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Database

DatabaseConfig

Bases: PrettyModel

Source code in passengersim/config/database.py 
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class DatabaseConfig(PrettyModel, extra="forbid", validate_assignment=True):
    engine: Literal["sqlite", "mysql", None] = "sqlite"
    """Database engine to use.

    Currently only `sqlite` is fully implemented."""

    filename: pathlib.Path | None = "passengersim-output.sqlite"
    """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 = False
    """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 = 250
    """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",
        ]
    ] = {"leg_final", "fare_final", "demand_final", "bookings"}
    """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.
    """

    dcp_write_hooks: list[Callable] = []
    """Additional callable functions that write to the database at each DCP.

    Each should have a signature matching `f(db, sim, dcp)`.
    """

    @field_validator("engine", mode="before")
    def _interpret_none(cls, v):
        """Allow engine to be "none"."""
        if isinstance(v, str) and v.lower() == "none":
            v = None
        return v

    store_leg_bid_prices: bool = True
    """Should leg bid prices be stored in the database."""

    store_displacements: bool = True
    """Should leg displacements be stored in the database."""

commit_count_delay class-attribute instance-attribute 

commit_count_delay: int | None = 250

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.

dcp_write_hooks class-attribute instance-attribute 

dcp_write_hooks: list[Callable] = []

Additional callable functions that write to the database at each DCP.

Each should have a signature matching f(db, sim, dcp).

engine class-attribute instance-attribute 

engine: Literal['sqlite', 'mysql', None] = 'sqlite'

Database engine to use.

Currently only sqlite is fully implemented.

fast class-attribute instance-attribute 

fast: bool = False

Whether to use pre-compiled SQL write instructions.

filename class-attribute instance-attribute 

filename: Path | None = 'passengersim-output.sqlite'

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.

pragmas class-attribute instance-attribute 

pragmas: list[str] = []

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

store_displacements class-attribute instance-attribute 

store_displacements: bool = True

Should leg displacements be stored in the database.

store_leg_bid_prices class-attribute instance-attribute 

store_leg_bid_prices: bool = True

Should leg bid prices be stored in the database.

write_items class-attribute instance-attribute 

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",
    ]
] = {"leg_final", "fare_final", "demand_final", "bookings"}

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.