Bejoy,

you should use COALESCE() whenever you are comparing values that could have
NULL values.

-Viral

On Fri, Mar 4, 2011 at 7:13 AM, Bejoy Ks <bejoy...@yahoo.com> wrote:

> Hi Everyone
>     I'm facing an issue with hive on a relatively  larger query which
> involves joins on six hive tables. My query is running fine without any
> errors, all the map reduce jobs run to completion but unfortunately it is
> not showing up any results. I tried debugging the query and to investigate
> the root cause, When i removed one of the last conditions from the query it
> is showing up results, this is the condition I removed
> and ((unix_timestamp(r4.flight_datetime) <=
> unix_timestamp(r8.removal_datetime ))or  R8.REMOVAL_DATETIME IS NULL)
> I have used a similar comparison operation within my working query on dates
> using the unix_timestamp method which is working as desired. But here it is
> not, I'm assuming this would be due to the fact that r8.removal_datetime has
> null values hence here the evaluation would happen against a valid unix
> stamp and null.
> ie (unix_timestamp(r4.flight_datetime) <=
> unix_timestamp(r8.removal_datetime )) would inturn lead to  valid
> timestamp<= NULL
>
> Has any one faced similar situations before? How can i get around this
> hurdle? Please advise.
>
> Regards
> Bejoy.K.S
>
>
>
>

Reply via email to