A pending patch requires exporting a function returning Bitmapset from
catalog/pg_constraint.c. As things stand, that would mean including
nodes/bitmapset.h in pg_constraint.h, which might be hazardous for the
client-side includability of that header. It's not entirely clear whether
any client-side code needs to include pg_constraint.h, but it seems prudent
to assume that there is some such code somewhere. Therefore, split off the
function definitions into a new file pg_constraint_fn.h, similarly to what
we've done for some other catalog header files.
This patch reduces pg_am to just two columns, a name and a handler
function. All the data formerly obtained from pg_am is now provided
in a C struct returned by the handler function. This is similar to
the designs we've adopted for FDWs and tablesample methods. There
are multiple advantages. For one, the index AM's support functions
are now simple C functions, making them faster to call and much less
error-prone, since the C compiler can now check function signatures.
For another, this will make it far more practical to define index access
methods in installable extensions.
A disadvantage is that SQL-level code can no longer see attributes
of index AMs; in particular, some of the crosschecks in the opr_sanity
regression test are no longer possible from SQL. We've addressed that
by adding a facility for the index AM to perform such checks instead.
(Much more could be done in that line, but for now we're content if the
amvalidate functions more or less replace what opr_sanity used to do.)
We might also want to expose some sort of reporting functionality, but
this patch doesn't do that.
Alexander Korotkov, reviewed by Petr Jelínek, and rather heavily
editorialized on by me.
FOREIGN KEY constraints have behaved this way for a long time, but for
some reason the behavior of CHECK constraints has been inconsistent up
until now.
Amit Langote and Amul Sul, with assorted tweaks by me.
I thought I'd gone through all of these before, but a fresh review found
this one too. (Perhaps it would be better to just delete this test and
let the failure occur later, but for the moment I'll preserve the logic.)
The case that this was rejecting is like
CREATE FOREIGN TABLE ft (f1 int ...) ...;
CREATE TABLE c1 (UNIQUE(f1)) INHERITS(ft);
pg_dump has historically assumed that default_with_oids affects only plain
tables and not other relkinds. Conceivably we could make it apply to some
newly invented relkind if we did so from the get-go, but changing the
behavior for existing object types will break existing dump scripts.
Add code comments warning about this interaction.
Also, make sure that default_with_oids doesn't cause parse_utilcmd.c to
think that CREATE FOREIGN TABLE will create an OID column. I think this is
only a latent bug right now, since we don't allow UNIQUE/PKEY constraints
in CREATE FOREIGN TABLE, but it's better to be consistent and future-proof.
This lets later stages have access to the transformed expression; in
particular it allows DDL-deparsing code during event triggers to pass
the transformed expression to ruleutils.c, so that the complete command
can be deparsed.
This shuffles the timing of the transform calls a bit: previously,
nothing was transformed during parse analysis, and only the
RELKIND_RELATION case was being handled during execution. After this
patch, all expressions are transformed during parse analysis (including
those for relkinds other than RELATION), and the error for other
relation kinds is thrown only during execution. So we do more work than
before to reject some bogus cases. That seems acceptable.
Commands such as ALTER USER, ALTER GROUP, ALTER ROLE, GRANT, and the
various ALTER OBJECT / OWNER TO, as well as ad-hoc clauses related to
roles such as the AUTHORIZATION clause of CREATE SCHEMA, the FOR clause
of CREATE USER MAPPING, and the FOR ROLE clause of ALTER DEFAULT
PRIVILEGES can now take the keywords CURRENT_USER and SESSION_USER as
user specifiers in place of an explicit user name.
This commit also fixes some quite ugly handling of special standards-
mandated syntax in CREATE USER MAPPING, which in particular would fail
to work in presence of a role named "current_user".
The special role specifiers PUBLIC and NONE also have more consistent
handling now.
Also take the opportunity to add location tracking to user specifiers.
Authors: Kyotaro Horiguchi. Heavily reworked by Álvaro Herrera.
Reviewed by: Rushabh Lathia, Adam Brightwell, Marti Raudsepp.
transformExpr() has for many years had provisions to do nothing when
applied to an already-transformed expression tree. However, this was
always ugly and of dubious reliability, so we'd be much better off without
it. The primary historical reason for it was that gram.y sometimes
returned multiple links to the same subexpression, which is no longer true
as of my BETWEEN fixes. We'd also grown some lazy hacks in CREATE TABLE
LIKE (failing to distinguish between raw and already-transformed index
specifications) and one or two other places.
