Adaptive Statistics

Adaptive Statistics

optimizer_adaptive_statistics

Adaptive statistics are disabled by default.

Adaptive statistics are enabled when the following initialization parameters are set:

• OPTIMIZER_ADAPTIVE_STATISTICS is TRUE (the default is FALSE)

• OPTIMIZER_FEATURES_ENABLE is 12.1.0.1 or late

Setting OPTIMIZER_ADAPTIVE_STATISTICS to TRUE enables the following features:

• SQL plan directives

• Statistics feedback for join cardinality

• Adaptive dynamic sampling