The magic that is DUAL!

Posted by David Yahalom under Oracle

I’ve stumbled across a very interesting write-up at AskTom regarding Oracle’s DUAL table. Some very interesting discussion going there including the origin of the name “Dual” for the obviously singular dual table. Recommended read.

And for some quick trivia. What’s the command masked below responsible for such output?

SVRMGR> select * from dual;
D
-
X
1 row selected.

SVRMGR> XXXXXXXXXXXXXXXXXXXX;
Statement processed.

SVRMGR> select * from dual;
ADDR     INDX       INST_ID    D
-------- ---------- ---------- -
01680288          0          1 X
1 row selected.

To find the answer browse the post at AskTom.