postgresql

History

Andres Freund 9cd00c457e Checkpoint sorting and balancing. Up to now checkpoints were written in the order they're in the BufferDescriptors. That's nearly random in a lot of cases, which performs badly on rotating media, but even on SSDs it causes slowdowns. To avoid that, sort checkpoints before writing them out. We currently sort by tablespace, relfilenode, fork and block number. One of the major reasons that previously wasn't done, was fear of imbalance between tablespaces. To address that balance writes between tablespaces. The other prime concern was that the relatively large allocation to sort the buffers in might fail, preventing checkpoints from happening. Thus pre-allocate the required memory in shared memory, at server startup. This particularly makes it more efficient to have checkpoint flushing enabled, because that'll often result in a lot of writes that can be coalesced into one flush. Discussion: alpine.DEB.2.10.1506011320000.28433@sto Author: Fabien Coelho and Andres Freund		2016-03-10 17:05:09 -08:00
..
README	pgindent: add typedef blog URL	2015-06-01 11:27:30 -04:00
exclude_file_patterns	Correct pg_indent to pgindent in various comments.	2015-10-08 12:27:54 -04:00
indent.bsd.patch	Fix pg_bsd_indent bug where newlines were not being trimmed from typedef	2011-10-26 17:24:19 -04:00
perltidyrc	Remove whitespace from end of lines	2013-05-30 21:05:07 -04:00
pgcppindent	Remove cvs keywords from all files.	2010-09-20 22:08:53 +02:00
pgindent	Fix more typos in comments.	2015-05-20 19:45:43 +03:00
pgindent.man	Fix whitespace issues found by git diff --check, add gitattributes	2013-11-10 14:48:29 -05:00
typedefs.list	Checkpoint sorting and balancing.	2016-03-10 17:05:09 -08:00

README

pgindent
========

This can format all PostgreSQL *.c and *.h files, but excludes *.y, and
*.l files.

1) Install pg_bsd_indent (see below for details).

2) Install entab (src/tools/entab/).

3) Change directory to the top of the build tree.

4) Remove all derived files (pgindent has trouble with one of the flex macros):

make maintainer-clean

Or:

git clean -fdx

5) Download the typedef file from the buildfarm:

wget -O src/tools/pgindent/typedefs.list http://buildfarm.postgresql.org/cgi-bin/typedefs.pl

(see http://www.pgbuildfarm.org/cgi-bin/typedefs.pl?show_list for a full list of typedefs,
also http://adpgtech.blogspot.com/2015/05/running-pgindent-on-non-core-code-or.html)

6) Run pgindent:

src/tools/pgindent/pgindent

7) Remove any files that generate errors and restore their original
versions.

8) Indent the Perl code:

(
find . -name \*.pl -o -name \*.pm

find . -type f -exec file {} \; |
egrep -i ':.*perl[0-9]*\>' |
cut -d: -f1
) |
sort -u |
xargs perltidy --profile=src/tools/pgindent/perltidyrc

9) Do a full test build:

> run configure
# stop is only necessary if it's going to install in a location with an
# already running server
pg_ctl stop
run configure
make -C src install
make -C contrib install
run initdb
pg_ctl start
make installcheck-world

10) Remove Perl backup files after testing (*.bak)

---------------------------------------------------------------------------

BSD indent
----------

We have standardized on NetBSD's indent, and renamed it pg_bsd_indent.
We have fixed a few bugs which requre the NetBSD source to be patched
with indent.bsd.patch patch. A fully patched version is available at
ftp://ftp.postgresql.org/pub/dev.

GNU indent, version 2.2.6, has several problems, and is not recommended.
These bugs become pretty major when you are doing >500k lines of code.
If you don't believe me, take a directory and make a copy. Run pgindent
on the copy using GNU indent, and do a diff -r. You will see what I
mean. GNU indent does some things better, but mangles too. For details,
see:

http://archives.postgresql.org/pgsql-hackers/2003-10/msg00374.php
http://archives.postgresql.org/pgsql-hackers/2011-04/msg01436.php

---------------------------------------------------------------------------

Notes about excluded files
--------------------------

src/include/storage/s_lock.h and src/include/port/atomics/ are excluded
because they contain assembly code that pgindent tends to mess up.

src/include/snowball/libstemmer/ and src/backend/snowball/libstemmer/
are excluded because those files are imported from an external project,
not maintained locally, and are machine-generated anyway.

src/interfaces/ecpg/test/expected/ is excluded to avoid breaking the ecpg
regression tests. Several *.h files are included in regression output so
should not be changed.

---------------------------------------------------------------------------

Obsolete typedef list creation instructions
-------------------------------------------

To use pgindent:

1) Build the source tree with _debug_ symbols and all possible configure options

2) Install to /usr/local/pgsql

3) Install all contrib modules

4) Save a list of typedefs by running:

src/tools/find_typedef /usr/local/pgsql/bin /usr/local/pgsql/lib > /tmp/pgtypedefs