Re: speed concerns with executemany()

On 12/23/2016 04:29 PM, Daniele Varrazzo wrote:
> On Sat, Dec 24, 2016 at 1:09 AM, Christophe Pettus <xof(at)thebuild(dot)com> wrote:
>> Are you running with the transaction isolation level set to ISOLATION_LEVEL_AUTOCOMMIT? If so, each of those INSERTs will be in its own transaction, and thus will go through the COMMIT overhead. That by itself wouldn't explain a jump that large (in most environments), but it will definitely be *much* slower.
>
> Why do you say this? Psycopg doesn't wrap statements in BEGIN/COMMIT
> when in autocommit mode. Are you referring about some implicit

I understood it did:

http://initd.org/psycopg/docs/usage.html#transactions-control

"It is possible to set the connection in autocommit mode: this way all
the commands executed will be immediately committed and no rollback is
possible. A few commands (e.g. CREATE DATABASE, VACUUM...) require to be
run outside any transaction: in order to be able to run these commands
from Psycopg, the connection must be in autocommit mode: you can use the
autocommit property (set_isolation_level() in older versions)."

> transaction created by the database?
>
> -- Daniele
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com