This fixes the gripe I made a few months ago about DO blocks getting
slower with repeated use. At least, it fixes it for the case where
the DO block isn't aborted by an error. We could try running
plpgsql_free_function_memory() even during error exit, but that seems
a bit scary since it makes a lot of presumptions about the data
structures being in good shape. It's probably reasonable to assume
that repeated failures of DO blocks isn't a performance-critical case.
Make plpgsql treat the input collation as a polymorphism variable, so
that we cache separate plans for each input collation that's used in a
particular session, as per recent discussion. Propagate the input
collation to all collatable input parameters.
I chose to also propagate the input collation to all declared variables of
collatable types, which is a bit more debatable but seems to be necessary
for non-astonishing behavior. (Copying a parameter into a separate local
variable shouldn't result in a change of behavior, for example.) There is
enough infrastructure here to support declaring a collation for each local
variable to override that default, but I thought we should wait to see what
the field demand is before adding such a feature.
In passing, remove exec_get_rec_fieldtype(), which wasn't used anywhere.
Documentation patch to follow.
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.
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.
This mostly just involves creating control, install, and
update-from-unpackaged scripts for them. However, I had to adjust plperl
and plpython to not share the same support functions between variants,
because we can't put the same function into multiple extensions.
catversion bump forced due to new contents of pg_pltemplate, and because
initdb now installs plpgsql as an extension not a bare language.
Add support for regression testing these as extensions not bare
languages.
Fix a couple of other issues that popped up while testing this: my initial
hack at pg_dump binary-upgrade support didn't work right, and we don't want
an extra schema permissions test after all.
Documentation changes still to come, but I'm committing now to see
whether the MSVC build scripts need work (likely they do).
(I'm not entirely sure that we've finished bikeshedding the syntax details,
but the functionality seems OK.)
Pavel Stehule, reviewed by Stephen Frost and Tom Lane
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
src/pl/plpgsql/src/plerrcodes.h, src/include/utils/errcodes.h, and a
big chunk of errcodes.sgml are now automatically generated from a single
file, src/backend/utils/errcodes.txt.
Jan Urbański, reviewed by Tom Lane.
Previously reported as ERRCODE_ADMIN_SHUTDOWN, this case is now
reported as ERRCODE_T_R_DATABASE_DROPPED. No message text change.
Unlikely to happen on most servers, so low impact change to allow
session poolers to correctly handle this situation.
Tatsuo Ishii, edits by me, review by Robert Haas
My previous commit, 85cff3ce7f360d139d87aee836d75a6202fee066 on
2010-12-25, failed to update errcodes.sgml or plerrcodes.h. This patch
corrects that oversight, per a gripe from Tom Lane, and also corrects
a typographical error.
Given a column reference foo.bar, where there is a composite plpgsql
variable foo but it doesn't contain a column bar, the pre-9.0 coding would
immediately throw a "record foo has no field bar" error. In 9.0 the parser
hook instead falls through to let the core parser see if it can resolve the
reference. If not, you get a complaint about "missing FROM-clause entry
for table foo", which while in some sense correct isn't terribly helpful.
Complicate things a bit so that we can throw the old error message if
neither the core parser nor the hook are able to resolve the column
reference, while not changing the behavior in any other case.
Per bug #5757 from Andrey Galkin.
Instead of using ExecPrepareExpr, call ExecInitExpr. The net change here
is that we don't apply expression_planner() to the expression tree. There
is no need to do so, because that tree is extracted from a fully planned
plancache entry, so all the needed work is already done. This reduces
the setup costs by about a factor of 2 according to some simple tests.
Oversight noted while fooling around with the simple-expression code for
previous fix.
In general, expression execution state trees aren't re-entrantly usable,
since functions can store private state information in them.
For efficiency reasons, plpgsql tries to cache and reuse state trees for
"simple" expressions. It can get away with that most of the time, but it
can fail if the state tree is dirty from a previous failed execution (as
in an example from Alvaro) or is being used recursively (as noted by me).
Fix by tracking whether a state tree is in use, and falling back to the
"non-simple" code path if so. This results in a pretty considerable speed
hit when the non-simple path is taken, but the available alternatives seem
even more unpleasant because they add overhead in the simple path. Per
idea from Heikki.
Back-patch to all supported branches.
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.
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.
