Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
Also update two error messages mentioned in the documenation to match.
In this case extractQuery should returns -1 as nentries. This changes
prototype of extractQuery method to use int32* instead of uint32* for
nentries argument.
Based on that gincostestimate may see two corner cases: nothing will be found
or seqscan should be used.
Per proposal at http://archives.postgresql.org/pgsql-hackers/2007-01/msg01581.php
PS tsearch_core patch should be sightly modified to support changes, but I'm
waiting a verdict about reviewing of tsearch_core patch.
>
> * Add REINDEX CONCURRENTLY, like CREATE INDEX CONCURRENTLY
>
> This is difficult because you must upgrade to an exclusive table lock
> to replace the existing index file. CREATE INDEX CONCURRENTLY does not
> have this complication. This would allow index compaction without
> downtime.
more, and standard_conforming_strings less, because in the future non-E
strings will not treat backslashes specially.
Also use E'' strings where backslashes are used in examples. (The
existing examples would have drawn warnings.)
Backpatch to 8.2.X.
- Add new SQL command SET XML OPTION (also available via regular GUC) to
control the DOCUMENT vs. CONTENT option in implicit parsing and
serialization operations.
- Subtle corrections in the handling of the standalone property in
xmlroot().
- Allow xmlroot() to work on content fragments.
- Subtle corrections in the handling of the version property in
xmlconcat().
- Code refactoring for producing XML declarations.
discussions.
<
<
< ---------------------------------------------------------------------------
<
<
< Developers who have claimed items are:
< --------------------------------------
< * Alvaro is Alvaro Herrera <alvherre@dcc.uchile.cl>
< * Andrew is Andrew Dunstan <andrew@dunslane.net>
< * Bruce is Bruce Momjian <bruce@momjian.us> of EnterpriseDB
< * Christopher is Christopher Kings-Lynne <chriskl@familyhealth.com.au> of
< Family Health Network
< * D'Arcy is D'Arcy J.M. Cain <darcy@druid.net> of The Cain Gang Ltd.
< * David is David Fetter <david@fetter.org>
< * Fabien is Fabien Coelho <coelho@cri.ensmp.fr>
< * Gavin is Gavin Sherry <swm@linuxworld.com.au> of Alcove Systems Engineering
< * Greg is Greg Sabino Mullane <greg@turnstep.com>
< * Jan is Jan Wieck <JanWieck@Yahoo.com> of Afilias, Inc.
< * Joe is Joe Conway <mail@joeconway.com>
< * Karel is Karel Zak <zakkr@zf.jcu.cz>
< * Magnus is Magnus Hagander <mha@sollentuna.net>
< * Marc is Marc Fournier <scrappy@hub.org> of PostgreSQL, Inc.
< * Matthew T. O'Connor <matthew@zeut.net>
< * Michael is Michael Meskes <meskes@postgresql.org> of Credativ
< * Neil is Neil Conway <neilc@samurai.com>
< * Oleg is Oleg Bartunov <oleg@sai.msu.su>
< * Pavel is Pavel Stehule <pavel.stehule@hotmail.com>
< * Peter is Peter Eisentraut <peter_e@gmx.net>
< * Philip is Philip Warner <pjw@rhyme.com.au> of Albatross Consulting Pty. Ltd.
< * Rod is Rod Taylor <pg@rbt.ca>
< * Simon is Simon Riggs <simon@2ndquadrant.com>
< * Stephan is Stephan Szabo <sszabo@megazone23.bigpanda.com>
< * Tatsuo is Tatsuo Ishii <ishii@sraoss.co.jp> of SRA OSS, Inc. Japan
< * Teodor is Teodor Sigaev <teodor@sigaev.ru>
< * Tom is Tom Lane <tgl@sss.pgh.pa.us> of Red Hat
FAMILY; and add FAMILY option to CREATE OPERATOR CLASS to allow adding a
class to a pre-existing family. Per previous discussion. Man, what a
tedious lot of cutting and pasting ...
columns procost and prorows, to allow simple user adjustment of the estimated
cost of a function call, as well as control of the estimated number of rows
returned by a set-returning function. We might eventually wish to extend this
to allow function-specific estimation routines, but there seems to be
consensus that we should try a simple constant estimate first. In particular
this provides a relatively simple way to control the order in which different
WHERE clauses are applied in a plan node, which is a Good Thing in view of the
fact that the recent EquivalenceClass planner rewrite made that much less
predictable than before.
provide just a boolean 'amcanorder', instead of fields that specify the
sort operator strategy numbers. We have decided to require ordering-capable
AMs to use btree-compatible strategy numbers, so the old fields are
overkill (and indeed misleading about what's allowed).
match the postgresql.conf file. Also add units to descriptions that
lacked them. Wording improvements. Mention pg_settings.unit as the way
to find the default units for setting.
Backpatch to 8.2.X.
representation of equivalence classes of variables. This is an extensive
rewrite, but it brings a number of benefits:
* planner no longer fails in the presence of "incomplete" operator families
that don't offer operators for every possible combination of datatypes.
