Re: LMDB usage with long or variable length keys

On Wed, Apr 22, 2015 at 3:17 AM, Alex V. alex.v.odesk@gmail.com wrote:

For example file path or URL.

We in KDE[1] have been using LMDB for building a file indexer. In order to store file paths we have also used a sequence of keys since file paths are hierarchical.

* Every file has an id. This is a combination of the device id + inode number. * We map fileId -> (parentId fileName) * We map parentId -> list of sub-file ids

For (id -> file path), multiple lookups are required For (file Path -> id), we can just rely on the file system

This obviously only works for files which exist in the file system. Also with this folder renames are very cheap.