Adaptive query execution (AQE) enables reoptimizing a query, if during the execution some trigger indicates that it is non-optimal, so a more optimal plan should be looked for.
AQE is disabled by default and can be enabled with the configuration parameter aqe_enable.
AQE currently has the following limitations:
Cursors are not supported.
SELECT statements are only supported
except SELECT FOR UPDATE and
SELECT FOR SHARE.
Statements with volatile functions are not supported.