Additional data segment

[EML]

Do I need to have the binary as EXEC_MAGIC or SHMEM_MAGIC before I could enable the 3rd and 4th quadrant by chatr? Will it just work if I only have the default SHARED_MAGIC binary?

[Dietmar Konermann]

It will work with SHARE_MAGIC.

Best regards...
Dietmar.

[Mike Stroyan]

You can apply +q3p enable and +q4p enable on a SHARED_MAGIC executable. Such a process could get close to 2.75GB of data on 11i. You would need to relink as EXEC_MAGIC to get to near 3.75GB of data.
There can be problems with applying chatr +q3p and +q4p to some programs. A program that has +q3p enabled cannot map shared memory segments that were created by other processes in the third quadrant. A program using +q3p and +q4p cannot map any shared memory segments created by other processes. Code compiled with +Oaggressive will have +Osignedpointers assumptions in the generated code. That can cause bad pointer comparisons between addresses in the first two and the last two quadrants. +q3p makes that kind of pointer comparison more likely.
After all those warnings, I should say that many programs have no trouble with +q3p and +q4p.