Re: Thanks for all the help on replacing 'unique' - Mailing list pgsql-general

From Bruce Momjian
Subject Re: Thanks for all the help on replacing 'unique'
Date
Msg-id 200611211605.kALG55605402@momjian.us
Whole thread Raw
In response to Thanks for all the help on replacing 'unique'  ("Wm.A.Stafford" <stafford@marine.rutgers.edu>)
List pgsql-general
Wm.A.Stafford wrote:
> I just wanted to issue a blanket "thanks" to all who responded to my
> inquiry about what to do about 'unique'.  Distinct is the equivalent
> aggregate function as many pointed out.  A co-worker said that Oracles
> 'unique' is probably an optimized version of distinct that takes
> advantage of some Oracle specific indexing.
>
> The example that I used to illustrate my problem in the first place was
> seriously flawed as many pointed out.  The PostgreSQL db had been
> created from a Fastreader control file that had all  column names in
> double quotes, ex. "total"  instead of total;  This produced a normal
> looking DB that did not react correctly to any SQL that used a column
> name.  So for example, select count(*) would return the correct row
> count but count(some_column) would produce a 'no such column error'.
>
> My difficulty with unique was mostly caused by the  failure of every
> attempt to come up with an alternate query which  was caused, in turn,
> by the columns names used to create the tables.
>
> All in all, a pretty revolting experience with one possible bright
> spot,  I think I  have proved a little known principle of computer
> science: "garbage in, garbage out".

I have updated an FAQ item to specifically mention capitalization, so
that should help people in the future.

--
  Bruce Momjian   bruce@momjian.us
  EnterpriseDB    http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +

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