kishore.giri

 Profile Answers by kishore.giri Questions by kishore.giri

• Dec 12th, 2007

 

When a query is submitted by the user it comes to the sharedpool and it is processed by the library cache i.e. statement is parsed their,execution plan is prepared and data is retrived from the datafile and stored in the database buffer cache so that if next time the same query is given then it doesn't go for the whole process instead it just retirves the data which is in the buffer.

dbashashi

 Profile Answers by dbashashi 

• Jul 14th, 2009

 

Select statement works in the same way as other querries. The result set is brought from the Datafile if not already in Buffer cache. As we are aware that Buffer cache works on LRU and MRU algorithm to retain or flush out the data to and from buffer cache.
But in Select statement it is placed at the end of LRU list, as we dont require it very often and thus flushed out once it has been used.