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This playbook support the deployment of cluster over already existing and running PostgreSQL. You must specify the variable postgresql_exists='true' in the inventory file. Attention! Your PostgreSQL will be stopped before running in cluster mode. You must planing downtime of existing databases.т.е. это когда у вас есть обычная бд из одного сервера, вы можете преобразовать её в HA кластер.
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5 seconds per test
O_DIRECT supported on this platform for open_datasync and open_sync.
Compare file sync methods using one 8kB write:
(in wal_sync_method preference order, except fdatasync is Linux's default)
open_datasync 2409.192 ops/sec 415 usecs/op
fdatasync 2604.794 ops/sec 384 usecs/op
fsync 126.190 ops/sec 7925 usecs/op
fsync_writethrough n/a
open_sync 106.442 ops/sec 9395 usecs/op
Compare file sync methods using two 8kB writes:
(in wal_sync_method preference order, except fdatasync is Linux's default)
open_datasync 1758.350 ops/sec 569 usecs/op
fdatasync 2465.963 ops/sec 406 usecs/op
fsync 100.991 ops/sec 9902 usecs/op
fsync_writethrough n/a
open_sync 47.574 ops/sec 21020 usecs/op
Compare open_sync with different write sizes:
(This is designed to compare the cost of writing 16kB in different write
open_sync sizes.)
1 * 16kB open_sync write 83.602 ops/sec 11961 usecs/op
2 * 8kB open_sync writes 38.940 ops/sec 25681 usecs/op
4 * 4kB open_sync writes 26.933 ops/sec 37129 usecs/op
8 * 2kB open_sync writes 14.568 ops/sec 68643 usecs/op
16 * 1kB open_sync writes 6.358 ops/sec 157272 usecs/op
Test if fsync on non-write file descriptor is honored:
(If the times are similar, fsync() can sync data written on a different
descriptor.)
write, fsync, close 91.906 ops/sec 10881 usecs/op
write, close, fsync 99.959 ops/sec 10004 usecs/op
Non-sync'ed 8kB writes:
write 320374.843 ops/sec 3 usecs/op
V
with pre1 as (
select * from table
), pre2 as (
select * from pre1 where condition
), pre3 as (
select * from pre1 where condition
)
select * from pre2 p2
join pre3 condition
with pre1 as (
select * from table where condition
),pre2 as (
select * from table where condition
)
select * from pre1 p1
join pre2 condition
П
with pre1 as (
select * from table
), pre2 as (
select * from pre1 where condition
), pre3 as (
select * from pre1 where condition
)
select * from pre2 p2
join pre3 condition
with pre1 as (
select * from table where condition
),pre2 as (
select * from table where condition
)
select * from pre1 p1
join pre2 condition
YS
5 seconds per test
O_DIRECT supported on this platform for open_datasync and open_sync.
Compare file sync methods using one 8kB write:
(in wal_sync_method preference order, except fdatasync is Linux's default)
open_datasync 2409.192 ops/sec 415 usecs/op
fdatasync 2604.794 ops/sec 384 usecs/op
fsync 126.190 ops/sec 7925 usecs/op
fsync_writethrough n/a
open_sync 106.442 ops/sec 9395 usecs/op
Compare file sync methods using two 8kB writes:
(in wal_sync_method preference order, except fdatasync is Linux's default)
open_datasync 1758.350 ops/sec 569 usecs/op
fdatasync 2465.963 ops/sec 406 usecs/op
fsync 100.991 ops/sec 9902 usecs/op
fsync_writethrough n/a
open_sync 47.574 ops/sec 21020 usecs/op
Compare open_sync with different write sizes:
(This is designed to compare the cost of writing 16kB in different write
open_sync sizes.)
1 * 16kB open_sync write 83.602 ops/sec 11961 usecs/op
2 * 8kB open_sync writes 38.940 ops/sec 25681 usecs/op
4 * 4kB open_sync writes 26.933 ops/sec 37129 usecs/op
8 * 2kB open_sync writes 14.568 ops/sec 68643 usecs/op
16 * 1kB open_sync writes 6.358 ops/sec 157272 usecs/op
Test if fsync on non-write file descriptor is honored:
(If the times are similar, fsync() can sync data written on a different
descriptor.)
write, fsync, close 91.906 ops/sec 10881 usecs/op
write, close, fsync 99.959 ops/sec 10004 usecs/op
Non-sync'ed 8kB writes:
write 320374.843 ops/sec 3 usecs/op
YS
with pre1 as (
select * from table
), pre2 as (
select * from pre1 where condition
), pre3 as (
select * from pre1 where condition
)
select * from pre2 p2
join pre3 condition
with pre1 as (
select * from table where condition
),pre2 as (
select * from table where condition
)
select * from pre1 p1
join pre2 condition
V
A