> > This patch improves the documentation of the UPDATE and ALTER TABLE
> > commands to elaborate on the effect of specifying an "ONLY" clause.
>
> Unfortunately this is still only half the truth ... see the
> SQL_INHERITANCE configuration variable.
Okay, I've attached an updated patch with more information on
SQL_INHERITANCE and inheritance behavior in prior releases.
Neil Conway
types for Table Functions, as previously proposed on HACKERS. Here is a
brief explanation:
1. Creates a new pg_type typtype: 'p' for pseudo type (currently either
'b' for base or 'c' for catalog, i.e. a class).
2. Creates new builtin type of typtype='p' named RECORD. This is the
first of potentially several pseudo types.
3. Modify FROM clause grammer to accept:
SELECT * FROM my_func() AS m(colname1 type1, colname2 type1, ...)
where m is the table alias, colname1, etc are the column names, and
type1, etc are the column types.
4. When typtype == 'p' and the function return type is RECORD, a list
of column defs is required, and when typtype != 'p', it is
disallowed.
5. A check was added to ensure that the tupdesc provide via the parser
and the actual return tupdesc match in number and type of
attributes.
When creating a function you can do:
CREATE FUNCTION foo(text) RETURNS setof RECORD ...
When using it you can do:
SELECT * from foo(sqlstmt) AS (f1 int, f2 text, f3 timestamp)
or
SELECT * from foo(sqlstmt) AS f(f1 int, f2 text, f3 timestamp)
or
SELECT * from foo(sqlstmt) f(f1 int, f2 text, f3 timestamp)
Included in the patches are adjustments to the regression test sql and
expected files, and documentation.
p.s.
This potentially solves (or at least improves) the issue of builtin
Table Functions. They can be bootstrapped as returning RECORD, and
we can wrap system views around them with properly specified column
defs. For example:
CREATE VIEW pg_settings AS
SELECT s.name, s.setting
FROM show_all_settings()AS s(name text, setting text);
Then we can also add the UPDATE RULE that I previously posted to
pg_settings, and have pg_settings act like a virtual table, allowing
settings to be queried and set.
Joe Conway
information about nulls and sort order.
This is based on information obtained from Peter Eisentraut and
Tom Lane on pgsql-hackers.
Please check my English and Docbook markup, as both are a second
language to me.
Rene Pijlman
ISO-compliant UNION/INTERSECT/EXCEPT. Revise discussion of rule
rewriter to reflect new subselect-in-FROM implementation of views.
Miscellaneous other cleanups.
option settings. Sort out SIGHUP vs BACKEND -- there is no total ordering
here, so make explicit checks. Add comments explaining all of this.
Removed permissions check on SHOW command.
Add examine_subclass to the game, rename to SQL_inheritance to fit the
official data model better. Adjust documentation.
Standalone backend needs to reset all options before it starts. To
facilitate that, have IsUnderPostmaster be set by the postmaster itself,
don't wait for the magic -p switch.
Also make sure that all environment variables and argv's survive
init_ps_display(). Use strdup where necessary.
Have initdb make configuration files (postgresql.conf, pg_hba.conf) mode
0600 -- having configuration files is no fun if you can't edit them.
after trying to resolve the item as an input-column name. This allows us
to be compliant with the SQL92 spec for queries that fall within the spec,
while still accepting the same out-of-spec queries as 6.5 did. You'll only
lose if there is an output column name that is the same as an input
column name, but doesn't refer to the same value. 7.0 will interpret
such a GROUP BY spec differently than 6.5 did. No way around that, because
6.5 was clearly not spec compliant.
SELECT DISTINCT ON (expr [, expr ...]) targetlist ...
and there is a check to make sure that the user didn't specify an ORDER BY
that's incompatible with the DISTINCT operation.
Reimplement nodeUnique and nodeGroup to use the proper datatype-specific
equality function for each column being compared --- they used to do
bitwise comparisons or convert the data to text strings and strcmp().
(To add insult to injury, they'd look up the conversion functions once
for each tuple...) Parse/plan representation of DISTINCT is now a list
of SortClause nodes.
initdb forced by querytree change...
