App Engine predefines a simple index on each property of an entity. An App
Engine application can define further custom indexes in an index configuration
index.yaml. The development server can generate the index
configuration needed by your application when it performs these
queries while you are testing your app. You can tune indexes manually by editing
index.yaml file before uploading the application. See
Configuring Datastore Indexes for information about how to deploy
and manage index configurations.
The following is an example of a
<?xml version="1.0" encoding="utf-8"?> <datastore-indexes autoGenerate="true"> <datastore-index kind="Employee" ancestor="false"> <property name="lastName" direction="asc" /> <property name="hireDate" direction="desc" /> </datastore-index> <datastore-index kind="Project" ancestor="false"> <property name="dueDate" direction="asc" /> <property name="cost" direction="desc" /> </datastore-index> </datastore-indexes>
<datastore-index> element can contain the following elements:
||Required. The kind of the entity for the query. Typically, this is the name of the Model class that defines the model for the entities.|
A list of properties to include as columns of the index, in the order to be sorted: properties used in equality filters first, followed by the property used in inequality filters, then the sort orders and their directions.
Each element in this list has the following elements:
Automatic and manual indexes
When the development web server adds a generated index definition to
index.yaml, it does so below the following line, inserting it if necessary:
The development web server considers all index definitions below this line to be automatic, and it may update existing definitions below this line as the application makes queries.
All index definitions above this line are considered to be under manual control,
and are not updated by the development web server. The web server will only
make changes below the line, and will only do so if the complete
file does not describe an index that accounts for a query executed by the
application. To take control of an automatic index definition, move it above
Deploying the index configuration fileTo deploy the index configuration file, run the following command:
gcloud app deploy datastore-indexes.yaml
If you install the original App Engine SDK, you can run:
appcfg.py update_indexes [YOUR_APP_DIR]
Deleting unused indexes
When you change or remove an index from the index configuration, the original index is not deleted from App Engine automatically. This gives you the opportunity to leave an older version of the app running while new indexes are being built, or to revert to the older version immediately if a problem is discovered with a newer version.
When you are sure that old indexes are no longer needed, you can delete them from App Engine as follows:
gcloud datastore cleanup-indexes index.yaml