CMPSC 431W Lecture Notes - Lecture 15: Serializability, Institute For Operations Research And The Management Sciences, Oracle Database
Document Summary
An application program with special properties to guarantee it maintains database correctness. Many applications use databases to store information about the state of the real world. When there are changes, a transaction is executed to reflect the change in the database state. Also, a unit of program execution that accesses and updates various data items in the database: must see a consistent database. Two main issues: concurrent execution of multiple transactions, failures of various kinds, such as hardware failures and system crashes. Serializability: ensures that a schedule for executing concurrent transactions is equivalent to one that executes the transactions serially in the same order. Assumes that all accesses to the database are done using read and write operations. Isolation: transactions are isolated or protected from the effects of other concurrently executing transactions: durability: once the dbms informs the user that a transaction is successfully completed, its effect should persist even if a system crash happens.
