Turn any key/value index into a high-performance two-dimensional spatial index



animated gif showing query zone and selected curve area

For the demo that this animated gif was generated from, see: https://git.sequentialread.com/forest/modular-spatial-index-demo-opengl

modular-spatial-index is a simple spatial index adapter for key/value databases like leveldb and Cassandra (or RDBMS like SQLite/Postgres if you want), based on https://github.com/google/hilbert.

It's called "modular" because it doesn't have any indexing logic inside, you bring your own index. It simply defines a mapping from two-dimensional space ([x,y] as integers) to 1-dimensional space (a single string of bytes for a point, or a handful of byte-ranges for a rectangle). You can use these strings of bytes (keys) and byte-ranges (query parameters) in any database to implement a spatial index.

Read amplification for range queries is ~2x-3x in terms of IOPS and bandwidth compared to a 1-dimensional query.

But that constant factor on top of your fast key/value database is a low price to pay for a whole new dimension, right? It's certainly better than the naive approach.

See https://sequentialread.com/building-a-spatial-index-supporting-range-query-using-space-filling-hilbert-curve for more information.

Implementation example

See writing keys and querying an area.

Note regarding sillyHilbertOptimizationOffset: The hilbert curve has some rough edges around the center of the curve plane at [0,0], so you will hit worse-case performance (about 3x slower than best case) around there. In my app I simply offset the universe a bit to avoid this.

If your database doesn't support arbitrary byte arrays as keys and values, you can simply convert the byte arrays to strings, as long as the sort order is preserved.



// This is the only way to create an instance of SpatialIndex2D. integerBits must be 32 or 64.
// To use the int size of whatever processor you happen to be running on, like what golang itself does 
// with the `int` type, you may simply pass in `bits.UintSize`.
NewSpatialIndex2D(integerBits int) (*SpatialIndex2D, error) { ... }


// returns the minimum and maximum values for x and y coordinates passed into the index.
// 64-bit SpatialIndex2D: -1073741823, 1073741823
// 32-bit SpatialIndex2D: -16383, 16383
(index *SpatialIndex2D) GetValidInputRange() (int, int) { ... }


// returns two byte slices of length 8, one representing the smallest key in the index
// and the other representing the largest possible key in the index
// returns (as hex) 0000000000000000, 4000000000000000
// 32-bit SpatialIndex2Ds always leave the last 4 bytes blank. 
(index *SpatialIndex2D) GetOutputRange() ([]byte, []byte) { ... }


// Returns a slice of 8 bytes which can be used as a key in a database index,
// to be spatial-range-queried by RectangleToIndexedRanges
(index *SpatialIndex2D) GetIndexedPoint(x int, y int) ([]byte, error) { ... }


// inverse of GetIndexedPoint. Return [x,y] position from an 8-byte spatial index key
(index *SpatialIndex2D) GetPositionFromIndexedPoint(indexedPoint []byte) (int, int, error) { ... }


// Returns a slice of 1 or more byte ranges (typically 1-4).
// The union of the results of database range queries over these ranges will contain AT LEAST
// all GetIndexedPoint(x,y) keys present within the rectangle defined by [x,y,width,height].
// The results will probably also contain records outside the rectangle, it's up to you to filter them out.
// iopsCostParam allows you to adjust a tradeoff between wasted I/O bandwidth and # of individual I/O operations.
// I think 1.0 is actually a very reasonable value to use for SSD & HDD
// (waste ~50% of bandwidth, save a lot of unneccessary I/O operations)
// if you have an extremely fast NVME SSD with a good driver, you might try 0.5 or 0.1, but I doubt it will make it any faster.
// 2 is probably way too much for any modern disk to benefit from, unless your data is VERY sparse
(index *SpatialIndex2D) RectangleToIndexedRanges(x, y, width, height int, iopsCostParam float32) ([]ByteRange, error) { ... }


// Use this with a range query on a database index.
type ByteRange struct {
	Start []byte
	End   []byte

MIT license

A mirror of some projects hosted on my git server.
Golang-key-value-store - Key Value Store API Service with Go DDD Architecture

This document specifies the tools used in the Key-Value store and reorganizes how to use them. In this created service, In-Memory Key-Value Service was created and how to use the API is specified in the HTML file in the folder named "doc"

Kemal Emre Ballı 2 Jul 31, 2022
Build a simple decomposed Key-Value store by implementing two services which communicate over gRPC.

