Hi guys..

I was told that different database engines have got different performance.... is it true??

i.e. if i have a table with say 20000 entries (rows)... if i create the same table say on Oracle and SQL Server and perform the same query on both engines... does retrieve performance i.e. execution time varies...


what are the key factors that determine performance??


regards

Absolutely true.

There are all kinds of things that will affect performance, but assuming we keep everything constant (hardware, Schema design, size etc.) the performance will vary depending on how the engine was designed. The designers will have made trade offs based on their understanding of the universe ie what kinds of data and quiries the engine will have to manage and process. Thus if your data and quiries closely match their vision you get "good" performance, and if your universe is very different, you may get "poor" performance. Alas, there is no simple answer to the question "Which is best?". The only way to determine which is best for you is to build a model of your universe, and try it out on different engines.

Externally, the single thing that affects performance most is the underlying hardware. A machine with a fast processor, lots of memory, and well tuned disk system will always outperform a "lessor" machine.

After that, there a libraries full of books that discuss schema design query structure, system tuning and so on, all of which will to a greater or lessor degree, affect the overall performance of you system.