The only reason this didn't work before was that parserOpenTable()
rejects composite types. So use relation_openrv() directly and
manually do the errposition() setup that parserOpenTable() does.
The hstore and json datatypes both have record-conversion functions that
pay attention to column names in the composite values they're handed.
We used to not worry about inserting correct field names into tuple
descriptors generated at runtime, but given these examples it seems
useful to do so. Observe the nicer-looking results in the regression
tests whose results changed.
catversion bump because there is a subtle change in requirements for stored
rule parsetrees: RowExprs from ROW() constructs now have to include field
names.
Andrew Dunstan and Tom Lane
We don't normally allow quals to be pushed down into a view created
with the security_barrier option, but functions without side effects
are an exception: they're OK. This allows much better performance in
common cases, such as when using an equality operator (that might
even be indexable).
There is an outstanding issue here with the CREATE FUNCTION / ALTER
FUNCTION syntax: there's no way to use ALTER FUNCTION to unset the
leakproof flag. But I'm committing this as-is so that it doesn't
have to be rebased again; we can fix up the grammar in a future
commit.
KaiGai Kohei, with some wordsmithing by me.
These were added to kwlist.h as unreserved keywords in separate patches,
but authors forgot to add them to the corresponding list in gram.y.
Because of that, even though they were supposed to be unreserved keywords,
they could not be used as identifiers. src/tools/check_keywords.pl is your
friend.
If somebody puts a window function in WHERE, we should complain about that
in so many words. The previous coding tended to complain about the window
function's arguments instead, which is likely to be misleading to users who
are unclear on the semantics of window functions; as seen for example in
bug #6440 from Matyas Novak.
Just another example of how "add new code at the end" is frequently a bad
heuristic.
In the previous coding, it was possible for a relation to be created
via CREATE TABLE, CREATE VIEW, CREATE SEQUENCE, CREATE FOREIGN TABLE,
etc. in a schema while that schema was meanwhile being concurrently
dropped. This led to a pg_class entry with an invalid relnamespace
value. The same problem could occur if a relation was moved using
ALTER .. SET SCHEMA while the target schema was being concurrently
dropped. This patch prevents both of those scenarios by locking the
schema to which the relation is being added using AccessShareLock,
which conflicts with the AccessExclusiveLock taken by DROP.
As a desirable side effect, this also prevents the use of CREATE OR
REPLACE VIEW to queue for an AccessExclusiveLock on a relation on which
you have no rights: that will now fail immediately with a permissions
error, before trying to obtain a lock.
We need similar protection for all other object types, but as everything
other than relations uses a slightly different set of code paths, I'm
leaving that for a separate commit.
Original complaint (as far as I could find) about CREATE by Nikhil
Sontakke; risk for ALTER .. SET SCHEMA pointed out by Tom Lane;
further details by Dan Farina; patch by me; review by Hitoshi Harada.
The original implementation of this interpreted it as a kind of
"inheritance" facility and named all the internal structures
accordingly. This turned out to be very confusing, because it has
nothing to do with the INHERITS feature. So rename all the internal
parser infrastructure, update the comments, adjust the error messages,
and split up the regression tests.
ALTER DOMAIN / DROP CONSTRAINT on a nonexistent constraint name did
not report any error. Now it reports an error. The IF EXISTS option
was added to get the usual behavior of ignoring nonexistent objects to
drop.
Because coerce_type recurses into the argument of a CollateExpr,
coerce_to_target_type's longstanding code for detecting whether coerce_type
had actually done anything (to wit, returned a different node than it
passed in) was broken in 9.1. This resulted in unexpected failures in
hide_coercion_node; which was not the latter's fault, since it's critical
that we never call it on anything that wasn't inserted by coerce_type.
(Else we might decide to "hide" a user-written function call.)
Fix by removing and replacing the CollateExpr in coerce_to_target_type
itself. This is all pretty ugly but I don't immediately see a way to make
it nicer.
Per report from Jean-Yves F. Barbier.
When a view is marked as a security barrier, it will not be pulled up
into the containing query, and no quals will be pushed down into it,
so that no function or operator chosen by the user can be applied to
rows not exposed by the view. Views not configured with this
option cannot provide robust row-level security, but will perform far
better.
Patch by KaiGai Kohei; original problem report by Heikki Linnakangas
(in October 2009!). Review (in earlier versions) by Noah Misch and
others. Design advice by Tom Lane and myself. Further review and
cleanup by me.
You could already rename domains using ALTER TYPE, but with this new
command it is more consistent with how other commands treat domains as
a subcategory of types.
This adds support for the more or less SQL-conforming USAGE privilege
on types and domains. The intent is to be able restrict which users
can create dependencies on types, which restricts the way in which
owners can alter types.
reviewed by Yeb Havinga
In the previous coding, callers were faced with an awkward choice:
look up the name, do permissions checks, and then lock the table; or
look up the name, lock the table, and then do permissions checks.
The first choice was wrong because the results of the name lookup
and permissions checks might be out-of-date by the time the table
lock was acquired, while the second allowed a user with no privileges
to interfere with access to a table by users who do have privileges
(e.g. if a malicious backend queues up for an AccessExclusiveLock on
a table on which AccessShareLock is already held, further attempts
to access the table will be blocked until the AccessExclusiveLock
is obtained and the malicious backend's transaction rolls back).
To fix, allow callers of RangeVarGetRelid() to pass a callback which
gets executed after performing the name lookup but before acquiring
the relation lock. If the name lookup is retried (because
invalidation messages are received), the callback will be re-executed
as well, so we get the best of both worlds. RangeVarGetRelid() is
renamed to RangeVarGetRelidExtended(); callers not wishing to supply
a callback can continue to invoke it as RangeVarGetRelid(), which is
now a macro. Since the only one caller that uses nowait = true now
passes a callback anyway, the RangeVarGetRelid() macro defaults nowait
as well. The callback can also be used for supplemental locking - for
example, REINDEX INDEX needs to acquire the table lock before the index
lock to reduce deadlock possibilities.
There's a lot more work to be done here to fix all the cases where this
can be a problem, but this commit provides the general infrastructure
and fixes the following specific cases: REINDEX INDEX, REINDEX TABLE,
LOCK TABLE, and and DROP TABLE/INDEX/SEQUENCE/VIEW/FOREIGN TABLE.
Per discussion with Noah Misch and Alvaro Herrera.
