It's time discuss another ACID property : Consistency
As mentioned in older post, Consistency ensures that the database always stays in a valid state before and after each transaction with respect to the rules and constraints of the database.
To understand it more clearly, we will take an example of database of company which stores the data related to his employees in EMP table.
Now, clearly this company is strict about the age of its employees. It wants its employees to be of age >= 17 and less than 50.No one can work in the company whose age is out of this range. So, there is a constraint applied over the table as highlighted yellow in the picture.
Now if the database is consistent, it must satisfy this constraint.And Any transaction or data operation which violated this state should de failed or undone(rolled back).
e.g. If we try to insert a record into the EMP table where age is out of this range like 15 or 55, it must fail or roll-back the running transaction/data operation.In other words, the database is consistent with the rules/constraints of database.
Here is a good article explaining this topic and other ACID rules of Database.
As mentioned in older post, Consistency ensures that the database always stays in a valid state before and after each transaction with respect to the rules and constraints of the database.
To understand it more clearly, we will take an example of database of company which stores the data related to his employees in EMP table.
Now if the database is consistent, it must satisfy this constraint.And Any transaction or data operation which violated this state should de failed or undone(rolled back).
e.g. If we try to insert a record into the EMP table where age is out of this range like 15 or 55, it must fail or roll-back the running transaction/data operation.In other words, the database is consistent with the rules/constraints of database.
Here is a good article explaining this topic and other ACID rules of Database.
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