This patch removes the need for and support for re-transforming already
transformed expressions. The index case is dealt with by adding a flag
to struct IndexStmt to indicate that it's already been transformed;
which has some benefit anyway in that tablecmds.c can now Assert that
transformation has happened rather than just assuming. The other main
reason was some rather sloppy code for array type coercion, which can
be fixed (and its performance improved too) by refactoring.
I did leave transformJoinUsingClause() still constructing expressions
containing untransformed operator nodes being applied to Vars, so that
transformExpr() still has to allow Var inputs. But that's a much narrower,
and safer, special case than before, since Vars will never appear in a raw
parse tree, and they don't have any substructure to worry about.
In passing fix some oversights in the patch that added CREATE INDEX
IF NOT EXISTS (missing processing of IndexStmt.if_not_exists). These
appear relatively harmless, but still sloppy coding practice.
Apart from enabling comments on domain constraints, this enables a
future project to replicate object dropping to remote servers: with the
current mechanism there's no way to distinguish between the two types of
constraints, so there's no way to know what to drop.
Also added support for the domain constraint comments in psql's \dd and
pg_dump.
Catalog version bumped due to the change in ObjectType enum.
As with NOT NULL constraints, we consider that such constraints are merely
reports of constraints that are being enforced by the remote server (or
other underlying storage mechanism). Their only real use is to allow
planner optimizations, for example in constraint-exclusion checks. Thus,
the code changes here amount to little more than removal of the error that
was formerly thrown for applying CHECK to a foreign table.
(In passing, do a bit of cleanup of the ALTER FOREIGN TABLE reference page,
which had accumulated some weird decisions about ordering etc.)
Shigeru Hanada and Etsuro Fujita, reviewed by Kyotaro Horiguchi and
Ashutosh Bapat.
If the name lookups come to different conclusions due to concurrent
activity, we might perform some parts of the DDL on a different table
than other parts. At least in the case of CREATE INDEX, this can be
used to cause the permissions checks to be performed against a
different table than the index creation, allowing for a privilege
escalation attack.
This changes the calling convention for DefineIndex, CreateTrigger,
transformIndexStmt, transformAlterTableStmt, CheckIndexCompatible
(in 9.2 and newer), and AlterTable (in 9.1 and older). In addition,
CheckRelationOwnership is removed in 9.2 and newer and the calling
convention is changed in older branches. A field has also been added
to the Constraint node (FkConstraint in 8.4). Third-party code calling
these functions or using the Constraint node will require updating.
Report by Andres Freund. Patch by Robert Haas and Andres Freund,
reviewed by Tom Lane.
Security: CVE-2014-0062
This patch adds the ability to write TABLE( function1(), function2(), ...)
as a single FROM-clause entry. The result is the concatenation of the
first row from each function, followed by the second row from each
function, etc; with NULLs inserted if any function produces fewer rows than
others. This is believed to be a much more useful behavior than what
Postgres currently does with multiple SRFs in a SELECT list.
This syntax also provides a reasonable way to combine use of column
definition lists with WITH ORDINALITY: put the column definition list
inside TABLE(), where it's clear that it doesn't control the ordinality
column as well.
Also implement SQL-compliant multiple-argument UNNEST(), by turning
UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)).
The SQL standard specifies TABLE() with only a single function, not
multiple functions, and it seems to require an implicit UNNEST() which is
not what this patch does. There may be something wrong with that reading
of the spec, though, because if it's right then the spec's TABLE() is just
a pointless alternative spelling of UNNEST(). After further review of
that, we might choose to adopt a different syntax for what this patch does,
but in any case this functionality seems clearly worthwhile.
Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and
significantly revised by me
In most cases, these were just references to the SQL standard in
general. In a few cases, a contrast was made between SQL92 and later
standards -- those have been kept unchanged.
Revert the matview-related changes in explain.c's API, as per recent
complaint from Robert Haas. The reason for these appears to have been
principally some ill-considered choices around having intorel_startup do
what ought to be parse-time checking, plus a poor arrangement for passing
it the view parsetree it needs to store into pg_rewrite when creating a
materialized view. Do the latter by having parse analysis stick a copy
into the IntoClause, instead of doing it at runtime. (On the whole,
I seriously question the choice to represent CREATE MATERIALIZED VIEW as a
variant of SELECT INTO/CREATE TABLE AS, because that means injecting even
more complexity into what was already a horrid legacy kluge. However,
I didn't go so far as to rethink that choice ... yet.)
