Appian Database is super slow

Appian Database connection get 504 error

When connection is successful but when expanding some table is slow: keep loading and never finish

Call support team many times, the solution they provided are all temproray like kill the long run query. But the root problem is the query should not be that long.

Typically the following operation will reproduce the slowness

1) change a column type using
ALTER TABLE `T_PolicyBasic` CHANGE `Add_Record_Date` `Add_Record_Date` DATETIME NULL DEFAULT NULL;

2) from UI, try to drop a column or table or a record
3) from UI, try to use "empty" to delete all record in table

Most of those table are empty or have at most 120 record. All operation on single table, no joins

Not rush hour related, this problem exist all day long even in mid-night