option style as
other statements that use a WITH clause for options.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
It turned out this approach had problems, because a DROP command should
not have any options other than CASCADE and RESTRICT. Instead, always
attempt to drop the slot if there is one configured, but also add an
ALTER SUBSCRIPTION action to set the slot to NONE.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/29431.1493730652@sss.pgh.pa.us
Storing passwords in plaintext hasn't been a good idea for a very long
time, if ever. Now seems like a good time to finally forbid it, since we're
messing with this in PostgreSQL 10 anyway.
Remove the CREATE/ALTER USER UNENCRYPTED PASSSWORD 'foo' syntax, since
storing passwords unencrypted is no longer supported. ENCRYPTED PASSWORD
'foo' is still accepted, but ENCRYPTED is now just a noise-word, it does
the same as just PASSWORD 'foo'.
Likewise, remove the --unencrypted option from createuser, but accept
--encrypted as a no-op for backward compatibility. AFAICS, --encrypted was
a no-op even before this patch, because createuser encrypted the password
before sending it to the server even if --encrypted was not specified. It
added the ENCRYPTED keyword to the SQL command, but since the password was
already in encrypted form, it didn't make any difference. The documentation
was not clear on whether that was intended or not, but it's moot now.
Also, while password_encryption='on' is still accepted as an alias for
'md5', it is now marked as hidden, so that it is not listed as an accepted
value in error hints, for example. That's not directly related to removing
'plain', but it seems better this way.
Reviewed by Michael Paquier
Discussion: https://www.postgresql.org/message-id/16e9b768-fd78-0b12-cfc1-7b6b7f238fde@iki.fi
Declarative partitioning duplicated the TypedTableElement productions,
evidently to remove the need to specify WITH OPTIONS when creating
partitions. Instead, simply make WITH OPTIONS optional in the
TypedTableElement production and remove all of the duplicate
PartitionElement-related productions. This change simplifies the
syntax and makes WITH OPTIONS optional when adding defaults, constraints
or storage parameters to columns when creating either typed tables or
partitions.
Also update pg_dump to no longer include WITH OPTIONS, since it's not
necessary, and update the documentation to reflect that WITH OPTIONS is
now optional.
addRangeTableEntryForENR had a check for pstate != NULL, which Coverity
pointed out was rather useless since it'd already dereferenced pstate
before that. More to the point, we'd established policy in commit
bc93ac12c that we'd require non-NULL pstate for all addRangeTableEntryFor*
functions; this test was evidently copied-and-pasted from some older
version of one of those functions. Make it look more like the others.
In passing, make an elog message look more like the rest of the code,
too.
Michael Paquier
This extends the castNode() notation introduced by commit 5bcab1114 to
provide, in one step, extraction of a list cell's pointer and coercion to
a concrete node type. For example, "lfirst_node(Foo, lc)" is the same
as "castNode(Foo, lfirst(lc))". Almost half of the uses of castNode
that have appeared so far include a list extraction call, so this is
pretty widely useful, and it saves a few more keystrokes compared to the
old way.
As with the previous patch, back-patch the addition of these macros to
pg_list.h, so that the notation will be available when back-patching.
Patch by me, after an idea of Andrew Gierth's.
Discussion: https://postgr.es/m/14197.1491841216@sss.pgh.pa.us
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>
A QueryEnvironment concept is added, which allows new types of
objects to be passed into queries from parsing on through
execution. At this point, the only thing implemented is a
collection of EphemeralNamedRelation objects -- relations which
can be referenced by name in queries, but do not exist in the
catalogs. The only type of ENR implemented is NamedTuplestore, but
provision is made to add more types fairly easily.
An ENR can carry its own TupleDesc or reference a relation in the
catalogs by relid.
Although these features can be used without SPI, convenience
functions are added to SPI so that ENRs can easily be used by code
run through SPI.
The initial use of all this is going to be transition tables in
AFTER triggers, but that will be added to each PL as a separate
commit.
An incidental effect of this patch is to produce a more informative
error message if an attempt is made to modify the contents of a CTE
from a referencing DML statement. No tests previously covered that
possibility, so one is added.
