paul-rogers commented on a change in pull request #1986: Additional changes for Drill Metastore docs URL: https://github.com/apache/drill/pull/1986#discussion_r384870788
########## File path: _docs/performance-tuning/drill-metastore/010-using-drill-metastore.md ########## @@ -48,42 +83,52 @@ drill.metastore: { } ``` -Note, that currently out of box Iceberg Metastore is available and is the default one. Though any custom - implementation can be added by placing the JAR into classpath which has the implementation of - `org.apache.drill.metastore.Metastore` interface and indicating custom class in the `drill.metastore.implementation.class`. - ### Metastore Components -Metastore can store metadata for various components: tables, views, etc. -Current implementation provides fully functioning support for tables component. -Views component support is not implemented but contains stub methods to show -how new Metastore components like UDFs, storage plugins, etc. can be added in the future. +The Drill 1.17 version of the Metastore stores metadata about tables: the table schema and table statistics. +The Metastore is an active subproject of Drill, See [DRILL-6552](https://issues.apache.org/jira/browse/DRILL-6552) for more information. + +### Table Metadata + +Table Metadata includes the following info: + + - Table schema, column name, type, nullability, scale and precision if available, and other info. For details please + refer to [Schema provisioning]({{site.baseurl}}/docs/create-or-replace-schema/#usage-notes). + - Table statistics. This itself has two categories: + - Summary statistics: `MIN`, `MAX`, `NULL count`, etc. + - Detail statistics: histograms, `NDV`, etc. -### Metastore Tables +Schema information and summary statistics also computed and stored for table segments, files, row groups, partitions. -Metastore Tables component contains metadata about Drill tables, including general information, as well as -information about table segments, files, row groups, partitions. +The detailed metadata schema is described [here](https://github.com/apache/drill/tree/master/metastore/metastore-api#metastore-tables). +You can try out the metadata, and get a sense of what is available, by using the Review comment: remove comma: "try out the metadata to get a sense" ---------------------------------------------------------------- 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