Rows per Block

[lesstjm]

I have a 4K block size. The avg_row_len of my table is 168. There are 4579201 rows in the table.

To figure out how many rows are in a block I did

SELECT (1024 * 4) /168 from dual;

(1024*4)/168
------------
24.3809524

to figure out how many blocks my table should consume I did:

SELECT 4579201 / 24 from dual;

4579201/24
----------
190800.042

but when I check how many blocks it has assigned to it I get:


select blocks,empty_blocks from dba_tables where table_name = 'MYTAB';

BLOCKS EMPTY_BLOCKS
---------- ------------
20624 15

What am I doing wrong?

[lesstjm]

I forgot to say that I want to know why the number of blocks I came up with does not match what is in dba_tables?

[jodie]

When was the last time you analyzed the table?