that's selecting into a RECORD variable returns zero rows, make it
assign an all-nulls row to the RECORD; this is consistent with what
happens when the SELECT INTO target is not a RECORD. In support of
this, tweak the SPI code so that a valid tuple descriptor is returned
even when a SPI select returns no rows.
There are two implementation techniques: the executor understands a new
JOIN_IN jointype, which emits at most one matching row per left-hand row,
or the result of the IN's sub-select can be fed through a DISTINCT filter
and then joined as an ordinary relation.
Along the way, some minor code cleanup in the optimizer; notably, break
out most of the jointree-rearrangement preprocessing in planner.c and
put it in a new file prep/prepjointree.c.
including:
- replacing all the appropriate usages of <citetitle>PostgreSQL
...</citetitle> with &cite-user;, &cite-admin;, and so on
- fix an omission in the EXECUTE documentation
- add some more text to the EXPLAIN documentation
- improve the PL/PgSQL RETURN NEXT documentation (more work to do here)
- minor markup fixes
Neil Conway
containing a volatile function), rather than only on 'Var = Var' clauses
as before. This makes it practical to do flatten_join_alias_vars at the
start of planning, which in turn eliminates a bunch of klugery inside the
planner to deal with alias vars. As a free side effect, we now detect
implied equality of non-Var expressions; for example in
SELECT ... WHERE a.x = b.y and b.y = 42
we will deduce a.x = 42 and use that as a restriction qual on a. Also,
we can remove the restriction introduced 12/5/02 to prevent pullup of
subqueries whose targetlists contain sublinks.
Still TODO: make statistical estimation routines in selfuncs.c and costsize.c
smarter about expressions that are more complex than plain Vars. The need
for this is considerably greater now that we have to be able to estimate
the suitability of merge and hash join techniques on such expressions.
costs for expression evaluation, not only per-tuple cost as before.
This extension is needed in order to deal realistically with hashed or
materialized sub-selects.
>
> I'd suggest that the runtime.sgml description explicitly say "values of
> at least a few thousand are recommended for production installations".
Neil Conway
required if a datatype is to be accepted by GROUP BY, DISTINCT, or
ORDER BY. This is documentation for code changes made pursuant to
pgsql-hackers discussion around 29-Nov-02.
beginning/end of cursor.
Have MOVE return 0/1 depending on cursor position.
Matches SQL spec.
Pass cursor counter from parser as a long rather than int.
Doc updates.
> I'm not objecting to improving the text. I am objecting to deleting it
> outright...
Ok, fair enough. I've attached a revised version of the patch -- let me
know you think it needs further improvements.
Neil Conway
>
> In pg.py the attributes of DB are defined as being the same as
> the attributes of the corresponding pgobject "db", using the following
...
> The problem is that the attributes of db (which are read only)
> are not static (they are actually function calls to PostgreSQL),
> especially "status" and "error", but those attributes are copied
> and this is done only once when initializing the DB object.
>
> So, in effect, only the attribute "db.error" of a DB instance
> will be updated, but not the attribute "error". Same with "status".
> Don't copy the (read only) attributes of the pgobject to the
> DB object, but only the methods, and all of them, like this:
>
> --------------- change in pg.py ------------------
> # Create convience methods, in a way that is still overridable.
> for e in self.db.__methods__:
> setattr(self, e, getattr(self.db, e))
> ----------------------------------------------------
>
> Furthermore, make an addition to the documentation of the
> DB wrapper class (i.e. in pygresql-pg-db.html):
> After the sentence "All pgobject methods are included in this class also."
> add the following sentence "The pgobject read-only attributes can be
> accessed py adding the prefix 'db.' to them."
Christoph Zwerschke
* Add schema, cast, and conversion backslash commands to psql
I had to create a new publically available function,
pg_conversion_is_visible, as it seemed to be missing from the catalogs.
This required me to do no small amount of hacking around in namespace.c
I have updated the \? help and sgml docs.
\dc - list conversions [PATTERN]
\dC - list casts
\dn list schemas
I didn't support patterns with casts as there's nothing obvious to match
against.
Catalog version incremented --- initdb required.
Christopher Kings-Lynne
make VALUE a non-reserved word again, use less invasive method of passing
ConstraintTestValue into transformExpr, fix problems with nested constraint
testing, do correct thing with NULL result from a constraint expression,
remove memory leak. Domain checks still need much more work if we are going
to allow ALTER DOMAIN, however.
documentation and regression test mods. It seemed small and unobtrusive enough
to not require a specific proposal on the hackers list -- but if not, let me
know and I'll make a pitch. Otherwise, if there are no objections please apply.
