1.3.2 - referential integrity / transactions / ACID / record locking

explain what data integrity / DBMS is

• data integrity - refers to the process of maintaining the consistency of a database

• DBMS - database management system, system that allows the user to interact with the datastore

what’s referential integrity / what’s a transaction

• set of rules used (by DBMS) to enforce data integrity

• a transaction is any operation done on a database

describe ACID

• all transactons need to be done in-line with ACID

• atomicy - all transactions should be completed fully, if they can’t be, then they’re aborted

• consistency - enforcement of referential integrity

• isolation - concurrent transactions shouldn’t effect other transactions

• durability - ensure that changes made to the database aren’t lost due to system failures

what’s record locking / how can this lead to deadlock

• record locking refers to how databases prevent multiple users from accessing the same record simultaneously

• this can lead to deadlock by the following: 1 user is accessing a record, another user is accessing another record. the first user tries to access the second record and the second user tries to access the first record. they’re both left waiting

what is database redundancy

• refers to making/storing back-ups of databases in different physical locations to ensure data security