psycopg2 and async/sync context

[micdeved]

This is not a question, this is not a bug report. I'm not sure what is this. It is for history and maybe it will be helpful for someone else.

It is known and recommended to use:

• psycopg2 - for production;
• psycopg2-binary for local development.

But in case when we use psycopg2 on production we often get following error:
You cannot call this from an async context - use a thread or sync_to_async.

Which is caused by the async_unsafe attribute and SynchronousOnlyOperation error.

As a workaround we can use next env var DJANGO_ALLOW_ASYNC_UNSAFE=1

There is no trouble just using psycopg2-binary package.

Versions:

• Alpine Linux: 3.18.*;
• Python: 3.11.4;
• Django: 3.2.* (wsgi app);
• psycopg2, psycopg2-binary: 2.9.6.

P.S.: we do not use explicitly async code in a project.

[dvarrazzo]

psycopg2-binary is just a precompiled version of psycopg. Everything else you mention are Django features: you should contact th for your enquiry.

[micdeved]

i understand it, but it is definitely strange if i replace psycopg2 with psycopg2-binary then everything else is just fine without any additional changes.