Looking for deeper understanding of the systemlog table.


Hi all,

I'm hoping someone can help me understand something better.  I'm curious about the size of the systemlog table for a number of our graphs.  On our backend data store this is the only table which reports having large cells.  On some nodes there is only a few of them, but on other nodes they number in the hundreds (the large cells that is).  

I have a few basic questions:
a) what is stored in this table?
b) what kind of maintenance can I safely perform on it from the backend, if any?
c) what might cause these large cells to show up in this table (and what could be done to avoid it)?