How to query GPU memory footprint of table


How do I query Mapdql to find out the size of a table loaded into GPU memory ?


\memory_summary command of mapdql will return the amount of memory allocated and used on cpu and gpu memory. This not will exactly respond to your question, because the memory manager will loads columns involved on filtering/grouping on gpu/cpu memory and in addition, dictionaries and other things needed by projection of fields on cpu memory.
Actually if you want know the amount of memory needed by the system to load all the columns of your table in memory you have to do by yourself with a simple math Calc, multiplying the number of records by the total bytes of a single row (on a columnar based database this information isn’t too useful)