vvysotskyi commented on a change in pull request #1728: DRILL-7089: Implement caching for TableMetadataProvider at query level and adapt statistics to use Drill metastore API URL: https://github.com/apache/drill/pull/1728#discussion_r272964601
########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/planner/logical/DrillTable.java ########## @@ -49,9 +50,7 @@ private final String userName; private GroupScan scan; private SessionOptionManager options; - // Stores the statistics(rowcount, NDV etc.) associated with the table - private DrillStatsTable statsTable; - private TupleMetadata schema; + private MetadataProviderManager metadataProviderManager; Review comment: This solution wasn't a result of following a particular Design Pattern. It was done in order to allow caching of `MetadataProvider` and preserve lazy initialization. `MetadataProviderManager` will be stored to the cache and once `MetadataProvider` is created, `MetadataProviderManager` will receive a link to it and it will be reused for constructing all further `MetadataProvider` instances. Yes, that's correct that "there's a 1-to-many relationship between Manager-->Provider and a 1-to-1 relationship between a Provider and its associated DrillTable". ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
