With spatial extensions, relational databases can support storing geometry data in database tables and also perform some geospatial functions. These are typically not part of standard installation but can be enabled through administration settings or by installing software extensions.

For open source Relational Database Management Systems (RDBMS), PostgreSQL, and MySQL both support spatial functionality. PostgreSQL is the by far most popular and is most fully functional. When the spatial components are enabled for PostgreSQL, it is commonly referred to as PostGIS. You will see the terms used interchangeably. PostgreSQL is a supported RDS option on AWS. The spatial extensions can be enabled, turning it into PostGIS.

For closed source RDBMS, Oracle (Spatial and Graph), and SQL Server are popular. Oracle is generally considered as the most capable one. These are not the only options as more and more databases are supporting spatial data. Amazon Aurora, a MySQL-compatible managed RDS database on AWS, has recently added spatial support.