so that precision of result is always at least as good as you'd get from
float8 arithmetic (ie, always at least 16 digits of accuracy). Per
pg_hackers discussion a few days ago.
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.
parse analysis and into the execution code (in tablecmds.c). This
eliminates a lot of unreasonably complex code that needed to have two
or more execution paths in case it was dealing with a not-yet-created
table column vs. an already-existing one. The execution code is always
dealing with already-created tables and so needs only one case. This
also eliminates some potential race conditions (the table wasn't locked
between parse analysis and execution), makes it easy to fix the gripe
about wrong referenced-column names generating a misleading error message,
and lets us easily add a dependency from the foreign-key constraint to
the unique index that it requires the referenced table to have. (Cf.
complaint from Kris Jurka 12-Sep-2002 on pgsql-bugs.)
Also, third try at building a deletion mechanism that is not sensitive
to the order in which pg_depend entries are visited. Adding the above-
mentioned dependency exposed the folly of what dependency.c had been
doing: it failed for cases where B depends on C while both auto-depend
on A. Dropping A should succeed in this case, but was failing if C
happened to be visited before B. It appears the only solution is two
separate walks over the dependency tree.
ruleutils display is not such a great idea. For arguments of functions
and operators I think we'd better keep the historical behavior of showing
such casts explicitly, to ensure that the function/operator is reparsed
the same way when the rule is reloaded. This also makes the output of
EXPLAIN less obscurantist about exactly what's happening.
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.
>
>>::sigh:: Is it me or does it look like all
>>of pl/pgsql is schema un-aware (ie, all of the declarations). -sc
>
>
> Yeah. The group of routines parse_word, parse_dblword, etc that are
> called by the lexer certainly all need work. There are some
> definitional issues to think about, too --- plpgsql presently relies on
> the number of names to give it some idea of what to look for, and those
> rules are probably all toast now. Please come up with a sketch of what
> you think the behavior should be before you start hacking code.
Attached is a diff -c format proposal to fix this. I've also attached a short
test script. Seems to work OK and passes all regression tests.
Here's a breakdown of how I understand plpgsql's "Special word rules" -- I
think it illustrates the behavior reasonably well. New functions added by this
patch are plpgsql_parse_tripwordtype and plpgsql_parse_dblwordrowtype:
Joe Conway
> 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
Eliminate the mysterious games that the Cygwin build plays with the linker
flag variables. DLLLIBS is gone, use SHLIB_LINK like everyone else.
Detect cygipc in configure, after the linker flags are set up, otherwise
configure might not work at all.
Make sure everything is covered by make clean.
Fix the build of the new conversion procedure modules.
Add new DLLIMPORT markers where required.
Finally, the compiler complains if we use an explicit
-I/usr/local/include, so don't do that. Curiously, -L/usr/local/lib is
still necessary.
into a separate parallel group. I can't confirm that this fixes the
problem for me (since it only occurs about one in ten or one in twenty
runs), but I think it's a good bet that it does...
Neil Conway
type for runtime constraint checks, instead of misusing the parse-time
Constraint node for the purpose. Fix some damage introduced into type
coercion logic; in particular ensure that a coerced expression tree will
read out the correct result type when inspected (patch had broken some
RelabelType cases). Enforce domain NOT NULL constraints against columns
that are omitted from an INSERT.
available (else there's no way to interpret the list links). Change
pg_locks view to show transaction ID locks separately from ordinary
relation locks. Avoid showing N duplicate rows when the same lock is
held multiple times (seems unlikely that users care about exact hold
count). Improve documentation.
column additions, deletions, and renames that would let a child table
get out of sync with its parent. Patch by Alvaro Herrera, with some
kibitzing by Tom Lane.
CVS HEAD):
Amended "strings" regression test. TOAST tests now insert two values
with storage set to "external", to exercise properly the TOAST slice
routines which fetch only a subset of the chunks.
Changed now-misleading comment on AlterTableCreateToastTable in
tablecmds.c, because both columns of the index on a toast table are now
used.
John Gray
bit on the indexes.
I also attach clusterdb and clusterdb.sgml; both of them are blatant
rips of vacuumdb and vacuumdb.sgml, but get the job done. Please review
them, as I'm probably making a lot of mistakes with SGML and I can't
compile it here.
vacuumdb itself is not very comfortable to use when the databases have
passwords, because it has to connect once for each table (I can probably
make it connect only once for each database; should I?). Because of
this I added a mention of PGPASSWORDFILE in the documentation, but I
don't know if that is the correct place for that.
Alvaro Herrera
array header, and to compute sizing and alignment of array elements
the same way normal tuple access operations do --- viz, using the
tupmacs.h macros att_addlength and att_align. This makes the world
safe for arrays of cstrings or intervals, and should make it much
easier to write array-type-polymorphic functions; as examples see
the cleanups of array_out and contrib/array_iterator. By Joe Conway
and Tom Lane.
value '-2' is used to indicate a variable-width type whose width is
computed as strlen(datum)+1. Everything that looks at typlen is updated
except for array support, which Joe Conway is working on; at the moment
it wouldn't work to try to create an array of cstring.
tighten foreign-key check (a self-reference should not prevent TRUNCATE),
improve error message, cause a relation's TOAST table to be truncated
along with the relation.
constraints
The issue with finding and removing foreign key constraints is no longer
an issue, so please apply the attached.
It does NOT check for rules or on delete triggers (old style foreign
keys) as those are difficult to deal with (remove, truncate, re-add).
Rod Taylor
replace(string, from, to)
-- replaces all occurrences of "from" in "string" to "to"
split(string, fldsep, column)
-- splits "string" on "fldsep" and returns "column" number piece
to_hex(int32_num) & to_hex(int64_num)
-- takes integer number and returns as hex string
Joe Conway
with OPAQUE, as per recent pghackers discussion. I still want to do some
more work on the 'cstring' pseudo-type, but I'm going to commit the bulk
of the changes now before the tree starts shifting under me ...
