Pogreb
Pogreb is an embedded key-value store for read-heavy workloads written in Go.
Key characteristics
- 100% Go.
 - Optimized for fast random lookups and infrequent bulk inserts.
 - Can store larger-than-memory data sets.
 - Low memory usage.
 - All DB methods are safe for concurrent use by multiple goroutines.
 
Installation
$ go get -u github.com/akrylysov/pogreb
Usage
Opening a database
To open or create a new database, use the pogreb.Open() function:
package main
import (
	"log"
	"github.com/akrylysov/pogreb"
)
func main() {
    db, err := pogreb.Open("pogreb.test", nil)
    if err != nil {
        log.Fatal(err)
        return
    }	
    defer db.Close()
}
Writing to a database
Use the DB.Put() function to insert a new key-value pair:
err := db.Put([]byte("testKey"), []byte("testValue"))
if err != nil {
	log.Fatal(err)
}
Reading from a database
To retrieve the inserted value, use the DB.Get() function:
val, err := db.Get([]byte("testKey"))
if err != nil {
	log.Fatal(err)
}
log.Printf("%s", val)
Iterating over items
To iterate over items, use ItemIterator returned by DB.Items():
it := db.Items()
for {
    key, val, err := it.Next()
    if err == pogreb.ErrIterationDone {
    	break
    }
    if err != nil { 
        log.Fatal(err)
    }
    log.Printf("%s %s", key, val)
}
Performance
The benchmarking code can be found in the pogreb-bench repository.
Results of read performance benchmark of pogreb, goleveldb, bolt and badgerdb
on DigitalOcean 8 CPUs / 16 GB RAM / 160 GB SSD + Ubuntu 16.04.3 (higher is better):