Space questions again

I posted this and have not received replies so I'll try again.

I inherited the DBA responsiblity in my group so I'm learning as I go. What we have are tables of fixed sizes (no variable chars). The tablespaces are stored on raw partitions. Here are a few questions:

A table named LINE resides in tablespace TBSP1. The table size is 366 bytes. The table LINE has 9598 rows. When I multiply the number of LINE entries (9598) by the LINE size (366 bytes) I get 3512868 which should indicate how much space is USED in TBSP1. The questions are:

• How can I verify the used space in TBSP1 using a query? I've used "select sum(bytes)" but the number I get is way off (8388608).
• How much overhead is used in TBSP1 besides the 366 bytes size of each LINE row?

Thanks in advanced. Please respond here or via email if you can help.

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