The EvalPlanQual machinery assumes that whole-row Vars generated for the
outputs of non-table RTEs will be of composite types. However, for the
case where the RTE is a function call returning a scalar type, we were
doing the wrong thing, as a result of sharing code with a parser case
where the function's scalar output is wanted. (Or at least, that's what
that case has done historically; it does seem a bit inconsistent.)
To fix, extend makeWholeRowVar's API so that it can support both use-cases.
This fixes Belinda Cussen's report of crashes during concurrent execution
of UPDATEs involving joins to the result of UNNEST() --- in READ COMMITTED
mode, we'd run the EvalPlanQual machinery after a conflicting row update
commits, and it was expecting to get a HeapTuple not a scalar datum from
the "wholerowN" variable referencing the function RTE.
Back-patch to 9.0 where the current EvalPlanQual implementation appeared.
In 9.1 and up, this patch also fixes failure to attach the correct
collation to the Var generated for a scalar-result case. An example:
regression=# select upper(x.*) from textcat('ab', 'cd') x;
ERROR: could not determine which collation to use for upper() function
The WITH [NO] DATA option was not supported, nor the ability to specify
replacement column names; the former limitation wasn't even documented, as
per recent complaint from Naoya Anzai. Fix by moving the responsibility
for supporting these options into the executor. It actually takes less
code this way ...
catversion bump due to change in representation of IntoClause, which might
affect stored rules.
This gets rid of an impressive amount of duplicative code, with only
minimal behavior changes. DROP FOREIGN DATA WRAPPER now requires object
ownership rather than superuser privileges, matching the documentation
we already have. We also eliminate the historical warning about dropping
a built-in function as unuseful. All operations are now performed in the
same order for all object types handled by dropcmds.c.
KaiGai Kohei, with minor revisions by me
For a very long time, one of the parser's heuristics for resolving
ambiguous operator calls has been to assume that unknown-type literals are
of the same type as the other input (if it's known). However, this was
only used in the first step of quickly checking for an exact-types match,
and thus did not help in resolving matches that require coercion, such as
matches to polymorphic operators. As we add more polymorphic operators,
this becomes more of a problem. This patch adds another use of the same
heuristic as a last-ditch check before failing to resolve an ambiguous
operator or function call. In particular this will let us define the range
inclusion operator in a less limited way (to come in a follow-on patch).
A transaction can export a snapshot with pg_export_snapshot(), and then
others can import it with SET TRANSACTION SNAPSHOT. The data does not
leave the server so there are not security issues. A snapshot can only
be imported while the exporting transaction is still running, and there
are some other restrictions.
I'm not totally convinced that we've covered all the bases for SSI (true
serializable) mode, but it works fine for lesser isolation modes.
Joachim Wieland, reviewed by Marko Tiikkaja, and rather heavily modified
by Tom Lane
transform_null_equals is only supposed to affect "foo = NULL" expressions
given directly by the user, not the internal "foo = NULL" expression
generated from CASE-WHEN.
This fixes bug #6242, reported by Sergey. Backpatch to all supported
branches.
We'll now use "exists" for EXISTS(SELECT ...), "array" for ARRAY(SELECT
...), or the sub-select's own result column name for a simple expression
sub-select. Previously, you usually got "?column?" in such cases.
Marti Raudsepp, reviewed by Kyotaro Horiugchi
As per my recent proposal, this refactors things so that these typedefs and
macros are available in a header that can be included in frontend-ish code.
I also changed various headers that were undesirably including
utils/timestamp.h to include datatype/timestamp.h instead. Unsurprisingly,
this showed that half the system was getting utils/timestamp.h by way of
xlog.h.
No actual code changes here, just header refactoring.
walsender.h should depend on xlog.h, not vice versa. (Actually, the
inclusion was circular until a couple hours ago, which was even sillier;
but Bruce broke it in the expedient rather than logically correct
direction.) Because of that poor decision, plus blind application of
pgrminclude, we had a situation where half the system was depending on
xlog.h to include such unrelated stuff as array.h and guc.h. Clean up
the header inclusion, and manually revert a lot of what pgrminclude had
done so things build again.
This episode reinforces my feeling that pgrminclude should not be run
without adult supervision. Inclusion changes in header files in particular
need to be reviewed with great care. More generally, it'd be good if we
had a clearer notion of module layering to dictate which headers can sanely
include which others ... but that's a big task for another day.
This requires adjusting the API for syscache callback functions: they now
get a hash value, not a TID, to identify the target tuple. Most of them
weren't paying any attention to that argument anyway, but plancache did
require a small amount of fixing.
Also, improve performance a trifle by avoiding sending duplicate inval
messages when a heap_update isn't changing the catcache lookup columns.
This requires a new shared catalog, pg_shseclabel.
Along the way, fix the security_label regression tests so that they
don't monkey with the labels of any pre-existing objects. This is
unlikely to matter in practice, since only the label for the "dummy"
provider was being manipulated. But this way still seems cleaner.
KaiGai Kohei, with fairly extensive hacking by me.
In the previous coding, we would look up a relation in RangeVarGetRelid,
lock the resulting OID, and then AcceptInvalidationMessages(). While
this was sufficient to ensure that we noticed any changes to the
relation definition before building the relcache entry, it didn't
handle the possibility that the name we looked up no longer referenced
the same OID. This was particularly problematic in the case where a
table had been dropped and recreated: we'd latch on to the entry for
the old relation and fail later on. Now, we acquire the relation lock
inside RangeVarGetRelid, and retry the name lookup if we notice that
invalidation messages have been processed meanwhile. Many operations
that would previously have failed with an error in the presence of
concurrent DDL will now succeed.
There is a good deal of work remaining to be done here: many callers
of RangeVarGetRelid still pass NoLock for one reason or another. In
addition, nothing in this patch guards against the possibility that
the meaning of an unqualified name might change due to the creation
of a relation in a schema earlier in the user's search path than the
one where it was previously found. Furthermore, there's nothing at
all here to guard against similar race conditions for non-relations.
For all that, it's a start.
Noah Misch and Robert Haas
get_op_btree_interpretation assumed this in order to save some duplication
of code, but it's not true in general anymore because we added <> support
to btree_gist. (We still assume it for btree opclasses, though.)
Also, essentially the same logic was baked into predtest.c. Get rid of
that duplication by generalizing get_op_btree_interpretation so that it
can be used by predtest.c.
