Re: database buffer cache / SGA

Thomas,

Please ignore the book question, little slow this am. Ordered your book. Thanks

Thomas Kyte wrote:
>
> In article <3B577825.1BB18144_at_att.net>, stevek says...
> >
> >Oracle server receives a request from a client, run sql through sqlarea
> >in cache, if there runs,if not runs through plan process then executes,
> >if data in buffer cache uses that data otherwise get block(s) from
> >tablespace.
> >
> >Question: oracle deals with data in blocks only, block 8K, record 1K.
> >Does oracle take 7 additional records on the block read? Does it use the
> >same block size/number of records when it puts changed data in redo logs
> >and rbs?
>
> data is cached in blocks, you get the block cached, even if you want just 1 of
> the rows on that block.
>
> redo -- changed bytes (not even entire rows), unless the tablespace is in HOT
> backup mode then the first time a block is modified the entire block is written
> to redo and then changed bytes only after that.
>
> rollback -- changed bytes only.
>
> --
> Thomas Kyte (tkyte@us.oracle.com) http://asktom.oracle.com/
> Expert one on one Oracle, programming techniques and solutions for Oracle.
> http://www.amazon.com/exec/obidos/ASIN/1861004826/
> Opinions are mine and do not necessarily reflect those of Oracle Corp
Received on Fri Jul 20 2001 - 06:35:47 CDT