DatabaseConfig¶

class passengersim.config.DatabaseConfig[source]¶

Bases: PrettyModel

Attributes:

engine	Database engine to use.
filename	Name of file for SQLite output.
fast	Whether to use pre-compiled SQL write instructions.
pragmas	A list of PRAGMA commands to execute upon opening a database connection.
commit_count_delay	Commit transactions to the database will only be honored this frequently.
write_items	Which items should be written to the database.
store_leg_bid_prices	Should leg bid prices be stored in the database.
store_displacements	Should leg displacements be stored in the database.

engine : Literal['sqlite', None]¶

Database engine to use.

Currently only sqlite is fully implemented.

filename : Path | None¶

Name of file for SQLite output.

When using the sqlite engine, an in-memory database can be created by setting this to ‘:memory:’. Note that in-memory databases are not persistent and will be lost when the database connection is closed. Also, in-memory databases cannot be shared between multiple processes. When using multiprocessing, all database operations must be performed in the same process that created the database connection. Be sure to run summary queries before closing the database connection, by identifying all database summary tables in the outputs.reports configuration option.

fast : bool¶

Whether to use pre-compiled SQL write instructions.

pragmas : list[str]¶

A list of PRAGMA commands to execute upon opening a database connection.

commit_count_delay : int | None¶

Commit transactions to the database will only be honored this frequently.

By setting this number greater than 1, the transaction frequency will be reduced, improving overall runtime performance by storing more data in RAM and writing to persistent storage less frequently.

write_items : set[Literal['leg', 'bucket', 'edgar', 'fare', 'demand', 'leg_daily', 'leg_final', 'bucket_final', 'fare_final', 'demand_final', 'bookings', 'pathclass', 'pathclass_daily', 'pathclass_final']]¶

Which items should be written to the database.

The following values can be provided in this set:

• leg: write every leg to the leg_detail table at every DCP.

• leg_final: write every leg to the leg_detail table only at DCP 0.

• bucket: write every leg bucket to the leg_bucket_detail table at every DCP.

• bucket_final: write every leg bucket to the leg_bucket_detail table only

  at DCP 0.

• fare: write every fare to the fare_detail table at every DCP.

• fare_final: write every fare to the fare_detail table only at DCP 0.

• demand: write every demand to the demand_detail table at every DCP.

• bookings: store booking summary data at every DCP and write an aggregate

  summary of bookings by DCP to the bookings_by_timeframe table at the end of the simulation.

store_leg_bid_prices : bool¶

Should leg bid prices be stored in the database.

store_displacements : bool¶

Should leg displacements be stored in the database.