AgateDB keep all files open, both SST files and VLog files. If the dataset is large and there are many files, most files may not will touch in a long time. In this scenario we may need a LRU list to maintain those most active files to keep the number of opened files under a specified limit.
Also, after we introduced block cache which used to keep the max memory usage of AgateDB under a limitation to prevent OOM issue, we need the LRU list to maintain those active data blocks.
AgateDB keep all files open, both SST files and VLog files. If the dataset is large and there are many files, most files may not will touch in a long time. In this scenario we may need a LRU list to maintain those most active files to keep the number of opened files under a specified limit.
Also, after we introduced block cache which used to keep the max memory usage of AgateDB under a limitation to prevent OOM issue, we need the LRU list to maintain those active data blocks.