pgsql: Track temporary file count and size in pg_stat_database

Track temporary file count and size in pg_stat_database

Add counters for number and size of temporary files used
for spill-to-disk queries for each database to the
pg_stat_database view.

Tomas Vondra, review by Magnus Hagander

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/bc3347484a7bf9eddb98e4352d84599cae9a31c6

Modified Files
--------------
doc/src/sgml/monitoring.sgml         |   25 ++++++++++++++++-
src/backend/catalog/system_views.sql |    2 +
src/backend/postmaster/pgstat.c      |   50 ++++++++++++++++++++++++++++++++++
src/backend/storage/file/fd.c        |   36 +++++++++++-------------
src/backend/utils/adt/pgstatfuncs.c  |   33 ++++++++++++++++++++++
src/include/catalog/catversion.h     |    2 +-
src/include/catalog/pg_proc.h        |    4 +++
src/include/pgstat.h                 |   19 ++++++++++++-
src/test/regress/expected/rules.out  |    2 +-
9 files changed, 149 insertions(+), 24 deletions(-)