Returns indexes of UPSERT and DELETE statements that have failed. Indexes returned
correspond to each failed statement's order of creation within a
PhoenixConnection up to
commit/rollback.
Statements whose index is returned in this set correspond to one or more HBase mutations that have failed.
Statement indexes are maintained correctly for connections that mutate and query
data (DELETE, UPSERT and SELECT) only. Statement (and their subsequent failure) order
is undefined for connections that execute metadata operations due to the fact that Phoenix rolls
back connections after metadata mutations.