ACID Properties
I am a Tech Enthusiast having 13+ years of experience in ๐๐ as a ๐๐จ๐ง๐ฌ๐ฎ๐ฅ๐ญ๐๐ง๐ญ, ๐๐จ๐ซ๐ฉ๐จ๐ซ๐๐ญ๐ ๐๐ซ๐๐ข๐ง๐๐ซ, ๐๐๐ง๐ญ๐จ๐ซ, with 12+ years in training and mentoring in ๐๐จ๐๐ญ๐ฐ๐๐ซ๐ ๐๐ง๐ ๐ข๐ง๐๐๐ซ๐ข๐ง๐ , ๐๐๐ญ๐ ๐๐ง๐ ๐ข๐ง๐๐๐ซ๐ข๐ง๐ , ๐๐๐ฌ๐ญ ๐๐ฎ๐ญ๐จ๐ฆ๐๐ญ๐ข๐จ๐ง ๐๐ง๐ ๐๐๐ญ๐ ๐๐๐ข๐๐ง๐๐. I have ๐๐๐๐๐๐๐ ๐๐๐๐ ๐๐๐๐ 10,000+ ๐ฐ๐ป ๐ท๐๐๐๐๐๐๐๐๐๐๐๐ and ๐๐๐๐ ๐๐๐๐๐ ๐๐๐๐ ๐๐๐๐ 500+ ๐๐๐๐๐๐๐๐ ๐๐๐๐๐๐๐๐ in the areas of ๐๐จ๐๐ญ๐ฐ๐๐ซ๐ ๐๐๐ฏ๐๐ฅ๐จ๐ฉ๐ฆ๐๐ง๐ญ, ๐๐๐ญ๐ ๐๐ง๐ ๐ข๐ง๐๐๐ซ๐ข๐ง๐ , ๐๐ฅ๐จ๐ฎ๐, ๐๐๐ญ๐ ๐๐ง๐๐ฅ๐ฒ๐ฌ๐ข๐ฌ, ๐๐๐ญ๐ ๐๐ข๐ฌ๐ฎ๐๐ฅ๐ข๐ณ๐๐ญ๐ข๐จ๐ง๐ฌ, ๐๐ซ๐ญ๐ข๐๐ข๐๐ข๐๐ฅ ๐๐ง๐ญ๐๐ฅ๐ฅ๐ข๐ ๐๐ง๐๐ ๐๐ง๐ ๐๐๐๐ก๐ข๐ง๐ ๐๐๐๐ซ๐ง๐ข๐ง๐ . I am interested in ๐ฐ๐ซ๐ข๐ญ๐ข๐ง๐ ๐๐ฅ๐จ๐ ๐ฌ, ๐ฌ๐ก๐๐ซ๐ข๐ง๐ ๐ญ๐๐๐ก๐ง๐ข๐๐๐ฅ ๐ค๐ง๐จ๐ฐ๐ฅ๐๐๐ ๐, ๐ฌ๐จ๐ฅ๐ฏ๐ข๐ง๐ ๐ญ๐๐๐ก๐ง๐ข๐๐๐ฅ ๐ข๐ฌ๐ฌ๐ฎ๐๐ฌ, ๐ซ๐๐๐๐ข๐ง๐ ๐๐ง๐ ๐ฅ๐๐๐ซ๐ง๐ข๐ง๐ new subjects.
RDBMS works under 4 properties (ACID)
Atomicity
If any operation is performed on the data, either the entire transaction should be executed or should not be executed at all.ย
Single unit of work = Multiple queries.
For example, in an application that transfers funds from one account to another, the atomicity property ensures that, if a debit is made successfully from one account, the corresponding credit is made to the other account.
- In the above diagram, it can be seen that after crediting $10, the amount is still $100 in account B. So, it is not an atomic transaction.
Consistency
Data is in a consistent state when a transaction starts and when it ends.
For example, in an application that transfers funds from one account to another, the consistency property ensures that the total value of funds in both the accounts is the same at the start and end of each transaction.
Isolation
Isolation means that any data being used during the processing of one transaction cannot be used by another transaction until the first transaction is complete.
For example, if two people deposit $100 into another account with a balance of $900, the first transaction must add $100 to $900, and the second must add $100 to $1000. If the second transaction reads the $900 before the first transaction has completed, both transactions will seem to succeed, but $100 will have gone missing. The second transaction must wait until it alone is accessing the data.
Durability
Durability refers to the fact that once data from a transaction has been committed, its effects will remain, even after a system failure.ย
While a transaction is under way, the effects are not persistent. If the database crashes, backups will always restore it to a consistent state prior to the transaction commencing. Nothing a transaction does should be able to change this fact.
For example, in an application that transfers funds from one account to another, the durability property ensures that the changes made to each account will not be reversed.
