'scalar op ALL (array)', where the operator is applied between the
lefthand scalar and each element of the array. The operator must
yield boolean; the result of the construct is the OR or AND of the
per-element results, respectively.
Original coding by Joe Conway, after an idea of Peter's. Rewritten
by Tom to keep the implementation strictly separate from subqueries.
comparison functions), replacing the highly bogus bitwise array_eq. Create
a btree index opclass for ANYARRAY --- it is now possible to create indexes
on array columns.
Arrange to cache the results of catalog lookups across multiple array
operations, instead of repeating the lookups on every call.
Add string_to_array and array_to_string functions.
Remove singleton_array, array_accum, array_assign, and array_subscript
functions, since these were for proof-of-concept and not intended to become
supported functions.
Minor adjustments to behavior in some corner cases with empty or
zero-dimensional arrays.
Joe Conway (with some editorializing by Tom Lane).
functions
* Document pg_conversion_is_visible() which was created in one of my
previous patches and didn't get documented for some reason
Christopher Kings-Lynne
performance of min() and max() is slow when applied to the entire table,
and suggesting the simple workaround most experienced Pg users
eventually learn about (SELECT xyz ... ORDER BY xyz LIMIT 1).
Neil Conway
takes two parameters, an OID x and an integer y, and returns "true" with
probability 1/y (the OID argument is ignored). This can be useful -- for
example, it can be used to select a random sampling of the rows in a
table (which is what the "random" regression test uses it for).
This patch removes that function, because it was old and messy. The old
function had the following problems:
- it was undocumented
- it was poorly named
- it was designed to workaround an optimizer bug that no longer exists
(the OID argument is to ensure that the optimizer won't optimize away
calls to the function; AFAIK marking the function as 'volatile' suffices
nowadays)
- it used a different random-number generation technique than the other
PSRNG-related functions in the backend do (it called random() like they
do, but it had its own logic for setting a set and deciding when to
reseed the RNG).
Ok, this patch removes oidrand(), oidsrand(), and userfntest(), and
improves the SGML docs a little bit (un-commenting the setseed()
documentation).
Neil Conway
expression accepted by the regex operators, per discussion yesterday.
Along the way, reduce deadlock_timeout from PGC_POSTMASTER to PGC_SIGHUP
category. It is probably best to insist that all backends share the same
setting, but that doesn't mean it has to be frozen at startup.
(extracted from Tcl 8.4.1 release, as Henry still hasn't got round to
making it a separate library). This solves a performance problem for
multibyte, as well as upgrading our regexp support to match recent Tcl
and nearly match recent Perl.
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
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.
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.
> 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
>>" It's also possible to select no escape character by writing ESCAPE ''.
>>In this case there is no way to turn off the special meaning of
>>underscore and percent signs in the pattern."
Joe Conway
> Quick system function to pull out the current database.
>
> I've used this a number of times to allow stored procedures to find out
> where they are. Especially useful for those that do logging or hit a
> remote server.
>
> It's called current_database() to match with current_user().
It's also a necessity for an informational schema. The catalog
(database) name is required in a number of places.
Rod Taylor
sets of triggers. Also modify psql \d command to show foreign key
constraints as such and hide the triggers. pg_get_constraintdef()
function added to backend to support these. From Rod Taylor, code
review and some editorialization by Tom Lane.
has_language_privilege, has_schema_privilege to let SQL queries test
all the new privilege types in 7.3. Also, add functions pg_table_is_visible,
pg_type_is_visible, pg_function_is_visible, pg_operator_is_visible,
pg_opclass_is_visible to test whether objects contained in schemas are
visible in the current search path. Do some minor cleanup to centralize
accesses to pg_database, as well.
Tom Lane
Bruce Momjian
Peter Eisentraut
Tatsuo Ishii