Per bug report from Denis de Bernardy and investigation by Jeff Davis,
though I didn't use Jeff's patch exactly as-is.
Back-patch to 9.1; we do not support this usage before that.
Unlike the relistemp field which it replaced, relpersistence must be
set correctly quite early during the table creation process, as we
rely on it quite early on for a number of purposes, including security
checks. Normally, this is set based on whether the user enters CREATE
TABLE, CREATE UNLOGGED TABLE, or CREATE TEMPORARY TABLE, but a
relation may also be made implicitly temporary by creating it in
pg_temp. This patch fixes the handling of that case, and also
disables creation of unlogged tables in temporary tablespace (such
table indeed skip WAL-logging, but we reject an explicit
specification) and creation of relations in the temporary schemas of
other sessions (which is not very sensible, and didn't work right
anyway).
Report by Amit Khandekar.
This means that they can initially be added to a large existing table
without checking its initial contents, but new tuples must comply to
them; a separate pass invoked by ALTER TABLE / VALIDATE can verify
existing data and ensure it complies with the constraint, at which point
it is marked validated and becomes a normal part of the table ecosystem.
An non-validated CHECK constraint is ignored in the planner for
constraint_exclusion purposes; when validated, cached plans are
recomputed so that partitioning starts working right away.
This patch also enables domains to have unvalidated CHECK constraints
attached to them as well by way of ALTER DOMAIN / ADD CONSTRAINT / NOT
VALID, which can later be validated with ALTER DOMAIN / VALIDATE
CONSTRAINT.
Thanks to Thom Brown, Dean Rasheed and Jaime Casanova for the various
reviews, and Robert Hass for documentation wording improvement
suggestions.
This patch was sponsored by Enova Financial.
Since the names try_relation_openrv() and try_heap_openrv() don't seem
quite appropriate, rename the functions to relation_openrv_extended()
and heap_openrv_extended(). This is also more general, if we have a
future need for additional parameters that are of interest to only a
few callers.
This is infrastructure for a forthcoming patch to allow
get_object_address() to take a missing_ok argument as well.
Patch by me, review by Noah Misch.
This is just like serial and bigserial, except it generates an int2
column rather than int4 or int8.
Mike Pultz, reviewed by Brar Piening and Josh Kupershmidt
Initially, we use this only to eliminate calls to the varchar()
function in cases where the length is not being reduced and, therefore,
the function call is equivalent to a RelabelType operation. The most
significant effect of this is that we can avoid a table rewrite when
changing a varchar(X) column to a varchar(Y) column, where Y > X.
Noah Misch, reviewed by me and Alexey Klyukin
The initial commit of the ALTER TABLE ADD FOREIGN KEY NOT VALID feature
failed to support labeling such constraints as deferrable. The best fix
for this seems to be to fold NOT VALID into ConstraintAttributeSpec.
That's a bit more general than the documented syntax, but it allows
better-targeted syntax error messages.
In addition, do some mostly-but-not-entirely-cosmetic code review for
the whole NOT VALID patch.
This use-case was broken in commit 529cb267a6
of 2010-10-21, in which I commented "For the moment, we just forbid such
matching. We might later wish to insert an automatic downcast to the
underlying array type, but such a change should also change matching of
domains to ANYELEMENT for consistency". We still lack consensus about what
to do with ANYELEMENT; but not matching ANYARRAY is a clear loss of
functionality compared to prior releases, so let's go ahead and make that
happen. Per complaint from Regina Obe and extensive subsequent discussion.
We were trying to make that strictly an internal implementation detail,
but it turns out that it's exposed anyway when dumping a view defined
like
CREATE VIEW test_view AS VALUES (1), (2), (3) ORDER BY 1;
This comes out as
CREATE VIEW ... ORDER BY "*VALUES*".column1;
which fails to parse when reloading the dump.
Hacking ruleutils.c to suppress the column qualification looks like it'd
be a risky business, so instead promote the RTE alias to full-fledged
usability.
Per bug #6049 from Dylan Adams. Back-patch to all supported branches.
The existence of a btree opclass accepting composite types caused us to
assume that every composite type is sortable. This isn't true of course;
we need to check if the column types are all sortable. There was logic
for this for the case of array comparison (ie, check that the element
type is sortable), but we missed the point for rowtypes. Per Teodor's
report of an ANALYZE failure for an unsortable composite type.
Rather than just add some more ad-hoc logic for this, I moved knowledge of
the issue into typcache.c. The typcache will now only report out array_eq,
record_cmp, and friends as usable operators if the array or composite type
will work with those functions.
Unfortunately we don't have enough info to do this for anonymous RECORD
types; in that case, just assume it will work, and take the runtime failure
as before if it doesn't.
This patch might be a candidate for back-patching at some point, but
given the lack of complaints from the field, I'd rather just test it in
HEAD for now.
Note: most of the places touched in this patch will need further work
when we get around to supporting hashing of record types.
Use ColLabel in place of ColId, so that reserved words are accepted as if
they were not reserved. Also, remove BCONST and XCONST, which were never
documented as allowed. Allowing those exposes to users an implementation
detail, namely the format in which the lexer outputs such constants, that
seems unwise to expose.
No documentation change needed, since this just makes the code act more
like you'd expect from reading the CREATE TRIGGER man page.
Per complaint from Szymon Guz and subsequent discussion.
These were labeled with precedences just to avoid attaching explicit
precedences to the productions in which they were the last terminal symbol.
Since a terminal symbol precedence marking can affect many other things
too, it seems like better practice to attach precedence labels to the
productions, and not mark the terminal symbols.
Ideally we'd also remove the precedence attached to NULL_P, but it turns
out that we are actually depending on that having a precedence higher than
POSTFIXOP, else we get a shift/reduce conflict for postfix operators in
b_expr. (Which more or less proves my point about these markings having a
high risk of unexpected consequences.) For the moment, move NULL_P into
the set of keywords grouped with IDENT, so that at least it will act
similarly to non-keywords; and document the interaction.
Per bug #5988, reported by Marko Tiikkaja, and further analyzed by Tom
Lane, the previous coding was broken in several respects: even if the
target table already existed, a subsequent CREATE TABLE IF NOT EXISTS
might try to add additional constraints or sequences-for-serial
specified in the new CREATE TABLE statement.
