Hi guys, I have a question about outer join. For example as follow (pg 8.4.1): ------------------------------ create table t_1(a int); create table t_3(a int); insert into t_1 values(1); insert into t_1 values(2); insert into t_3 values(1); insert into t_3 values(3); postgres=# select version(); version ------------------------------------------------------------- PostgreSQL 8.4.1, compiled by Visual C++ build 1400, 32-bit (1 row) postgres=# select * from t_1 full outer join t_3 on t_1.a=1; ERROR: FULL JOIN is only supported with merge-joinable join conditions -------------------------- My question is: why on clause restrict "t_1.a=1"? I test it in Oracle, it support to such as "t_1.a=1": ------------------------ SQL> SELECT * FROM TAB1; A B C ---------- ---------- ---------- 2 3 SQL> SELECT * FROM TAB2; A ---------- 1 2 SQL> select * from tab1 full outer join tab2 on tab1.a=2; A B C A ---------- ---------- ---------- ---------- 2 1 2 2 3 SQL> select * from tab1 left outer join tab2 on tab1.a=2; A B C A ---------- ---------- ---------- ---------- 2 1 2 2 3 SQL> select * from tab1 right outer join tab2 on tab1.a=2; A B C A ---------- ---------- ---------- ---------- 2 1 2 2 SQL> select * from tab1 right outer join tab2 on 1=1; A B C A ---------- ---------- ---------- ---------- 2 1 3 1 2 2 3 2 SQL> select * from tab1 right outer join tab2 on tab2.a=2; A B C A ---------- ---------- ---------- ---------- 1 2 2 3 2 -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general