Re: Tablespace Header Blocks??

You header blocks are just like your boot sector areas on the HDD, they are usually predefined (pre-allocated) areas so oracle knows exactly where they are for future references/updates. In the scheme of things, 4k is nothing, say you lost 50 bytes per block for block headers within each extent, again its nothing when you are talking 000's or 0000's of Mb. HDD Space is too cheap!

Virtually all blocks will have some free space, as record sizes can vary dramatically it is impossible to have an optimal block size that all records fit nicely into, careful use of pctfree can reduce chaining to allow for the growth of records within a block so your rows are not migrated into different blocks, or chained all over the place.

This is really dependent on the data going in and what happens to it throughout the day, ie. large updates etc.

Dont feel so bad about the 4k.

Own Free Member Forum Received on Wed Aug 12 1998 - 20:30:34 CDT