In passing, this also fixes a minor information leak: it's no longer
possible to figure out whether a schema to which you don't have CREATE
access contains a sequence named like "x_y_seq" by attempting to create a
table in that schema called "x" with a serial column called "y".
Some more refactoring of this code in the future might be warranted,
but that will need to wait for a later major release.
Instead, foreign tables are treated just like views: permissions can
be granted using GRANT privilege ON [TABLE] foreign_table_name TO role,
and revoked similarly. GRANT/REVOKE .. FOREIGN TABLE is no longer
supported, just as we don't support GRANT/REVOKE .. VIEW. The set of
accepted permissions for foreign tables is now identical to the set for
regular tables, and views.
Per report from Thom Brown, and subsequent discussion.
This patch is almost entirely cosmetic --- mostly cleaning up a lot of
neglected comments, and fixing code layout problems in places where the
patch made lines too long and then pgindent did weird things with that.
I did find a bug-of-omission in equalTupleDescs().
This syntax allows a standalone table to be made into a typed table,
or a typed table to be made standalone. This is possibly a mildly
useful feature in its own right, but the real motivation for this
change is that we need it to make pg_upgrade work with typed tables.
This doesn't actually fix that problem, but it's necessary
infrastructure.
Noah Misch
Per spec we ought to apply select_common_collation() across the expressions
in each column of the VALUES table. The original coding was just taking
the first row and assuming it was representative.
This patch adds a field to struct RangeTblEntry to carry the resolved
collations, so initdb is forced for changes in stored rule representation.
This also ensures that we take a relation lock on the composite type when
creating a typed table, which is necessary to prevent the composite type
and the typed table from getting out of step in the face of concurrent
DDL.
Noah Misch, with some changes.
If the referencing and referenced columns have different collations,
the parser will be unable to resolve which collation to use unless it's
helped out in this way. The effects are sometimes masked, if we end up
using a non-collation-sensitive plan; but if we do use a mergejoin
we'll see a failure, as recently noted by Robert Haas.
The SQL spec states that the referenced column's collation should be used
to resolve RI checks, so that's what we do. Note however that we currently
don't append a COLLATE clause when writing a query that examines only the
referencing column. If we ever support collations that have varying
notions of equality, that will have to be changed. For the moment, though,
it's preferable to leave it off so that we can use a normal index on the
referencing column.
This warning is new in gcc 4.6 and part of -Wall. This patch cleans
up most of the noise, but there are some still warnings that are
trickier to remove.
Remove crude hack that tried to propagate collation through a
function-returning-record, ie, from the function's arguments to individual
fields selected from its result record. That is just plain inconsistent,
because the function result is composite and cannot have a collation;
and there's no hope of making this kind of action-at-a-distance work
consistently. Adjust regression test cases that expected this to happen.
Meanwhile, the behavior of casting to a domain with a declared collation
stays the same as it was, since that seemed to be the consensus.
All the other fields of the constant are being extracted from the syscache
entry we already have, so handle collation similarly. (There don't seem
to be any other uses for the new function at the moment.)
Previous patches took care of assorted places that call transformExpr from
outside the main parser, but I overlooked the fact that some places use
transformWhereClause as a shortcut for transformExpr + coerce_to_boolean.
In particular this broke collation-sensitive index WHERE clauses, as per
report from Thom Brown. Trigger WHEN and rule WHERE clauses too.
I'm not forcing initdb for this fix, but any affected indexes, triggers,
or rules will need to be dropped and recreated.
This mostly involves making it work with the objectaddress.c framework,
which does most of the heavy lifting. In that vein, change
GetForeignDataWrapperOidByName to get_foreign_data_wrapper_oid and
GetForeignServerOidByName to get_foreign_server_oid, to match the
pattern we use for other object types.
Robert Haas and Shigeru Hanada
I'm not sure these have any non-cosmetic implications, but I'm not sure
they don't, either. In particular, ensure the CaseTestExpr generated
by transformAssignmentIndirection to represent the base target column
carries the correct collation, because parse_collate.c won't fix that.
Tweak lsyscache.c API so that we can get the appropriate collation
without an extra syscache lookup.
In nearly all cases, the caller already knows the correct collation, and
in a number of places, the value the caller has handy is more correct than
the default for the type would be. (In particular, this patch makes it
significantly less likely that eval_const_expressions will result in
changing the exposed collation of an expression.) So an internal lookup
is both expensive and wrong.
Ensure that parameter symbols receive collation from the function's
resolved input collation, and fix inlining to behave properly.
BTW, this commit lays about 90% of the infrastructure needed to support
use of argument names in SQL functions. Parsing of parameters is now
done via the parser-hook infrastructure ... we'd just need to supply
a column-ref hook ...
This restores a parse error that was thrown (though only in the ORDER BY
case) by the original collation patch. I had removed it in my recent
revisions because it was thrown at a place where collations now haven't
been computed yet; but I thought of another way to handle it.
Throwing the error at parse time, rather than leaving it to be done at
runtime, is good because a syntax error pointer is helpful for localizing
the problem. We can reasonably assume that the comparison function for a
collatable datatype will complain if it doesn't have a collation to use.
Now the planner might choose to implement GROUP or DISTINCT via hashing,
in which case no runtime error would actually occur, but it seems better
to throw error consistently rather than let the error depend on what the
planner chooses to do. Another possible objection is that the user might
specify a nondefault sort operator that doesn't care about collation
... but that's surely an uncommon usage, and it wouldn't hurt him to throw
in a COLLATE clause anyway. This change also makes the ORDER BY/GROUP
BY/DISTINCT case more consistent with the UNION/INTERSECT/EXCEPT case,
which was already coded to throw this error even though the same objections
could be raised there.
All expression nodes now have an explicit output-collation field, unless
they are known to only return a noncollatable data type (such as boolean
or record). Also, nodes that can invoke collation-aware functions store
a separate field that is the collation value to pass to the function.
This avoids confusion that arises when a function has collatable inputs
and noncollatable output type, or vice versa.
Also, replace the parser's on-the-fly collation assignment method with
a post-pass over the completed expression tree. This allows us to use
a more complex (and hopefully more nearly spec-compliant) assignment
rule without paying for it in extra storage in every expression node.
Fix assorted bugs in the planner's handling of collations by making
collation one of the defining properties of an EquivalenceClass and
by converting CollateExprs into discardable RelabelType nodes during
expression preprocessing.
