The FIRST FROM expression works in two steps:
o It forms the record stream as specified by the record
selection expression.
o If at least one record matches the RSE, Oracle Rdb uses the
values stored in the first record of the record stream to
evaluate the value expression.
Format
(B)0[mfirst-from-expr
qqq> [4mFIRST[m qqq> value-expr qqq> [4mFROM[m qqq> rse qqq>