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A nosql database schema change would force you to update every document requiring the change. I would say rdms schemas are straight forward. Remove constrants
by wolco 8y ago
A nosql database schema change would force you to update every document requiring the change.
I would say rdms schemas are straight forward. Remove constrants, alter tables/move data, add constrants.
Changing a nosql schema going forward is simple. Adding new columns is equally simple. Deleting columns: rdms is much easier. Updating rdms is simplier.
- paulryanrogers 8y agoWith RDBMS the integrity constraints can make gradually changes to large data sets more difficult. It often means a lot of downtime or the code must tolerate old and new structures for a while. With NoSQL the constraints are probably already in the application layer.
- wolco 8y agoI usually remove db constraints and implement constrains at the application level for both types.
- tatersolid 8y agoWhen you remove constraints from an RDBMS you slow it down, sometimes catastrophically. The query planner/compiler in all modern RDBMS use foreign key constraints, unique constraints, and check constraints to optimize their execution code. For instance, having a foreign key constraint allows the query planner to omit any code that checks if a value is in the child table but not the parent during a join. It can sometimes avoid accessing one table or the other entirely (so-called “join elimination”).