vvysotskyi commented on a change in pull request #1986: Additional changes for
Drill Metastore docs
URL: https://github.com/apache/drill/pull/1986#discussion_r387077646
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File path:
_docs/sql-reference/sql-commands/007-analyze-table-refresh-metadata.md
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@@ -1,35 +1,18 @@
---
title: "ANALYZE TABLE REFRESH METADATA"
parent: "SQL Commands"
-date: 2020-01-30
+date: 2020-02-17
---
Starting from Drill 1.17, you can store table metadata (including schema and
computed statistics) into Drill Metastore.
This metadata will be used when querying a table for more optimal plan
creation.
-The Metastore is an Alpha feature; it is subject to change. We encourage you
to try it and provide feedback.
-Because the Metastore is in Beta, the SQL commands and Metastore formats may
change in the next release.
-{% include startnote.html %}In Drill 1.17, this feature is supported for
Parquet tables only and is disabled by default.{% include endnote.html %}
-
To use the Drill Metastore, you must enable it at the session or system level
with one of the following commands:
SET `metastore.enabled` = true;
ALTER SYSTEM SET `metastore.enabled` = true;
-Alternatively, you can enable the option in the Drill Web UI at
`http://<drill-hostname-or-ip-address>:8047/options`.
-
-Once you enable the Metastore, the next step is to populate it with data.
Drill can query a table whether that table
- has a Metastore entry or not. (If you are familiar with Hive, then you know
that Hive requires that all tables have
- Hive Metastore entries before you can query them.) In Drill, only add data to
the Metastore when doing so improves
- query performance. In general, large tables benefit from statistics more than
small tables do.
-
-Unlike Hive, Drill does not require you to declare a schema. Instead, Drill
infers the schema by scanning your table
- and computes some metadata like MIN / MAX column values and NULLS COUNT
designated as "metadata" to be able to
- produce more optimizations like filter push-down, etc. If
`planner.statistics.use` option is enabled, this command
- will also calculate and store table statistics into Drill Metastore.
-
-Unlike Hive, Drill does not require you to declare a schema. Instead, Drill
infers the schema by scanning your table
- in the same way as it is done during regular select.
+Please refer to [Using Drill
Metastore]({{site.baseurl}}/docs/using-drill-metastore) for more details about
Drill Metastore, its purpose and usage information.
Review comment:
Thanks, reworded.
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