> the DB has information on access patterns and table format that the OS is not aware of
Aren't system calls such as madvise supposed to allow user space to let the kernel know precisely that information?
Aren't system calls such as madvise supposed to allow user space to let the kernel know precisely that information?
A user space buffer pool gives you precise and deterministic control of many of these behaviors.
In this case, there is the issue of who is the you on question
For the database in isolation, maybe not ideal
For a system whre db and app run on the same machine? The OS can make sure you are on friendly terms and not fighting
Same for trying to SSH to a bust server and the OS can balance things out
Madvise is discussed in the paper, and it notes specifically that:
* madvise is not precise
* madvise is... an advice, which the system is completely free to disregard
* madvise is error-prone, providing the wrong hint can have dire consequences