Spanner Batch Reader
SpannerBatchReader is identical to Incremental Batch Reader, minus the Username and Password properties, plus the Augment Query Clause and Statement Timeout properties.
Augment Query Clause
Optionally, use this property to specify FORCE_INDEX directives (see Table hints) using the syntax:
{"<table name>": {"tablehints": {"FORCE_INDEX": "<index name>"}}
You may specify multiple indexes (no more than one per table) separated by commas, for example:
{"order": {"tablehints": {"FORCE_INDEX": "order_amount_index"}}, {"customer": {"tablehints": {"FORCE_INDEX": "customer_ID_index"}}
Connection URL
Specify this as jdbc:cloudspanner:/projects/<project ID>/instances/<instance ID>/databases/<database name>?credentials=<service account key>
. See Spanner Writer for a detailed description of the service account key.
Statement Timeout
If you encounter deadline exceeded errors (see Troubleshoot Cloud Spanner deadline exceeded errors) with tables that have a large number of rows, set this property to increase the amount of time allowed to read tables. For example, to set the timeout to five seconds, specify 5s
. You may specify the timeout in seconds (s
), milliseconds (ms
), microseconds (us
), or nanoseconds (ns
). If this property is blank, the timeout will be controlled by Spanner.