by supporting conversions in places that used to demand exact rowtype match.
Since this issue is certain to come up elsewhere (in fact, already has,
in ExecEvalConvertRowtype), factor out the support code into new core
functions for tuple conversion. I chose to put these in a new source
file since heaptuple.c is already overly long.
Heavily revised version of a patch by Pavel Stehule.
more nearly matching the core SQL scanner. The user-visible effects are:
* Block comments (slash-star comments) now nest, as per SQL spec.
* In standard_conforming_strings mode, backslash as the last character of a
non-E string literal is now correctly taken as an ordinary character;
formerly it was misinterpreted as escaping the ending quote. (Since the
string also had to pass through the core scanner, this invariably led
to syntax errors.)
* Formerly, backslashes in the format string of RAISE were always treated as
quoting the next character, regardless of mode. Now, they are ordinary
characters with standard_conforming_strings on, while with it off, they
introduce the same set of escapes as in the core SQL scanner. Also,
escape_string_warning is now effective for RAISE format strings. These
changes make RAISE format strings work just like any other string literal.
This is implemented by copying and pasting a lot of logic from the core
scanner. It would be a good idea to look into getting rid of plpgsql's
scanner entirely in favor of using the core scanner. However, that involves
more change than I can justify making during beta --- in particular, the core
scanner would have to become re-entrant.
In passing, remove the kluge that made the plpgsql scanner emit T_FUNCTION or
T_TRIGGER as a made-up first token. That presumably had some value once upon
a time, but now it's just useless complication for both the scanner and the
grammar.
by my patch of 2007-01-28 to use per-subtransaction ExprContexts/EStates:
since we re-prepared any expression tree when the current subtransaction ID
changed, we'd accumulate more and more leaked expression state trees in the
outermost subtransaction if the same function was executed at multiple levels
of subtransaction nesting. To fix, go back to the previous scheme where
there was only one EState per transaction for simple plpgsql expressions.
We really only need an ExprContext per subtransaction, not a whole EState,
so it's possible to keep prepared expression state trees in the one EState
throughout the transaction. This should be more efficient as well as not
leaking memory for cases involving lots of subtransactions.
The added regression test is the case that inspired the 2007-01-28 patch in
the first place, just to make sure we didn't go backwards. The current
memory leak complaint is unfortunately hard to test for in the regression
test framework, though manual testing shows it's fixed.
Although this is a pre-existing bug, I'm not back-patching because I'd like to
see this method get some field testing first. Consider back-patching if it
gets through 8.4beta unscathed.
instead of vice versa. Update the regression test expectations to support
that. In the plpgsql test, adjust the test data so that this isn't an
issue. In the char and varchar tests, add new expected files.
so long as all the trailing arguments are of the same (non-array) type.
The function receives them as a single array argument (which is why they
have to all be the same type).
It might be useful to extend this facility to aggregates, but this patch
doesn't do that.
This patch imposes a noticeable slowdown on function lookup --- a follow-on
patch will fix that by adding a redundant column to pg_proc.
Pavel Stehule
HINT fields to a user-thrown error message, and to specify the SQLSTATE
error code to use. The syntax has also been tweaked so that the
Oracle-compatible case "RAISE exception_name" works (though you won't get a
very nice error message if you just write that much). Lastly, support
the Oracle-compatible syntax "RAISE" with no parameters to re-throw
the current error from within an EXCEPTION block.
In passing, allow the syntax SQLSTATE 'nnnnn' within EXCEPTION lists,
so that there is a way to trap errors with custom SQLSTATE codes.
Pavel Stehule and Tom Lane
sugar for PL/PgSQL set-returning functions that want to return the result
of evaluating a query; it should also be more efficient than repeated
RETURN NEXT statements. Based on an earlier patch from Pavel Stehule.
name. With this patch, it is always possible for the user to qualify a
plpgsql variable name if needed to avoid ambiguity. While there is much more
work to be done in this area, this simple change removes one unnecessary
incompatibility with Oracle. Per discussion.
We have once or twice seen failures suggesting that control didn't get
to the exception block before the timeout elapsed, which is unlikely
but not impossible in a parallel regression test (with a dozen other
backends competing for cycles). This change doesn't completely prevent
the problem of course, but it should reduce the probability enough that
we don't see it anymore. Per buildfarm results.
---------------------------------------------------------------------------
Add dynamic record inspection to PL/PgSQL, useful for generic triggers:
tval2 := r.(cname);
or
columns := r.(*);
Titus von Boxberg
command or expression, rather than one copy for each textual occurrence as
it did before. This might result in some small performance improvement,
but the compelling reason to do it is that not doing so can result in
unexpected grouping failures because the main SQL parser won't see different
parameter numbers as equivalent. Add a regression test for the failure case.
