How long charactors can stored in 'STRING' type?

Question

HI
I'm just curious how long charactors can stored in 'string' type.
and if there is limit number to store what kind of type is unlimited length type?
and is it possible send a parameter page to page with 'form'  'post' way unlimited length of string?
and is there any type of DB field which is save last number of records  automatically when one record is inserted like MANDT?
MANDT is client number though.
Regards.

Answer 1

Here is what ABAP key word documentation says about string
The elementary data type STRING is similar to data type C and refers to a variable-length string. Accordingly, the elementary data type XSTRING is similar to data type X and refers to a variable-length byte sequence.
In contrast to a C or X field, the length of a string is not static but variable and adjusts itself to the current field content at runtime. Dynamic memory management is used internally. Strings can have any length.
The initial value of a string is an empty string with length 0. A structure containing a string is seen as deep. A deep structure cannot be used like a C field. Strings can be displayed in the ABAP Debugger and used in the ABAP Dictionary.
It is not yet possible to use strings in screens or database tables. However, strings can be stored in database tables as clusters using EXPORT and transferred using IMPORT.
As far as I know the limit is 4 Giga Byte which equals more or less no limit. I donnot expect that you will meet this limit in practice. Its very likely that will run out of memory before you reach this limit.
In short there is no limit to the data stored in STRING var but the system memory has a limit....
This can be proved with the below program:
For the program system dumps with mess.
"Unable to fulfil request for 127683972 bytes of memory space. "
here's the test prog.:
TABLES ekko.
DATA testmax TYPE string.
DATA z(16) TYPE i.
SELECT * FROM ekko.
  CONCATENATE testmax ekko INTO testmax.
  z = strlen( testmax ).
  IF  z = 63841496.
    BREAK-POINT.
  ENDIF.
ENDSELECT.