Include the ORDERED
directive to instruct the query optimizer to join tables in the order in which they are listed in the FROM
clause. If you do not include the ORDERED
keyword, the query optimizer will choose the order in which to join the tables.
In the ORDERED
version of the command, Advanced Server will first join emp e
with dept d
before joining the results with jobhist h
. Without the ORDERED
directive, the join order is selected by the query optimizer.
Please note: the ORDERED
directive does not work for Oracle-style outer joins (those joins that contain a '+' sign).