This patch causes unknown-type Consts to be coerced to the resolved output
type of the set operation at parse time. Formerly such Consts were left
alone until late in the planning stage. The disadvantage of that approach
is that it disables some optimizations, because the planner sees the set-op
leaf query as having different output column types than the overall set-op.
We saw an example of that in a recent performance gripe from Claudio
Freire.
Fixing such a Const requires scribbling on the leaf query in
transformSetOperationTree, but that should be all right since if the leaf
query's semantics depended on that output column, it would already have
resolved the unknown to something else.
Most of the bulk of this patch is a simple adjustment of
transformSetOperationTree's API so that upper levels can get at the
TargetEntry containing a Const to be replaced: it now returns a list of
TargetEntries, instead of just the bare expressions.
CollateClause is now used only in raw grammar output, and CollateExpr after
parse analysis. This is for clarity and to avoid carrying collation names
in post-analysis parse trees: that's both wasteful and possibly misleading,
since the collation's name could be changed while the parsetree still
exists.
Also, clean up assorted infelicities and omissions in processing of the
node type.
The initial collations patch treated a COLLATE spec as part of a TypeName,
following what can only be described as brain fade on the part of the SQL
committee. It's a lot more reasonable to treat COLLATE as a syntactically
separate object, so that it can be added in only the productions where it
actually belongs, rather than needing to reject it in a boatload of places
where it doesn't belong (something the original patch mostly failed to do).
In addition this change lets us meet the spec's requirement to allow
COLLATE anywhere in the clauses of a ColumnDef, and it avoids unfriendly
behavior for constructs such as "foo::type COLLATE collation".
To do this, pull collation information out of TypeName and put it in
ColumnDef instead, thus reverting most of the collation-related changes in
parse_type.c's API. I made one additional structural change, which was to
use a ColumnDef as an intermediate node in AT_AlterColumnType AlterTableCmd
nodes. This provides enough room to get rid of the "transform" wart in
AlterTableCmd too, since the ColumnDef can carry the USING expression
easily enough.
Also fix some other minor bugs that have crept in in the same areas,
like failure to copy recently-added fields of ColumnDef in copyfuncs.c.
While at it, document the formerly secret ability to specify a collation
in ALTER TABLE ALTER COLUMN TYPE, ALTER TYPE ADD ATTRIBUTE, and
ALTER TYPE ALTER ATTRIBUTE TYPE; and correct some misstatements about
what the default collation selection will be when COLLATE is omitted.
BTW, the three-parameter form of format_type() should go away too,
since it just contributes to the confusion in this area; but I'll do
that in a separate patch.
We really need an automated check for this ... and did VALIDATE really
need to become a keyword at all, rather than picking some other syntax
using existing keywords?
Remove the unconditional superuser permissions check in CREATE EXTENSION,
and instead define a "superuser" extension property, which when false
(not the default) skips the superuser permissions check. In this case
the calling user only needs enough permissions to execute the commands
in the extension's installation script. The superuser property is also
enforced in the same way for ALTER EXTENSION UPDATE cases.
In other ALTER EXTENSION cases and DROP EXTENSION, test ownership of
the extension rather than superuserness. ALTER EXTENSION ADD/DROP needs
to insist on ownership of the target object as well; to do that without
duplicating code, refactor comment.c's big switch for permissions checks
into a separate function in objectaddress.c.
I also removed the superuserness checks in pg_available_extensions and
related functions; there's no strong reason why everybody shouldn't
be able to see that info.
Also invent an IF NOT EXISTS variant of CREATE EXTENSION, and use that
in pg_dump, so that dumps won't fail for installed-by-default extensions.
We don't have any of those yet, but we will soon.
This is all per discussion of wrapping the standard procedural languages
into extensions. I'll make those changes in a separate commit; this is
just putting the core infrastructure in place.
This patch implements data-modifying WITH queries according to the
semantics that the updates all happen with the same command counter value,
and in an unspecified order. Therefore one WITH clause can't see the
effects of another, nor can the outer query see the effects other than
through the RETURNING values. And attempts to do conflicting updates will
have unpredictable results. We'll need to document all that.
This commit just fixes the code; documentation updates are waiting on
author.
Marko Tiikkaja and Hitoshi Harada
The recent additions for FDW support required checking foreign-table-ness
in several places in the parse/plan chain. While it's not clear whether
that would really result in a noticeable slowdown, it seems best to avoid
any performance risk by keeping a copy of the relation's relkind in
RangeTblEntry. That might have some other uses later, anyway.
Per discussion.
File encodings can be specified separately from client encoding.
If not specified, client encoding is used for backward compatibility.
Cases when the encoding doesn't match client encoding are slower
than matched cases because we don't have conversion procs for other
encodings. Performance improvement would be be a future work.
Original patch by Hitoshi Harada, and modified by me.
This commit provides the core code and documentation needed. A contrib
module test case will follow shortly.
Shigeru Hanada, Jan Urbanski, Heikki Linnakangas
Add a fdwhandler column to pg_foreign_data_wrapper, plus HANDLER options
in the CREATE FOREIGN DATA WRAPPER and ALTER FOREIGN DATA WRAPPER commands,
plus pg_dump support for same. Also invent a new pseudotype fdw_handler
with properties similar to language_handler.
This is split out of the "FDW API" patch for ease of review; it's all stuff
we will certainly need, regardless of any other details of the FDW API.
FDW handler functions will not actually get called yet.
In passing, fix some omissions and infelicities in foreigncmds.c.
Shigeru Hanada, Jan Urbanski, Heikki Linnakangas
- collowner field
- CREATE COLLATION
- ALTER COLLATION
- DROP COLLATION
- COMMENT ON COLLATION
- integration with extensions
- pg_dump support for the above
- dependency management
- psql tab completion
- psql \dO command
This follows recent discussions, so it's quite a bit different from
Dimitri's original. There will probably be more changes once we get a bit
of experience with it, but let's get it in and start playing with it.
This is still just core code. I'll start converting contrib modules
shortly.
