Why SGEN needed after 640 Kernel Upg

you mean from a 640 patchlevel to a higher 640 patchlevel? Or from 620
to 640?

Hi,
sgen is required to compile and keep ready all the programs which
could improve the access time of different programs.

You dont need any SGEN run for any kernel update.
Well you mentioned "640 Kernal Updrade" . Normally any upgrade does mean that there are support packages impletionation and then you need to run SGEN.
Please clarify if its an update or upgrade ?

Its kernel Upgrade (NOT UPDATE).It definitely needs a SGEN of the ABAPS but the question is why it needs it?Please note that no support packs are being applied here only the kernel upgrade and after that i see the usual clock symbol that comes after the patch upgrade.
Can you tell me why
On Mon, 09 May 2005 Sachin Jadhav wrote :

But the question is why would a SGEN be needed after the kernel upgrade.
On Wed, 04 May 2005 Srinivas Reddy wrote :

hi,
Is SGEN is available in all sap versions i.e, 4.6b,4.6C/D
Best
well as
needed but