Joe Conway
-hackers a couple days ago.
Notes/caveats:
- added regression tests for the new functionality, all
regression tests pass on my machine
- added pg_dump support
- updated PL/PgSQL to support per-statement triggers; didn't
look at the other procedural languages.
- there's (even) more code duplication in trigger.c than there
was previously. Any suggestions on how to refactor the
ExecXXXTriggers() functions to reuse more code would be
welcome -- I took a brief look at it, but couldn't see an
easy way to do it (there are several subtly-different
versions of the code in question)
- updated the documentation. I also took the liberty of
removing a big chunk of duplicated syntax documentation in
the Programmer's Guide on triggers, and moving that
information to the CREATE TRIGGER reference page.
- I also included some spelling fixes and similar small
cleanups I noticed while making the changes. If you'd like
me to split those into a separate patch, let me know.
Neil Conway
results due to doing arithmetic on uninitialized values. Add some
documentation about the AT TIME ZONE construct. Update some other
date/time documentation that seemed out of date for 7.3.
database access outside a transaction; revert bogus performance improvement
in SIBackendInit(); improve comments; add documentation (this part courtesy
Neil Conway).
parameter to allow it to be forced off for comparison purposes.
Add ORDER BY clauses to a bunch of regression test queries that will
otherwise produce randomly-ordered output in the new regime.
- CLUSTER ALL clusters all the tables that have some index with
indisclustered set and the calling user owns.
- CLUSTER tablename clusters the named table, using the index with
indisclustered set. If no index has the bit set, throws elog(ERROR).
- The multi-relation version (CLUSTER ALL) uses a multitransaction
approach, similar to what VACUUM does.
Alvaro Herrera
before commit, not after :-( --- the original coding is not only unsafe
if an error occurs while it's processing, but it generates an invalid
sequence of WAL entries. Resurrect 7.2 logic for deleting items when
no longer needed. Use an enum instead of random macros. Editorialize
on names used for routines and constants. Teach backend/nodes routines
about new field in CreateTable struct. Add a regression test.
PL/PgSQL. Previously, it had been bundled together with the assign
statement implementation, for some reason that wasn't clear to me
(they certainly don't share any code with one another). So I separated
them and made PERFORM a statement like any other. No changes in
functionality.
Along the way, I added some regression tests for PERFORM, added a
bunch more SGML tags to the PL/PgSQL docs, and removed an obsolete
comment relating to the implementation of RETURN NEXT.
Neil Conway
"traditional" behavior, so the change should be transparent. Use the
command "\pset pager always" to turn it on. Anything else does the
normal toggle between "on" and "off"
Greg Sabino Mullane
precision for float4, float8, and geometric types. Set it in pg_dump
so that float data can be dumped/reloaded exactly (at least on platforms
where the float I/O support is properly implemented). Initial patch by
Pedro Ferreira, some additional work by Tom Lane.
the documentation and behavior of "pg_result $res -oid" when $res is not
from an INSERT. The documentation says it should return an empty
string, but in fact it returns 0. I think it used to return an empty
string around PostgreSQL-7.1.3 when PQoidStatus() was used, but now it
uses PQoidValue() which returns InvalidOid, 0 in this case.
Assuming the current behavior is desired, here is a patch to the
documentation doc/src/sgml/libpgtcl.sgml to match what really happens:
ljb
where it's safe to do database access. Along the way, fix core dump
for 'DEFAULT' parameters to CREATE DATABASE. initdb forced due to
change in pg_proc entry.
rather than being reordered according to INSTEAD attribute for
implementation convenience.
Also, increase compiled-in recursion depth limit from 10 to 100 rewrite
cycles. 10 seems pretty marginal for situations where multiple rules
exist for the same query. There was a complaint about this recently,
so I'm going to bump it up. (Perhaps we should make the limit a GUC
parameter, but that's too close to being a new feature to do in beta.)
a column list. Bring its parsing of quoted names and quoted strings
somewhat up to speed --- I believe it now handles all non-error cases
the same way the backend would, but weird boundary conditions are not
necessarily done the same way.
- Wrap them in the <database class="table"> tags, since thats what they
are (no markup rules for this, so it inherits from parent -- no style
change)
- Mention that pg_database, pg_shadow, and pg_group are global, and the
rest are local to the specific DB. (I believe this is correct).