Per report from Robert Davidson.
end of the block:
<<label>>
begin
...
end label;
Similarly for loops. This is per PL/SQL. Update the documentation and
add regression tests. Patch from Pavel Stehule, code review by Neil
Conway.
we need to be careful to reset rc to PLPGSQL_RC_OK, depending on how
the loop's logic is structured. If we continue a loop but it then
exits without executing the loop's body again, we want to return
PLPGSQL_RC_OK to our caller. Enhance the regression tests to catch
this problem. Per report from Michael Fuhr.
instead of just scalar variables. Add regression tests and update the
documentation. Along the way, remove some redundant error checking
code from exec_stmt_perform().
Original patch from Pavel Stehule, reworked by Neil Conway.
These contain the SQLSTATE and error message of the current exception,
respectively. They are scope-local variables that are only defined
in exception handlers (so attempting to reference them outside an
exception handler is an error). Update the regression tests and the
documentation.
Also, do some minor related cleanup: export an unpack_sql_state()
function from the backend and use it to unpack a SQLSTATE into a
string, and add a free_var() function to pl_exec.c
Original patch from Pavel Stehule, review by Neil Conway.
This allows the result of executing a SELECT to be assigned to a row
variable, record variable, or list of scalars. Docs and regression tests
updated. Per Pavel Stehule, improvements and cleanup by Neil Conway.
output parameters or VOID or a set. There seems no particular reason to
insist on a RETURN in these cases, since the function return value is
determined by other elements anyway. Per recent discussion.
and parsing work in PL/PgSQL:
- memory management is now done via palloc(). The compiled representation
of each function now has its own memory context. Therefore, the storage
consumed by a function can be reclaimed via MemoryContextDelete().
During compilation, the CurrentMemoryContext is the function's memory
context. This means that a palloc() is sufficient to allocate memory
that will have the same lifetime as the function itself. As a result,
code invoked during compilation should be careful to pfree() temporary
allocations to avoid leaking memory. Since a lot of the code in the
backend is not careful about releasing palloc'ed memory, that means
we should switch into a temporary memory context before invoking
backend functions. A temporary context appropriate for such allocations
is `compile_tmp_cxt'.
- The ability to use palloc() allows us to simply a lot of the code in
the parser. Rather than representing lists of elements via ad hoc
linked lists or arrays, we can use the List type. Rather than doing
malloc followed by memset(0), we can just use palloc0().
- We now check that the user has supplied the right number of parameters
to a RAISE statement. Supplying either too few or too many results in
an error (at runtime).
- PL/PgSQL's parser needs to accept arbitrary SQL statements. Since we
do not want to duplicate the SQL grammar in the PL/PgSQL grammar, this
means we need to be quite lax in what the PL/PgSQL grammar considers
a "SQL statement". This can lead to misleading behavior if there is a
syntax error in the function definition, since we assume a malformed
PL/PgSQL construct is a SQL statement. Furthermore, these errors were
only detected at runtime (when we tried to execute the alleged "SQL
statement" via SPI).
To rectify this, the patch changes the parser to invoke the main SQL
parser when it sees a string it believes to be a SQL expression. This
means that synctically-invalid SQL will be rejected during the
compilation of the PL/PgSQL function. This is only done when compiling
for "validation" purposes (i.e. at CREATE FUNCTION time), so it should
not impose a runtime overhead.
- Fixes for the various buffer overruns I've patched in stable branches
in the past few weeks. I've rewritten code where I thought it was
warranted (unlike the patches applied to older branches, which were
minimally invasive).
- Various other minor changes and cleanups.
- Updates to the regression tests.
advancing ActiveSnapshot when we are inside a volatile function.
Per example from Gaetano Mendola. Add a regression test to catch
similar problems in future.
We don't really want to start a new SPI connection, just keep using the old
one; otherwise we have memory management problems as illustrated by
John Kennedy's bug report of today. This requires a bit of a hack to
ensure the SPI stack state is properly restored, but then again what we
were doing before was a hack too, strictly speaking. Add a regression
test to cover this case.
rather than when returning to the idle loop. This makes no particular
difference for interactively-issued queries, but it makes a big difference
for queries issued within functions: trigger execution now occurs before
the calling function is allowed to proceed. This responds to numerous
complaints about nonintuitive behavior of foreign key checking, such as
http://archives.postgresql.org/pgsql-bugs/2004-09/msg00020.php, and
appears to be required by the SQL99 spec.
Also take the opportunity to simplify the data structures used for the
pending-trigger list, rename them for more clarity, and squeeze out a
bit of space.
more nearly Oracle-equivalent. Allow matching by category as well as
specific error code. Document the set of available condition names
(or more accurately, synchronize it with the existing documentation). In
passing, update errcodes.sgml to include codes added during 7.5 development.
There are still some things that need refinement; in particular I fear
that the recognized set of error condition names probably has little in
common with what Oracle recognizes. But it's a start.
large objects. Dump all these in pg_dump; also add code to pg_dump
user-defined conversions. Make psql's large object code rely on
the backend for inserting/deleting LOB comments, instead of trying to
hack pg_description directly. Documentation and regression tests added.
Christopher Kings-Lynne, code reviewed by Tom
Tom Lane