SQL Server Blocking

SQL Server blocking occurs when one transaction or process holds a lock on a resource (like a table or a row) and another transaction or process tries to access the same resource but is forced to wait. This waiting is due to the lock held by the first transaction, causing a blockage or obstruction for the second transaction.

Let’s create Blocking example;

Create a table and insert some data with below code.

CREATE TABLE People (
  Id int IDENTITY PRIMARY KEY,
  FirstName varchar(50) NOT NULL,
  LastName varchar(50) NOT NULL
);

INSERT INTO…