The following bug has been logged on the website:
Bug reference: 12834
Logged by: Bryce Nesbitt
Email address: bryce2@obviously.com
PostgreSQL version: 9.4.1
Operating system: Linux
Description:
This is an issue primarily for home computers and laptops which run
postgres, but not under heavy load.
Every minute postgresql runs the "stats" process which writes the following
files:
postgres(3814): CW /var/lib/postgresql/9.4/main/pg_stat_tmp/db_0.tmp
postgres(3814): CW /var/lib/postgresql/9.4/main/pg_stat_tmp/global.tmp
postgres(3814): CW /var/lib/postgresql/9.4/main/pg_stat_tmp/db_12066.tmp
postgres(3814): CW /var/lib/postgresql/9.4/main/pg_stat_tmp/global.stat
postgres(568): CW /var/lib/postgresql/9.4/main/base/12066/11868
unknown(568): CW /var/lib/postgresql/9.4/main/global/12062
unknown(568): CW /var/lib/postgresql/9.4/main/base/12066/11828
unknown(568): CW /var/lib/postgresql/8.4/main/base/12066/11833
This data was collected with "fatrace". There's one set of writes per
installed version of postgres on the test system (8.1,9.1,9.3,9.4).
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Would it be possible to have the stats process take no action and make no
writes to the disk, if there has been no database activity in the interval?
---
For laptops disk writes wake up the machine and/or harddrive. For SSD's
it's a wear leveling issue. With this write happening 24/7 on millions of
computers this is also an energy use optimization potential (reduce
electricity use from your keyboard!)