IN: Prepared statement generated by hc_pstmt_create.
IN: Points to an array of hc_string_t, each of which is the name of a field to retrieve from the metadata (select clause). Set to NULL to only retrieve OIDs matching the query.
IN: The number of items in the select clause.
IN: The number of results per internal fetch.
OUT: Updated to point to the new result set. See hc_query_result_set_t.