Table Memory

Question

Can anyone tell me how do I calculate the internal database memory required per record of a given table?  A rough estimate would do.  I am thinking that adding up the memory required by each field can be construed as memory required by a single record.  Going further, the memory of each field can be determined by it's data type.  But how do I calculate how many bytes of memory is taken by a given data type?  Please help.  I will assign the points to helpful posts.  Thanks!

Answer 1

Hi Sameer,
Consider this sample code it gives approx single record length and table size based on the no of records.
Just copy the code and execute it , give any table name in the selection screen it will return you the details.
REPORT zes_sample.
*--Give any Table Name
PARAMETERS : tabname TYPE dd02l-tabname.
DATA:  prc_line_len TYPE i VALUE 0,
       lv_tablename TYPE string,
       lv_dref TYPE REF TO data,
       tlen   TYPE i VALUE 0,
       rsize(50),
       tsize(50).
lv_tablename = tabname.
*--Dynamically creating the Internal table
CREATE DATA lv_dref TYPE TABLE OF (lv_tablename).
FIELD-SYMBOLS: <fs> TYPE STANDARD TABLE,
               <f> TYPE ANY.
*--Assigning the dynamically created Internal table to Field Symbol
ASSIGN lv_dref->* TO <fs>.
*--Selecting single row for calculating the reord length
SELECT *
  FROM (tabname)
  INTO TABLE <fs> UP TO 1 ROWS.
*--Calculating the record length
READ TABLE <fs> ASSIGNING <f> INDEX 1.
DESCRIBE FIELD <f> LENGTH prc_line_len IN BYTE MODE.
*--Getting the No of records in the Table
SELECT COUNT( * ) FROM (tabname).
*--Calculating the Approx Table size
IF sy-subrc EQ 0.
  tlen =   prc_line_len * sy-dbcnt.
ENDIF.
tsize = tlen.
rsize =   prc_line_len .
WRITE : / 'Single Record Size : ' , rsize, 'Bytes'.
SKIP 2.
WRITE : / 'Approxiamte  size of table ' , tabname, 'with', sy-dbcnt, 'records is :',
       /  tsize, 'Bytes'.
Regards,
<b>AS</b>