mysql - MySQL: precompute data for better performance

Question

Is it ok to precompute data for better performance? For example, when player wins a game, I count number of won games for the particular player and write it to a dedicated table. Then, when I show overall ratings, I don't need to count number of won games for the players once again — I already have it precomputed.

Of course, it's possible, that precomputed data becomes unsyncronized with real values, but it's bearable.

Or is there another, more "professional" way to resolve the issue?

Answer 1

No, its perfectly fine and is mostly done for large datasets you'd else had to perform sum/count/group by statements that cost alot performance.

if "out of sync" is not a problem to realtime, use nightly-jobs to verify they are still in sync, or update them if they are not.

Answer 2

さまざまなアプローチが使用されます -

1. 集計値を別の集計テーブルに保存する
2. 元のテーブルに対して集計値を保存する

正解も不正解もありません。おそらくあなたの場合、1) を使用したいので、次のような集計テーブルがあります。

PlayerID AggregateName AggregateValue

その後、テーブル構造を変更することなく、集計を簡単に拡張できます。