topic Re: Internal Table ???? in Application Development and Automation Discussions

Internal Table ????

Former Member — Fri, 22 Dec 2006 06:27:14 GMT

Hi Experts,

While creating an internal table, we mention occurs 0 or occurs 1. what is the difference between occurs 0 and occurs 1. which is better?what happens if we give occurs 0?

Thanks in acvance,

Ramana

Re: Internal Table ????

Former Member — Fri, 22 Dec 2006 06:30:01 GMT

The number 0 or 1 is a indicator to the system about the approximate number of rows that will be appended to the internal table.

It really doesn't matter much whether you give 0 or 1.

With the latest syntax, the OCCURS clause has been removed.

Regards,

Ravi

Note - Please mark all the helpful answers

Re: Internal Table ????

Former Member — Fri, 22 Dec 2006 06:32:19 GMT

Hello Venkata,

When u declare an internal table as occurs 1 it allocates a memory exactly as req by 1 record and with addition of any new entries it gets extended. However when u declare as 0 memory is not allocated by done at runtime.

When u are using internal table to load fixed entires then u should declare the table with specific names. e.g if u reading entries from material type and u know there will be only 5 entries then u should declare the internal table as occurs 5.

Re: Internal Table ????

Former Member — Fri, 22 Dec 2006 06:35:24 GMT

Hi,

There are two methods that the system uses to perform allocations. In the first, occurs is non-zero, and the size of the internal table (calculated from occurs * number of bytes per row) is less than or equal to 8KB. (The number of bytes per row can be obtained using the describe table statement detailed in the next chapter, or via the Field view in the debugger.) When the first row is added to the internal table, memory is allocated from the program roll area. The amount allocated is equal to the calculated size of the internal table. If this amount is exceeded, an equal amount is allocated and the process is repeated until the total exceeds 8KB. When this happens, subsequent allocations obtain 8KB pages from the paging area.

If you specify occurs 0, all allocations are done in the paging area, causing one 8KB page to be allocated at a time. If the calculated size of the internal table is greater than 8KB, the system changes the occurs value to zero when the first allocation is done and all allocations are satisfied from the paging area.

Don't use occurs 0 if you expect to store less than 8KB in an internal table. If you do, the system will allocate 8KB from the paging area. Memory will be wasted and paging could increase, resulting in poorer performance.

But as suggested by SAP we should not use Occurs 0.

Rather we should use declare seperate workarea for the internal table.

Re: Internal Table ????

former_member632991 — Fri, 22 Dec 2006 06:36:26 GMT

Hi,

Don't use occur while declaring internal tables. it is obsolete now.

occurs is related to the amount of memory that will be allocated for the internal table.

Regards,

Sonika

Re: Internal Table ????

Former Member — Fri, 22 Dec 2006 06:38:21 GMT

0 Allocates 8kb of memory to table by default. If data exceeds 8kb, it assigns 8kb again.

1 means, It assigns one record memory every time dynamically. By default it contains memory for one record.

So, Memorywise 1 is better.

Regards.