fix(query): return error code when connecting to database failed.

enh(sync): raft config change

fix: some problems of planner

fix(query): merge updated data from cache.

fix(rpc): regArg mem leak

feat: alter table

fix(query): extract correct join condition from physical plan.

fix: change function name for tearing down udf handles

fix: change udf comment

refactor(stream)

feat: move sma module from tsdb to vnode