vvysotskyi commented on a change in pull request #1986: Additional changes for
Drill Metastore docs
URL: https://github.com/apache/drill/pull/1986#discussion_r386537049
##########
File path:
_docs/performance-tuning/drill-metastore/010-using-drill-metastore.md
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@@ -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.
Review comment:
Thanks, removed comma.
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