Events That Prompt Flushing of Buffer-Pool Buffers

Flushing of the buffers is initiated by any one of the following three conditions:

• The number of buffers in an MLRU queue reaches the number specified by LRU_MAX_DIRTY. (See Flushing the Shared-Memory Pool Buffer.)
• The page-cleaner threads cannot keep up. In other words, a user thread needs to acquire a buffer, but no unmodified buffers are available.
• The database server needs to execute a checkpoint. (See Checkpoints.)