Build a simple decomposed Key-Value store by implementing two services which communicate over gRPC.

Robert Otting 0 Feb 13, 2022
A key-value db api with multiple storage engines and key generation

Jet is a deadly-simple key-value api. The main goals of this project are : Making a simple KV tool for our other projects. Learn tests writing and git

null 12 Apr 5, 2022
An embedded key/value database for Go.

Bolt Bolt is a pure Go key/value store inspired by Howard Chu's LMDB project. The goal of the project is to provide a simple, fast, and reliable datab

BoltDB 13.1k Aug 8, 2022
A disk-backed key-value store.

What is diskv? Diskv (disk-vee) is a simple, persistent key-value store written in the Go language. It starts with an incredibly simple API for storin

Peter Bourgon 1.2k Aug 8, 2022
Distributed reliable key-value store for the most critical data of a distributed system

etcd Note: The master branch may be in an unstable or even broken state during development. Please use releases instead of the master branch in order

etcd-io 40.8k Aug 15, 2022
Distributed cache and in-memory key/value data store. It can be used both as an embedded Go library and as a language-independent service.

Olric Distributed cache and in-memory key/value data store. It can be used both as an embedded Go library and as a language-independent service. With

Burak Sezer 2.3k Aug 12, 2022
Simple, ordered, key-value persistence library for the Go Language

gkvlite gkvlite is a simple, ordered, ACID, key-value persistence library for Go. Overview gkvlite is a library that provides a simple key-value persi

Steve Yen 254 Aug 6, 2022
LevelDB key/value database in Go.

This is an implementation of the LevelDB key/value database in the Go programming language. Installation go get github.com/syndtr/goleveldb/leveldb R

Suryandaru Triandana 5.3k Aug 8, 2022
Distributed, fault-tolerant key-value storage written in go.

A simple, distributed, fault-tolerant key-value storage inspired by Redis. It uses Raft protocotol as consensus algorithm. It supports the following data structures: String, Bitmap, Map, List.

Igor German 360 Aug 4, 2022
a persistent real-time key-value store, with the same redis protocol with powerful features

a fast NoSQL DB, that uses the same RESP protocol and capable to store terabytes of data, also it integrates with your mobile/web apps to add real-time features, soon you can use it as a document store cause it should become a multi-model db. Redix is used in production, you can use it in your apps with no worries.

Mohammed Al Ashaal 1.1k Aug 7, 2022
Pogreb is an embedded key-value store for read-heavy workloads written in Go.

Embedded key-value store for read-heavy workloads written in Go

Artem Krylysov 914 Aug 2, 2022
HA LDAP based key/value solution for projects configuration storing with multi master replication support

Recon is the simple solution for storing configs of you application. There are no specified instruments, no specified data protocols. For the full power of Recon you only need curl.

Mikhail Panfilov 12 Jun 15, 2022
RocksDB/LevelDB inspired key-value database in Go

Pebble Nightly benchmarks Pebble is a LevelDB/RocksDB inspired key-value store focused on performance and internal usage by CockroachDB. Pebble inheri

CockroachDB 3k Aug 12, 2022
Key-value database stored in memory with option of persistence

Easy and intuitive command line tool allows you to spin up a database avaliable from web or locally in a few seconds. Server can be run over a custom TCP protocol or over HTTP.

Mario Petričko 6 Aug 1, 2022
Fault tolerant, sharded key value storage written in GoLang

Ravel is a sharded, fault-tolerant key-value store built using BadgerDB and hashicorp/raft. You can shard your data across multiple clusters with mult

Aditya Meharia 75 May 11, 2022
CrankDB is an ultra fast and very lightweight Key Value based Document Store.

CrankDB is a ultra fast, extreme lightweight Key Value based Document Store.

Shrey Batra 30 Apr 12, 2022
yakv is a simple, in-memory, concurrency-safe key-value store for hobbyists.

yakv (yak-v. (originally intended to be "yet-another-key-value store")) is a simple, in-memory, concurrency-safe key-value store for hobbyists. yakv provides persistence by appending transactions to a transaction log and restoring data from the transaction log on startup.

Aadhav Vignesh 5 Feb 24, 2022
Multithreaded key value pair store using thread safe locking mechanism allowing concurrent reads

Project Amnesia A Multi-threaded key-value pair store using thread safe locking mechanism allowing concurrent reads. Curious to Try it out?? Check out

Nikhil Nayak 6 Apr 7, 2022