Kevin Grittner and Thomas Munro
Reviewed by Heikki Linnakangas, David Fetter, and Thomas Munro
with valuable comments and suggestions from many others
This reverts commit 8355a011a0, which
turns out to have been a misguided effort. We can't really support
this in a partitioning hierarchy after all for exactly the reasons
stated in the documentation removed by that commit. It's still
possible to use ON CONFLICT .. DO NOTHING (or for that matter ON
CONFLICT .. DO UPDATE) on individual partitions if desired, but
but to allow this on a partitioned table implies that we have some
way of evaluating uniqueness across the whole partitioning
hierarchy, which is false.
Shinoda Noriyoshi noticed that the old code was crashing (which we
could fix, though not in a nice way) and Amit Langote realized
that this was indicative of a fundamental problem with the commit
being reverted here.
Discussion: http://postgr.es/m/ff3dc21d-7204-c09c-50ac-cf11a8c45c81@lab.ntt.co.jp
copyObject() is declared to return void *, which allows easily assigning
the result independent of the input, but it loses all type checking.
If the compiler supports typeof or something similar, cast the result to
the input type. This creates a greater amount of type safety. In some
cases, where the result is assigned to a generic type such as Node * or
Expr *, new casts are now necessary, but in general casts are now
unnecessary in the normal case and indicate that something unusual is
happening.
Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
Fix all perlcritic warnings of severity level 5, except in
src/backend/utils/Gen_dummy_probes.pl, which is automatically generated.
Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
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
Add a column collprovider to pg_collation that determines which library
provides the collation data. The existing choices are default and libc,
and this adds an icu choice, which uses the ICU4C library.
The pg_locale_t type is changed to a union that contains the
provider-specific locale handles. Users of locale information are
changed to look into that struct for the appropriate handle to use.
Also add a collversion column that records the version of the collation
when it is created, and check at run time whether it is still the same.
This detects potentially incompatible library upgrades that can corrupt
indexes and other structures. This is currently only supported by
ICU-provided collations.
initdb initializes the default collation set as before from the `locale
-a` output but also adds all available ICU locales with a "-x-icu"
appended.
Currently, ICU-provided collations can only be explicitly named
collations. The global database locales are still always libc-provided.
ICU support is enabled by configure --with-icu.
Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com>
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
Add functionality for a new subscription to copy the initial data in the
tables and then sync with the ongoing apply process.
For the copying, add a new internal COPY option to have the COPY source
data provided by a callback function. The initial data copy works on
the subscriber by receiving COPY data from the publisher and then
providing it locally into a COPY that writes to the destination table.
A WAL receiver can now execute full SQL commands. This is used here to
obtain information about tables and publications.
Several new options were added to CREATE and ALTER SUBSCRIPTION to
control whether and when initial table syncing happens.
Change pg_dump option --no-create-subscription-slots to
--no-subscription-connect and use the new CREATE SUBSCRIPTION
... NOCONNECT option for that.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Tested-by: Erik Rijkers <er@xs4all.nl>
There is still some inconsistency with the error messages surrounding
foreign servers. Some use the word "foreign" and some don't. My
inclination is to remove all such uses of "foreign" on the basis that
the CREATE/ALTER/DROP SERVER commands don't use the word. However, that
is left for another day. In this patch I have kept to the existing usage
in the affected commands, which omits "foreign".
Anastasia Lubennikova, reviewed by Arthur Zakirov and Ashtosh Bapat.
Discussion: http://postgr.es/m/7c2ab9b8-388a-1ce0-23a3-7acf2a0ed3c6@postgrespro.ru
In DDL commands referring to an existing function, allow omitting the
argument list if the function name is unique in its schema, per SQL
standard.
This uses the same logic that the regproc type uses for finding
functions by name only.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
XMLTABLE is defined by the SQL/XML standard as a feature that allows
turning XML-formatted data into relational form, so that it can be used
as a <table primary> in the FROM clause of a query.
This new construct provides significant simplicity and performance
benefit for XML data processing; what in a client-side custom
implementation was reported to take 20 minutes can be executed in 400ms
using XMLTABLE. (The same functionality was said to take 10 seconds
using nested PostgreSQL XPath function calls, and 5 seconds using
XMLReader under PL/Python).
