Hi,

We have a table with 200 Columns and 200,000 rows.

The Table looks something like this

table_a

col1
col2
col3

I am trying to update col3 with (col1-col2) value for all the 200,000 rows.

whats the most efficient way to do this. please suggest. I need to do a similar thing for atleast 50 columns.

Thanks