What is Lazy Writer Process

The job of the lazy writer is to find dirty pages in the buffer pool and write them out to disk and drop those pages from cache.

It does this to keep a certain amount of free pages available within the buffer pool for data that may be requested by other queries. The pages that it writes out are ‘older’ pages, ones that haven’t been used for a while.

If there’s lots of available buffers, the lazy writer will be doing relatively little work and the number of pages written to disk will be quite low. If the lazy writer’s consistently writing lots of data, it may indicate that there’s a memory bottleneck.