mobilitydb

Multi-Entry Search Trees for MobilityDB

This directory contains an implementation of Multi-Entry Search Trees for MobilityDB data types.

Dependencies

• PostgreSQL 17 or 18
• MobilityDB 1.4
• MEOS 1.4
• MEST

The extension compiles against the MEOS headers that a MobilityDB installation provides, and those headers include <json-c/json.h>, so the json-c development files must be on the include path as well.

The following setting in postgresql.conf names the installed PostGIS and MobilityDB libraries, here PostGIS 3 and MobilityDB 1.4:

shared_preload_libraries = 'postgis-3,libMobilityDB-1.4'

Installation

Compiling and installing the extension

make PG_CONFIG=path_to_postgresql_installation/bin/pg_config
sudo make PG_CONFIG=path_to_postgresql_installation/bin/pg_config install

You may omit the PG_CONFIG overrides if running pg_config in your shell locates the correct PostgreSQL installation.

Enabling the mobilitydb_mest extension

CREATE EXTENSION mobilitydb_mest CASCADE;

Create a Multi-Entry R-Tree on the tstzspanset column from the table tbl_tstzspanset(id int, t tstzspanset)

CREATE INDEX tbl_tstzspanset_mrtree_idx ON tbl_tstzspanset USING MGIST(t);

Create a Multi-Entry Quadtree on the tgeompoint column trip from the table trips(id int, trip tgeompoint)

CREATE INDEX trips_trip_mquadtree_idx ON trips USING MSPGIST(trip);

The operator classes have optional parameters that set the maximum number of “boxes” stored in the index. These parameters control the size of the resulting index.

Create a Multi-Entry R-Tree on the tstzspanset column from the table tbl_tstzspanset(id int, t tstzspanset) specifying a maximum number of spans per row.

CREATE INDEX tbl_tstzspanset_mrtree_opts_idx ON tbl_tstzspanset 
  USING MGIST(t tstzspanset_mrtree_equisplit_ops (num_spans = 3));

Create a Multi-Entry Quadtree on the tgeompoint column from the table tbl_tgeompoint(id int, temp tgeompoint) specifying a maximum number of boxes per row.

CREATE INDEX tbl_tgeompoint_mquadtree_opts_idx ON tbl_tgeompoint
  USING MSPGIST(temp tgeompoint_mquadtree_equisplit_ops (num_boxes = 3));

Contact: Maxime Schoemans maxime.schoemans@ulb.be