Hi, what performs better i have 2 tables joined, probably no more then 20 cols. What is better for performance if i use wild card and select all or if i select the exact cols i need ? Just wondering what is better performance wise ?
It depends on how many fields you need, if it's most of them then you may as well go ahead and use a wildcard to save having a long list of fileld names. Otherwise just select the fields you need, it will be save resources.
When you don't need all the columns, its always better to list the columns you need, rather than using wild card! The performance difference could be very big if you're working with a lot of data, though that's not the case. The only 'bad' thing about listing the columns is that you need to do it (writing some column names is harder than writing a simple wild card )