paul-rogers commented on a change in pull request #2030: Update docs for Metastore to point that all format plugins are supported URL: https://github.com/apache/drill/pull/2030#discussion_r394552697
########## File path: _docs/performance-tuning/drill-metastore/010-using-drill-metastore.md ########## @@ -117,6 +119,14 @@ Drill can connect to any number of data sources, each of which may have its own As a result, the Metastore labels tables with a combination of (plugin configuration name, workspace name, table name). Note that if before renaming any of these items, you must delete table's Metadata entry and recreate it after renaming. +### Using schema provisioning feature with Drill Metastore + +Drill Metastore allows specifying schema using the same syntax as + [Schema provisioning]({{site.baseurl}}/docs/plugin-configuration-basics/#specifying-the-schema-as-table-function-parameter) feature when used as a table function. +User can specify table schema in the `ANALYZE` command, so it will be used for collecting table statistics and will be stored + to Drill Metastore to be used when submitting queries for this table similar to the case when user specifies schema + explicitly in the table function. Review comment: The Drill Metastore holds both schema and statistics information for a table. The `ANALYZE` command can infer the table schema for well-defined tables (such as many Parquet tables). Some tables are too complex or variable for Drill's schema inference to work well. For example, JSON tables often omit fields or have long runs of nulls so that Drill cannot determine column types. In these cases you can specify the correct schema based on your knowledge of the a table's structure. You specify a schema in the `ANALYZE` command using the [Schema provisioning]({{site.baseurl}}/docs/plugin-configuration-basics/#specifying-the-schema-as-table-function-parameter) syntax. (Please provide an example.) ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services