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Home -> Community -> Mailing Lists -> Oracle-L -> RE: dual
It's because we designed it that way. In earlier releases (can't remember
the specific version we brought this in with), you could put more than one
row in DUAL and then select them all, but all the things that should have
returned only one row then failed with a 1403 (?) error - single row query
returning more than one row. I remember well way way back in time before I
joined Oracle having the fun of trying to debug why all our clients apps
failed the night after we let a "manager" do the database maintenance. The
forms that the apps used all included the date and time on the screen, and
of course the "manager" had somehow ended up with two rows in DUAL, hence
the failure. Very simple to address, by just deleting the extra row (and of
course, never letting that manager do database maintenance again!).
In due course, Oracle realized that DUAL was a special table and built into the kernel the functionality you mention to ensure that only one row is ever returned and hence those types of problems should not occur any more.
Pete
"Controlling developers is like herding cats."
Kevin Loney, Oracle DBA Handbook
"Oh no, it's not. It's much harder than that!"
Bruce Pihlamae, long-term Oracle DBA
-----Original Message-----
bulbultyagi_at_now-india.net.in
Sent: Friday, October 31, 2003 3:55 AM
To: Multiple recipients of list ORACLE-L
List, here is a rtfm question which I was scared to ask, but its bothering me too much so I just can't stay quite :
"why do multiple inserts into sys.dual complete sucessfully when connected as sysdba, but a subsequent select * from dual show only 1 row ?"
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Author: <bulbultyagi_at_now-india.net.in
INET: bulbultyagi_at_now-india.net.in
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Author: Pete Sharman
INET: peter.sharman_at_oracle.com
Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services ---------------------------------------------------------------------To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Thu Oct 30 2003 - 12:19:47 CST
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