The recommended minimum is 512MB, so in theory it should be enough.613 MB of RAM enough for running XE ?
That's less than 250MB. With most Oracle installs, for 11gR2, I'd prefer to have at least 512MB for the SGA. But you have to leave some room for the OS, and PGA is a separate memory allocation for the instance as well. May be able to shrink PGA, and give a bit more room either to SGA_TARGET or MEMORY_TARGET, depends on what's been tweeked, and what is still at the default settings.Total System Global Area 250523648 bytes