Question

I have a table 1 lac row with 50 columns. I know I have to select exactly one row and one column based on primary key. So what query I have to use either

SELECT * FROM <TAB_NAME> WHERE <IND_COL_NAME> = XXXXXX  

or

SELECT COL_NAME FROM <TAB_NAME> WHERE <IND_COL_NAME> = XXXXXX  

So any one tell me please which approach is better and why. from performance point of view. suppose this query is running frequently in an scalable application. Please specify the cause.

Answer 1

The ideal approach would be

 SELECT yourcolumn FROM yourtable WHERE yourcondition

It will generate less network traffic, and is a more precise statement of your requirements.

Additionally, if your table has columns of certain types, it avoids expensive querying of them, thus giving you improved performance