<<Previous Next>>
Oracle -
Delete Vs TRUNCATE VS Drop - April 10, 2009
at 11:00 AM
Delete Vs TRUNCATE VS Drop
The DELETE command is used to remove some or
all rows from a table. After performing a DELETE operation you need
to COMMIT or ROLLBACK the transaction to make the change permanent
or to undo it. It causes all DELETE triggers on the table to fire.
TRUNCATE removes all rows from a table. The operation cannot be
rolled back and no triggers will be fired. TRUNCATE is faster and
doesn't use as much space as a DELETE.
The DROP command removes a table from the
database. All the tables' rows, indexes and privileges will also be
removed. No DML triggers will be fired. The operation cannot be
rolled back.
Also read
Nested Table is a table inside a table. It can have several rows
for each row of its parent table............
Clusters group together tables that share common columns. These
tables are often used together.........
Use the ALTER TABLE command to do this ALTER TABLE employee ADD
(department VARCHAR2);.........
Ordinary (heap-organized) table, Clustered table, Index-organized table, Partitioned table............
|
