Storing vs calculating aggregate values
At an old job, we had this database, it wasn't normalized rigth, some tables wheren't used anymore, it was patch after patch. In conclusion, it was a mess.
Once, while I was trying to fix it I saw that some fields where calculated on the fly and this made the db very slow performing simple select querys. Since then, I don't calculate any field anymore, I just store the data as is.
Is this recomendend? when is better to store data than calculate it?