discussion (including making def_arg allow reserved words), add missed
opt_definition for UNIQUE case. Put the reloptions support code in a less
random place (I chose to make a new file access/common/reloptions.c).
Eliminate header inclusion creep. Make the index options functions safely
user-callable (seems like client apps might like to be able to test validity
of options before trying to make an index). Reduce overhead for normal case
with no options by allowing rd_options to be NULL. Fix some unmaintainably
klugy code, including getting rid of Natts_pg_class_fixed at long last.
Some stylistic cleanup too, and pay attention to keeping comments in sync
with code.
Documentation still needs work, though I did fix the omissions in
catalogs.sgml and indexam.sgml.
< o Add ALTER TABLE tab ADD/DROP INHERITS parent
<
< This allows tables to be added/removed from an inheritance
< hierarchy. This is particularly useful for table partitioning.
< http://archives.postgresql.org/pgsql-hackers/2006-05/msg00988.php
<
> o -Add ALTER TABLE tab INHERIT / NO INHERIT parent
Open items:
There were a few tangentially related issues that have come up that I think
are TODOs. I'm likely to tackle one or two of these next so I'm interested in
hearing feedback on them as well.
. Constraints currently do not know anything about inheritance. Tom suggested
adding a coninhcount and conislocal like attributes have to track their
inheritance status.
. Foreign key constraints currently do not get copied to new children (and
therefore my code doesn't verify them). I don't think it would be hard to
add them and treat them like CHECK constraints.
. No constraints at all are copied to tables defined with LIKE. That makes it
hard to use LIKE to define new partitions. The standard defines LIKE and
specifically says it does not copy constraints. But the standard already has
an option called INCLUDING DEFAULTS; we could always define a non-standard
extension LIKE table INCLUDING CONSTRAINTS that gives the user the option to
request a copy including constraints.
. Personally, I think the whole attislocal thing is bunk. The decision about
whether to drop a column from children tables or not is something that
should be up to the user and trying to DWIM based on whether there was ever
a local definition or the column was acquired purely through inheritance is
hardly ever going to match up with user expectations.
. And of course there's the whole unique and primary key constraint issue. I
think to get any traction at all on this you have a prerequisite of a real
partitioned table implementation where the system knows what the partition
key is so it can recognize when it's a leading part of an index key.
Greg Stark
be delivered directly to the collector process. The extra process context
swaps required to transfer data through the buffer process seem to outweigh
any value the buffering might have. Per recent discussion and tests.
I modified Bruce's draft patch to use poll() rather than select() where
available (this makes a noticeable difference on my system), and fixed
up the EXEC_BACKEND case.
< o Add support for WITH HOLD cursors
> o Add support for WITH HOLD and SCROLL cursors
>
> PL/pgSQL cursors should support the same syntax as
> backend cursors.
>
< * %Disallow changing DEFAULT expression of a SERIAL column?
<
< This should be done only if the existing SERIAL problems cannot be
< fixed.
<
> * -Disallow changing DEFAULT expression of a SERIAL column
will be expanded to a list of their member fields, rather than creating
a nested rowtype field as formerly. (The old behavior is still available
by omitting '.*'.) This syntax is not allowed by the SQL spec AFAICS,
so changing its behavior doesn't violate the spec. The new behavior is
substantially more useful since it allows, for example, triggers to check
for data changes with 'if row(new.*) is distinct from row(old.*)'. Per
my recent proposal.
< * Reuse index tuples that point to rows that are not visible to anyone?
> * Reuse index tuples that point to heap tuples that are not visible to
> anyone?
< * Allow heap reuse of UPDATEd rows if old and new versions are on the
< same heap page?
> * Allow heap reuse of UPDATEd rows if no indexed columns are changed,
> and old and new versions are on the same heap page?
< This is possible for same-page updates because a single index row
< can point to both old and new values.
> While vacuum handles DELETEs fine, updating of non-indexed columns, like
> counters, are difficult for VACUUM to handle efficiently. This method
> is possible for same-page updates because a single index row can be
> used to point to both old and new values.
>
> * Allow heap reuse of UPDATEd rows if old and new versions are on the
> same heap page?
>
> This is possible for same-page updates because a single index row
> can point to both old and new values.
> http://archives.postgresql.org/pgsql-hackers/2006-06/msg01305.php
current commands; instead, store current-status information in shared
memory. This substantially reduces the overhead of stats_command_string
and also ensures that pg_stat_activity is fully up to date at all times.
Per my recent proposal.
section into PL/pgSQL and non-PL/pgSQL sections:
< o Fix PL/pgSQL RENAME to work on variables other than OLD/NEW
< o Allow function parameters to be passed by name,
< get_employee_salary(emp_id => 12345, tax_year => 2001)
< o Add Oracle-style packages
< o Add table function support to pltcl, plpython
< o Add capability to create and call PROCEDURES
< o Allow PL/pgSQL to handle %TYPE arrays, e.g. tab.col%TYPE[]
< o Allow function argument names to be statements from PL/PgSQL
< o Add MOVE to PL/pgSQL
< o Add support for polymorphic arguments and return types to
< languages other than PL/PgSQL
< o Add support for OUT and INOUT parameters to languages other
< than PL/PgSQL
< o Add single-step debugging of PL/PgSQL functions
< o Allow PL/PgSQL to support WITH HOLD cursors
< o Allow PL/PgSQL RETURN to return row or record functions
<
< http://archives.postgresql.org/pgsql-patches/2005-11/msg00045.php
> o PL/pgSQL
> o Fix RENAME to work on variables other than OLD/NEW
> o Allow function parameters to be passed by name,
> get_employee_salary(emp_id => 12345, tax_year => 2001)
> o Add Oracle-style packages
> o Allow handling of %TYPE arrays, e.g. tab.col%TYPE[]
> o Allow listing of record column names, and access to
> record columns via variables, e.g. columns := r.(*),
> tval2 := r.(colname)
>
> http://archives.postgresql.org/pgsql-patches/2005-07/msg00458.php
> http://archives.postgresql.org/pgsql-patches/2006-05/msg00302.php
> http://archives.postgresql.org/pgsql-patches/2006-06/msg00031.php
>
> o Add MOVE
> o Add single-step debugging of functions
> o Add support for WITH HOLD cursors
> o Allow PL/RETURN to return row or record functions
>
> http://archives.postgresql.org/pgsql-patches/2005-11/msg00045.php
>
>
> o Other
> o Add table function support to pltcl, plpython
> o Add support for polymorphic arguments and return types to
> languages other than PL/PgSQL
> o Add capability to create and call PROCEDURES
> o Add support for OUT and INOUT parameters to languages other
> than PL/PgSQL
<
< o Add new version of PQescapeString() that doesn't double backslashes
< that are part of a client-only multibyte sequence
<
< Single-quote is not a valid byte in any supported client-only
< encoding. This requires using mblen() to determine if the
< backslash is inside or outside a multi-byte sequence.
