DB Specification

Summary

• Constraints
• Task Decomposition

Constraints

There are some constraints that can’t be modeled in EER and need to be handled in app code.

Task Decomposition

There are times where you need to break up a task to better fit how a db models it.

• Lookups vs Insert/Delete/Updates
  • Grouping reads together and writes together can help minimize what types of locks are needed for a given action.
• Number of schema constructs
  • Minimizing this number lowers the number of locks needed.
• Enabling conditions
  • Keeping enabling conditions consistent ensures the task can be scheduled.
• Keep task frequencies consistent
  • This can impact the usefulness of indexes.
• Is consistency essential?
  • Atomic transactions are not always needed.
• Is a mother task needed to control subtasks?