gdb debugger cannot access the memory

I tried to attach particular process and set the breakpoint using by gdb, but I could not set the breakpoint.

The error message is,

(gdb) b exec_simple_query

Cannot access memory at address 0x1003cc9aa

How can I solve it?

Please give me advice.

$ gdb --version

GNU gdb (GDB) 7.6.2

Copyright (C) 2013 Free Software Foundation, Inc.

License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

This is free software: you are free to change and redistribute it.

There is NO WARRANTY, to the extent permitted by law. Type "show copying"

and "show warranty" for details.

This GDB was configured as "x86_64-apple-darwin13.0.0".

For bug reporting instructions, please see:

<http://www.gnu.org/software/gdb/bugs/>.

Regards,