$MachinePrecision gives the number of decimal digits of precision used for machine-precision numbers.
$OutputSizeLimit specifies the maximum size in bytes of expressions that will automatically be output in their entirety in a Mathematica notebook.
JDBC
(DatabaseLink Symbol) JDBC[arg, ...] is an object that holds parameters for making a JDBC connection to a database.
SQLBeginTransaction[conn] initiates an SQL transaction.
SQLCommitTransaction[conn] commits an SQL transaction.
SQLExpr[expr] allows a Mathematica expression to be stored in a database.
SQLSchemaInformation[conn] returns information about the schemas available through an SQL connection.
The raw SQL command DROP TABLE drops tables from a database. An alternative is to use the Mathematica command SQLDropTable, described in "Dropping Tables". If you find that ...
ShowJavaConsole[] displays the Java console window and begins capturing output sent to the Java System.out and System.err streams. ShowJavaConsole["stdout"] captures only ...
DoNETModeless[form] displays the specified .NET form in the foreground and then returns.