PostgresHarness¶

class qcfractal.PostgresHarness(config: Union[Dict[str, Any], qcfractal.config.FractalConfig], quiet: bool = True, logger: print = <built-in function print>)[source]¶

Bases: object

Methods Summary

`alembic_commands`()
`backup_database`([filename])
`command`(cmd[, check])	Runs psql commands and returns their output while connected to the correct postgres instance.
`connect`([database])	Builds a psycopg2 connection object.
`create_database`(database_name)	Creates a new database for the current postgres instance.
`create_tables`()	Create database tables using SQLAlchemy models
`database_size`()	Returns a pretty formatted string of the database size.
`database_uri`()	Provides the full PostgreSQL URI string.
`init_database`()
`initialize_postgres`()	Initializes and starts the current postgres instance.
`is_alive`([database])	Checks if the postgres is alive, and optionally if the database is present.
`logger`(msg)	Prints a logging message depending on quiet settings.
`pg_ctl`(cmds)	Runs pg_ctl commands and returns their output while connected to the correct postgres instance.
`restore_database`(filename)
`shutdown`()	Shutsdown the current postgres instance.
`start`()	Starts a PostgreSQL server based off the current configuration parameters.
`update_db_version`()	Update current version of QCFractal in the DB
`upgrade`()	Upgrade the database schema using the latest alembic revision.

Methods Documentation

alembic_commands() → List[str][source]¶

backup_database(filename: Optional[str] = None) → None[source]¶

command(cmd: str, check: bool = True) → Any[source]¶

Runs psql commands and returns their output while connected to the correct postgres instance.

Parameters: cmd (str) – A psql command string. Description

connect(database: Optional[str] = None) → Connection[source]¶

Builds a psycopg2 connection object.

Parameters: database (Optional[str], optional) – The database to connect to, otherwise defaults to None
Returns: A live Connection object.
Return type: Connection

create_database(database_name: str) → bool[source]¶

Creates a new database for the current postgres instance. If the database is existing, no changes to the database are made.

Parameters: database_name (str) – The name of the database to create.
Returns: If the operation was successful or not.
Return type: bool

create_tables()[source]¶: Create database tables using SQLAlchemy models

database_size() → str[source]¶: Returns a pretty formatted string of the database size.

database_uri() → str[source]¶

Provides the full PostgreSQL URI string.

Returns: The database URI
Return type: str

init_database() → None[source]¶

initialize_postgres() → None[source]¶: Initializes and starts the current postgres instance.

is_alive(database: Optional[str] = None) → bool[source]¶

Checks if the postgres is alive, and optionally if the database is present.

Parameters: database (Optional[str], optional) – The datbase to connect to
Returns: If True, the postgres database is alive.
Return type: bool

logger(msg: str) → None[source]¶

Prints a logging message depending on quiet settings.

Parameters: msg (str) – The message to show.

pg_ctl(cmds: List[str]) → Any[source]¶

Runs pg_ctl commands and returns their output while connected to the correct postgres instance.

Parameters: cmds (List[str]) – A list of PostgreSQL pg_ctl commands to run.

restore_database(filename) → None[source]¶

shutdown() → Any[source]¶: Shutsdown the current postgres instance.

start() → Any[source]¶: Starts a PostgreSQL server based off the current configuration parameters. The server must be initialized and the configured port open.

update_db_version()[source]¶: Update current version of QCFractal in the DB

upgrade()[source]¶: Upgrade the database schema using the latest alembic revision. The database data won’t be deleted.