Various places were testing TRIGGER_FIRED_BEFORE() where what they really
meant was !TRIGGER_FIRED_AFTER(), or vice versa. This needs to be cleaned
up because there are about to be more than two possible states.
We might want to note this in the 9.1 release notes as something for
trigger authors to double-check.
For consistency's sake I also changed some places that assumed that
TRIGGER_FIRED_FOR_ROW and TRIGGER_FIRED_FOR_STATEMENT are necessarily
mutually exclusive; that's not in immediate danger of breaking, but
it's still sloppier than it should be.
Extracted from Dean Rasheed's patch for triggers on views. I'm committing
this separately since it's an identifiable separate issue, and is the
only reason for the patch to touch most of these particular files.
Aside from being more forgiving, this prevents a rather surprising misbehavior
when the "wrong" order was used: the old code didn't throw a syntax error,
but absorbed the INTO clause into the last USING expression, which then did
strange things downstream.
Intentionally not changing the documentation; we'll continue to advertise
only the "standard" clause order.
Backpatch to 8.4, where the USING clause was added to EXECUTE.
It's not clear if this situation can occur in plpgsql other than via the
EXECUTE USING case Heikki illustrated, which I will shortly close off.
However, ignoring the intoClause if it's there is surely wrong, so let's
patch it for safety.
Backpatch to 8.3, which is as far back as this code has a PlannedStmt
to deal with. There might be another way to make an equivalent test
before that, but since this is just preventing hypothetical bugs,
I'm not going to obsess about it.
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.
expressions. We need to deal with this when handling subscripts in an array
assignment, and also when catching an exception. In an Assert-enabled build
these omissions led to Assert failures, but I think in a normal build the
only consequence would be short-term memory leakage; which may explain why
this wasn't reported from the field long ago.
Back-patch to all supported versions. 7.4 doesn't have exceptions, but
otherwise these bugs go all the way back.
Heikki Linnakangas and Tom Lane
can be caught in the same places that could catch an ordinary RAISE ERROR
in the same location. The previous coding insisted on throwing the error
from the block containing the active exception handler; which is arguably
more surprising, and definitely unlike Oracle's behavior.
Not back-patching, since this is a pretty obscure corner case. The risk
of breaking somebody's code in a minor version update seems to outweigh
any possible benefit.
Piyush Newe, reviewed by David Fetter
While this hack arguably has some benefit in terms of making PL/pgsql's
line numbering match the programmer's expectations, it also makes
PL/pgsql inconsistent with the remaining PLs, making it difficult for
clients to reliably determine where the error actually is. On balance,
it seems better to be consistent.
Pavel Stehule
being used in a PL/pgSQL FOR loop is closed was inadequate, as Tom Lane
pointed out. The bug affects FOR statement variants too, because you can
close an implicitly created cursor too by guessing the "<unnamed portal X>"
name created for it.
To fix that, "pin" the portal to prevent it from being dropped while it's
being used in a PL/pgSQL FOR loop. Backpatch all the way to 7.4 which is
the oldest supported version.
of YYSTYPE, and hence returning the wrong answer for cases where a plpgsql
"unreserved keyword" really does conflict with a variable name. Obviously
I didn't test this enough :-(. Per bug #5524 from Peter Gagarinov.
might close the cursor, rendering the Portal pointer to it invalid.
Closing the cursor in the middle of the loop is not a very sensible thing
to do, but we must handle it gracefully and throw an error instead of
crashing.
even when the expression is a query that returns no rows.
So far as I can tell, the only caller that actually fails when a garbage
OID is returned is exec_stmt_case(), which is new in 8.4 --- in all other
cases, we might make a useless trip through casting logic, but we won't
fail since the isnull flag will be set. Hence, backpatch only to 8.4,
just in case there are apps out there that aren't expecting an error to
be thrown if the query returns more or less than one column. (Which seems
unlikely, since the error would be thrown if the query ever did return a
row; but it's possible there's some never-exercised code out there.)
Per report from Mario Splivalo.
section, throw an error message saying explicitly that the label must go
before DECLARE. Per investigation of a recent pgsql-novice question,
this code did not work as intended in any modern PG version, maybe not ever.
Allowing such a thing would only create ambiguity anyway, so it seems better
to remove it than fix it.
Per bug #5352, this helps to provide a useful error message if the user
tries to do something presently unsupported, namely use a rowtype variable
as a member of a multiple-item INTO list.
