Is there any buffer for the disk-based column store?


Is there any in-memory buffer/cache for hot or recent data in the disk-based column store? How to check and set the size of this buffer?


We rely on the linux file system buffer cache to buffer recently-accessed columnstore data in memory. So you can use the free program and look at the cached column to see the size of the file cache.

Columnstores have an in-memory rowstore segment. Below a threshold, inserts write to this segment. Updates and deletes on small numbers of rows will move rows from disk to memory and perform the update there.

the rowstore segment periodically gets flushed to disk by the background flusher.

there’s an info schema table called columnar_segments that may be useful here