Re: [HACKERS] Index not used on simple select - Mailing list pgsql-hackers

From Ole Gjerde
Subject Re: [HACKERS] Index not used on simple select
Date
Msg-id Pine.LNX.4.05.9907231445360.8120-100000@snowman.icebox.org
Whole thread Raw
In response to Re: [HACKERS] Index not used on simple select  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses UPDATE memory exhaustion
List pgsql-hackers
On Fri, 23 Jul 1999, Tom Lane wrote:
> It looks like the highly skewed distribution of nsn values (what you
> sent me had 997 '' entries, only 3 non-empty strings) is confusing the

As a note, it doesn't seem to matter wether the field has '' or NULL.
Even after I do a update to set all all rows with '' to NULL, it still
does the same thing.

Also, my full set of data is not quite so skewed.  The nsn field has about
450,000 non-empty rows in it.

Thanks,
Ole Gjerde




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