null

how i can verifiy the null occupied the memory...

[QUOTE=deepakbit2;32239]how i can verifiy the null occupied the memory...[/QUOTE]

NULL is absence of value. How can a non existent value occupy space in memory?

[code]
SQL> CREATE TABLE TEST_DATA( X NUMBER);

Table created.

SQL> INSERT INTO TEST_DATA VALUES(NULL);

1 row created.

SQL> SELECT DUMP(X) FROM TEST_DATA;

DUMP(X)
--------------------------------------------
NULL
[/code]

null does not occupy any memory.