1. Estimate timearithmeticexpr instead of setting Double.MAX Double.MIN directly 2. Enable histogram to derive stats 3. Loose the condition for histogram usage 4. Improve the accuracy for agg on TPC-H 1G greatly 5. Fix avg qerror calculation
1. Add Http interface for query q-error 2. Fix the selectivity calculation of inner join, it would always be 0 if there is only one join condition before