<
< o Add new version of PQescapeString() that doesn't double
< backslashes when standard_conforming_strings is true and
< non-E strings are used
< Right now only one encoding is allowed per database.
> Right now only one encoding is allowed per database. [locale]
> * Add CREATE COLLATE? [locale]
< pg_get_tabledef(), pg_get_domaindef(), pg_get_functiondef(), and
< make use of them in pg_dump
> pg_get_tabledef(), pg_get_domaindef(), pg_get_functiondef()
< pg_get_tabledef(), pg_get_domaindef(), pg_get_functiondef()
> pg_get_tabledef(), pg_get_domaindef(), pg_get_functiondef(), and
> make use of them in pg_dump
< * Allow a database in tablespace t1 with tables created in
> o Allow a database in tablespace t1 with tables created in
125c125
< * Allow reporting of which objects are in which tablespaces
> o Allow reporting of which objects are in which tablespaces
593c593
< * Allow GRANT/REVOKE permissions to be inherited by objects based on
> o Allow GRANT/REVOKE permissions to be inherited by objects based on
596c596
< * Allow SERIAL sequences to inherit permissions from the base table?
> o Allow SERIAL sequences to inherit permissions from the base table?
that the Mackert-Lohmann formula applies across all the repetitions of the
nestloop, not just each scan independently. We use the M-L formula to
estimate the number of pages fetched from the index as well as from the table;
that isn't what it was designed for, but it seems reasonably applicable
anyway. This makes large numbers of repetitions look much cheaper than
before, which accords with many reports we've received of overestimation
of the cost of a nestloop. Also, change the index access cost model to
charge random_page_cost per index leaf page touched, while explicitly
not counting anything for access to metapage or upper tree pages. This
may all need tweaking after we get some field experience, but in simple
tests it seems to be giving saner results than before. The main thing
is to get the infrastructure in place to let cost_index() and amcostestimate
functions take repeated scans into account at all. Per my recent proposal.
Note: this patch changes pg_proc.h, but I did not force initdb because
the changes are basically cosmetic --- the system does not look into
pg_proc to decide how to call an index amcostestimate function, and
there's no way to call such a function from SQL at all.
This shouldn't affect simple indexscans much, while for bitmap scans that
are touching a lot of index rows, this seems to bring the estimates more
in line with reality. Per recent discussion.
assumed that a sequential page fetch has cost 1.0. This patch doesn't
in itself change the system's behavior at all, but it opens the door to
people adopting other units of measurement for EXPLAIN costs. Also, if
we ever decide it's worth inventing per-tablespace access cost settings,
this change provides a workable intellectual framework for that.
< o Allow COPY to output from views
> o Allow COPY to output from SELECT
570c570
< Another idea would be to allow actual SELECT statements in a COPY.
> COPY should also be able to output views.
as this seems only likely to create headaches for module developers. Put
the macro in the pre-existing fmgr.h file instead. Avoid being too cute
about how many fields we can cram into a word, and avoid trying to fetch
from a library we've already unlinked.
Along the way, it occurred to me that the magic block really ought to be
'const' so it can be stored in the program text area. Do the same for
the existing data blocks for PG_FUNCTION_INFO_V1 functions.
It now only checks four things:
Major version number (7.4 or 8.1 for example)
NAMEDATALEN
FUNC_MAX_ARGS
INDEX_MAX_KEYS
The three constants were chosen because:
1. We document them in the config page in the docs
2. We mark them as changable in pg_config_manual.h
3. Changing any of these will break some of the more popular modules:
FUNC_MAX_ARGS changes fmgr interface, every module uses this NAMEDATALEN
changes syscache interface, every PL as well as tsearch uses this
INDEX_MAX_KEYS breaks tsearch and anything using GiST.
Martijn van Oosterhout
---------------------------------------------------------------------------
Add dynamic record inspection to PL/PgSQL, useful for generic triggers:
tval2 := r.(cname);
or
columns := r.(*);
Titus von Boxberg
An article at WebProNews quoted from the PG docs as to the merits of
stored procedures. I have added a bit more material on their merits,
as well as making a few changes to improve the introductions to
PL/Perl and PL/Tcl.
Chris Browne
kept but now deprecated. Patch from Adam Sjøgren. Add regression test to
show plperl trigger data (Andrew).
TBD: apply similar changes to plpgsql, plpython and pltcl.
Bruce Momjian
Tom Lane
Neil Conway
Peter Eisentraut
Andrew Dunstan
Alvaro Herrera