ztta / roll _ first why used?

[Former Member]

Hi,

I've see many recommendations for this parameter like ztta / roll _ first = 1024 or ztta / roll _ first = 1.

Can someone explain why to set this parameter to a low value?

Why this parameter is important if we have extended memory?

Is this parameter deprecated in 64 bits, because extended memory is no more limited?

Regards

[Former Member · Accepted solution]

Hi,

USE OF ztta/roll_first

ztta/roll_first profile parameter is used for First amount of roll area used in a dialog Work Process

This parameter determines the amount of roll memory in bytes that is allocated to a dialog work process, before SAP Extended Memory is allocated.

On 64 bit platforms where there is sufficient amount of extended memory the default value for ztta/roll_first is set to 1 and this value should not normally be changed.

why to set this parameter to a low value?

To make more use of extended memory only a small portion of the roll area is used initially for this we use the profile parameter ztta/roll_first

Why this parameter is important if we have extended memory?

The standard format of memory allocation to the sap work process is

If a User starts a Transaction, the Usercontext allocate Memory from the local workprocess until ztta\roll_first is reached. So that there should be no Roll Memory used after reaching ztta\roll_first, the usercontext allocates memory until the SAP Extended Memory is reached.(em/initial_size_MB) If the maximum of extended Memory, or if ztta/roll_extension is reached, the rest of the roll Area will be used, until ztta/roll_are is reached and then assigns the heap memory

Hope this helps you

Thanks

Rama

[Former Member]

Thank you all.

[Former Member]

Hi,

"ztta/roll_first" should be set "1", because of the new SAP memory management model. Extended memory can be shared and user context exchange occurs faster than roll memory. Because of this reason, SAP recommend that you set ztta/roll_first=1 and use extended memory.

Best regards,

Orkun Gedik