An ABAP question about memory leak and object instances

[TMNielsen]

Hi

I trying to use SAP ADBC to connect to an external database. So I read documentation and see some warnings about the risk of memory leak. 
Usually when I write ABAP programs I more or less rely on the standard garbage collection that frees memory when a program is exit'et.

However if I have a program that is not really exiting for a longer period and the user can repeatedly call a method that creates object instances I guess it would be a good idea to free this instances when they are no longer in use.

The ADBC documentation contains some programming examples and they contains code I doesn't know how works memory wise.

NEW cl_sql_statement( con_ref = con_ref )->execute_ddl( create_string ).

As I understands this compact syntax an object instance of cl_sql_statement is created and the method execute_dll is executed.

But when is the instance of cl_sql_statement freed again. The instance doesn't have a name, so I have no handle I can use in a free command.

[Sandra_Rossi]

DATA(instance) = NEW cl_sql_statement( con_ref = con_ref ).
instance->execute_ddl( create_string ).
FREE instance.

[TMNielsen]

Hi Sandra

Yes I understand the syntax you suggest, but I was just wondering how garbage collection takes place in the example from SAP standard documentation:

NEW cl_sql_statement( con_ref = con_ref )->execute_ddl( create_string ).

I think the syntax suggested by SAP is bad because the object (and memory) can't be free'ed again, but maybe I'm wrong. That is what I would like to know.

[Sandra_Rossi]

You should first make sure that there is a problem in garbage collection. If in doubt, run the garbage collector from time to time, it will free automatically the memory. If the reference of NEW is not stored in a variable, it means that it can be freed by the garbage collector.