The TRIM statement is used to truncate the most recent data in a table.
The general syntax is
TRIM table_name num_rows
Above statement means number of rows to be truncated.
On the other hand, the user can also specify certain number of record to be preserved with following general syntax:
TRIM table_name TO row_number
Data will be permanently removed with TRIM statement, users should use this command with caution.
To remove the last 20 rows of data in the sales table:
TRIM sales 20
To keep the first 20 rows in the sales table:
TRIM sales TO 20