Comment 2 for bug 897858

We have now 2 variables related to fast index creation:

- expand_fast_index_creation controls Percona's improvements, i.e. ability to use fast index creation on table rebuilds and automatic statistics updates after creating an index using fast index creation;

- fast_index_creation allows to disable fast index creation globally, i.e. even for explicit index create operations. With fast_index_creation disabled, expand_fast_index_creation has no effect.

So this bug is about documenting expand_fast_index_creation introduced by the fix for bug #858945.