Package: volttron-postgresql-historian
VOLTTRON historian agent that stores data into a PostgreSQL databaseInstallation notesThe PostgreSQL database driver supports recent PostgreSQL versions.
It was tested on 10.x, but should work with 9.x and 11.x.The user must have SELECT, INSERT, and UPDATE privileges on
historian tables.The tables in the database are created as part of the execution of
the SQLHistorianAgent, but this will fail if the database user does
not have CREATE privileges.Care must be exercised when using multiple historians with the same
database. This configuration may be used only if there is no overlap
in the topics handled by each instance. Otherwise, duplicate topic
IDs may be created, producing strange results.ConfigurationPostgreSQL historian supports two configuration parametersconnection -  This is a mandatory parameter with type indicating the type of sql historian (i.e. postgresql) and params containing the database access detailstables_def - Optional parameter to provide custom table names for topics, data, and metadata.The configuration can be in a json or yaml formatted file. The following examples show minimal connection
configurations for a psycopg2-based historian. Other options are available and aredocumented hereNot all parameters have been tested,  use at your own risk.Local PostgreSQL DatabaseThe following snippet demonstrates how to configure the historian to use a PostgreSQL database on the local system that
is configured to use Unix domain sockets. The user executing volttron must have appropriate privileges.Yaml Format:connection:# type should be postgresqltype:postgresqlparams:# Relative to the agents data directorydbname:"volttron"tables_def:# prefix for data, topics, and (in version < 4.0.0 metadata tables)# default is ""table_prefix:""# table name for time series data. default "data"data_table:data# table name for list of topics. default "topics"topics_table:topicsJSON format:{"connection":{"type":"postgresql","params":{"dbname":"volttron"}}}Remote PostgreSQL DatabaseThe following snippet demonstrates how to configure the historian to use a remote PostgreSQL database.{"connection":{"type":"postgresql","params":{"dbname":"volttron","host":"historian.example.com","port":5432,"user":"volttron","password":"secret"}}}TimescaleDB SupportBoth of the above PostgreSQL connection types can make use of TimescaleDB's high performance Hypertable backend for
the primary timeseries table. The agent assumes you have completed the TimescaleDB installation and setup the
database by following the instructions here:https://docs.timescale.com/latest/getting-started/setupTo use, simply
add 'timescale_dialect: true' to the connection params in the agent config as below{"connection":{"type":"postgresql","params":{"dbname":"volttron","host":"historian.example.com","port":5432,"user":"volttron","password":"secret","timescale_dialect":true}}}RequirementsPython >= 3.10psycopg2 libraryInstallationCreate and activate a virtual environment.python-mvenvenvsourceenv/bin/activateInstalling volttron-postgresql-historian requires a running volttron instance and the psycopg2 librarypipinstallvolttron
pipinstallpsycopg2-binary# Start platform with output going to volttron.logvolttron-vv-lvolttron.log&Setup databaseIf this is not a development environment we highly recommend that you create the database and database tables using
a user with appropriate permissions. This way the database user used by the historian need not have CREATE privileges
Postgres historian expects two tables
a. A topics tables that stores the list of unique topics and its metadata. The default name is "topics". If you use
a different name please specify it as part of "tables_def" configuration parameter in agent config. Seeexample configurationb. A data table that stores the timeseries data and refers to the topic table using a topic id. The default name is
"data". If you use a different name please specify it as part of "tables_def" configuration parameter in
agent config. Seeexample configurationBelow are the sql statements to create database and tables
Create DatabaseCREATE DATABASE volttronTOPICS tables:CREATE TABLE IF NOT EXISTS topics (
        topic_id SERIAL PRIMARY KEY NOT NULL, 
        topic_name VARCHAR(512) NOT NULL, 
        metadata TEXT, 
        UNIQUE (topic_name)
   )DATA table:CREATE TABLE IF NOT EXISTS data (
       ts TIMESTAMP NOT NULL, 
       topic_id INTEGER NOT NULL, 
       value_string TEXT NOT NULL, 
       UNIQUE (topic_id, ts)
   )Optional timescale hypertableSELECT create_hypertable(data, 'ts', if_not_exists => true)Create index to speed up data access
If using hypertables:CREATE INDEX IF NOT EXISTS idx_data ON data (topic_id, ts)If not using hypertables:CREATE INDEX IF NOT EXISTS idx_data ON data (ts ASC)Provide correct user permissions for database user to be used by historian agentCREATE USER <some username> with encrypted password <some password>
    GRANT SELECT, INSERT, UPDATE on database <historian db name> to <username used above>NOTEFor development environments, you can create a test database and test user, grant all privileges on that test
database to the test user and let the historian create tables and indexes at startup. We do not recommend this for
production environmentsCreate an agent configuration fileCreate an agent configuration with appropriate connection parameters as described in theConfigurations sectionInstall and start the volttron-postgresql-historian.vctlinstallvolttron-postgresql-historian--agent-config<pathtoconfiguration>--startView the status of the installed agentvctlstatusDevelopmentPlease see the following for contributing guidelinescontributing.Please see the following helpful guide aboutdeveloping modular VOLTTRON agentsDisclaimer NoticeThis material was prepared as an account of work sponsored by an agency of the
United States Government.  Neither the United States Government nor the United
States Department of Energy, nor Battelle, nor any of their employees, nor any
jurisdiction or organization that has cooperated in the development of these
materials, makes any warranty, express or implied, or assumes any legal
liability or responsibility for the accuracy, completeness, or usefulness or any
information, apparatus, product, software, or process disclosed, or represents
that its use would not infringe privately owned rights.Reference herein to any specific commercial product, process, or service by
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constitute or imply its endorsement, recommendation, or favoring by the United
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