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unique-constraintvoltdb

Does VoltDB support unique indexes?

Our schema has a USER table...

USER( 
   userId,
   firstname,
   lastname,
   email)

and we want to ensure all user's have unique email addresses. Is it possible to create a unique index in VoltDB to enforce this constraint?

Solution

  • VoltDB supports primary key indexes (which are always unique) as well as secondary indexes that can be defined as unique.

    For your particular table you have two choices to enforce uniqueness on the email column:

    1. Define the USER table as replicated.
    2. Partition the USER table on the email column.

    If you create a unique index on email and partition the table on userId then the uniqueness enforcement of the email column will be within individual partitions.