Struct TableReadOptions

pub struct TableReadOptions {
    pub selected_fields: Vec<String>,
    pub row_restriction: String,
    pub sample_percentage: Option<f64>,
    pub response_compression_codec: Option<i32>,
    pub output_format_serialization_options: Option<OutputFormatSerializationOptions>,
}

Options dictating how we read a table.

Fields

selected_fields: Vec<String>

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.

row_restriction: String

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.

sample_percentage: Option<f64>

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)

response_compression_codec: Option<i32>

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

output_format_serialization_options: Option<OutputFormatSerializationOptions>

Implementations

impl TableReadOptions

pub fn sample_percentage(&self) -> f64

Returns the value of sample_percentage, or the default value if sample_percentage is unset.

pub fn response_compression_codec(&self) -> ResponseCompressionCodec

Returns the enum value of response_compression_codec, or the default if the field is unset or set to an invalid enum value.

pub fn set_response_compression_codec( &mut self, value: ResponseCompressionCodec, )

Sets response_compression_codec to the provided enum value.

Trait Implementations

impl Clone for TableReadOptions

fn clone(&self) -> TableReadOptions

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TableReadOptions

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for TableReadOptions

fn default() -> Self

Returns the “default value” for a type.

impl Message for TableReadOptions

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode(&self, buf: &mut impl BufMut) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited( &self, buf: &mut impl BufMut, ) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl PartialEq for TableReadOptions

fn eq(&self, other: &TableReadOptions) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for TableReadOptions