This is related to internal issue number 344.

Aqua Data Studio's autocompletion for Snowflake fails when objects are qualified with schema-name. For following 4 tests sql 1 and 2 is suggesting column-name after where statement. For sql 3-4 AutoComplete flashes "Please wait" and den disappears.

To debug this, open an SQL.log and try to auto complete on select * from ACCOUNT_USAGE.VIEWS where. Clear the cache first. You will see in the log that the statement is not getting parsed correctly. It is using ACCOUNT_USAGE.VIEWS as a table name and then adding ACCOUNT_USAGE as a database.