Dimitri Fontaine and Tom Lane
This follows my proposal of yesterday, namely that we try to recreate the
previous state of the extension exactly, instead of allowing CREATE
EXTENSION to run a SQL script that might create some entirely-incompatible
on-disk state. In --binary-upgrade mode, pg_dump won't issue CREATE
EXTENSION at all, but instead uses a kluge function provided by
pg_upgrade_support to recreate the pg_extension row (and extension-level
pg_depend entries) without creating any member objects. The member objects
are then restored in the same way as if they weren't members, in particular
using pg_upgrade's normal hacks to preserve OIDs that need to be preserved.
Then, for each member object, ALTER EXTENSION ADD is issued to recreate the
pg_depend entry that marks it as an extension member.
In passing, fix breakage in pg_upgrade's enum-type support: somebody didn't
fix it when the noise word VALUE got added to ALTER TYPE ADD. Also,
rationalize parsetree representation of COMMENT ON DOMAIN and fix
get_object_address() to allow OBJECT_DOMAIN.
This is an essential component of making the extension feature usable;
first because it's needed in the process of converting an existing
installation containing "loose" objects of an old contrib module into
the extension-based world, and second because we'll have to use it
in pg_dump --binary-upgrade, as per recent discussion.
Loosely based on part of Dimitri Fontaine's ALTER EXTENSION UPGRADE
patch.
This patch adds the server infrastructure to support extensions.
There is still one significant loose end, namely how to make it play nice
with pg_upgrade, so I am not yet committing the changes that would make
all the contrib modules depend on this feature.
In passing, fix a disturbingly large amount of breakage in
AlterObjectNamespace() and callers.
Dimitri Fontaine, reviewed by Anssi Kääriäinen,
Itagaki Takahiro, Tom Lane, and numerous others
This adds collation support for columns and domains, a COLLATE clause
to override it per expression, and B-tree index support.
Peter Eisentraut
reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch
FK constraints that are marked NOT VALID may later be VALIDATED, which uses an
ShareUpdateExclusiveLock on constraint table and RowShareLock on referenced
table. Significantly reduces lock strength and duration when adding FKs.
New state visible from psql.
Simon Riggs, with reviews from Marko Tiikkaja and Robert Haas
Until now, our Serializable mode has in fact been what's called Snapshot
Isolation, which allows some anomalies that could not occur in any
serialized ordering of the transactions. This patch fixes that using a
method called Serializable Snapshot Isolation, based on research papers by
Michael J. Cahill (see README-SSI for full references). In Serializable
Snapshot Isolation, transactions run like they do in Snapshot Isolation,
but a predicate lock manager observes the reads and writes performed and
aborts transactions if it detects that an anomaly might occur. This method
produces some false positives, ie. it sometimes aborts transactions even
though there is no anomaly.
To track reads we implement predicate locking, see storage/lmgr/predicate.c.
Whenever a tuple is read, a predicate lock is acquired on the tuple. Shared
memory is finite, so when a transaction takes many tuple-level locks on a
page, the locks are promoted to a single page-level lock, and further to a
single relation level lock if necessary. To lock key values with no matching
tuple, a sequential scan always takes a relation-level lock, and an index
scan acquires a page-level lock that covers the search key, whether or not
there are any matching keys at the moment.
A predicate lock doesn't conflict with any regular locks or with another
predicate locks in the normal sense. They're only used by the predicate lock
manager to detect the danger of anomalies. Only serializable transactions
participate in predicate locking, so there should be no extra overhead for
for other transactions.
Predicate locks can't be released at commit, but must be remembered until
all the transactions that overlapped with it have completed. That means that
we need to remember an unbounded amount of predicate locks, so we apply a
lossy but conservative method of tracking locks for committed transactions.
If we run short of shared memory, we overflow to a new "pg_serial" SLRU
pool.
We don't currently allow Serializable transactions in Hot Standby mode.
That would be hard, because even read-only transactions can cause anomalies
that wouldn't otherwise occur.
Serializable isolation mode now means the new fully serializable level.
Repeatable Read gives you the old Snapshot Isolation level that we have
always had.
Kevin Grittner and Dan Ports, reviewed by Jeff Davis, Heikki Linnakangas and
Anssi Kääriäinen
There isn't any need to track this state on a table-wide basis, and trying
to do so introduces undesirable semantic fuzziness. Move the flag to
pg_index, where it clearly describes just a single index and can be
immutable after index creation.
This feature allows a unique or pkey constraint to be created using an
already-existing unique index. While the constraint isn't very
functionally different from the bare index, it's nice to be able to do that
for documentation purposes. The main advantage over just issuing a plain
ALTER TABLE ADD UNIQUE/PRIMARY KEY is that the index can be created with
CREATE INDEX CONCURRENTLY, so that there is not a long interval where the
table is locked against updates.
On the way, refactor some of the code in DefineIndex() and index_create()
so that we don't have to pass through those functions in order to create
the index constraint's catalog entries. Also, in parse_utilcmd.c, pass
around the ParseState pointer in struct CreateStmtContext to save on
notation, and add error location pointers to some error reports that didn't
have one before.
Gurjeet Singh, reviewed by Steve Singer and Tom Lane
Foreign tables are a core component of SQL/MED. This commit does
not provide a working SQL/MED infrastructure, because foreign tables
cannot yet be queried. Support for foreign table scans will need to
be added in a future patch. However, this patch creates the necessary
system catalog structure, syntax support, and support for ancillary
operations such as COMMENT and SECURITY LABEL.
Shigeru Hanada, heavily revised by Robert Haas
The contents of an unlogged table are WAL-logged; thus, they are not
available on standby servers and are truncated whenever the database
system enters recovery. Indexes on unlogged tables are also unlogged.
Unlogged GiST indexes are not currently supported.
This privilege is required to do Streaming Replication, instead of
superuser, making it possible to set up a SR slave that doesn't
have write permissions on the master.
Superuser privileges do NOT override this check, so in order to
use the default superuser account for replication it must be
explicitly granted the REPLICATION permissions. This is backwards
incompatible change, in the interest of higher default security.
This commit replaces pg_class.relistemp with pg_class.relpersistence;
and also modifies the RangeVar node type to carry relpersistence rather
than istemp. It also removes removes rd_istemp from RelationData and
instead performs the correct computation based on relpersistence.
For clarity, we add three new macros: RelationNeedsWAL(),
RelationUsesLocalBuffers(), and RelationUsesTempNamespace(), so that we
can clarify the purpose of each check that previous depended on
rd_istemp.
This is intended as infrastructure for the upcoming unlogged tables
patch, as well as for future possible work on global temporary tables.
