> -----Original Message----- > From: Stephan Szabo [mailto:sszabo@xxxxxxxxxxxxxxxxxxxxx] > Sent: Wednesday, October 19, 2005 2:34 PM > To: Dann Corbit > Cc: Terry Fielder; Tino Wildenhain; Marc G. Fournier; > Richard_D_Levine@xxxxxxxxxxxx; pgsql-hackers@xxxxxxxxxxxxxx; pgsql- > general@xxxxxxxxxxxxxx > Subject: Re: [HACKERS] 'a' == 'a ' (Was: RE: [pgsql-advocacy] > Oracle buysInnobase) > > On Wed, 19 Oct 2005, Dann Corbit wrote: > > > > -----Original Message----- > > > From: Terry Fielder [mailto:terry@xxxxxxxxxxxxxxxxxxxx] > > > Sent: Wednesday, October 19, 2005 2:05 PM > > > To: Dann Corbit > > > Cc: Tino Wildenhain; Marc G. Fournier; Richard_D_Levine@xxxxxxxxxxxx; > > > pgsql-hackers@xxxxxxxxxxxxxx; pgsql-general@xxxxxxxxxxxxxx > > > Subject: Re: 'a' == 'a ' (Was: RE: [pgsql-advocacy] Oracle > > > buysInnobase) > > > > > > > > > > > > Dann Corbit wrote: > > > > Try this query in Oracle, SQL*Server, DB/2, Informix, etc.: > > > > > > > > connxdatasync=# select 1 where cast('a' as varchar(30)) = cast('a ' > > as > > > > varchar(30)); > > > > ?column? > > > > ---------- > > > > (0 rows) > > > > > > > > I see how you can interpret the SQL Standard to make the above > > response > > > > a correct one. But is it the response that you would like? > > > > > > When the compared datatypes are VARCHAR: YES > > > > What is the value of doing that? > > > > I can see plenty of harm and absolutely no return. We are talking about > > blank padding before comparison. Do you really want 'Danniel ' > > considered distinct from 'Danniel ' in a comparison? In real life, > > what does that buy you? > > It buys you the ability to store things where trailing spaces are > signficant (for example passwords) within the existing limitations of not > having a full set of the collation behavior. I suppose that there may be some value in having 'J&^% ' be different from 'J&^% '. I would expect to insert a password with trailing blanks to be the same as inserting a password with no trailing blanks. I think that whatever is done ought to be whatever the standard says. If I misinterpret the standard and PostgreSQL is doing it right, then that is fine. It is just that PostgreSQL is very counter-intuitive compared to other database systems that I have used in this one particular area. When I read the standard, it looked to me like PostgreSQL was not performing correctly. It is not unlikely that I read it wrong. ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
