cancel pg_squeeze and delete temporary files about pg_squeeze

[ahouska]

@kmoppel ok, I'll do that in the next version.

[MichaelDBA]

Yeah i would like to know that too if it is safe to cancel a pgsqueeze full vacuum

[ahouska]

pg_squeeze can be cancelled.

As for temporary files (I assume you mean those used to sort data), pg_squeeze does nothing special. So it pg_squeeze makes the database server crash, the expected behavior is the same as if CLUSTER command crashed: temporary files are removed during cluster restart.

[kmoppel]

FYI - use pg_cancel_backend() to stop an active squeezing process. Note though that this also stops the worker process so if you want to retry call squeeze.start_worker() manually.

@ahouska Would probably make sense also to add canceling support via pg_terminate_backend() as most PG activity monitoring tools use that function.

[kovmir]

Implemented in 4a5f97e.