Re: to_date_valid()

On Sun, Jul 3, 2016 at 6:34 AM, Andreas 'ads' Scherbaum
<adsmail(at)wars-nicht(dot)de> wrote:
>
> Hello,
>
> we have customers complaining that to_date() accepts invalid dates, and
> returns a different date instead. This is a known issue:
>
> http://sql-info.de/postgresql/notes/to_date-to_timestamp-gotchas.html
>
> On the other hand this leads to wrong dates when loading dates into the
> database, because the database happily accepts invalid dates and ends up
> writing something completely different into the table.
>
> The attached patch adds a new function "to_date_valid()" which will validate
> the date and return an error if the input and output date do not match.
> Tests included, documentation update as well.
>

It seems that you are calling many additional function calls
(date_out, timestamp_in, etc.) to validate the date. Won't the
additional function calls make to_date much costlier than its current
implementation? I don't know if there is a better way, but I think it
is worth to consider, if we can find a cheaper way to detect validity
of date.

Note - Your patch is small (~13KB) enough that it doesn't need to zipped.

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com