Hi,
Note that CURRENT_TIMESTAMP is only evaluated once, when you assign to the
variable.
Why not using something like:
set hivevar:start_tm=current_timestamp;
select ${hivevar:start_tm};
select query;
select CURRENT_TIMESTAMP;
Cheers,
Pau.
Missatge de Zoltan Haindrich <[email protected]> del dia dt., 30 de nov. 2021 a
les 9:17:
> Hey Elango!
>
> Variables are not evaluated at assignment time - instead they are
> evaluated at the time of usage.
>
> If you want to save the current time somehow I think you could:
> * put the current_timestamp into a temporary table:
> create temporary table start_time as select current_timestamp() as t;
> * not sure about your use case; but if you need the start date of the
> session you could set it as an external variable when you start the session:
> beeline -hivevar start_time=`date "+%Y-%m-%d %H:%M:%S"
> select current_timestamp() - cast('${hivevar:start_time}' as timestamp);
> * consider using hplsql I think with that it might be possible to store it
> in a variable; however hplsql approaches things a bit differently...
> I can't give you an example how to do this right the top of my head
>
>
> cheers,
> Zoltan
>
> On 11/30/21 7:03 AM, elango vaidyanathan wrote:
> >
> >
> > Hi All, any updates on this?
> >
> > Thanks,
> > Elango
> >
> > On Fri, Nov 26, 2021, 11:09 AM elango vaidyanathan <[email protected]
> <mailto:[email protected]>> wrote:
> >
> >
> > Hi all,
> >
> > I am trying to create a hive variable and store the current time
> stamp. Then run some complex select queries and then create another
> variable to store current timestamp
> > and then find the runtime.
> > The problem I am facing is every time I use the variable it gives me
> the current time instead of the assigned value. It just runs the current
> timestamp function every
> > time. Below is the code snippet.
> >
> > Code
> >
> > set hivevar:start_tm=current_timestamp();____
> >
> > select ${hivevar:start_tm};____
> >
> > select query;__
> >
> > select ${hivevar:start_tm};
> >
> >
> > Here the start_tm variable calculates every time the current time
> and returns always the current time. How can I just store the value once
> and use that value for this
> > variable. Please clarify.
> >
> >
> > Thanks,
> > Elango
> >
>
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