This adds support for changing the schema of a conversion, operator,
operator class, operator family, text search configuration, text search
dictionary, text search parser, or text search template.
Dimitri Fontaine, with assorted corrections and other kibitzing.
This commit adds columns amoppurpose and amopsortfamily to pg_amop, and
column amcanorderbyop to pg_am. For the moment all the entries in
amcanorderbyop are "false", since the underlying support isn't there yet.
Also, extend the CREATE OPERATOR CLASS/ALTER OPERATOR FAMILY commands with
[ FOR SEARCH | FOR ORDER BY sort_operator_family ] clauses to allow the new
columns of pg_amop to be populated, and create pg_dump support for dumping
that information.
I also added some documentation, although it's perhaps a bit premature
given that the feature doesn't do anything useful yet.
Teodor Sigaev, Robert Haas, Tom Lane
PG 8.4 added a built-in feature for casting pretty much any data type to
string types (text, varchar, etc). We allowed this to work in any of the
historically-allowed syntaxes: CAST(x AS text), x::text, text(x), or
x.text. However, multiple complaints have shown that it's too easy to
invoke such casts unintentionally in the latter two styles, particularly
field selection. To cure the problem with the narrowest possible change
of behavior, disallow use of I/O conversion casts from composite types to
string types via functional/attribute syntax. The new functionality is
still available via cast syntax.
In passing, document the equivalence of functional and attribute syntax
in a more visible place.
The core of this patch is hash_array() and associated typcache
infrastructure, which works just about exactly like the existing support
for array comparison.
In addition I did some work to ensure that the planner won't think that an
array type is hashable unless its element type is hashable, and similarly
for sorting. This includes adding a datatype parameter to op_hashjoinable
and op_mergejoinable, and adding an explicit "hashable" flag to
SortGroupClause. The lack of a cross-check on the element type was a
pre-existing bug in mergejoin support --- but it didn't matter so much
before, because if you couldn't sort the element type there wasn't any good
alternative to failing anyhow. Now that we have the alternative of hashing
the array type, there are cases where we can avoid a failure by being picky
at the planner stage, so it's time to be picky.
The issue of exactly how to combine the per-element hash values to produce
an array hash is still open for discussion, but the rest of this is pretty
solid, so I'll commit it as-is.
Split the old typenameTypeId() into two functions: A new typenameTypeId() that
returns only a type OID, and typenameTypeIdAndMod() that returns type OID and
typmod. This isolates call sites better that actually care about the typmod.
After much expenditure of effort, we've got this to the point where the
performance penalty is pretty minimal in typical cases.
Andrew Dunstan, reviewed by Brendan Jurd, Dean Rasheed, and Tom Lane
as a variable or column name, and it's not reserved in recent versions of
the SQL spec either. This became particularly annoying in 9.0, before that
PL/pgSQL replaced variable names in queries with parameter markers, so
it was possible to use OFF and many other backend parser keywords as
variable names. Because of that, backpatch to 9.0.
This patch eliminates various bizarre behaviors caused by sloppy thinking
about the difference between a domain type and its underlying array type.
In particular, the operation of updating one element of such an array
has to be considered as yielding a value of the underlying array type,
*not* a value of the domain, because there's no assurance that the
domain's CHECK constraints are still satisfied. If we're intending to
store the result back into a domain column, we have to re-cast to the
domain type so that constraints are re-checked.
For similar reasons, such a domain can't be blindly matched to an ANYARRAY
polymorphic parameter, because the polymorphic function is likely to apply
array-ish operations that could invalidate the domain constraints. For the
moment, we just forbid such matching. We might later wish to insert an
automatic downcast to the underlying array type, but such a change should
also change matching of domains to ANYELEMENT for consistency.
To ensure that all such logic is rechecked, this patch removes the original
hack of setting a domain's pg_type.typelem field to match its base type;
the typelem will always be zero instead. In those places where it's really
okay to look through the domain type with no other logic changes, use the
newly added get_base_element_type function in place of get_element_type.
catversion bumped due to change in pg_type contents.
Per bug #5717 from Richard Huxton and subsequent discussion.
A couple of places in the planner need to generate whole-row Vars, and were
cutting corners by setting vartype = RECORDOID in the Vars, even in cases
where there's an identifiable named composite type for the RTE being
referenced. While we mostly got away with this, it failed when there was
also a parser-generated whole-row reference to the same RTE, because the
two Vars weren't equal() due to the difference in vartype. Fix by
providing a subroutine the planner can call to generate whole-row Vars
the same way the parser does.
Per bug #5716 from Andrew Tipton. Back-patch to 9.0 where one of the bogus
calls was introduced (the other one is new in HEAD).
This is not the hoped-for facility of using INSERT/UPDATE/DELETE inside
a WITH, but rather the other way around. It seems useful in its own
right anyway.
Note: catversion bumped because, although the contents of stored rules
might look compatible, there's actually a subtle semantic change.
A single Query containing a WITH and INSERT...VALUES now represents
writing the WITH before the INSERT, not before the VALUES. While it's
not clear that that matters to anyone, it seems like a good idea to
have it cited in the git history for catversion.h.
Original patch by Marko Tiikkaja, with updating and cleanup by
Hitoshi Harada.
This patch adds the SQL-standard concept of an INSTEAD OF trigger, which
is fired instead of performing a physical insert/update/delete. The
trigger function is passed the entire old and/or new rows of the view,
and must figure out what to do to the underlying tables to implement
the update. So this feature can be used to implement updatable views
using trigger programming style rather than rule hacking.
In passing, this patch corrects the names of some columns in the
information_schema.triggers view. It seems the SQL committee renamed
them somewhere between SQL:99 and SQL:2003.
Dean Rasheed, reviewed by Bernd Helmle; some additional hacking by me.
In versions 8.2 and up, the grammar allows attaching ORDER BY, LIMIT,
FOR UPDATE, or WITH to VALUES, and hence to INSERT ... VALUES. But the
special-case code for VALUES in transformInsertStmt() wasn't expecting any
of those, and just ignored them, leading to unexpected results. Rather
than complicate the special-case path, just ensure that the presence of any
of those clauses makes us treat the query as if it had a general SELECT.
Per report from Hitoshi Harada.
This is intended as infrastructure to support integration with label-based
mandatory access control systems such as SE-Linux. Further changes (mostly
hooks) will be needed, but this is a big chunk of it.
