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Amazon Athena Google BigQuery connector

The Amazon Athena connector for Google BigQuery enables Amazon Athena to run SQL queries on your Google BigQuery data.

Prerequisites

Limitations

Parameters

Use the Lambda environment variables in this section to configure the Google BigQuery connector.

Splits and views

Because the BigQuery connector uses the BigQuery Storage Read API to query tables, and the BigQuery Storage API does not support views, the connector uses the BigQuery client with a single split for views.

Performance

To query tables, the BigQuery connector uses the BigQuery Storage Read API, which uses an RPC-based protocol that provides fast access to BigQuery managed storage. For more information about the BigQuery Storage Read API, see Use the BigQuery Storage Read API to read table data in the Google Cloud documentation.

Selecting a subset of columns significantly speeds up query runtime and reduces data scanned. The connector is subject to query failures as concurrency increases, and generally is a slow connector.

The Athena Google BigQuery connector performs predicate pushdown to decrease the data scanned by the query. LIMIT clauses, ORDER BY clauses, simple predicates, and complex expressions are pushed down to the connector to reduce the amount of data scanned and decrease query execution run time.

LIMIT clauses

A LIMIT N statement reduces the data scanned by the query. With LIMIT N pushdown, the connector returns only N rows to Athena.

Top N queries

A top N query specifies an ordering of the result set and a limit on the number of rows returned. You can use this type of query to determine the top N max values or top N min values for your datasets. With top N pushdown, the connector returns only N ordered rows to Athena.

Predicates

A predicate is an expression in the WHERE clause of a SQL query that evaluates to a Boolean value and filters rows based on multiple conditions. The Athena Google BigQuery connector can combine these expressions and push them directly to Google BigQuery for enhanced functionality and to reduce the amount of data scanned.

The following Athena Google BigQuery connector operators support predicate pushdown:

Combined pushdown example

For enhanced querying capabilities, combine the pushdown types, as in the following example:

SELECT * 
FROM my_table 
WHERE col_a > 10 
    AND ((col_a + col_b) > (col_c % col_d)) 
    AND (col_e IN ('val1', 'val2', 'val3') OR col_f LIKE '%pattern%') 
ORDER BY col_a DESC 
LIMIT 10;

Passthrough queries

The Google BigQuery connector supports passthrough queries. Passthrough queries use a table function to push your full query down to the data source for execution.

To use passthrough queries with Google BigQuery, you can use the following syntax:

SELECT * FROM TABLE(
        system.query(
            query => 'query string'
        ))

The following example query pushes down a query to a data source in Google BigQuery. The query selects all columns in the customer table, limiting the results to 10.

SELECT * FROM TABLE(
        system.query(
            query => 'SELECT * FROM customer LIMIT 10'
        ))

License information

The Amazon Athena Google BigQuery connector project is licensed under the Apache-2.0 License.

By using this connector, you acknowledge the inclusion of third party components, a list of which can be found in the pom.xml file for this connector, and agree to the terms in the respective third party licenses provided in the LICENSE.txt file on GitHub.com.

See also

For additional information about this connector, visit the corresponding site on GitHub.com.