A fast key value storage application using B+ tree indexing in nodejs.

DB containing 130,000,000 records (~10 GB)

• Index loaded in 0.432 sec
• Single read operation 0.001 sec
• Single write operation 0.003 sec

The data is organized in increasing order of the keys, with each single data file containing 1000 records. Names of the files and the first key value that it contains, are stored as index values in the file index.txt. The key of last record with last created file are stored in metadata.txt, to keep track of auto increment value.

The values contained in index.txt are loaded when a new instance of KeyStore is created. These indices are organized as a B+ tree with leaf nodes containing filenames and keys from the index.txt. For a given key, the application searches the tree for the filename in the key-filename pair such that the desired record is present in that file. Once the filename is obtained, the file consisting of 1000 records is loaded in memory and target key is searched for. Similarly for insertion, filename is obtained from B+ tree and desired key-value pair are inserted in the file. The B+ tree has an order of 101, so it can hold large number of records within few levels.