| From: | "Iain" <iain(at)mst(dot)co(dot)jp> |
|---|---|
| To: | "Enver ALTIN" <enver(dot)altin(at)frontsite(dot)com(dot)tr> |
| Cc: | <pgsql-sql(at)postgresql(dot)org> |
| Subject: | Re: randomized order in select? |
| Date: | 2004-03-11 05:31:26 |
| Message-ID: | 009301c4072a$19b28fd0$7201a8c0@mst1x5r347kymb |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-sql |
If you have a lot of tips, you could create a unique indexed tip number
column. Select the highest tip number using:
select tip_number from tips order by tip_number desc limit 1;
Then generate a random number and select using that tip_number.
Of course, you would have to allow for the possibility of missing tip
numbers, by repeating the random number generation/read sequence until you
find something. Since the tip_number isn't the PK of the table, you can
regenerate the tip numbers to eliminate holes from deletions any time you
like. Just reset the sequence to 1 and update all rows with the
nextval(tipnumber_seq).
Sounds like a lot of work to me though...
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