Enhancements:
- Performance optimization for select count(*)
- Optimization about Performance scalability for STMT inserting
Fixed Bugs:
- taosd can't start after being stopped forced during high stress writing
- taosd can't be restarted after crashing
- tasod crash when creating 200 million tables and can't restart
- taosd OOM when querying the number of subtables in parallel with creating subtables
- taosdump crash when exporting data
- taosBenchmark crash during high stress writing
- Calculation error in SUM() function
- Error "Table not exists" after dropping database
- "Show create table" command can't show the comment
- A few other crash problems in taosd
- A few memory leak problems in taosd