I recently ran accross a SQL by Jonathan that uses "materialize" hint. As was unable to find the hint documented anywhere, and God knows I tried before asking the question, I must ask the folowing two =20 questions: 1) What does "materialize" hint do and where is it documented? I was unable to find it documented in either 10g documentation or 9.2 documentation. 2) The same question for "with generator" clause. This question is, of course, meant for Jonathan but I'd appreciate anybody else's answer as well. Here is the SQL: ******************************************************************* drop table t1; create table t1 nologging pctfree 0 as with generator as ( select --+ materialize rownum id from all_objects where rownum <=3D 1000 ) select /*+ ordered use_nl(v2) */ rownum - 1 id from generator v1, generator v2 where rownum <=3D 65536 ; delete from t1 where id =3D 65001; delete from t1 where id =3D 65535; alter table t1 add constraint t1_pk primary key (id); begin dbms_stats.gather_table_stats(user, 't1', cascade =3D> true); end; . / select placed from ( select id, rank() over (order by id) placed from t1 ) where placed =3D id - 1 and rownum =3D 1 ; --=20 Regards Jonathan Lewis http://www.jlcomp.demon.co.uk/faq/ind_faq.html The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/seminar.html Public Appearances - schedule updated Dec 23rd 2004 ***************************************************************** --=20 Mladen Gogala Oracle DBA -- //www.freelists.org/webpage/oracle-l