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From Ayelet Morris <>
Subject Re: Advise on ClassCastException in Linq4j$EnumeratorIterator
Date Tue, 05 May 2020 04:27:04 GMT
+ Calcite support mailing list.

Hi again,

I didn't receive any response from you guys, but I continued to debug this
today and managed to print the generated code and I saw a weird casting
that might explain what happens there:
 public Object current() {
              final Object[] current = (Object[]) inputEnumerator.current();
              return* (java.sql.Timestamp) *current[8] == null ?* (Long)*
null : *Long.valueOf*(org.apache.calcite.avatica.util.DateTimeUtils.unixDateExtract(org.apache.calcite.avatica.util.TimeUnitRange.DAY,
org.apache.calcite.avatica.util.DateTimeUtils.floorDiv((Long) current[8],

public Class getElementType() {
   return *java.lang.Long.class*;

I marked in *bold* the interesting casting that happens there that I need
your help understanding:
it seems that the code casts the value into long and then re-casts it to
timestamp only to return as long, as you can see the element type is marked
as long...
Do you know why the generated code was generated this way? the field is
TIMESTAMP and the return value from the SQL function should be long...

Hope you are all well.

On Mon, Apr 27, 2020 at 4:49 PM Ayelet Morris <>

> Hi Calcite Developers,
> Hope you are all doing well at this crazy time.
> I have a question regarding Linq4j$EnumeratorIterator
> throwing ClassCastException.
> *Background*: I'm running a Tableau testing framework called TDVT (it's
> in beta) in order to test our product's JDBC connector.  Our product uses
> Calcite 1.21.0 and Avatics 1.15.0.
> I encountered this class cast exception when running timestamp related sql
> functions (I have about 127 different SQLs failing with the same class cast
> exception).
> *My SQL**:* select DAYOFMONTH(datetime0) from Calcs
> datetime0 is a java.sql.Timestamp field in my POJO, the data in the CSV
> I'm using to fill in the POJO is written like this: '2004-07-23 21:13:37'
> *The exception:*
> ClassCastException: java.sql.Timestamp cannot be cast to java.lang.Long
> at Baz$1$1.current(Unknown Source)
> at
> org.apache.calcite.linq4j.Linq4j$
> at
> at
> at com.gigaspaces.jdbc.TimestampTest.test(
> This exception is thrown when trying to perform "next()"
> I cannot debug the generated code... I just see it being thrown there.
> I looked into the generated code for performing this (and similar) sql
> function and couldn't find a specific time format that is required, but in
> the documentation I saw the use of java.sql.Date as the function type, I
> tried to run my test with Date field I have in my POJO and it did return a
> correct result.
> I suspect it might not be compatible with Timestamp data type, though I
> saw in your tests you do test with timestamp '2008-1-23 12:12:12', I
> didn't try to run the test in the DruidAdapter suite but I saw that you are
> using a timestamp based column there.
> Do you know of a reason for this exception at this location? Did you see
> this exception before at this location? Do you have any idea where I should
> look for further information/clues?
> Thanks,
> Ayelet

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