Is there any logical reason of having different tablespace for indexes?

Question

Hi Can some let me know why we created different table space for Index and data.

Answer 1

It is a widespread belief that keeping indexes and tables in separate tablespaces improves performance. This is now considered a myth by many respectable experts (see this Ask Tom thread - search for "myth"), but is still a common practice because old habits die hard!

Answer 2

It makes a sense in 80th, when there were not to many users and the databases size was not too big. At that time it was usefull to store indexes and tables in the different physical volumes.

Now there are the logical volumes, raid and so on and it is not necessary to store the indexes and tables in different tablespaces.

But all tablespaces must be locally managed with uniform extends size. From this point of view the indexes must be stored in different tablespace as the table with the 50 columns could be stored in the tablespace with 5Mb exteds size, when the tablespace for indexes will be enought 512Kb extended size.