dwsmith1983 commented on code in PR #5365: URL: https://github.com/apache/datafusion-comet/pull/5365#discussion_r4006945812
########## contrib/delta-spark/README.md: ########## @@ -0,0 +1,60 @@ +<!-- +Licensed to the Apache Software Foundation (ASF) under one +or more contributor license agreements. See the NOTICE file +distributed with this work for additional information +regarding copyright ownership. The ASF licenses this file +to you under the Apache License, Version 2.0 (the +"License"); you may not use this file except in compliance +with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, +software distributed under the License is distributed on an +"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +KIND, either express or implied. See the License for the +specific language governing permissions and limitations +under the License. +--> + +# Comet Delta Lake Contrib (experimental) + +Native Delta Lake reads for Comet. Delta tables are scanned through Comet's +existing native Parquet reader, so they get row-group pruning, page-index +pruning, and filter pushdown, with deletion vectors applied inside the scan. + +Support is experimental and explicitly opt-in. Two things are required: + +1. This module's jar (`comet-contrib-delta-spark`) on the classpath, alongside + `delta-spark`. It is never bundled into `comet-spark`; without it, Comet + has no Delta surface at all. +2. `spark.comet.scan.delta.enabled=true`. The default is `false`, so the jar + alone does nothing. + +Unsupported tables and features fall back to Spark's reader. See the +[user guide](https://datafusion.apache.org/comet/user-guide/delta.html) Review Comment: > Could the README say the same, or run the full reactor? Link fixed to `user-guide/latest/delta.html`. The build section now installs `common,spark` from the same checkout immediately before the contrib line, as CI does, and says why. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
