using data dictionary views in application logic

[CHALAVADI]

Can someone please advise if it is good pratice to query data dictionary views from application code using java. For example to query dba_tab_columns to dynamically find number of columns in a table and code some logic based upon number of columns. Thanks in advance for your time and help.

[davey23uk]

if you need that info and you cannot get it anywhere else, then sure go for it.

[CHALAVADI]

Are these queries expensive? Is it better to use them in stored procedures.

[davey23uk]

they can be expensive if overused, dba_tab_columns one of the lesser one.

The in memory ones can cause you trouble.

SP are better as far as I am concerned (all sql should be in them) but if you write it correctly put the code where you want it