5092309e_SQL_Statements__Description
[Parameter] [Owner.]TableName [CorrelationName] [Description] 
[Owner.]TableName identifies the table to be updated. CorrelationName specifies an alias for the table and must conform to the syntax rules for a basic name according to "Basic names". When accessing columns of that table elsewhere in the UPDATE statement, use the correlation name instead of the actual table name. The scope of the correlation name is the SQL statement in which it is used. All correlation names within one statement must be unique.
SQL Statements