Read Concern

Definitions

1. A MongoDB setting that controls the consistency and isolation level of data returned by read operations. Read concern levels include "local" (returns the node's latest data, which may be rolled back), "majority" (returns only data acknowledged by a majority of replica set members), and "linearizable" (provides a single-copy guarantee with a real-time ordering of operations).

   In plain English: A MongoDB setting that controls how certain you want to be that the data you're reading won't change or disappear.

   Example: "We set read concern to 'majority' on the billing query so we never read a write that could get rolled back during a failover."

Related Terms

• CAP Theorem
• Saga
• Scatter-Gather
• Shared Nothing Architecture
• Split Brain
• TLA+
• Transactional Outbox
• Write Concern