Google BigQuery Storage v1 API - Class ReadSession.Types.TableReadOptions (3.15.0)

Reference documentation and code samples for the Google BigQuery Storage v1 API class ReadSession.Types.TableReadOptions.

Options dictating how we read a table.

Optional. Options specific to the Apache Arrow output format.

Optional. Options specific to the Apache Avro output format

Gets whether the "response_compression_codec" field is set

Gets whether the "sample_percentage" field is set

Optional. Set response_compression_codec when creating a read session to enable application-level compression of ReadRows responses.

SQL text filtering statement, similar to a WHERE clause in a query. Aggregates are not supported.

Examples: "int_field > 5" "date_field = CAST('2014-9-27' as DATE)" "nullable_field is not NULL" "st_equals(geo_field, st_geofromtext("POINT(2, 2)"))" "numeric_field BETWEEN 1.0 AND 5.0"

Restricted to a maximum length for 1 MB.

Optional. Specifies a table sampling percentage. Specifically, the query planner will use TABLESAMPLE SYSTEM (sample_percentage PERCENT). The sampling percentage is applied at the data block granularity. It will randomly choose for each data block whether to read the rows in that data block. For more details, see https://cloud.google.com/bigquery/docs/table-sampling)

Optional. The names of the fields in the table to be returned. If no field names are specified, then all fields in the table are returned.

Nested fields -- the child elements of a STRUCT field -- can be selected individually using their fully-qualified names, and will be returned as record fields containing only the selected nested fields. If a STRUCT field is specified in the selected fields list, all of the child elements will be returned.

As an example, consider a table with the following schema:

{ "name": "struct_field", "type": "RECORD", "mode": "NULLABLE", "fields": [ { "name": "string_field1", "type": "STRING", . "mode": "NULLABLE" }, { "name": "string_field2", "type": "STRING", "mode": "NULLABLE" } ] }

Specifying "struct_field" in the selected fields list will result in a read session schema with the following logical structure:

struct_field { string_field1 string_field2 }

Specifying "struct_field.string_field1" in the selected fields list will result in a read session schema with the following logical structure:

struct_field { string_field1 }

The order of the fields in the read session schema is derived from the table schema and does not correspond to the order in which the fields are specified in this list.