File backed "dicts"

leveldb_result

$ time python leveldb_test.py

real	0m0.153s
user	0m0.040s
sys	0m0.010s

leveldb_test.py

import leveldb

key = '1234567789'
db = leveldb.LevelDB('./db')
for i in range(1, 50000):
    try:
        db.Get(key)
    except KeyError:
        db.Put(key, '')

sqlite_raw_results

$ time python sqlite_raw_test.py

real	0m1.817s
user	0m1.000s
sys	0m0.810s

sqlite_raw_test.py

import sqlite3

key = '1234567789'
conn = sqlite3.connect('/tmp/sqlite.db', isolation_level=None, check_same_thread=False)
conn.execute('PRAGMA journal_mode = OFF')
MAKE_TABLE = 'CREATE TABLE IF NOT EXISTS t (key TEXT PRIMARY KEY)'
conn.execute(MAKE_TABLE)
conn.commit()

cur = conn.cursor()
for i in range(1, 50000):
    HAS_ITEM = 'SELECT 1 FROM t WHERE key = ?'
    conn.execute(HAS_ITEM, (key,))
    selected = cur.fetchone()
    if selected is None:
        ADD_ITEM = 'REPLACE INTO t (key) VALUES (?)'
        conn.execute(ADD_ITEM, (key,))

sqlitedict_results

$ time python sqlitedict_test.py

real	0m9.525s
user	0m9.150s
sys	0m3.550s

sqlitedict_test.py

from sqlitedict import SqliteDict

d = SqliteDict("/tmp/sqlite.db", flag='n', autocommit = True)
key = '1234567789'
for i in range(1, 50000):
    if key not in d:
        d['key'] = ''