add data extractor
diff --git a/data_extractor.py b/data_extractor.py
new file mode 100644
index 0000000..d4e6ed1
--- /dev/null
+++ b/data_extractor.py
@@ -0,0 +1,116 @@
+import sys
+import json
+import sqlite3
+import contextlib
+
+
+def connect(url):
+    return sqlite3.connect(url)
+
+
+create_db_sql_templ = """
+CREATE TABLE build (id integer primary key,
+                    build text,
+                    type text,
+                    md5 text);
+
+CREATE TABLE params_combination (id integer primary key, {params});
+
+CREATE TABLE result (build_id integer,
+                     params_combination integer,
+                     bandwith float,
+                     deviation float);
+"""
+
+
+PARAM_COUNT = 20
+
+
+def get_all_tables(conn):
+    cursor = conn.cursor()
+    cursor.execute("SELECT name FROM sqlite_master WHERE type='table';")
+    return cursor.fetchall()
+
+
+def drop_database(conn):
+    cursor = conn.cursor()
+    cursor.execute("drop table result")
+    cursor.execute("drop table params_combination")
+    cursor.execute("drop table build")
+
+
+def init_database(conn):
+    cursor = conn.cursor()
+
+    params = ["param_{0} text".format(i) for i in range(PARAM_COUNT)]
+    create_db_sql = create_db_sql_templ.format(params=",".join(params))
+
+    for sql in create_db_sql.split(";"):
+        cursor.execute(sql)
+
+
+def insert_build(cursor, build_id, build_type, iso_md5):
+    cursor.execute("insert into build (build, type, md5) values (?, ?, ?)",
+                   (build_id, build_type, iso_md5))
+    return cursor.lastrowid
+
+
+def insert_params(cursor, *param_vals):
+    param_vals = param_vals + ("",) * (PARAM_COUNT - len(param_vals))
+
+    params = ",".join(['?'] * PARAM_COUNT)
+    select_templ = "select id from params_combination where {params_where}"
+
+    params_where = ["param_{0}=?".format(i) for i in range(PARAM_COUNT)]
+    req = select_templ.format(params_where=" AND ".join(params_where))
+    cursor.execute(req, param_vals)
+    res = cursor.fetchall()
+    if [] != res:
+        return res[0][0]
+
+    params = ",".join(['?'] * PARAM_COUNT)
+    param_insert_templ = "insert into params_combination ({0}) values ({1})"
+    param_names = ",".join("param_{0}".format(i) for i in range(PARAM_COUNT))
+    req = param_insert_templ.format(param_names, params)
+    cursor.execute(req, param_vals)
+    return cursor.lastrowid
+
+
+def insert_results(cursor, build_id, params_id, bw, dev):
+    req = "insert into result values (?, ?, ?, ?)"
+    cursor.execute(req, (build_id, params_id, bw, dev))
+
+
+@contextlib.contextmanager
+def transaction(conn):
+    try:
+        cursor = conn.cursor()
+        yield cursor
+    except:
+        conn.rollback()
+        raise
+    else:
+        conn.commit()
+
+
+def json_to_db(json_data, conn):
+    data = json.loads(json_data)
+    with transaction(conn) as cursor:
+        for build_data in data:
+            build_id = insert_build(cursor,
+                                    build_data.pop("build_id"),
+                                    build_data.pop("type"),
+                                    build_data.pop("iso_md5"))
+
+            for params, (bw, dev) in build_data.items():
+                param_id = insert_params(cursor, *params.split(" "))
+                insert_results(cursor, build_id, param_id, bw, dev)
+
+
+conn = sqlite3.connect(sys.argv[1])
+json_data = open(sys.argv[2]).read()
+
+if len(get_all_tables(conn)) == 0:
+    init_database(conn)
+
+json_to_db(json_data, conn)