This demonstration compares the use of parallel and serial processing for the same SQL query. This demonstration is associated with lessons 2 and 3 of the Oracle University seminar: Parallel Processing in Oracle 11g.
Release Date: 08-Jun-11
Duration: 3.5 minutes
Credited To: -
No Flash Plugin Needed
05-Aug-12
It is all because of caches and statistics.
12-Jan-12
It is almost impossible to reduce query responce time from 75 to 2 seconds with 8 parallel processes. Even if every slave process would read data blocks as fast as single server process the responce time can be aboute 8 times less (not 30 times). I think the reason of such expressive result is just file system cache. To get the accurate result we should use direct reads (ASM, raw devices) or compare the responce time of the second non-parallel query execution (after restarting database or flushing buffer cache).
17-Dec-11
Good Demo.................!
04-Dec-11
short & sweet demo.
11-Jul-11
-
30-Jun-11
This demo is a brief and clear demonstration of parallel query processing in 11g.a
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