The implemented syntax deviates slightly from what the standard
requires. First, the standard indicates that the PASSING clause is
optional and that multiple XML input documents may be given to it; we
make it mandatory and accept a single document only. Second, we don't
currently support a default namespace to be specified.
This implementation relies on a new executor node based on a hardcoded
method table. (Because the grammar is fixed, there is no extensibility
in the current approach; further constructs can be implemented on top of
this such as JSON_TABLE, but they require changes to core code.)
Author: Pavel Stehule, Álvaro Herrera
Extensively reviewed by: Craig Ringer
Discussion: https://postgr.es/m/CAFj8pRAgfzMD-LoSmnMGybD0WsEznLHWap8DO79+-GTRAPR4qA@mail.gmail.com
The SQL standard says that you should be able to write "CHARACTER SET foo"
as part of the declaration of a char-type column. We don't implement that,
but a rough form of support has existed in gram.y since commit f10b63923.
That's now sat there for nigh 20 years without anyone fleshing it out ---
and even if someone did, the contemplated approach of having separate data
type name(s) for every character set certainly isn't what we'd do today.
Let's just remove the grammar production; if anyone is ever motivated to
work on this, reinventing the grammar support is a trivial fraction of
what they'd have to do. And we've never documented anything about
supporting such a clause.
Per gripe from Neha Khatri.
Discussion: https://postgr.es/m/CAFO0U+-iOS5oYN5v3SBuZvfhPUTRrkDFEx8w7H17B07Rwg3YUA@mail.gmail.com
Combine DROP of FOREIGN DATA WRAPPER, SERVER, POLICY, RULE, and TRIGGER
into generic DropStmt grammar.
Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
The generic drop support already supported dropping multiple objects of
the same kind at once. But the previous representation
of function signatures across two grammar symbols and structure members
made this cumbersome to do for functions, so it was not supported. Now
that function signatures are represented by a single structure, it's
trivial to add this support. Same for aggregates and operators.
Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
The old function took function name and function argument list as
separate arguments. Now that all function signatures are passed around
as ObjectWithArgs structs, this is no longer necessary and can be
replaced by a function that takes ObjectWithArgs directly. Similarly
for aggregates and operators.
Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
In simpler times, it might have worked to refer to all kinds of objects
by a list of name components and an optional argument list. But this
doesn't work for all objects, which has resulted in a collection of
hacks to place various other nodes types into these fields, which have
to be unpacked at the other end. This makes it also weird to represent
lists of such things in the grammar, because they would have to be lists
of singleton lists, to make the unpacking work consistently. The other
problem is that keeping separate name and args fields makes it awkward
to deal with lists of functions.
Change that by dropping the objargs field and have objname, renamed to
object, be a generic Node, which can then be flexibly assigned and
managed using the normal Node mechanisms. In many cases it will still
be a List of names, in some cases it will be a string Value, for types
it will be the existing Typename, for functions it will now use the
existing ObjectWithArgs node type. Some of the more obscure object
types still use somewhat arbitrary nested lists.
Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
This makes the handling of operators similar to that of functions and
aggregates.
Rename node FuncWithArgs to ObjectWithArgs, to reflect the expanded use.
Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
This makes it consistent with the usage in opclass_item.
Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Versions of flex before 2.5.36 might generate code that results in an
"unused variable" warning, when using %option reentrant. Historically
we've worked around that by specifying -Wno-error, but that's an
unsatisfying solution. The official "fix" for this was just to insert a
dummy reference to the variable, so write a small perl script that edits
the generated C code similarly.
The MSVC side of this is untested, but the buildfarm should soon reveal
if I broke that.
Discussion: https://postgr.es/m/25456.1487437842@sss.pgh.pa.us
Jeff Janes noted that the error cursor position shown for some errors
would vary when operator_precedence_warning is turned on. We'd prefer
that option to have no undocumented effects, so this isn't desirable.
To fix, make sure that an AEXPR_PAREN node has the same exprLocation
as its child node.
(Note: it would be a little cheaper to use @2 here instead of an
exprLocation call, but there are cases where that wouldn't produce
the identical answer, so don't do it like that.)
