feat(query): add irate function

test : add case for selective query about sample function 

enh: drop qnode and snode on dnode

feat: drop dnode

feat: add merge interval operator

fix(wal): return correct msg for open wal file

fix: release/redirect problem

refactor(sync): add syncLogStoreCheck tool

fix: change merge interval to merge aligned interval

refactor:  add gtid to log 

refactor: add gtid for trace

fix(query): reserve correct buffer before loading data

feat: sql function 'last_row' and sql command 'select constant'

feat: add sort group operator