This determines what percent of a table is sampled with the TABLESAMPLE operator.

データ型

string

デフォルト値

""

解説

This option can be set to make the connector use the TABLESAMPLE for each table referenced by a query. The value determines what percent is provided to the PERCENT clause. That clause will only be generated if this property's value is above zero.

-- Input SQL
SELECT * FROM `tbl`

-- Generated Google BigQuery SQL when TableSamplePercent=10
SELECT * FROM `tbl` TABLESAMPLE SYSTEM (10 PERCENT)

This option is subject to a few limitations:

• It is applied during query converison and has no effect when QueryPassthrough is set.
• More rows may be returned than expected due to how the server implements TABLESAMPLE. Please see the Google BigQuery documentation for more information.
• TABLESAMPLE is not supported on views. If a view is queried in sampling mode, the connector will omit the TABLESAMPLE clause for the view.