> I am curious what the situation is where the recovery log grows to large size
From the link, "if a writer writes to the database while a checkpoint is ongoing [...] it does mean that the wal file may grow indefinitely if the checkpointer never gets a chance to finish without a writer appending to the wal file. There are also circumstances in which long-running readers may prevent a checkpointer from checkpointing the entire wal file - also causing the wal file to grow indefinitely in a busy system."
From the link, "if a writer writes to the database while a checkpoint is ongoing [...] it does mean that the wal file may grow indefinitely if the checkpointer never gets a chance to finish without a writer appending to the wal file. There are also circumstances in which long-running readers may prevent a checkpointer from checkpointing the entire wal file - also causing the wal file to grow indefinitely in a busy system."