๐ง๐ต๐ฒ ๐ก+๐ญ ๐ค๐๐ฒ๐ฟ๐ ๐ฃ๐ฟ๐ผ๐ฏ๐น๐ฒ๐บ
You check your logs. You see hundreds of SQL calls. You wrote one query. This is the N+1 problem.
It happens when you fetch a main list. Then you fetch details for each item one by one.
Think of a classroom. You ask for a list of 30 students. You get 30 names. Then you ask for each grade one by one. You make 31 trips to the office.
Slow approach:
- Fetch all stores.
- Loop through stores.
- Fetch machine counts for each store.
- This creates too many queries.
Fast approach 1: Use a JOIN.
- One query gets the store and the count together.
Fast approach 2: Use batching.
- Fetch all stores first.
- Fetch all counts using one IN query.
- This takes only 2 trips.
Why this works:
- Fewer network trips.
- Less database stress.
- Better speed.
Check your code. Look for queries inside loops. Fetch data in bulk.