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".
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.
aggregates, conversions, functions, operators, operator classes,
schemas, types, and tablespaces. Fold the existing implementations
of alter domain owner and alter database owner in with these.
Christopher Kings-Lynne
including:
- replacing all the appropriate usages of <citetitle>PostgreSQL
...</citetitle> with &cite-user;, &cite-admin;, and so on
- fix an omission in the EXECUTE documentation
- add some more text to the EXPLAIN documentation
- improve the PL/PgSQL RETURN NEXT documentation (more work to do here)
- minor markup fixes
Neil Conway
capabilities of specifying time zones as intervals per SQL9x.
Put refentrytitle contents on the same line as the tag.
Otherwise, leading whitespace is propagated into the product, which
(at least) messes up the ToC layout.
Remove (some) docinfo tags containing dates. Best to omit if the dates
are not accurate; maybe use CVS dates instead or leave them out.
qualified operator names directly, for example CREATE OPERATOR myschema.+
( ... ). To qualify an operator name in an expression you need to write
OPERATOR(myschema.+) (thanks to Peter for suggesting an escape hatch).
I also took advantage of having to reformat pg_operator to fix something
that'd been bugging me for a while: mergejoinable operators should have
explicit links to the associated cross-data-type comparison operators,
rather than hardwiring an assumption that they are named < and >.
===================
In Notes:
Refer to CREATE FUNCTION for information on creating aggregate functions.
^^^^^^^^^^^^^^^^^^^
I assume it must read C function instead.
In Compatibility SQL/PSM:
SQL/PSM is a proposed standard.
We had that before: remove proposed.
drop_index.sgml:
================
<REFNAME>: Removes existing indexes from a database
as far as I can see index should be singular. The command description is
written as if only one index can be removed at a time. Interestingly
enough, in v7.0.2 it was in fact singular. Am I mistaken here?
drop_operator.sgml:
===================
In Outputs the arguments are referred to as type and type2, but the synopsis
and Inputs section these are left_type and right_type, respectively. Also,
oper is used in Outputs versus id in Inputs/Synopsis. In the translation I
follow the replaceables used in the Inputs/Synopsis part.
Frank Wegmann
16-Mar-00: trailing + or - is not part of the operator unless the operator
also contains characters not present in SQL92-defined operators. This
solves the 'X=-Y' problem without unduly constraining users' choice of
operator names --- in particular, no existing Postgres operator names
become invalid.
Also, remove processing of // comments, as agreed in the same thread.
No big deal; fixed lots of other markup at the same time.
Bigest change: make sure there is no whitespace
in front of <term> contents.
This will probably help the other output types too.