> Works for me, though I suppose we could explain what the exceptions are
> like in general terms. Perhaps something like
>
> 'Most system catalogs are copied from the template database during
> database creation, and are thereafter database-specific. A few
> catalogs are physically shared across all databases in an installation;
> these are marked in the descriptions of the individual catalogs.'
Ok, new patch.
Rod Taylor
discussion some weeks ago. Also, add a check that two types to be
binary-equivalenced match as to typlen, typbyval, and typalign; if
they don't then it's surely a mistake to equivalence them.
be able to do that, but the ability seems to have got lost in the
shuffle). Add a -o nextOID switch for completeness. Improve the
documentation to explain how and why to use these switches.
The error message said so :-)
In 25.3. Using PL/Python
If the trigger "when" is BEFORE, you may return None or "OK"
from the Python function to indicate the tuple is unmodified, "SKIP"
to abort the event, or "MODIFIED" to indicate you've modified the tuple.
should read
If the trigger "when" is BEFORE, you may return None or "OK"
from the Python function to indicate the tuple is unmodified, "SKIP"
to abort the event, or "MODIFY" to indicate you've modified the tuple.
elein
the SQL99 standard. (I'm not sure that the character-class features are
quite right, but that can be fixed later.) Document SQL99 and POSIX
regexps as being different features; provide variants of SUBSTRING for
each.
with OPAQUE. CREATE LANGUAGE, CREATE TRIGGER, and CREATE TYPE will all
accept references to functions declared with OPAQUE --- but they will
issue a NOTICE, and will modify the function entries in pg_proc to have
the preferred type-safe argument or result types instead of OPAQUE.
Per recent pghackers discussions.
to be flexible about assignment casts without introducing ambiguity in
operator/function resolution. Introduce a well-defined promotion hierarchy
for numeric datatypes (int2->int4->int8->numeric->float4->float8).
Change make_const to initially label numeric literals as int4, int8, or
numeric (never float8 anymore).
Explicitly mark Func and RelabelType nodes to indicate whether they came
from a function call, explicit cast, or implicit cast; use this to do
reverse-listing more accurately and without so many heuristics.
Explicit casts to char, varchar, bit, varbit will truncate or pad without
raising an error (the pre-7.2 behavior), while assigning to a column without
any explicit cast will still raise an error for wrong-length data like 7.3.
This more nearly follows the SQL spec than 7.2 behavior (we should be
reporting a 'completion condition' in the explicit-cast cases, but we have
no mechanism for that, so just do silent truncation).
Fix some problems with enforcement of typmod for array elements;
it didn't work at all in 'UPDATE ... SET array[n] = foo', for example.
Provide a generalized array_length_coerce() function to replace the
specialized per-array-type functions that used to be needed (and were
missing for NUMERIC as well as all the datetime types).
Add missing conversions int8<->float4, text<->numeric, oid<->int8.
initdb forced.
> Hannu Krosing wrote:
>
>> It seems that my last mail on this did not get through to the list
>> ;(
>>
>> Please consider renaming the new builtin function
>> split(text,text,int)
>>
>> to something else, perhaps
>>
>> split_part(text,text,int)
>>
>> (like date_part)
>>
>> The reason for this request is that 3 most popular scripting
>> languages (perl, python, php) all have also a function with similar
>> signature, but returning an array instead of single element and the
>> (optional) third argument is limit (maximum number of splits to
>> perform)
>>
>> I think that it would be good to have similar function in (some
>> future release of) postgres, but if we now let in a function with
>> same name and arguments but returning a single string instead an
>> array of them, then we will need to invent a new and not so easy to
>> recognise name for the "real" split function.
>>
>
> This is a good point, and I'm not opposed to changing the name, but
> it is too bad your original email didn't get through before beta1 was
> rolled. The change would now require an initdb, which I know we were
> trying to avoid once beta started (although we could change it
> without *requiring* an initdb I suppose).
>
> I guess if we do end up needing an initdb for other reasons, we
> should make this change too. Any other opinions? Is split_part an
> acceptable name?
>
> Also, if we add a todo to produce a "real" split function that
> returns an array, similar to those languages, I'll take it for 7.4.
No one commented on the choice of name, so the attached patch changes
the name of split(text,text,int) to split_part(text,text,int) per
Hannu's recommendation above. This can be applied without an initdb if
current beta testers are advised to run:
update pg_proc set proname = 'split_part' where proname = 'split';
in the case they want to use this function. Regression and doc fix is
also included in the patch.
Joe Conway
