response database

(Beverly)Preserving data integrity is particularly important in a database where multiple users access data simultaneously. The interleaving of a user’s query with another user optimizes the time in which data is retrieved. When the database is accessed by one user, before that user is finished, to optimize the time, another user can begin their query. This is an example of interleaving.    Concurrency controls are set in place to coordinate the simultaneous execution of transactions within a multiprocessing database system and to ensure the integrity of the data.  The scheduler is the DBMS component that establishes the order in which concurrent transaction operations are executed (Carlos Coronel, 2020, p. 494). This action is done by interleaving the execution of the database operations in a specific sequence that will ensure serializability.  Serializability is the main job of the scheduler and makes sure that all queries that are interleaved are yielding the same results as if they were executed in serial order or one after another.  This action will ensure the integrity of the data.

     During all transactions, data is moved and is in an unavoidable state of inconsistency. This is more so a threat with multiprocessing database systems. If the system used a serial type of schedule then each transaction would be executed one at a time, with no interference or threat of inconsistency. If the system uses a non-serial type of schedule, this would mean that the execution of data would be accessed simultaneously by users and could cause inconsistencies within the movement of data.  The scheduler then would use the serializable schedule to assure that the interleaving of the execution of two or more transactions is maintaining database consistency.

REFERENCES

Carlos Coronel, S. M. (2020).  Database Systems. Boston: Cengage Learning, Inc.

Gaurav, S. (2022, June 20).  Serializability in DBMS. Retrieved from Scaler Topics: https://www.scaler.com/topics/dbms/serializability-in-dbms/