#exec_raw_query was renamed to #exec_query_raw
need to re-def oracle's #exec_insert as well - does not like #execute_insert
fix broken explain on oracle due exec_xxx refactoring
need to handle boolean conversion for oracle since we get 1.0 decimals
... this is due "corrected" JDBC type to Ruby conversion
minor cleanup + update for simple tests, make sure index name <= 30 chars
eliminate #do_exec helper - adapters should override exec_xxx methods