Overview For our investigation of execution plan as it is stored in memory, we need in the first place to be able to read the memory. We have the options of x$ksmmem, reading SGA using SQL. Personally I don't like it, it's cumbersome and slow. direct SGA read: obviously reading SGA only; it's fast and easy to do read process memory: can read PGA, process stack - and since the processes do map the SGA, too, you can read it as well. Unfortunately ptrace sends signals to the processes and the process is paused when reading it, but so far all my reads were short and fast and the processes did not notice. Some OS configurations can prevent you from using ptrace (e.g. docker by default), google for CAP_SYS_PTRACE. gdb: using your favorite debugger, you can read memory as well. Useful when investigating. Direct SGA read I always considered direct SGA read of some dark magic, but the fundamentals are actually very easy. It still looks like sorcery when actually reading...
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