Should I keep calculated values in a table or code the calculations

dolfandave

Hi,

Beginner to PHP here. I wanted to know if I wish to output averages that are calculated from other fields being displayed is it better to store the calculated values in the database by adding a field in my table or should I calculate them on the fly as records for certain individuals are requested? The number of records will be relatively small per person, from 5 to 150, for the most part and usually closer to the 5.

konsu

i would calculate them.

dolfandave

OK, I am not sure if you're trying to be humourous but my question is at what point should the averages be calculated? Sorry if I was vague. Are you saying they should be done on the webpage itself and therefore not stored in the table? If so, what is the reasoning please. I am a database person by trade so this front end stuff is very new to me. Thanks.

ddave

konsu

i am not trying to be humorous. i am assuming that you have a database and you want to output some statistics about the data in the database. so i would calculate statistics every time they are required. unless it is very time consuming, which is not judging from your posting. the reasoning is that since it requires little time doing database queries to get the statistics it is more expensive to maintain additional fields in your tables.

dolfandave

OK,

Thanks for clarifying. I will work it that way.

ddave

superwormy

In general, if you can calculate a field from a bunch of database entries, calculate it instead of storing it in a table. You'll make much less work for yourself maintaining your database and keeping things in sync if you do it this way.

The only exception is if you REALLY need the speed. And if you're asking this question... your database isn't nearly complicated enough to really need that speed boost... yet.