Are they any decent on-disk implementations of Java's Map?

Question

I\'m looking for an on-disk implementation of java.util.Map. Nothing too fancy, just something that I can point at a directory or file and have it store its co

Answer 1

You could have a look at the Disk-Backed-map project.

A library that implements a disk backed map in Java

A small library that provide a disk backed map implementation for storing large number of key value pairs. The map implementations (HashMap, HashTable) max out around 3-4Million keys/GB of memory for very simple key/value pairs and in most cases the limit is much lower. DiskBacked map on the other hand can store betweeen 16Million (64bit JVM) to 20Million(32bit JVM) keys/GB, regardless the size of the key/value pairs.