mysql - New table (with derived_data) or SQL query? -


from best-practice point of view, better create new table in database derived_data field other tables, or calculate using sql-query everytime?

details: more precicely, have table orders(id_order,date,time,sum) , want track daily profits , preview them everytime administrator selects drop-down menu. shall make sql-query everytime asks it, or new table profits(date,day_profit)with derived_data field takes value other tables?

for simple calculations (a+b), them in select.

for aggregates (count(sales), sum(revenue)) results regularly calculate, build "summary table(s)".

for example, daily counts, totals, etc, broken down region. otherwise take group by, etc.

note can compute weekly or monthly totals daily table, not build more tables.

see my summary tables blog.

for thousand rows, not important; million or billion vital performance in "data warehousing".

keep in mind summary table no-no (to database purists) since holds 'redundant' data. policies should avoid letting out of sync.


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