We will install VerdictDB (using PyVerdict), create a connection, and issue a simple query through VerdictDB. In this Quickstart Guide, we will use an MySQL database for VerdictDB’s backend database. See How to Connect for the examples of connecting to other databases.

For more details, please see this page (for Java) or this page (for Python).

Install Prerequisites

  1. Miniconda for Python 3.7: You can locally install miniconda by following the instructions on this page.
  2. Test Data (TPC-H 1G): Please follow the instructions on this page.

Install and Import

Install PyVerdict as follows. If you are using locally-installed miniconda, PyVerdict will also be locally installed.

pip install pyverdict --upgrade

Now, you can import PyVerdict as a regular module and check its version. Note that PyVerdict’s version number has no relationship with the version of core Java library.

import pyverdict
pyverdict.__version__              # prints pyverdict version
pyverdict.__verdictdb_version__    # prints the core VerdictDB version

verdict = pyverdict.mysql('localhost', 'root', 'password')    # make a connection
verdict.sql('show schemas')        # retrieves schemas

Run Queries

This examples assumes that the lineitem table (in the test data) has been created under the tpch1g schema.

# VerdictDB relies on a special table called scramble to speed up its queries.
verdict.sql('create scramble tpch1g.lineitem_x from tpch1g.lineitem')

# Automatically use tpch1g.lineitem_x to speed up
# 1 row(s) in the result (3.915 seconds)
#           c2
# 0  4291411.0
verdict.sql("select count(*) from tpch1g.lineitem where l_shipdate > '1994-01-02'")

To run the same query without any speedup, prepend bypass in front of the query.

# 1 row(s) in the result (57.561 seconds)
#    count(*)
# 0   4331220
verdict.sql("bypass select count(*) from tpch1g.lineitem where l_shipdate > '1994-01-02'")

VerdictDB (and pyverdict) also supports other aggregates, e.g., sum, avg, count(distinct col).

Note: When the same query is issued multiple times, some systems return answers immediately using cached results. If you want more accurate comparisons, simply change the query predicates slightly, e.g., ‘1994-01-03’ instead of ‘1994-01-02’.