Back-patch to 9.5 where this feature was introduced.
Discussion: https://postgr.es/m/CAMkU=1ykK+VhhcQ4Ky8KBo9FoaUJH3f3rDQB8TkTXi-ZsBRUkQ@mail.gmail.com
The core of the functionality was already implemented when
pg_import_system_collations was added. This just exposes it as an
option in the SQL command.
This stores a data type, required to be an integer type, with the
sequence. The sequences min and max values default to the range
supported by the type, and they cannot be set to values exceeding that
range. The internal implementation of the sequence is not affected.
Change the serial types to create sequences of the appropriate type.
This makes sure that the min and max values of the sequence for a serial
column match the range of values supported by the table column. So the
sequence can no longer overflow the table column.
This also makes monitoring for sequence exhaustion/wraparound easier,
which currently requires various contortions to cross-reference the
sequences with the table columns they are used with.
This commit also effectively reverts the pg_sequence column reordering
in f3b421da5f, because the new seqtypid
column allows us to fill the hole in the struct and create a more
natural overall column ordering.
Reviewed-by: Steve Singer <steve@ssinger.info>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
When I wrote commit ab1f0c822, I really missed the castNode() macro that
Peter E. had proposed shortly before. This back-fills the uses I would
have put it to. It's probably not all that significant, but there are
more assertions here than there were before, and conceivably they will
help catch any bugs associated with those representation changes.
I left behind a number of usages like "(Query *) copyObject(query_var)".
Those could have been converted as well, but Peter has proposed another
notational improvement that would handle copyObject cases automatically,
so I let that be for now.
There's really no situation where we don't want these unknown-to-text
conversions to happen. The alternative is failure anyway, and the one
caller that was passing "false" did so only because it expected the
case could not arise. Might as well simplify the code.
Discussion: https://postgr.es/m/CAH2L28uwwbL9HUM-WR=hromW1Cvamkn7O-g8fPY2m=_7muJ0oA@mail.gmail.com
Previously, we left such literals alone if the query or subquery had
no properties forcing a type decision to be made (such as an ORDER BY or
DISTINCT clause using that output column). This meant that "unknown" could
be an exposed output column type, which has never been a great idea because
it could result in strange failures later on. For example, an outer query
that tried to do any operations on an unknown-type subquery output would
generally fail with some weird error like "failed to find conversion
function from unknown to text" or "could not determine which collation to
use for string comparison". Also, if the case occurred in a CREATE VIEW's
query then the view would have an unknown-type column, causing similar
failures in queries trying to use the view.
To fix, at the tail end of parse analysis of a query, forcibly convert any
remaining "unknown" literals in its SELECT or RETURNING list to type text.
However, provide a switch to suppress that, and use it in the cases of
SELECT inside a set operation or INSERT command. In those cases we already
had type resolution rules that make use of context information from outside
the subquery proper, and we don't want to change that behavior.
Also, change creation of an unknown-type column in a relation from a
warning to a hard error. The error should be unreachable now in CREATE
VIEW or CREATE MATVIEW, but it's still possible to explicitly say "unknown"
in CREATE TABLE or CREATE (composite) TYPE. We want to forbid that because
it's nothing but a foot-gun.
This change creates a pg_upgrade failure case: a matview that contains an
unknown-type column can't be pg_upgraded, because reparsing the matview's
defining query will now decide that the column is of type text, which
doesn't match the cstring-like storage that the old materialized column
would actually have. Add a checking pass to detect that. While at it,
we can detect tables or composite types that would fail, essentially
for free. Those would fail safely anyway later on, but we might as
well fail earlier.
This patch is by me, but it owes something to previous investigations
by Rahila Syed. Also thanks to Ashutosh Bapat and Michael Paquier for
review.
Discussion: https://postgr.es/m/CAH2L28uwwbL9HUM-WR=hromW1Cvamkn7O-g8fPY2m=_7muJ0oA@mail.gmail.com
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
INSERT ... VALUES with a single VALUES row is implemented quite differently
from the general VALUES case. A user-visible implication of that is that
we accept SRFs in the single-row case, but not in the multi-row case.
