Block contention


In database management systems, block contention refers to multiple processes or instances competing for access to the same index or data block at the same time. In general this can be caused by very frequent index or table scans, or frequent updates. Concurrent statement executions by two or more instances may also lead to contention, and subsequently busy waiting for the process without the lock.

Solutions

In most situations the goal is to spread queries over a greater number of blocks, to avoid concentrating on any single one.