Re: Re: [GENERAL] Trouble with float4 after upgrading from 6.5.3 to 7.0.2 - Mailing list pgsql-hackers

From Philip Warner
Subject Re: Re: [GENERAL] Trouble with float4 after upgrading from 6.5.3 to 7.0.2
Date
Msg-id 3.0.5.32.20000808015718.0281ad70@mail.rhyme.com.au
Whole thread Raw
In response to Re: [GENERAL] Trouble with float4 after upgrading from 6.5.3 to 7.0.2  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Re: [GENERAL] Trouble with float4 after upgrading from 6.5.3 to 7.0.2  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
At 11:35 7/08/00 -0400, Tom Lane wrote:
>
>Perhaps the old way of considering equality only to float accuracy
>is more useful, even though it opens us up to problems like overflow
>errors in "float4var = 1e100".  Comments anyone?
>

The following frightened me a little:

pjw=# select float4(10.1);
 float4
--------
   10.1
(1 row)

pjw=# select float8(float4(10.1));
      float8
------------------
 10.1000003814697
(1 row)


I would have expected the latter to be at worst 10.10000000000000 +/-
.00000000000001.

Am I missing something?


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