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How doese oracle work when getting some cols from database [message #259256]

Tue, 14 August 2007 21:08

lzfhope
Messages: 69
Registered: July 2006

Member

hi,all
I want to know how oracle work when getting some cols from the db. Mostly,We retrive only some cols from a table or a view,those sqls are like this:

select tname from tab;

To surpose,at first,the oracle gets data blocks from disks.In fact .in my conditions, i do not need the whole block,but parts of a block.for example,if the orale get 100 blocks from disk,i only need parts of the first block,the parts of the second block,and ... and parts ot the one hundredth block.
so,I suppose the oracle separates the given datas from all of those block，then return oracle clients those datas.the clients only receice necessary datas from the servers.
is that reasoning right?

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