optimizer_use_condition_selectivity

Controls selectivity of which conditions the optimizer takes into account to calculate cardinality of a partial join when it searches for the best execution plan Meaning: 1 - use selectivity of index backed range conditions to calculate the cardinality of a partial join if the last joined table is accessed by full table scan or an index scan, 2 - use selectivity of index backed range conditions to calculate the cardinality of a partial join in any case, 3 - additionally always use selectivity of range conditions that are not backed by any index to calculate the cardinality of a partial join, 4 - use histograms to calculate selectivity of range conditions that are not backed by any index to calculate the cardinality of a partial join.5 - additionally use selectivity of certain non-range predicates calculated on record samples

See also: System Variables in 10.5 ES and in 10.4 ES

DETAILS

PARAMETERS

Dynamic

Yes

Scope

Global, Session

Data Type

BIGINT UNSIGNED

Minimum Value

1

Maximum Value

5

Default Value

4

SKYSQL

Cloud

SkySQL Topology

ES Ver

Default

AWS

HA (Primary/Replica)

10.4

4

AWS

HA (Primary/Replica)

10.5

4

AWS

Transactional Standalone

10.4

4

AWS

Transactional Standalone

10.5

4

AWS

Distributed Transactions

10.5

4

GCP

ColumnStore

10.5

4

GCP

ColumnStore Multi

10.5

4

GCP

Galera

10.4

4

GCP

Galera

10.5

4

GCP

HA (Primary/Replica)

10.4

4

GCP

HA (Primary/Replica)

10.5

4

GCP

HTAP

10.5

4

GCP

Transactional Standalone

10.4

4

GCP

Transactional Standalone

10.5

4

GCP

Distributed Transactions

10.5

4

CHANGE HISTORY

Release Series

History

10.5 Enterprise

  • Present starting in MariaDB Enterprise Server 10.5.3-1.

10.4 Enterprise

  • Present starting in MariaDB Enterprise Server 10.4.6-1.

EXTERNAL REFERENCES