Hello Tom,
Tom Lane wrote:
T E Schmitz <[EMAIL PROTECTED]> writes:
Greg Stark wrote:
Which book is it?
PostgreSQL by Korry Douglas + Susan Douglas, ISBN 0-7357-1257-3; Feb 2003
Hmm, I've heard of that book but never seen it. The authors are not participants in the PG community --- AFAICT neither of them have ever posted anything in the mailing lists.
The paragraph continues:
"If the SELECT command included the clause WHERE phone NOT NULL, PostgreSQL could use the index to satisfy the ORDER BY clause.
An index that covers optional (NOT NULL) columns will not be used to speed table joins either."
My goodness, it seems to be a veritable fount of misinformation :-(
Well, that's great. My knowledge of SQL is good enough to model a DB and do run of the mill queries; but when it comes to some fine details I rely on sensible input ;-)
Thanks for chipping in here and answering what I thought was a dummy question.
--
Kind Regards/Gruß,
Tarlika
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