Preview —Spanner columnar engine

This feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of theService Specific Terms. Pre-GA features are available "as is" and might have limited support. For more information, see thelaunch stage descriptions.

For information about access to this release, see the access request page.

Note: This feature is available with the Spanner Enterprise edition and Enterprise Plus edition. For more information, see theSpanner editions overview.

This page describes how to monitor Spanner's columnar engine. Youcan monitor using:

• The query execution plan
• Storage usage graphs insystem insights

View columnar data in the query plan

1. Run a query.
2. View itsquery plan.

3. In theQuery summary section of the query execution, check for theColumnar read share information.

   The following image shows theColumnar read share percentage:

   

This metric shows the percentage of bytes read from columnar storage out oftotal bytes read from both row-based and columnar storage. A high percentage isoptimal, while a low percentage suggests that much of the data remainsunconverted to columnar format.

Columnar data storage metrics

To view columnar data storage metrics:

1. Go to theSpanner Instances page in the Google Cloud console.

   Go to the Instances page

2. Select the instance you want to view metrics for.

3. ClickSystem insights.

4. In theStorage usage section, you can see two new metrics:

   columnar storage - hdd andcolumnar storage - ssd. These metricsshow the columnar representation usage of HDD and SSD. The total storagemetrics include both PAX and columnar data. You can see these metrics onstorage usage graphs on theSystem insights page. For example:

   

What's next

• Learn aboutcolumnar engine.
• Learn how toenable columnar engine.
• Learn how toquery columnar data.