I also moved several error checks into matview parse analysis, and
made the check for external Params in a matview more accurate.
In passing, clean things up a bit more around interpretOidsOption(),
and fix things so that we can use that to force no-oids for views,
sequences, etc, thereby eliminating the need to cons up "oids = false"
options when creating them.
catversion bump due to change in IntoClause. (I wonder though if we
really need readfuncs/outfuncs support for IntoClause anymore.)
There's still some discussion about exactly how postgres_fdw ought to
handle this case, but there seems no debate that we want to allow defaults
to be used for inserts into foreign tables. So remove the core-code
restrictions that prevented it.
While at it, get rid of the special grammar productions for CREATE FOREIGN
TABLE, and instead add explicit FEATURE_NOT_SUPPORTED error checks for the
disallowed cases. This makes the grammar a shade smaller, and more
importantly results in much more intelligible error messages for
unsupported cases. It's also one less thing to fix if we ever start
supporting constraints on foreign tables.
A materialized view has a rule just like a view and a heap and
other physical properties like a table. The rule is only used to
populate the table, references in queries refer to the
materialized data.
This is a minimal implementation, but should still be useful in
many cases. Currently data is only populated "on demand" by the
CREATE MATERIALIZED VIEW and REFRESH MATERIALIZED VIEW statements.
It is expected that future releases will add incremental updates
with various timings, and that a more refined concept of defining
what is "fresh" data will be developed. At some point it may even
be possible to have queries use a materialized in place of
references to underlying tables, but that requires the other
above-mentioned features to be working first.
Much of the documentation work by Robert Haas.
Review by Noah Misch, Thom Brown, Robert Haas, Marko Tiikkaja
Security review by KaiGai Kohei, with a decision on how best to
implement sepgsql still pending.
Commit 8cb53654db, which introduced DROP
INDEX CONCURRENTLY, managed to break CREATE INDEX CONCURRENTLY via a poor
choice of catalog state representation. The pg_index state for an index
that's reached the final pre-drop stage was the same as the state for an
index just created by CREATE INDEX CONCURRENTLY. This meant that the
(necessary) change to make RelationGetIndexList ignore about-to-die indexes
also made it ignore freshly-created indexes; which is catastrophic because
the latter do need to be considered in HOT-safety decisions. Failure to
do so leads to incorrect index entries and subsequently wrong results from
queries depending on the concurrently-created index.
To fix, add an additional boolean column "indislive" to pg_index, so that
the freshly-created and about-to-die states can be distinguished. (This
change obviously is only possible in HEAD. This patch will need to be
back-patched, but in 9.2 we'll use a kluge consisting of overloading the
formerly-impossible state of indisvalid = true and indisready = false.)
In addition, change CREATE/DROP INDEX CONCURRENTLY so that the pg_index
flag changes they make without exclusive lock on the index are made via
heap_inplace_update() rather than a normal transactional update. The
latter is not very safe because moving the pg_index tuple could result in
concurrent SnapshotNow scans finding it twice or not at all, thus possibly
resulting in index corruption. This is a pre-existing bug in CREATE INDEX
CONCURRENTLY, which was copied into the DROP code.
In addition, fix various places in the code that ought to check to make
sure that the indexes they are manipulating are valid and/or ready as
appropriate. These represent bugs that have existed since 8.2, since
a failed CREATE INDEX CONCURRENTLY could leave a corrupt or invalid
index behind, and we ought not try to do anything that might fail with
such an index.
Also fix RelationReloadIndexInfo to ensure it copies all the pg_index
columns that are allowed to change after initial creation. Previously we
could have been left with stale values of some fields in an index relcache
entry. It's not clear whether this actually had any user-visible
consequences, but it's at least a bug waiting to happen.
In addition, do some code and docs review for DROP INDEX CONCURRENTLY;
some cosmetic code cleanup but mostly addition and revision of comments.
This will need to be back-patched, but in a noticeably different form,
so I'm committing it to HEAD before working on the back-patch.
Problem reported by Amit Kapila, diagnosis by Pavan Deolassee,
fix by Tom Lane and Andres Freund.
This reduces unnecessary exposure of other headers through htup.h, which
is very widely included by many files.
