Block level row structure

From: Michael J. Moore <NOhicamelSPAM_at_comcast.net>
Date: Sun, 16 Nov 2003 16:27:31 GMT
Message-ID: <TzNtb.162912$mZ5.1117512@attbi_s54>

I understand that there is a row header that contains a count of the number of rows in the record. There is also a 1 or 3 byte length field for each field in the row, unless the field is NULL in which case there is nothing there. So, given a table with two columns defined as EL1 NUMBER and EL2 NUMBER, how can Oracle tell if the value stored in a given row represents EL1 or EL2 when one value is NULL and the other is not?

From my understand, all it would know is that it has 2 fields, and one data value, but would not know if that data value is for EL1 or EL2. Obviously I am missing a piece of the puzzle.

Mike Received on Sun Nov 16 2003 - 10:27:31 CST