55 lines
2.0 KiB
Plaintext
55 lines
2.0 KiB
Plaintext
From: aaron_watters at my-dejanews.com (aaron_watters at my-dejanews.com)
|
|
Date: Thu, 08 Apr 1999 15:15:30 GMT
|
|
Subject: GadFly - MemoryError
|
|
References: <Pine.SOL2.3.96.SK.990403182611.18369K-100000@sun.med.ru> <370B5E83.C796BFF3@palladion.com>
|
|
Message-ID: <7eih6b$ck2$1@nnrp1.dejanews.com>
|
|
Content-Length: 1636
|
|
X-UID: 144
|
|
|
|
It would be interesting to try this, but my guess is that this would be
|
|
slower than the first query since equalities are optimized and "in" is not.
|
|
I hope oleg is using gadfly 1.0 too (not beta 0.2 or whatever). -- Aaron
|
|
Watters
|
|
|
|
In article <370B5E83.C796BFF3 at palladion.com>,
|
|
Tres Seaver <tseaver at palladion.com> wrote:
|
|
> Oleg Broytmann wrote:
|
|
> >
|
|
> > Hello!
|
|
> >
|
|
> > I tried to add yeat another database backend to my project "Bookmarks
|
|
> > database". My database contains now about 3000 URLs, not too much, I think.
|
|
> > I subclass by BookmarksParser to parse bookmarks.html into gadfly database
|
|
> > and got a database of 500 Kbytes - very small database, I hope.
|
|
> > Then I tried to find duplicates (there are duplicates). I ran the query:
|
|
> >
|
|
> > SELECT b1.rec_no, b2.rec_no, b1.URL
|
|
> > FROM bookmarks b1, bookmarks b2
|
|
> > WHERE b1.URL = b2.URL
|
|
> > AND b1.rec_no < b2.rec_no
|
|
>
|
|
> How many duplicates are there? Something like
|
|
>
|
|
> SELECT URL FROM bookmarks GROUP BY URL HAVING COUNT(*) > 1
|
|
>
|
|
> will produce the URL's with duplicates; you could then do
|
|
>
|
|
> SELECT rec_no, URL FROM bookmarks
|
|
> WHERE URL IN
|
|
> (SELECT URL FROM bookmarks GROUP BY URL HAVING COUNT(*) > 1)
|
|
>
|
|
> or create a temp table first with the results of the subquery, then join it in a
|
|
> separate query.
|
|
> --
|
|
> =========================================================
|
|
> Tres Seaver tseaver at palladion.com 713-523-6582
|
|
> Palladion Software http://www.palladion.com
|
|
>
|
|
|
|
-----------== Posted via Deja News, The Discussion Network ==----------
|
|
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
|
|
|
|
|
|
|
|
|