That's a historical artifact no doubt, but in view of the lack of field
complaints, I'm not excited about fixing it right now.
However, check_srf_call_placement() needs to know about this, first because
it should throw an error in the unsupported case, and second because it
should set p_hasTargetSRFs in the single-row case (because we treat that
like a SELECT tlist). That's an oversight in commit a4c35ea1c.
To fix, split EXPR_KIND_VALUES into two values. So far as I can see,
this is the only place where we need to distinguish the two cases at
present; but there might be more later.
Patch by me, per report from Andres Freund.
Discussion: https://postgr.es/m/20170116081548.zg63zltblwimpfgp@alap3.anarazel.de
This patch makes several changes that improve the consistency of
representation of lists of statements. It's always been the case
that the output of parse analysis is a list of Query nodes, whatever
the types of the individual statements in the list. This patch brings
similar consistency to the outputs of raw parsing and planning steps:
* The output of raw parsing is now always a list of RawStmt nodes;
the statement-type-dependent nodes are one level down from that.
* The output of pg_plan_queries() is now always a list of PlannedStmt
nodes, even for utility statements. In the case of a utility statement,
"planning" just consists of wrapping a CMD_UTILITY PlannedStmt around
the utility node. This list representation is now used in Portal and
CachedPlan plan lists, replacing the former convention of intermixing
PlannedStmts with bare utility-statement nodes.
Now, every list of statements has a consistent head-node type depending
on how far along it is in processing. This allows changing many places
that formerly used generic "Node *" pointers to use a more specific
pointer type, thus reducing the number of IsA() tests and casts needed,
as well as improving code clarity.
Also, the post-parse-analysis representation of DECLARE CURSOR is changed
so that it looks more like EXPLAIN, PREPARE, etc. That is, the contained
SELECT remains a child of the DeclareCursorStmt rather than getting flipped
around to be the other way. It's now true for both Query and PlannedStmt
that utilityStmt is non-null if and only if commandType is CMD_UTILITY.
That allows simplifying a lot of places that were testing both fields.
(I think some of those were just defensive programming, but in many places,
it was actually necessary to avoid confusing DECLARE CURSOR with SELECT.)
Because PlannedStmt carries a canSetTag field, we're also able to get rid
of some ad-hoc rules about how to reconstruct canSetTag for a bare utility
statement; specifically, the assumption that a utility is canSetTag if and
only if it's the only one in its list. While I see no near-term need for
relaxing that restriction, it's nice to get rid of the ad-hocery.
The API of ProcessUtility() is changed so that what it's passed is the
wrapper PlannedStmt not just the bare utility statement. This will affect
all users of ProcessUtility_hook, but the changes are pretty trivial; see
the affected contrib modules for examples of the minimum change needed.
(Most compilers should give pointer-type-mismatch warnings for uncorrected
code.)
There's also a change in the API of ExplainOneQuery_hook, to pass through
cursorOptions instead of expecting hook functions to know what to pick.
This is needed because of the DECLARE CURSOR changes, but really should
have been done in 9.6; it's unlikely that any extant hook functions
know about using CURSOR_OPT_PARALLEL_OK.
Finally, teach gram.y to save statement boundary locations in RawStmt
nodes, and pass those through to Query and PlannedStmt nodes. This allows
more intelligent handling of cases where a source query string contains
multiple statements. This patch doesn't actually do anything with the
information, but a follow-on patch will. (Passing this information through
cleanly is the true motivation for these changes; while I think this is all
good cleanup, it's unlikely we'd have bothered without this end goal.)
catversion bump because addition of location fields to struct Query
affects stored rules.
This patch is by me, but it owes a good deal to Fabien Coelho who did
a lot of preliminary work on the problem, and also reviewed the patch.
Discussion: https://postgr.es/m/alpine.DEB.2.20.1612200926310.29821@lancre
Tom Lane
Peter Eisentraut
Alvaro Herrera
Robert Haas
Bruce Momjian
Magnus Hagander
Dean Rasheed
Simon Riggs
Andres Freund
Heikki Linnakangas
Stephen Frost
Kevin Grittner
Teodor Sigaev
Andrew Dunstan