KaiGai Kohei and Robert Haas
the same number of columns expected by the insert. This suggests that there
were extra parentheses that converted the intended column list into a row
expression.
Original patch by Marko Tiikkaja, rather heavily editorialized by me.
pointed out, it would need a 2nd pass after the whole query is processed to
correctly check that an unknown Param is coerced to the same target type
everywhere. Adding the 2nd pass would add a lot more code, which doesn't
seem worth the risk given that there isn't much of a use case for passing
unknown Params in the first place. The code would work without that check,
but it might be confusing and the behavior would be different from the
varparams case.
Instead, just coerce all unknown params in a PL/pgSQL USING clause to text.
That's simple, and is usually what users expect.
Revert the patch in CVS HEAD and master, and backpatch the new solution to
8.4. Unlike the previous solution, this applies easily to 8.4 too.
The implicitly created sequence was created as owned by the current user,
who could be different from the table owner, eg if current user is a
superuser or some member of the table's owning role. This caused sanity
checks in the SEQUENCE OWNED BY code to spit up. Although possibly we
don't need those sanity checks, the safest fix seems to be to make sure
the implicit sequence is assigned the same owner role as the table has.
(We still do all permissions checks as the current user, however.)
Per report from Josh Berkus.
Back-patch to 9.0. The bug goes back to the invention of SEQUENCE OWNED BY
in 8.2, but the fix requires an API change for DefineRelation(), which seems
to have potential for breaking third-party code if done in a minor release.
Given the lack of prior complaints, it's probably not worth fixing in the
stable branches.
parse_analyze() function. That case occurs e.g with PL/pgSQL
EXECUTE ... USING 'stringconstant'.
The coercion with a CoerceViaIO node. The result is similar to the coercion
via input function performed for unknown constants in coerce_type(),
except that this happens at runtime.
Backpatch to 9.0. The issue is present in 8.4 as well, but the coerce param
hook infrastructure this patch relies on was introduced in 9.0. Given the
lack of user reports and harmlessness of the bug, it's not worth attempting
a different fix just for 8.4.
other columns to be referenced without listing them in GROUP BY, so long as
the primary key column(s) are listed in GROUP BY.
Eventually we should also allow functional dependency on a UNIQUE constraint
when the columns are marked NOT NULL, but that has to wait until NOT NULL
constraints are represented in pg_constraint, because we need to have
pg_constraint OIDs for all the conditions needed to ensure functional
dependency.
Peter Eisentraut, reviewed by Alex Hunsaker and Tom Lane
matching a call like f(x, ORDER BY y,z). It could be that what the user
really wants is f(x,z ORDER BY y). We now have pretty conclusive evidence
that many people won't understand this problem without concrete guidance,
so give it to them. Per further discussion of the string_agg() problem.
- Rename TSParserGetPrsid to get_ts_parser_oid.
- Rename TSDictionaryGetDictid to get_ts_dict_oid.
- Rename TSTemplateGetTmplid to get_ts_template_oid.
- Rename TSConfigGetCfgid to get_ts_config_oid.
- Rename FindConversionByName to get_conversion_oid.
- Rename GetConstraintName to get_constraint_oid.
- Add new functions get_opclass_oid, get_opfamily_oid, get_rewrite_oid,
get_rewrite_oid_without_relid, get_trigger_oid, and get_cast_oid.
The name of each function matches the corresponding catalog.
Thanks to KaiGai Kohei for the review.
look through join alias Vars to avoid breaking join queries, and
move the test to someplace where it will catch more possible ways
of calling a function. We still ought to throw away the whole thing
in favor of a data-type-based solution, but that's not feasible in
the back branches.
This needs to be back-patched further than 9.0, but I don't have time
to do so today. Committing now so that the fix gets into 9.0beta4.
Avoid hard-coding lockmode used for many altering DDL commands, allowing easier
future changes of lock levels. Implementation of initial analysis on DDL
sub-commands, so that many lock levels are now at ShareUpdateExclusiveLock or
ShareRowExclusiveLock, allowing certain DDL not to block reads/writes.
First of number of planned changes in this area; additional docs required
when full project complete.
any implicit casting previously applied to the targetlist item. This is
reasonable because the implicit cast, by definition, wasn't written by the
user; so we are preserving the expected behavior that ORDER BY items match
textually equivalent tlist items. The case never arose before because there
couldn't be any implicit casting of a top-level SELECT item before we process
ORDER BY etc. But now it can arise in the context of aggregates containing
ORDER BY clauses, since the "targetlist" is the already-casted list of
arguments for the aggregate. The net effect is that the datatype used for
ORDER BY/DISTINCT purposes is the aggregate's declared input type, not that
of the original input column; which is a bit debatable but not horrendous,
and to do otherwise would require major rework that doesn't seem justified.
Per bug #5564 from Daniel Grace. Back-patch to 9.0 where aggregate ORDER BY
was implemented.
but we have nevertheless exposed them to users via pg_get_expr(). It would
be too much maintenance effort to rigorously check the input, so put a hack
in place instead to restrict pg_get_expr() so that the argument must come
from one of the system catalog columns known to contain valid expressions.
Per report from Rushabh Lathia. Backpatch to 7.4 which is the oldest
supported version at the moment.
"val AS name" to "name := val", as per recent discussion.
This patch catches everything in the original named-parameters patch,
but I'm not certain that no other dependencies snuck in later (grepping
the source tree for all uses of AS soon proved unworkable).
In passing I note that we've dropped the ball at least once on keeping
ecpg's lexer (as opposed to parser) in sync with the backend. It would
be a good idea to go through all of pgc.l and see if it's in sync now.
I didn't attempt that at the moment.
My initial impression that glibc was measuring the precision in characters
(which is what the Linux man page says it does) was incorrect. It does take
the precision to be in bytes, but it also tries to truncate the string at a
character boundary. The bottom line remains the same: it will mess up
if the string is not in the encoding it expects, so we need to avoid %.*s
anytime there's a significant risk of that. Previous code changes are still
good, but adjust the comments to reflect this knowledge. Per research by
Hernan Gonzalez.
Peter Eisentraut
Robert Haas
Tom Lane
Heikki Linnakangas
Simon Riggs
Bruce Momjian
Alvaro Herrera
Itagaki Takahiro
Michael Meskes
Magnus Hagander
Andrew Dunstan