Strong Consistency vs Weak Consistency
|
Feature |
Strong Consistency |
Weak Consistency |
|---|---|---|
|
Data View |
All nodes observe the same view of data at any given time. |
Different nodes may see different views of the data. |
|
Write Operation |
Updates on one node are immediately visible to all other nodes. |
Updates may not be seen by all nodes immediately. |
|
Read Operation |
Read operations return only up-to-date value. |
Reading operation can contain obsolete or stale data. |
|
Consistency Guarantees |
Ensures strong consistency guarantees |
Gives weaker consistency guarantees with eventual consistency. |
|
Performance |
Usually higher latency and lower availability due to synchronous operations. |
Typically better performance, scalability, and availability. |
Consistency in DBMS
Data integrity and reliability are key in the domain of Database Management Systems (DBMS). Consistency, one of the core principles in DBMS, ensures that every transaction is made according to predefined rules and limits thus preserving the accuracy and authenticity of data kept within. The change to the database must take it from one consistent state into another.
Consistency, in DBMS, requires that any modification to a single piece of data be reflected uniformly across all linked tables as well as entities. For example, suppose you have a driver’s license database. Updating a driver’s house address should consistently appear in all relevant tables just to avoid mismatching data.
It is not enough for consistency in DBMS since it may not result in transactional correctness at all times but it plays an important role in shielding against programming errors that violate set up database constraints. To make sure that data remains reliable and intact, RDBMS go through the process of enforcing consistency to create a firm foundation for robust and trusted applications based on stored data.
Consistency in DBMS