rebuild your table, bulk deletes can kill performance,

you have some good suggestions but i highly recommend you rebuild afterwards to reset the high water mark.

here's a simple example of what can happen......

REM ==================================================
REM Step 1
REM
REM Turn timing on, create a sample table
REM and insert some data
REM ==================================================


SQL> SET TIMING ON

SQL> CREATE TABLE my_table
2 AS SELECT * FROM ALL_OBJECTS;

Table created.

Elapsed: 00:00:19.02
SQL> INSERT INTO my_table SELECT * FROM my_table;

26895 rows created.

Elapsed: 00:00:03.00
SQL> /

53790 rows created.

Elapsed: 00:00:04.07
SQL> /

107580 rows created.

Elapsed: 00:00:09.05
SQL> /

215160 rows created.

Elapsed: 00:00:18.00
SQL> COMMIT
2 ;

Commit complete.
Elapsed: 00:00:00.00


REM ==================================================
REM Step 2
REM
REM See how long it takes to count all the rows
REM ==================================================


SQL> SELECT COUNT(*) FROM my_table;

COUNT(*)
----------
430320

Elapsed: 00:00:12.07


REM ==================================================
REM Step 3
REM
REM Delete all the hows in the table.
REM This does not reset the high water mark
REM ==================================================


SQL> DELETE FROM my_table;

430320 rows deleted.

Elapsed: 00:01:58.07


REM ==================================================
REM Step 4
REM
REM Now that there is no data, how long does it take
REM to determine there are zero rows
REM ==================================================

SQL> SELECT COUNT(*) FROM my_table;

COUNT(*)
----------
0

Elapsed: 00:00:04.00


REM ==================================================
REM Step 5
REM
REM Now truncate the table and count all the rows. This
REM action resets the high water mark.
REM ==================================================


SQL> TRUNCATE TABLE my_table;

Table truncated.

Elapsed: 00:00:00.07

SQL> SELECT COUNT(*) FROM my_table;

COUNT(*)
----------
0

Elapsed: 00:00:00.00
SQL> spool off