Struct QueryOptions

pub struct QueryOptions {
    pub optimizer_statistics_package: Option<String>,
    pub optimizer_version: Option<String>,
}

Query optimizer configuration.

This type is not used in any activity, and only used as part of another schema.

Fields

optimizer_statistics_package: Option<String>

An option to control the selection of optimizer statistics package. This parameter allows individual queries to use a different query optimizer statistics package. Specifying latest as a value instructs Cloud Spanner to use the latest generated statistics package. If not specified, Cloud Spanner uses the statistics package set at the database level options, or the latest package if the database option is not set. The statistics package requested by the query has to be exempt from garbage collection. This can be achieved with the following DDL statement: ALTER STATISTICS SET OPTIONS (allow_gc=false) The list of available statistics packages can be queried from INFORMATION_SCHEMA.SPANNER_STATISTICS. Executing a SQL statement with an invalid optimizer statistics package or with a statistics package that allows garbage collection fails with an INVALID_ARGUMENT error.

optimizer_version: Option<String>

An option to control the selection of optimizer version. This parameter allows individual queries to pick different query optimizer versions. Specifying latest as a value instructs Cloud Spanner to use the latest supported query optimizer version. If not specified, Cloud Spanner uses the optimizer version set at the database level options. Any other positive integer (from the list of supported optimizer versions) overrides the default optimizer version for query execution. The list of supported optimizer versions can be queried from SPANNER_SYS.SUPPORTED_OPTIMIZER_VERSIONS. Executing a SQL statement with an invalid optimizer version fails with an INVALID_ARGUMENT error. See https://cloud.google.com/spanner/docs/query-optimizer/manage-query-optimizer for more information on managing the query optimizer. The optimizer_version statement hint has precedence over this setting.

Trait Implementations

impl Clone for QueryOptions

fn clone(&self) -> QueryOptions

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for QueryOptions

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

Formats the value using the given formatter.

impl Default for QueryOptions

fn default() -> QueryOptions

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for QueryOptions

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for QueryOptions

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Part for QueryOptions