mobilitydb_datagen

Overview

Pigsty 1.3.1 bundles MobilityDB DataGen; upgrading from 1.2 to 1.3 requires upstream backup/restore.

Version

Build

You can build the RPM / DEB packages for mobilitydb using pig build:

pig build pkg mobilitydb         # build RPM / DEB packages

Install

You can install mobilitydb directly. First, make sure the PGDG and PIGSTY repositories are added and enabled:

pig repo add pgsql -u          # Add repo and update cache

Install the extension using pig or apt/yum/dnf:

pig install mobilitydb;          # Install for current active PG version

pig ext install -y mobilitydb -v 18  # PG 18
pig ext install -y mobilitydb -v 17  # PG 17
pig ext install -y mobilitydb -v 16  # PG 16
pig ext install -y mobilitydb -v 15  # PG 15
pig ext install -y mobilitydb -v 14  # PG 14

dnf install -y mobilitydb_18       # PG 18
dnf install -y mobilitydb_17       # PG 17
dnf install -y mobilitydb_16       # PG 16
dnf install -y mobilitydb_15       # PG 15
dnf install -y mobilitydb_14       # PG 14

apt install -y postgresql-18-mobilitydb   # PG 18
apt install -y postgresql-17-mobilitydb   # PG 17
apt install -y postgresql-16-mobilitydb   # PG 16
apt install -y postgresql-15-mobilitydb   # PG 15
apt install -y postgresql-14-mobilitydb   # PG 14

Create Extension:

CREATE EXTENSION mobilitydb_datagen CASCADE;  -- requires: mobilitydb

Usage

Sources:

• Version 1.3.1 data-generator manual
• Extension control file
• Temporal generators
• Temporal point generators

mobilitydb_datagen 1.3.1 provides PL/pgSQL functions for generating synthetic PostgreSQL, PostGIS, and MobilityDB values. It is mainly useful for regression data, demos, and benchmark fixtures that need random temporal values or trajectories.

-- After the main MobilityDB extension is loaded:
CREATE EXTENSION mobilitydb_datagen;

Generating Random Temporal Values

-- A random temporal float sequence.
SELECT random_tfloat_seq(
    -100.0, 100.0,                                  -- value bounds
    '2025-06-01 00:00+00', '2025-06-02 00:00+00',  -- time bounds
    10.0,                                           -- max value delta
    10,                                             -- max minutes between instants
    5, 10                                           -- min/max instants
);

-- Step interpolation instead of the default linear interpolation.
SELECT random_tfloat_seq(
    -100.0, 100.0,
    '2025-06-01 00:00+00', '2025-06-02 00:00+00',
    10.0, 10, 5, 10,
    false
);

-- A random temporal geometry point sequence.
SELECT asEWKT(
    random_tgeompoint_contseq(
        2.20, 2.50, 48.80, 48.95,                  -- x/y bounds
        '2025-06-01 08:00+00', '2025-06-01 18:00+00',
        0.02, 5, 20, 40,                           -- max delta, max minutes, min/max instants
        srid => 4326
    )
);

Other confirmed generator families include scalar helpers such as random_bool, random_int, random_float, random_text, and random_timestamptz; array, set, span, and range helpers; temporal helpers such as random_tbool_inst, random_tint_discseq, random_tfloat_seq, and random_tfloat_seqset; and spatial/temporal-point helpers such as random_geom_point, random_geom_linestring, random_tgeompoint_contseq, random_tgeompoint_seqset, random_tgeogpoint_contseq, and random_tgeogpoint_seqset.

Generating Test Datasets

Create bulk test data for benchmarking trip queries:

CREATE TABLE trip_samples AS
SELECT
    vehicle_id,
    random_tgeompoint_contseq(
        2.20, 2.50, 48.80, 48.95,
        '2025-06-01 08:00+00', '2025-06-01 18:00+00',
        0.02, 5, 20, 40,
        srid => 4326
    ) AS trip
FROM generate_series(1, 1000) AS vehicle_id;

Caveats

• The control file requires the main mobilitydb extension; mobilitydb_datagen is not standalone.
• The generator is distributed with mobilitydb version 1.3.1. Keep the dependency and generator files aligned; build flags and package availability determine which optional type families are present.
• Upstream docs intentionally omit detailed parameter lists for many generator functions and point users to the SQL source files for exact signatures.

The generator functions create synthetic values, not reproducible application datasets by default. Set a deliberate random seed when comparing runs, and review bounds, time zones, interpolation, and SRID for the workload.