* avoid generating and then discarding redundant equality clauses.
* remove bogus assumption that derived equalities always use operators
named "=".
* mergejoins can work with a variety of sort orders (e.g., descending) now,
instead of tying each mergejoinable operator to exactly one sort order.
* better recognition of redundant sort columns.
* can make use of equalities appearing underneath an outer join.
The implementation is somewhat ugly logic-wise, but I don't see an
easy way to make it more concise.
When writing this, I noticed that my previous implementation of
width_bucket() doesn't handle NaN correctly:
postgres=# select width_bucket('NaN', 1, 5, 5);
width_bucket
--------------
6
(1 row)
AFAICS SQL:2003 does not define a NaN value, so it doesn't address how
width_bucket() should behave here. The patch changes width_bucket() so
that ereport(ERROR) is raised if NaN is specified for the operand or the
lower or upper bounds to width_bucket(). For float8, NaN is disallowed
for any of the floating-point inputs, and +/- infinity is disallowed
for the histogram bounds (but allowed for the operand).
Update docs and regression tests, bump the catversion.
standard convention the 21st century runs from 2001-2100, not 2000-2099,
so make it work like that. Per bug #2885 from Akio Iwaasa.
Backpatch to 8.2, but no further, since this is really a definitional
change; users of older branches are probably more interested in stability.
< * Allow the creation of indexes with mixed ascending/descending
> * -Allow the creation of indexes with mixed ascending/descending
<
< This is possible now by creating an operator class with reversed sort
< operators. One complexity is that NULLs would then appear at the start
< of the result set, and this might affect certain sort types, like
< merge join.
<
per-column options for btree indexes. The planner's support for this is still
pretty rudimentary; it does not yet know how to plan mergejoins with
nondefault ordering options. The documentation is pretty rudimentary, too.
I'll work on improving that stuff later.
Note incompatible change from prior behavior: ORDER BY ... USING will now be
rejected if the operator is not a less-than or greater-than member of some
btree opclass. This prevents less-than-sane behavior if an operator that
doesn't actually define a proper sort ordering is selected.
< * Improve the MONEY data type
> * -Make 64-bit version of the MONEY data type
> * Add locale-aware MONEY type, and support multiple currencies
< Change the MONEY data type to use DECIMAL internally, with special
< locale-aware output formatting.
< http://archives.postgresql.org/pgsql-hackers/2006-09/msg01107.php
>
> * Make consistent use of long/short command options --- pg_ctl needs
> long ones, pg_config doesn't have short ones, postgres doesn't have
> enough long ones, etc.
> o Consider parsing the -c string into individual queries so each
> is run in its own transaction
>
> o Consider disallowing multiple queries in PQexec() as an
> additional barrier to SQL injection attacks
< * Allow inherited tables to inherit index, UNIQUE constraint, and primary
< key, foreign key
< * UNIQUE INDEX on base column not honored on INSERTs/UPDATEs from
< inherited table: INSERT INTO inherit_table (unique_index_col) VALUES
< (dup) should fail
<
< The main difficulty with this item is the problem of creating an index
< that can span more than one table.
<
< * Allow SELECT ... FOR UPDATE on inherited tables
> * Inheritance
>
> o Allow inherited tables to inherit indexes, UNIQUE constraints,
> and primary/foreign keys
> o Honor UNIQUE INDEX on base column in INSERTs/UPDATEs
> on inherited table, e.g. INSERT INTO inherit_table
> (unique_index_col) VALUES (dup) should fail
>
> The main difficulty with this item is the problem of
> creating an index that can span multiple tables.
>
> o Allow SELECT ... FOR UPDATE on inherited tables
>
>
>
an optarg). Add some comments noting that code in three different files has
to be kept in sync. Fix erroneous description of -S switch (it sets work_mem
not silent_mode), and do some light copy-editing elsewhere in postgres-ref.
< * Move some /contrib modules out to their own project sites
<
< Particularly, move GPL-licensed /contrib/userlock and
< /contrib/dbmirror/clean_pending.pl.
<
the XmlExpr code in various lists, use a representation that has some hope
of reverse-listing correctly (though it's still a de-escaping function
shy of correctness), generally try to make it look more like Postgres
coding conventions.
cases. Operator classes now exist within "operator families". While most
families are equivalent to a single class, related classes can be grouped
into one family to represent the fact that they are semantically compatible.
Cross-type operators are now naturally adjunct parts of a family, without
having to wedge them into a particular opclass as we had done originally.
This commit restructures the catalogs and cleans up enough of the fallout so
that everything still works at least as well as before, but most of the work
needed to actually improve the planner's behavior will come later. Also,
there are not yet CREATE/DROP/ALTER OPERATOR FAMILY commands; the only way
to create a new family right now is to allow CREATE OPERATOR CLASS to make
one by default. I owe some more documentation work, too. But that can all
be done in smaller pieces once this infrastructure is in place.
Bruce Momjian
Peter Eisentraut
Neil Conway
Tom Lane
Teodor Sigaev
Alvaro Herrera
Andrew Dunstan