On 09/09/16 14:50, Mark Kirkwood wrote:
>
> Yeah, good suggestion about replacing (essentially) all the indexes
> with hash ones and testing. I did some short runs with this type of
> schema yesterday (actually to get a feel for if hash performance vs
> btree was compareable - does seem tp be) - but probably longer ones
> with higher concurrency (as high as I can manage on a single socket i7
> anyway) is a good plan. If Ashutosh has access to seriously large
> numbers of cores then that is even better :-)
>
>
I managed to find a slightly bigger server (used our openstack cloud to
run a 16 cpu vm). With the schema modified as follows:
bench=# \d pgbench_accounts Table "public.pgbench_accounts" Column | Type | Modifiers
----------+---------------+----------- aid | integer | not null bid | integer | abalance |
integer | filler | character(84) |
Indexes: "pgbench_accounts_pkey" hash (aid)
bench=# \d pgbench_branches Table "public.pgbench_branches" Column | Type | Modifiers
----------+---------------+----------- bid | integer | not null bbalance | integer | filler |
character(88)|
Indexes: "pgbench_branches_pkey" hash (bid)
bench=# \d pgbench_tellers Table "public.pgbench_tellers" Column | Type | Modifiers
----------+---------------+----------- tid | integer | not null bid | integer | tbalance |
integer | filler | character(84) |
Indexes: "pgbench_tellers_pkey" hash (tid)
bench=# \d pgbench_history Table "public.pgbench_history" Column | Type | Modifiers
--------+-----------------------------+----------- tid | integer | bid | integer
| aid | integer | delta | integer | mtime | timestamp without time
zone| filler | character(22) |
Indexes: "pgbench_history_pkey" hash (bid)
performed several 10 hour runs on size 100 database using 32 and 64
clients. For the last run I rebuilt with assertions enabled. No hangs or
assertion failures.
regards
Mark