I have chosen to move the function prototypes to the new file as well,
because that means htup.h no longer needs to include tupdesc.h. In
itself this doesn't have much effect in indirect inclusion of tupdesc.h
throughout the tree, because it's also required by execnodes.h; but it's
something to explore in the future, and it seemed best to do the htup.h
change now while I'm busy with it.
Formerly we relied on checking after-the-fact to see if an expression
contained aggregates, window functions, or sub-selects when it shouldn't.
This is grotty, easily forgotten (indeed, we had forgotten to teach
DefineIndex about rejecting window functions), and none too efficient
since it requires extra traversals of the parse tree. To improve matters,
define an enum type that classifies all SQL sub-expressions, store it in
ParseState to show what kind of expression we are currently parsing, and
make transformAggregateCall, transformWindowFuncCall, and transformSubLink
check the expression type and throw error if the type indicates the
construct is disallowed. This allows removal of a large number of ad-hoc
checks scattered around the code base. The enum type is sufficiently
fine-grained that we can still produce error messages of at least the
same specificity as before.
Bringing these error checks together revealed that we'd been none too
consistent about phrasing of the error messages, so standardize the wording
a bit.
Also, rewrite checking of aggregate arguments so that it requires only one
traversal of the arguments, rather than up to three as before.
In passing, clean up some more comments left over from add_missing_from
support, and annotate some tests that I think are dead code now that that's
gone. (I didn't risk actually removing said dead code, though.)
Formerly, when trying to copy both indexes and comments, CREATE TABLE LIKE
had to pre-assign names to indexes that had comments, because it made up an
explicit CommentStmt command to apply the comment and so it had to know the
name for the index. This creates bad interactions with other indexes, as
shown in bug #6734 from Daniele Varrazzo: the preassignment logic couldn't
take any other indexes into account so it could choose a conflicting name.
To fix, add a field to IndexStmt that allows it to carry a comment to be
assigned to the new index. (This isn't a user-exposed feature of CREATE
INDEX, only an internal option.) Now we don't need preassignment of index
names in any situation.
I also took the opportunity to refactor DefineIndex to accept the IndexStmt
as such, rather than passing all its fields individually in a mile-long
parameter list.
Back-patch to 9.2, but no further, because it seems too dangerous to change
IndexStmt or DefineIndex's API in released branches. The bug exists back
to 9.0 where CREATE TABLE LIKE grew the ability to copy comments, but given
the lack of prior complaints we'll just let it go unfixed before 9.2.
If a CHECK constraint or index definition contained a whole-row Var (that
is, "table.*"), an attempt to copy that definition via CREATE TABLE LIKE or
table inheritance produced incorrect results: the copied Var still claimed
to have the rowtype of the source table, rather than the created table.
For the LIKE case, it seems reasonable to just throw error for this
situation, since the point of LIKE is that the new table is not permanently
coupled to the old, so there's no reason to assume its rowtype will stay
compatible. In the inheritance case, we should ideally allow such
constraints, but doing so will require nontrivial refactoring of CREATE
TABLE processing (because we'd need to know the OID of the new table's
rowtype before we adjust inherited CHECK constraints). In view of the lack
of previous complaints, that doesn't seem worth the risk in a back-patched
bug fix, so just make it throw error for the inheritance case as well.
Along the way, replace change_varattnos_of_a_node() with a more robust
function map_variable_attnos(), which is capable of being extended to
handle insertion of ConvertRowtypeExpr whenever we get around to fixing
the inheritance case nicely, and in the meantime it returns a failure
indication to the caller so that a helpful message with some context can be
thrown. Also, this code will do the right thing with subselects (if we
ever allow them in CHECK or indexes), and it range-checks varattnos before
using them to index into the map array.
Per report from Sergey Konoplev. Back-patch to all supported branches.
The latter was already the dominant use, and it's preferable because
in C the convention is that intXX means XX bits. Therefore, allowing
mixed use of int2, int4, int8, int16, int32 is obviously confusing.
Remove the typedefs for int2 and int4 for now. They don't seem to be
widely used outside of the PostgreSQL source tree, and the few uses
can probably be cleaned up by the time this ships.
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.
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.
Tom Lane
Bruce Momjian
Robert Haas
Alvaro Herrera
Heikki Linnakangas
Peter Eisentraut
Noah Misch
Kevin Grittner
Simon Riggs