Difference between Truncate & Delete

Question

Hi,
I've a table D with child tables A,B,C. I've truncated in the below order:
truncate table A;
truncate table B;
truncate table C;
truncate table D;
And got a foreign key dependency error, though I've truncated all the child tables;
When I issue delete from D, all the rows got deleted without any error.
How is Truncate different from Delete other than the AutoCommit?

Answer 1

Truncating a Table
TRUNCATE TABLE is a DDL statement, which is used to remove all rows from a
table and to release the storage space used by that table. When using the TRUNCATE TABLE statement,
you cannot rollback row removal.
Syntax
TRUNCATE TABLE table;
You must be the owner of the table or have DELETE TABLE system privileges to truncate a table.
Deleting a Table Record
The DELETE statement can also remove all rows from a table, but it does not release storage space. The
TRUNCATE command is faster. Removing rows with the TRUNCATE statement is faster than removing
them with the DELETE statement for the following reasons
1 ) The TRUNCATE statement is a data definition language (DDL) statement and generates no rollback
information.
2 ) Truncating a table does not fire the delete triggers of the table.
3 ) If the table is the parent of a referential integrity constraint, you cannot truncate the table. Disable the
constraint before issuing the TRUNCATE statement.