How to perform parallel execution on the `cstore_fdw` partition table ?

[suuuch]

I was use cstore_fdw, and I created 20 partition table ,when i query the partition table ,I realize the query plan did not show the parallel.But when use the normal table ,the parallel is worked.

This make me confuse. Is there anyone can help?

[mtuncer]

hi @suuuch unfortunately cstore_fdw does not support parallel scans yet. It looks like postgresql is not using parallel scan when one partition does not support paralel execution (needs verification).

[damirda]

Any plans to address this issue?

[martin-loetzsch]

A colleague of mine tried this on partitioned cstore tables and said it's working, making things faster: https://gist.github.com/masayuki038/6820f551f1a6d4e1ec7b3929ffad35ad

[damirda]

Basically, he just set ForeignScanParallelSafe to true. That is nice, but I would like to hear why wasn't it safe in the first place, @mtuncer ?