Re:Hydra: Column-Oriented Postgres
by refset on Friday August 25, 2023 @06:29AM
(#37260062)
The presence and use of column families is only half of the puzzle - it doesn't strictly imply that the execution engine is capable of working in a vectorized columnar style (which is necessary for competitive OLAP).
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Indeed. As I commented alsewhere this is just about the general design. It is not targeting OLAP in this case (even though I do believe cockroach employs vectorization for reads)
Was unable to edit my previous. It does use vectorization: https://www.cockroachlabs.com/docs/stable/vectorized-executi...
Thanks for sharing that - TIL! These blog posts elaborate with more detail:
https://www.cockroachlabs.com/blog/vectorized-hash-joiner/
https://www.cockroachlabs.com/blog/vectorizing-the-merge-joi...
...it seems the distinction here is that the vectorization is only present in the execution layer and not the storage layer also. I would guess that from a storage perspective, even with column families in play, everything is being streamed out of sorted a LSM engine regardless. So there isn't additionally some highly-tuned buffer pool serving up batches of compressed column files etc.