malthe/pq

Any interest in porting to cockroach

Closed this issue · 3 comments

retr0h commented

I was curious if you would be interested in porting to cockroach. As I understand it, cockroach has implemented SKIP LOCKED, and while I like pg, I am currently using cockroach b/c of it's wonderful clustering capabilities.

I do understand this request is probably out of scope for what this project is doing, but was curious if you might be interested if it is minimal effort.

John

stas commented

CockroachDB is built to be largely compatible with PostgreSQL, meaning that software written to use PostgreSQL can sometimes (often!) be used with CockroachDB without changes.

This suggests a lot of stuff should be working out of the box, would you be kind to give it a try and suggest what's not working?

retr0h commented

Yeah, I have started going down that path, and unfortunately it looks like most of the stuff we care about is unimplemented.

psycopg2.errors.FeatureNotSupported: unimplemented: SKIP LOCKED lock wait policy is not supported
HINT:  You have attempted to use a feature that is not yet implemented.
See: https://github.com/cockroachdb/cockroach/issues/40476

Indexes would need to change to support the alternative nulls last

create index if not exists priority_idx_%(name)s on %(name)s
    (schedule_at nulls first, (CASE WHEN expected_at IS NULL THEN 1 ELSE 0 END), q_name)
    where dequeued_at is null
          and q_name = '%(name)s';

DETAIL:  source SQL:
create index if not exists priority_idx_queue on queue
    (schedule_at nulls first, (CASE WHEN expected_at IS NULL THEN 1 ELSE 0 END), q_name)
                                                                               ^
HINT:  You have attempted to use a feature that is not yet implemented.
See: https://github.com/cockroachdb/cockroach/issues/9682
retr0h commented

I'll close this ticket as most of the functionality this module relies upon, does not exist yet in cockroach.

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