Yeah, that's why they're supported in PostgreSQL, MySQL, Oracle, DB2, MSSQL, even SQLite... Multi-dimensional data isn't restricted to the world of GIS, and B-T

Yeah, that's why they're supported in PostgreSQL, MySQL, Oracle, DB2, MSSQL, even SQLite... Multi-dimensional data isn't restricted to the world of GIS, and B-Trees are not up to the task.