tpch-pgsql

Implements the TPC-H benchmark for Postgres

Requirements

• The benchmark requires TPC-H dbgen:

wget -q https://github.com/electrum/tpch-dbgen/archive/32f1c1b92d1664dba542e927d23d86ffa57aa253.zip -O tpch-dbgen.zip
unzip -q tpch-dbgen.zip && mv tpch-dbgen-32f1c1b92d1664dba542e927d23d86ffa57aa253 tpch-dbgen && rm tpch-dbgen.zip

• gcc

gcc --version

• python3

python3 --version

• python requirements

pip3 install -r requirements.txt

• some running instance of Postgres, e.g. if running locally, the following command should not fail

pg_config --version

• if you want to run the database locally, please find below the commands for Ubuntu 14.04

sudo apt-get install -y postgresql postgresql-contrib

sudo -u postgres createuser tpch
sudo -u postgres createdb tpchdb

sudo -u postgres psql  << PSQL
ALTER USER tpch WITH ENCRYPTED PASSWORD '********';
GRANT ALL PRIVILEGES ON DATABASE tpchdb TO tpch;
\l
\q
PSQL

these can be adjusted for your OS easily.

In case you are using a remote PostgreSQL database, make sure your connection is working and you have a valid username and password.

$ psql -h <host> -p 5432 -d <database> -U <username> -W
Password for user tpch:
psql (9.3.23)
SSL connection (cipher: DHE-RSA-AES256-GCM-SHA384, bits: 256)
Type "help" for help.

tpchdb=> \q

Also make sure that you have full rights on the target database (GRANT ALL PRIVILEGES)

Usage

There is a single python file that implements all phases of the benchmark.

usage: tpch_pgsql.py [-h] [-H HOST] [-p PORT] [-U USERNAME] [-W [PASSWORD]]
                     [-d DBNAME] [-i DATA_DIR] [-q QUERY_ROOT] [-g DBGEN_DIR]
                     [-s SCALE] [-n NUM_STREAMS] [-b] [-r]
                     {prepare,load,query}

tpch_pgsql

positional arguments:
  {prepare,load,query}  Phase of TPC-H benchmark to run.

optional arguments:
  -h, --help            show this help message and exit
  -H HOST, --host HOST  Address of host on which PostgreSQL instance runs;
                        default is localhost
  -p PORT, --port PORT  Port on which PostgreSQL instance runs; default is
                        5432
  -U USERNAME, --username USERNAME
                        User for the PostgreSQL instance; default is postgres
  -W [PASSWORD], --password [PASSWORD]
                        Password for the PostgreSQL instance; default is
                        test123
  -d DBNAME, --dbname DBNAME
                        Name of the database; default is tpch
  -i DATA_DIR, --data-dir DATA_DIR
                        Directory for generated data; default is ./data
  -q QUERY_ROOT, --query-root QUERY_ROOT
                        Directory for query files; default is ./query_root
  -g DBGEN_DIR, --dbgen-dir DBGEN_DIR
                        Directory containing tpch dbgen source; default is
                        ./tpch-dbgen
  -s SCALE, --scale SCALE
                        Size of the data generated, scale factor; default is
                        1.0 = 1GB
  -n NUM_STREAMS, --num-streams NUM_STREAMS
                        Number of streams to run the throughput test with;
                        default is 0, i.e. based on scale factor SF
  -b, --verbose         Print more information to standard output
  -r, --read-only       Do not execute refresh functions during the query
                        phase, which allows for running it repeatedly

Phases

• prepare
  The prepare phase builds TPC-H dbgen and querygen and creates the load and refresh (update/delete) files.

• load
  The load phase cleans the database (if required), loads the tables into the database and creates indexes for querying. The results for this phase consist of the following metrics:

  • Schema creation time
  • Data loading time
  • Foreign key constraint and index creation time

• query
  The query phase is the actual performance test. Ir runs twice, with a reboot. Each run consists of two parts:

  • Power test: This consists of sequential execution of the refresh functions and the query streams. It reports back with the execution times for:
    • refresh function 1
    • query execution time for the 22 TPC-H queries
    • refresh function 2
  • Throughput test: This consists of parallel execution of the query streams and the pairs of refresh functions

TPC-H Process

The complete process for executing TPC-H tests is illustrated in the following figure:

Database Schema

Known Issues

• Sometimes the data generation phase fails due to file permission issues. In such a scenario delete the data directory and all generated .tbl files inside your tpch-dbgen directory.

References

• For notes on how to the TPC-H benchmark works see the paper iceis2012.
• For the TPC-H benchmark specification see this document.