Thanks a lot~
> 2021年5月8日 下午2:41，Yik San Chan <evan.chanyik...@gmail.com> 写道：
>
> Hi Dian,
>
> Thanks for the confirmation, I have created a ticket
> https://issues.apache.org/jira/browse/FLINK-22605
> <https://issues.apache.org/jira/browse/FLINK-22605>
>
> Best,
> Yik San
>
> On Sat, May 8, 2021 at 2:32 PM Dian Fu <dian0511...@gmail.com
> <mailto:dian0511...@gmail.com>> wrote:
> There is still no such optimization at framework level. However, I think this
> maybe a good point that we could optimize. Would you like to create a ticket
> for this?
>
> Regards,
> Dian
>
>> 2021年5月8日 下午2:27，Yik San Chan <evan.chanyik...@gmail.com
>> <mailto:evan.chanyik...@gmail.com>> 写道：
>>
>> Hi Dian,
>>
>> Thanks for pointing that out, it is a work around that I have also
>> considered.
>>
>> I wonder if there is a framework level optimization on this, so that a UDF
>> is only initiated once, no matter how many times it is called?
>>
>> Thank you!
>>
>> Best,
>> Yik San
>>
>> On Sat, May 8, 2021 at 1:32 PM Dian Fu <dian0511...@gmail.com
>> <mailto:dian0511...@gmail.com>> wrote:
>> Hi Yik San,
>>
>> Is it acceptable to rewrite the UDF a bit to accept multiple parameters and
>> then rewrite the program as following:
>>
>> ```
>> SELECT
>> LABEL_ENCODE(a, b, c)
>> ...
>> ```
>>
>> Regards,
>> Dian
>>
>>> 2021年5月8日 上午11:56，Yik San Chan <evan.chanyik...@gmail.com
>>> <mailto:evan.chanyik...@gmail.com>> 写道：
>>>
>>> Hi community,
>>>
>>> I am using PyFlink and Pandas UDF in my job.
>>>
>>> The job executes a SQL like this:
>>>
>>> ```
>>> SELECT
>>> LABEL_ENCODE(a),
>>> LABEL_ENCODE(b),
>>> LABEL_ENCODE(c)
>>> ...
>>> ```
>>>
>>> And my LABEL_ENCODE UDF is defined below:
>>>
>>> ```
>>> class LabelEncode(ScalarFunction):
>>> def open(self, function_context):
>>> logging.info <http://logging.info/>("LabelEncode.open")
>>> self.encoder = load_encoder()
>>> def eval(self, x):
>>> ...
>>>
>>> labelEncode = udf(LabelEncode(), ...)
>>> ```
>>>
>>> When I run the job, according to taskmanger log, "LabelEncode.open" is
>>> printed 3 times, which is exactly the times LABEL_ENCODE udf is called.
>>>
>>> Since every LabelEncode.open causes an I/O (load_encoder() does so), I
>>> wonder if I can only initiate the UDF once, and use it 3 times?
>>>
>>> Thank you!
>>>
>>> Best,
>>> Yik San
>>
>
