The XSLT toolchain requires an empty <index> element where the index is
supposed to appear. Add that with conditionals to hide it from the
DSSSL build.
Background workers are postmaster subprocesses that run arbitrary
user-specified code. They can request shared memory access as well as
backend database connections; or they can just use plain libpq frontend
database connections.
Modules listed in shared_preload_libraries can register background
workers in their _PG_init() function; this is early enough that it's not
necessary to provide an extra GUC option, because the necessary extra
resources can be allocated early on. Modules can install more than one
bgworker, if necessary.
Care is taken that these extra processes do not interfere with other
postmaster tasks: only one such process is started on each ServerLoop
iteration. This means a large number of them could be waiting to be
started up and postmaster is still able to quickly service external
connection requests. Also, shutdown sequence should not be impacted by
a worker process that's reasonably well behaved (i.e. promptly responds
to termination signals.)
The current implementation lets worker processes specify their start
time, i.e. at what point in the server startup process they are to be
started: right after postmaster start (in which case they mustn't ask
for shared memory access), when consistent state has been reached
(useful during recovery in a HOT standby server), or when recovery has
terminated (i.e. when normal backends are allowed).
In case of a bgworker crash, actions to take depend on registration
data: if shared memory was requested, then all other connections are
taken down (as well as other bgworkers), just like it were a regular
backend crashing. The bgworker itself is restarted, too, within a
configurable timeframe (which can be configured to be never).
More features to add to this framework can be imagined without much
effort, and have been discussed, but this seems good enough as a useful
unit already.
An elementary sample module is supplied.
Author: Álvaro Herrera
This patch is loosely based on prior patches submitted by KaiGai Kohei,
and unsubmitted code by Simon Riggs.
Reviewed by: KaiGai Kohei, Markus Wanner, Andres Freund,
Heikki Linnakangas, Simon Riggs, Amit Kapila
They don't actually do anything yet; that will get fixed in a
follow-on commit. But this gets the basic infrastructure in place,
including CREATE/ALTER/DROP EVENT TRIGGER; support for COMMENT,
SECURITY LABEL, and ALTER EXTENSION .. ADD/DROP EVENT TRIGGER;
pg_dump and psql support; and documentation for the anticipated
initial feature set.
Dimitri Fontaine, with review and a bunch of additional hacking by me.
Thom Brown extensively reviewed earlier versions of this patch set,
but there's not a whole lot of that code left in this commit, as it
turns out.
SP-GiST is comparable to GiST in flexibility, but supports non-balanced
partitioned search structures rather than balanced trees. As described at
PGCon 2011, this new indexing structure can beat GiST in both index build
time and query speed for search problems that it is well matched to.
There are a number of areas that could still use improvement, but at this
point the code seems committable.
Teodor Sigaev and Oleg Bartunov, with considerable revisions by Tom Lane
This commit provides the core code and documentation needed. A contrib
module test case will follow shortly.
Shigeru Hanada, Jan Urbanski, Heikki Linnakangas
This switches the man page building process to use the DocBook XSL stylesheet
toolchain. The previous targets for Docbook2X are removed. configure has been
updated to look for the new tools. The Documentation appendix contains the
new build instructions. There are also a few isolated tweaks in the
documentation to improve places that came out strangely in the man pages.
Set up proper makefile dependencies in the documentation build rules,
especially around the HTML/index build. The problem we've had with all
previous solutions is that we have used the same file name, such as HTML.index
or bookindex.sgml, to mean different things at different stages of the build,
and make can't distinguish that. The solution here is that the first jade run
produces HTML.index, but does not require bookindex.sgml at all, and produces
no other html output (the latter an idea from Alvaro). The second jade run
includes bookindex.sgml, but does not recreate HTML.index. That way, when you
change an sgml file, jade is run twice and at the end all dependencies are
satisfied. Omitting the html output in the first stage also makes the full
build a lot faster.
When you run one of the print format targets, only the first jade run is run,
then the print target-specific commands. If an HTML build has completed
previously, the first jade run is skipped because the dependencies have
already been satisfied.
The draft and check targets for quick builds and syntax verification are still
there.
pages for the new SQL commands. I also committed Bruce's text search
introductory chapter, as-is except for fixing some markup errors,
so that there would be a place for the reference pages to link to.
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.
language handler to the 'Internals' area, per my proposal of yesterday.
Clean up the trigger documentation a bit. Push SPI chapter to the end
of its part, and reorder the Internals chapters into what seems a more
sensible order (at the moment anyway).
Use question marks rather than brackets to delimit optional elements in
Tcl synopses.
Fix stylesheet misfeature leading to excessively long cross-reference text
when linking to a different "part".
Remove <body> attributes -- CSS stylesheets should handle that.
Improve bibliography formatting.
Add fast-forward links for more convenient navigation.
