Code RoomCustomer deletion locks orders table

MediumPrep Room Coding #1847

Customer deletion locks orders table

Code reviewDatabases & SQLMid–Senior~24 min

Review this SQL. Deleting a single customer takes 40 seconds and locks up the orders table.

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1CREATE TABLE orders (

2 id BIGSERIAL PRIMARY KEY,

3 customer_id BIGINT NOT NULL REFERENCES customers(id) ON DELETE CASCADE,

4 total NUMERIC,

5 created TIMESTAMPTZ

6);

7-- orders has 200M rows; the only index is the primary key.

8

9DELETE FROM customers WHERE id = $1;

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