Re: Big Performance drop of Exceptions in UDFs between V11.2 and 13.4

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От Pavel Stehule
Тема Re: Big Performance drop of Exceptions in UDFs between V11.2 and 13.4
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Msg-id CAFj8pRDPew1rg3c-WNxQmUugO0FQRyg3MTy67-qoUtGA=fwZ6Q@mail.gmail.com
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Ответ на RE: Big Performance drop of Exceptions in UDFs between V11.2 and 13.4  ("ldh@laurent-hasson.com" <ldh@laurent-hasson.com>)
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Hi

po 30. 8. 2021 v 2:44 odesílatel ldh@laurent-hasson.com <ldh@laurent-hasson.com> napsal:



At this point, I am not sure how to proceed except to rethink that toFloat() function and many other places where we use exceptions. We get such dirty data that I need a "safe" way to convert a string to float without throwing an exception. BTW, I tried other combinations in case there may have been some weird interactions with the ::REAL conversion operator, but nothing made any change. Could you recommend another approach off the top of your head? I could use regexes for testing etc... Or maybe there is another option like a no-throw conversion that's built in or in some extension that you may know of? Like the "SAFE." Prefix in BigQuery.

CREATE OR REPLACE FUNCTION safe_to_double_precision(t text)
RETURNS double precision AS $$
BEGIN
  IF $1 SIMILAR TO '[+-]?([0-9]*[.])?[0-9]+' THEN
    RETURN $1::double precision;
  ELSE
    RETURN NULL;
  END IF;
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT;

Regards

Pavel
 

Thank you,
Laurent.



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