What will happen at runtime when accessing a buffered table?

When accessing a buffered table, it is essential to discern how the buffer interacts with the underlying database structure and operational processes. The assertion that if data is read from the table buffer, the existing indexes are not used is accurate because buffered data is fetched directly from the buffer in memory, bypassing the need to consult the underlying indexes.

When a SELECT statement targets a buffered table, and the required data is found in the buffer, the system retrieves it from memory rather than searching through the indexes first. This process enhances performance by reducing the number of accesses to the database storage, leading to faster data retrieval. The buffer primarily serves as a cache that holds frequently accessed records, allowing quick access without recalculating indexes.

Independent of this, when an update occurs on a record that is buffered, the change is reflected in the buffer for the sessions that are current at that time, but it does not automatically propagate to all system table buffers immediately. Only the relevant instance where the change is made is impacted, not all buffers across the system. This means that other sessions may still see the old data until they refresh their view or the buffer is flushed.

Additionally, using indexes during queries that involve buffered data does not directly populate the buffer. The presence of index usage