Archives of the TeradataForum

Message Posted: Thu, 06 Mar 2014 @ 14:55:33 GMT

	<Prev	Next>		<<First	<Prev	Next>	Last>>

You can do the MVC and PI analysis on any table.

In case of MVC if done on small table can lead to execution of your query for longer time as it has to traverse via bit pattern in case of joins. Also if your table is small , but not as small as metadata tables and have PPI then the column on which MVC is done will not take advantage of partition.

If the table is really very small with few records and it is joined to big one, then obiviously it will duplicate on all amp if PI is not same, you dont need to do MVC for it really. But if all or most of the fields are varchar (> 100) then you can plan for it. SO in short, it depends on the scenario to decide whether we should go for MVC or not.

Regarding PI analysis, it depends on business requirement. same PI on joins or UPI always fetches better result. But there are times when you can really make the same PI join as its business thing. So for that we have join index, PPI and lot many things. But if you have the option of having same PI on joining table then its best. else one more thumb rule, you should have multiset table if its PI and not unique. it will give better performance while insert as it will eliminate the process of duplicate row check. So its again scenario based. :)

Best Regards,

Pawan Kumar Verma

	<Prev	Next>		<<First	<Prev	Next>	Last>>