Here are some basic techniques a developer should follow in order to help manage memory usage in 4D:

• use CLEAR VARIABLE when done using a variable
  
• use CLEAR SET when done using a set
  
• use CLEAR NAMED SELECTION when done using a named selection
  
• use CLEAR LIST when done using a list
  
• resize your BLOBs to 0 with SET BLOB SIZE when done using the BLOB or use CLEAR VARIABLE
  
• resize your arrays to 0 when done using the array or use CLEAR VARIABLE
  
• don't forget to close any open XML trees such as XML, DOM, SVG, etc (DOM CLOSE XML, SVG_CLEAR)
  
• if using ODBC always remember to free the connection using ODBC_SQLFreeConnect
  
• make sure to cleanup any offscreen areas used