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citusdata / cstore_fdw

Columnar storage extension for Postgres built as a foreign data wrapper. Check out https://github.com/citusdata/citus for a modernized columnar storage implementation built as a table access method.
Apache License 2.0
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How to perform parallel execution on the `cstore_fdw` partition table ? #178

Open suuuch opened 6 years ago

suuuch commented 6 years ago

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 commented 6 years ago

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 commented 5 years ago

Any plans to address this issue?

martin-loetzsch commented 5 years ago

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 commented 5 years ago

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 ?