Hello,
I'm trying to understand why autovacuum runs to prevent
wraparound on tables that should be static and don't change. For example, we
have tables, in one of our databases, that get created every day. Those
tables are then actively updated throughout the day. Once a new day begins, a
new table is created for that days data. The previous days table is no
longer changed or updated and used for historical queries only.
So, the way I understand transaction wrap around, I would
think the only table needing vacuuming to prevent wraparound, would be the
active table? But, I also notice the older
tables getting vacuumed to prevent wrap around as well. Can
someone help me understand this?
Here is an example:
30551 tracks None
local 2.6 0.1 31.81M
0.00B 01:51.58 N N
active autovacuum: VACUUM public.fused_xyz20191222 (to
prevent wraparound)
34151 tracks None
local 5.5 0.1 29.96M
2.61K 01:13.31 N N
active autovacuum: VACUUM public.fused_xyz20191119 (to
prevent wraparound)
34613 tracks None
local 2.3 0.1 29.67M
0.00B 01:07.83 N N
active autovacuum: VACUUM public.fused_xyz20191128 (to
prevent wraparound)
39686 tracks None
local 2.9 0.0 29.67M
0.00B 00:09.00 N N
active autovacuum: VACUUM public.fused_xyz20200112 (to
prevent wraparound)
The tables listed above are static at this point, but as you
can see, they are actively being vacuumed to prevent wraparound.
Thanks,
Jay
Jerome Talbert
Senior IT Infrastructure Engineer
PASSUR Aerospace, Inc.
O: 407-205-0688
C: 407-619-9868
