Andy Grove created ARROW-10995: ---------------------------------- Summary: [Rust] [DataFusion] Improve parallelism when reading Parquet files Key: ARROW-10995 URL: https://issues.apache.org/jira/browse/ARROW-10995 Project: Apache Arrow Issue Type: Improvement Components: Rust - DataFusion Reporter: Andy Grove
Currently the unit of parallelism is the number of parquet files being read. For example, if we run a query against a Parquet table that consists of 8 partitions then we will attempt to run 8 async tasks in parallel and if there is a single Parquet file then we will only try and run 1 async task so this does not scale well. A better approach would be to have one parallel task per "chunk" in each parquet file. This would involve an upfront step in the planner to scan the parquet meta-data to get a list of chunks and then split these up between the configured number of parallel tasks. -- This message was sent by Atlassian Jira (v8.3.4#803005)