dir = "/home/ffliu/data/test.csv"
sym = dir.split('/').tail(1).split('.')[0]

dropDatabase("dfs://valuedb")
db=database(directory="dfs://valuedb", partitionType=VALUE, partitionScheme=2000.01.01..2000.01.02)
t = table(1:0, `symbol`datetime`val, [SYMBOL, DATETIME, DOUBLE])
pt = db.createPartitionedTable(t, `pt, `datetime);

def mytrans(mutable t, sym){
    t.replaceColumn!(`dt, datetime(t.dt))
    return select sym, * from t
}

loadTextEx(db, `pt, `dt, dir, transform=mytrans{,sym})
select * from loadTable("dfs://valuedb", `pt)