Hi Rex, Prefix seek iterator has not ever been used in Flink when seeking. I hope you could first read more details about this from RocksDB wiki as prefix extractor could impact the performance.
Best Yun Tang ________________________________ From: Rex Fenley <r...@remind101.com> Sent: Wednesday, March 17, 2021 2:02 To: Yun Tang <myas...@live.com> Cc: user <user@flink.apache.org>; Brad Davis <brad.da...@remind101.com> Subject: Re: Prefix Seek RocksDB Thanks for the input, I'll look more into that. Does your answer then imply that Joins and Aggs do not inherently always use prefix seeks? I'd imagine that the join key on join and groupby key on aggs would always be used as prefix keys. Is this not the case? Also, is there good information on what the correct prefix extractor is for Flink? This feature is something I only just discovered so I was hoping to gain clarity. Thanks On Mon, Mar 15, 2021 at 8:33 PM Yun Tang <myas...@live.com<mailto:myas...@live.com>> wrote: Hi Rex, You could configure prefix seek via RocksDB's column family options [1]. Be careful to use correct prefix extractor. [1] https://ci.apache.org/projects/flink/flink-docs-stable/ops/state/state_backends.html#passing-options-factory-to-rocksdb Best ________________________________ From: Rex Fenley <r...@remind101.com<mailto:r...@remind101.com>> Sent: Tuesday, March 16, 2021 8:29 To: user <user@flink.apache.org<mailto:user@flink.apache.org>> Cc: Brad Davis <brad.da...@remind101.com<mailto:brad.da...@remind101.com>> Subject: Prefix Seek RocksDB Hello! I'm wondering if Flink RocksDB state backend is pre-configured to have Prefix Seeks enabled, such as for Joins and Aggs on the TableAPI [1]? If not, what's the easiest way to configure this? I'd imagine this would be beneficial. Thanks! [1] https://github.com/facebook/rocksdb/wiki/Prefix-Seek -- Rex Fenley | Software Engineer - Mobile and Backend Remind.com<https://www.remind.com/> | BLOG<http://blog.remind.com/> | FOLLOW US<https://twitter.com/remindhq> | LIKE US<https://www.facebook.com/remindhq> -- Rex Fenley | Software Engineer - Mobile and Backend Remind.com<https://www.remind.com/> | BLOG<http://blog.remind.com/> | FOLLOW US<https://twitter.com/remindhq> | LIKE US<https://www.facebook.com/remindhq>
