SQLite Forum

memory vs mmap
Hi Keith.

In my use case, only one copy of the database is needed by a single process, so sharing at that level doesn't help me.

But could you please elaborate on the comment about sharing a memory database across multiple processes using a ramdisk. A file on a ramdisk will have a particular name, and therefore it will be opened by that name, not :memory:.

And therefore the fastest way of accessing the ramdisk database is to use "pragma mmap", correct? All processes will point to that virtual memory address of that file on ramdisk which is already at a particular virtual address anyway.

If mmap() and xFetch() are being used anyway, surely there is only marginal benefit in moving the database from hard disk to ramdisk? For a process that is expected to run for maybe 30 minutes, accessing a 1.6 GB database. Alongside other processes doing the same thing to the exact same database, read-only.

Thanks. Paul.