The InfluxDB 3 Last Value Cache (LVC) is a powerful tool that allows users to cache the most recent values for specific fields in a table, improving the performance of queries that return the most recent value of a field or the last N values of a field. The LVC stores data in memory and can provide query responses in under 10ms, simplifying common query types such as retrieving the latest reported values for specific fields. The LVC is associated with a table and has its own unique name, key columns, value columns, and count. It's essential to balance the size of the LVCs with the amount of memory required to maintain them, considering factors like high cardinality key columns and value counts. When using the LVC, users can query data from it using SQL queries, excluding the `last_cache()` function in InfluxQL. The cache is flushed when the server stops, and new values are written only when data is updated.