Performance and view-on-view approach


Performance and view-on-view approach

Hi Guys, thanks for reading the post. I did do a search for "view on view" and there was no result.

I'm at a client and they insist on the standard that the tables are only queried through a "base view". This base view is a "select * from dbname.table_name" with the same name as the table but from a different database; so the tables are in one database and the views in another.

If I am to create a new view combining a few "base views" to show a result I should only query the base views. Is there a underlying Teradata infrastructure reason that could warrant this approach? My second question is related to the performance of such an approach; would there be any impact at all considering the base view always does a select * from the table.

thanks for you comments.

Re: Performance and view-on-view approach

usually end users will have only select access. if select access is provided on final table then there is a chance that end user access the table directly, it places read lock on the table, except select queries all other queries which access the table will be blocked.  views are created with "locking row for access" statement which makes the table accessable to every one without any blocking