Update the comments for the MOD function to explain the behavior
Update the comments for the MOD function to explain the behavior

zuowang/voltdb,migue/voltdb,ingted/voltdb,creative-quant/voltdb,creative-quant/voltdb,paulmartel/voltdb,flybird119/voltdb,simonzhangsm/voltdb,paulmartel/voltdb,kumarrus/voltdb,paulmartel/voltdb,zuowang/voltdb,simonzhangsm/voltdb,simonzhangsm/voltdb,simonzhangsm/voltdb,deerwalk/voltdb,creative-quant/voltdb,simonzhangsm/voltdb,zuowang/voltdb,creative-quant/voltdb,flybird119/voltdb,creative-quant/voltdb,ingted/voltdb,zuowang/voltdb,ingted/voltdb,zuowang/voltdb,kumarrus/voltdb,zuowang/voltdb,VoltDB/voltdb,deerwalk/voltdb,creative-quant/voltdb,VoltDB/voltdb,migue/voltdb,ingted/voltdb,flybird119/voltdb,migue/voltdb,deerwalk/voltdb,ingted/voltdb,flybird119/voltdb,flybird119/voltdb,kumarrus/voltdb,VoltDB/voltdb,deerwalk/voltdb,simonzhangsm/voltdb,kumarrus/voltdb,ingted/voltdb,migue/voltdb,VoltDB/voltdb,migue/voltdb,paulmartel/voltdb,migue/voltdb,kumarrus/voltdb,VoltDB/voltdb,flybird119/voltdb,flybird119/voltdb,deerwalk/voltdb,ingted/voltdb,simonzhangsm/voltdb,flybird119/voltdb,ingted/voltdb,paulmartel/voltdb,kumarrus/voltdb,paulmartel/voltdb,migue/voltdb,simonzhangsm/voltdb,creative-quant/voltdb,paulmartel/voltdb,kumarrus/voltdb,VoltDB/voltdb,zuowang/voltdb,migue/voltdb,VoltDB/voltdb,deerwalk/voltdb,zuowang/voltdb,kumarrus/voltdb,deerwalk/voltdb,deerwalk/voltdb,creative-quant/voltdb,paulmartel/voltdb