Re: [PATCH] Add crc32(text) & crc32(bytea) - Mailing list pgsql-hackers

From Aleksander Alekseev
Subject Re: [PATCH] Add crc32(text) & crc32(bytea)
Date
Msg-id CAJ7c6TMatgSxgZ30h4_wH_AO+40chU4pcJvYnGj7BW5sv+6ESQ@mail.gmail.com
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In response to Re: [PATCH] Add crc32(text) & crc32(bytea)  (Nathan Bossart <nathandbossart@gmail.com>)
Responses Re: [PATCH] Add crc32(text) & crc32(bytea)
List pgsql-hackers
Hi Nathan,

> I don't think adding crc32c() would sufficiently increase the scope.  We'd
> use the existing implementations for both crc32() and crc32c().  And
> besides, this could be useful for adding tests for that code.
>
> +        <function>crc32</function> ( <type>text</type> )
>
> Do we need a version of the function that takes a text input?  It's easy
> enough to cast to a bytea.
>
> +        <returnvalue>text</returnvalue>
>
> My first reaction is that we should just have this return bytea like the
> SHA ones do, if for no other reason than commit 10cfce3 seems intended to
> move us away from returning text for these kinds of functions.  Upthread,
> you mentioned the possibility of returning a bigint, too.  I think I'd
> still prefer bytea in case we want to add, say, crc64() or crc16() in the
> future.  That would allow us to keep all of these functions consistent
> instead of returning different types for each.  However, I understand that
> returning the numeric types might be more convenient.  I'm curious what
> others think about this.
>
> +        Computes the CRC32 <link linkend="functions-hash-note">hash</link> of
> +        the binary string, with the result written in hexadecimal.
>
> I'm not sure we should call the check values "hashes."  Wikipedia does
> include them in the "List of hash functions" page [0], but it seems to
> deliberately avoid calling them hashes in the CRC page [1].  I'd suggest
> calling them "CRC32 values" instead.

Thanks for the code review. Here is the updated patch.

-- 
Best regards,
Aleksander Alekseev

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