Tell the users what the default SQL DB backend is

vector/vectorintro.html

@@ -10,6 +10,17 @@ tied to a set of attribute layers stored in a database (road names,
 site ID, geologic type, etc.). As a general rule these can exist in 2D
 or 3D space and are independent of the GIS's computation region.
 
+<h3>Attribute management</h3>
+
+The default database driver used by GRASS GIS 7 is SQLite. GRASS GIS 
+handles multiattribute vector data by default. The <em>db.*</em> set of
+commands  provides basic SQL support for attribute management, while the
+<em>v.db.*</em> set of commands operates on vector maps.
+
+<p>
+Note: The list of available database drivers can vary in various binary
+distributions of GRASS GIS, for details see
+<a href="sql.html">SQL support in GRASS GIS</a>.
 
 <h3>Vector data import and export</h3>
 
@@ -199,10 +210,12 @@ default. Using <em>layer=-1</em> one can access all layers.
 </li>
 
 <li><b>SQL support</b><br>
-The DBF driver provides only very limited SQL support (as DBF is not an
-SQL DB) while the other DBMS backends (such as SQLite, PostgreSQL, MySQL
-etc) provide full SQL support since the SQL commands are sent directly
-to the DBMI. SQL commands can be directly executed with
+By default, SQLite is used as the attribute database. Also other
+supported DBMS backends (such as SQLite, PostgreSQL, MySQL etc.)
+provide full SQL support as the SQL statements are sent directly
+to GRASS' database management interface (DBMI). Only the DBF driver
+provides just very limited SQL support (as DBF is not an SQL DB).
+SQL commands can be directly executed with
 <a href="db.execute.html">db.execute</a>,
 <a href="db.select.html">db.select</a> and the other db.* modules.
 </li>