Advisory Lock
Introduction Unlike Level Locks created by the database at the physical layer, developers can freely create Advisory Locks based on custom logic at the application level The database does not know the meaning of this lock and it only acts as an intermediary to hold the lock (usually a bigint number) The process that arrives first is granted the lock for processing Meanwhile, subsequent processes must line up and wait to acquire the lock When a process finishes processing, it returns the lock to the next process Advantages When using other types of locks (such as Table level lock, Row level lock or Page level lock), you must rely on an actual existing data row in the table to lock, whereas Advisory Lock does not require any available data row, you can use any random number to lock It is extremely lightweight because it only exists on the Database RAM, does not write to the hard drive and does not generate redundant data (dead tuples) Functions To create an advisory lock, Postgres provid...