[Bucardo-general] Latency on delete
abalashov at evaristesys.com
Fri Jan 17 15:21:53 UTC 2014
Oh, and I should add, for the sake of completeness, that the q table and
delta cleanup cron jobs are in place, running every few minutes.
On 01/17/2014 10:15 AM, Alex Balashov wrote:
> How long is a DELETE of ~4.5 million rows (in a relatively narrow table)
> supposed to take in a scenario with a simple pushdelta replication
> setup? Mine took 1 hour and 45 minutes. While I realise that Bucardo's
> row level-trigger based system incurs some additional latency, the
> latency is just inserting those deltas, by and large, right? It
> shouldn't take quite so long as that, I would hypothesise.
> Both databases - including the 'bucardo' schema of the source - are
> tidily vacuumed nightly.
> The servers are both quad-core 2 GHz Xeons with 32 GB of RAM each with
> decent SATA drives on a Dell PERC.
> In addition, the following PostgreSQL tuning measures are in place:
> shared_buffers = 512 MB
> work_mem = 1024MB
> wal_level = minimal
> fsync = off
> synchronous_commit = off
> The 'bucardo_ctl status' output does not show any delays, failures or
> other anomalies.
> The table on which I ran the DELETE statement had about 38 million rows,
> of which I was attempting to delete 4.5. The table also has two indexes
> (primary key index and one additional indexed column) and a foreign key
> Is it reasonable and expected for this DELETE to have taken close to two
> Thank much!
> -- Alex
Alex Balashov - Principal
Evariste Systems LLC
235 E Ponce de Leon Ave
Decatur, GA 30030
Web: http://www.evaristesys.com/, http://www.alexbalashov.com/
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