This optimization improves the efficiency of direct
comparisons between a nonindexed column and a constant. In
such cases, the condition is “pushed down” to the
storage engine for evaluation. This optimization can be used
only by the
NDB storage engine.
NDB storage engine is
currently not available in MySQL 8.0. If you
are interested in using NDB Cluster, see
MySQL NDB Cluster 7.5 and NDB Cluster 7.6, which provides
information about MySQL Cluster NDB 7.5 (based on MySQL 5.7
but containing the latest improvements and fixes for the
NDBCLUSTER storage engine).