Tarantool development patches archive
 help / color / mirror / Atom feed
From: Timur Safin via Tarantool-patches <tarantool-patches@dev.tarantool.org>
To: <imeevma@tarantool.org>
Cc: <tarantool-patches@dev.tarantool.org>
Subject: Re: [Tarantool-patches] [PATCH v1 1/1] sql: fix comparison between DECIMAL and big DOUBLE
Date: Tue, 31 Aug 2021 22:46:40 +0300
Message-ID: <017301d79ea0$eba3de60$c2eb9b20$@tarantool.org> (raw)
In-Reply-To: <6229320676324201d74e78ac1f2832b79fd159cb.1630303937.git.imeevma@gmail.com>

> From: imeevma@tarantool.org <imeevma@tarantool.org>
> Subject: [PATCH v1 1/1] sql: fix comparison between DECIMAL and big
> DOUBLE
> 
> This patch fixes comparison between DECIMAL value and DOUBLE values
> greater or equal to 1e38 or less or equal to -1e38. Now any DOUBLE
> value
> greater or equal to 1e38 is more than any DECIMAL value and DOUBLE
> value less or equal to -1e38 is less than any DECIMAL value.
> 
> Closes #6376
...
> diff --git a/changelogs/unreleased/gh-6376-fix-incorrect-dec-inf-
> cmp.md b/changelogs/unreleased/gh-6376-fix-incorrect-dec-inf-cmp.md
> new file mode 100644
> index 000000000..70de655f1
> --- /dev/null
> +++ b/changelogs/unreleased/gh-6376-fix-incorrect-dec-inf-cmp.md
> @@ -0,0 +1,3 @@
> +## bugfix/sql
> +
> +* Fixed wrong comparison between DECIMAL and large DOUBLE values
> (gh-6376).
> diff --git a/src/box/sql/mem.c b/src/box/sql/mem.c
> index 4c40f15dc..a3ab31af5 100644
> --- a/src/box/sql/mem.c
> +++ b/src/box/sql/mem.c
> @@ -2451,9 +2451,9 @@ mem_cmp_num(const struct Mem *a, const struct
> Mem *b)
>  		}
>  		case MEM_TYPE_DOUBLE: {
>  			if (b->u.r >= 1e38)
> -				return 1;
> -			if (b->u.r <= -1e38)
>  				return -1;
> +			if (b->u.r <= -1e38)
> +				return 1;

Well, while we are here. I do understand that these kind of constants
already spreading all corners of mem.c when you deal with decimals,
but it's not entirely clear that this all about DECIMAL_MAX_DIGITS
limitation in our decimal implementation. 
And beyond all of that - hardcoded constant are evil. Could you please
introduce any symbolic constant defines for such DECIMAL_MAX_DIGITS-
derivative values? And use them wherever possible.

(I'm not insisting on fixing whole mem.c, that might be done separately,
but at least this tricky case worth it)

>  			decimal_t dec;
>  			decimal_t *d = decimal_from_double(&dec, b->u.r);
>  			assert(d != NULL && d == &dec);

Thanks,
Timur


  reply	other threads:[~2021-08-31 19:47 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-30  6:13 Mergen Imeev via Tarantool-patches
2021-08-31 19:46 ` Timur Safin via Tarantool-patches [this message]
2021-09-01  8:52   ` Mergen Imeev via Tarantool-patches
2021-09-07  9:28     ` Safin Timur via Tarantool-patches
2021-09-07 11:26       ` Igor Munkin via Tarantool-patches
2021-09-07 11:40 ` Igor Munkin via Tarantool-patches
2021-09-09  7:39   ` Mergen Imeev via Tarantool-patches
2021-09-09 10:24 ` Kirill Yukhin via Tarantool-patches

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='017301d79ea0$eba3de60$c2eb9b20$@tarantool.org' \
    --to=tarantool-patches@dev.tarantool.org \
    --cc=imeevma@tarantool.org \
    --cc=tsafin@tarantool.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Tarantool development patches archive

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://lists.tarantool.org/tarantool-patches/0 tarantool-patches/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 tarantool-patches tarantool-patches/ https://lists.tarantool.org/tarantool-patches \
		tarantool-patches@dev.tarantool.org.
	public-inbox-index tarantool-patches

Example config snippet for mirrors.


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git