Re: [pgsql-advocacy] Oracle buys Innobase

Hi Dann

Without looking at the internals to see if the 1 column or the other is
being converted to the other columns type before the compare, it really
demonstrates nothing.

It could perhaps be used to help demonstrate that when comparing a
datatype of CHAR to VARCHAR that
MS-SQL converts the VARCHAR to CHAR and then does the compare
Postgres converts the CHAR to VARCHAR and then does the compare

But there isn't even enough evidence here to support that.

Terry

Dann Corbit wrote:
> create table foo (col1 varchar(30))
> go
> create table bar (col1 char(30))
> go
> insert into foo values ('Danniel ')
> go
> insert into bar values ('Danniel ')
> go
> select * from foo,bar where foo.col1=bar.col1
> go
>
> Result set:
> Danniel Danniel
>
>
>>-----Original Message-----
>>From: Terry Fielder [mailto:terry(at)ashtonwoodshomes(dot)com]
>>Sent: Wednesday, October 19, 2005 1:39 PM
>>To: Dann Corbit
>>Cc: Marc G. Fournier; Richard_D_Levine(at)raytheon(dot)com; pgsql-
>>general(at)postgresql(dot)org
>>Subject: Re: [pgsql-advocacy] [GENERAL] Oracle buys Innobase
>>
>>I agree with you, but...
>>
>>Actually that's not how the compare works usually.
>>
>>Generally one of the operands is converted to the same datatype as the
>>other, and THEN the compare is performed.
>>
>>I expect MS SQL is converting a 'sdas' typeless string to be assumed
>>CHAR and Postgresql is converting a 'sdas' typeless string to be
>
> assumed
>
>>VARCHAR.
>>
>>Hence, the different behaviour.
>>
>>Terry
>>
>>Dann Corbit wrote:
>>
>>>Would you want varchar(30) 'Dann Corbit' to compare equal to
>
> bpchar(30)
>
>>>'Dann Corbit'?
>>>
>>>I would.
>>>
>>>If both are considered character types by the language, then they
>
> must
>
>>>compare that way.
>>>
>>>Perhaps there are some nuances that I am not aware of. But that is
>
> how
>
>>>things ought to behave, if I were king of the forest.
>>>
>>>
>>>
>>>>-----Original Message-----
>>>>From: pgsql-general-owner(at)postgresql(dot)org [mailto:pgsql-general-
>>>>owner(at)postgresql(dot)org] On Behalf Of Terry Fielder
>>>>Sent: Wednesday, October 19, 2005 12:37 PM
>>>>To: Marc G. Fournier
>>>>Cc: Richard_D_Levine(at)raytheon(dot)com; pgsql-general(at)postgresql(dot)org
>>>>Subject: Re: [pgsql-advocacy] [GENERAL] Oracle buys Innobase
>>>>
>>>>OK, I am not an expert on the SQL standard, but I thought the
>>>
>>>definition
>>>
>>>
>>>>varied by data type e.g. varchar <> bpchar
>>>>
>>>>Terry
>>>>
>>>>Marc G. Fournier wrote:
>>>>
>>>>
>>>>>On Wed, 19 Oct 2005, Richard_D_Levine(at)raytheon(dot)com wrote:
>>>>>
>>>>>
>>>>>
>>>>>>I was referring to trailing blanks, but did not explicitly say it,
>>>>>>though showed it in the examples. I am pretty sure that the SQL
>>>>>>standard says that trailing whitespace is insignificant in string
>>>>>>comparison.
>>>>>
>>>>>
>>>>>Then we are broken too :)
>>>>>
>>>>># select 'a ' = 'a ';
>>>>>?column?
>>>>>----------
>>>>>f
>>>>>(1 row)
>>>>>
>>>>>----
>>>>>Marc G. Fournier Hub.Org Networking Services
>>>>
>>>>(http://www.hub.org)
>>>>
>>>>
>>>>>Email: scrappy(at)hub(dot)org Yahoo!: yscrappy ICQ:
>>>>
>>>>7615664
>>>>
>>>>
>>>>>---------------------------(end of
>>>
>>>broadcast)---------------------------
>>>
>>>
>>>>>TIP 4: Have you searched our list archives?
>>>>>
>>>>> http://archives.postgresql.org
>>>>>
>>>>
>>>>--
>>>>Terry Fielder
>>>>terry(at)greatgulfhomes(dot)com
>>>>Associate Director Software Development and Deployment
>>>>Great Gulf Homes / Ashton Woods Homes
>>>>Fax: (416) 441-9085
>>>>
>>>>---------------------------(end of
>>>
>>>broadcast)---------------------------
>>>
>>>
>>>>TIP 6: explain analyze is your friend
>>>
>>>
>>--
>>Terry Fielder
>>terry(at)greatgulfhomes(dot)com
>>Associate Director Software Development and Deployment
>>Great Gulf Homes / Ashton Woods Homes
>>Fax: (416) 441-9085
>
>

--
Terry Fielder
terry(at)greatgulfhomes(dot)com
Associate Director Software Development and Deployment
Great Gulf Homes / Ashton Woods Homes
Fax: (416) 441-9085