Timestamp data type on S[range C on E] constant value-based range windows

Question

Hello,
My questiong is about how can we use timestamp value on S[range C on E] constant value-based range windows.
I have a LotEvent which i should collect and sum lastQty data for last ten minutes of market time (sendDate)
A normal [range 600] query does not work for me because i would like to use the exact time which data has been generated by the market (sendDate).
Here is the event;
public class LotEvent{
     private Double totalQty;
     private float lastQty;
     private String symbol;
     private String messageType;
     private Integer dataInterval;
     private String sendDate;
send date is always in "MM-dd-yyyy HH:mm:ss" format.
I have tried to use the following query but this gives an error;
Invalid statement: "select symbol, sum(lastQty) as lastQty, 10 AS dataInterval
+from lotInputChannel [range INTERVAL "0 0:0:15.0" DAY TO SECOND on >>sendDate<<]+
group by symbol"
Cause: Datatype char is not valid for value based windows
Action: Use a valid datatype for value based windows>
Here is the CQL;
<?xml version="1.0" encoding="UTF-8"?>
<wlevs:config xmlns:wlevs="http://www.bea.com/ns/wlevs/config/application">
<processor>
<name>lotProcTenMin</name>
<rules>
     <query id="tenMin"> <![CDATA[select symbol, sum(lastQty) as lastQty, 10 AS dataInterval 
            from lotInputChannel [range INTERVAL "0 00:10:00.0" DAY TO SECOND on sendDate]
group by symbol]]> </query>
</rules>
</processor>
</wlevs:config>
i have tried this cql after changing the sendDate data type to long which is the time in milliseconds value but it did not work.
select symbol, sum(lastQty) as lastQty, 10 AS dataInterval
from lotInputChannel [range INTERVAL "0 00:10:00.0" DAY TO SECOND on to_timestamp(sendDate)]
group by symbol
The query above does not work also when sendDate is a String in "MM-dd-yyyy HH:mm:ss" format
At last i tried the following query with sendDate as time in milliseconds (long) value. It works! but i still would like to know how to use timestamp in S[range C on E] queries
select symbol, sum(lastQty) as lastQty, 10 AS dataInterval
from lotInputChannel [range *600000* on sendDate]
group by symbol
public class LotEvent{
     private Double totalQty;
     private float lastQty;
     private String symbol;
     private String messageType;
     private Integer dataInterval;
     private long sendDate;
Could anybody please help me with this issue?
Edited by: user8830791 on 01-Aug-2011 06:39

Answer 1

It seems that you should configure the channel "lotInputChannel" as an application timestamped channel.
You can do that as follows -
- Have "sendDate" as a long and let its unit be milliseconds
- Use the following child elements of <channel> for the "lotInputChannel"
<wlevs:application-timestamped is-total-order="true">
<wlevs:expression>sendDate*1000*1000</wlevs:expression>
</wlevs:application-timestamped>
The multiplication by 10^6 is required since the units need to be converted into nanos
With this, you could use the query -
select symbol, sum(lastQty) as lastQty, 10 AS dataInterval
from lotInputChannel [range 10 minutes]
group by symbol
Of course, for the above to work, a requirement is that the value of "sendDate" is non-decreasing.
That is if e1 is before e2 in the "lotInputChannel" then e1.sendDate <= e2.sendDate
Edited by: Anand Srinivasan on Aug 2, 2011 6:57 AM