function queryColumnSet queryColumnSet(sql: string,column: string,args?: InValue[],): Promise<Set<string>> Run a single-column SELECT and collect that column's values into a Set of strings — the shared shape of the "which hashes/names already exist" reads (e.g. the live table names, the unsubscribed contact hashes). Parameters sql: string column: string optional args: InValue[] Return Type Promise<Set<string>>