Re: Okay- I give up - what on earth is a "hash" ?

Okaaaaaaaay.....now the light is coming on!

Thank you so much Vladimir.......and Jonathan, as always, thank you too.

"Vladimir M. Zakharychev" <bob_at_dpsp-yes.com> wrote in message news:a7ffhg$3ja$1_at_babylon.agtel.net...
> More than that, a really good hash function would produce unique
> reproducible output for each distinct input. Such hash functions are
> referred to as cryptographically strong and are used for message
> authentication. The idea is that being applied over a message, the
> function produces unique hash value which can be verified by
> receiver by applying the same function and comparing the hash
> value. Simpler hash functions are usually used for fast node
> grouping and search. As far as I understood, the hash join
> works by creating a table of hash values for one table and then
> filtering columns from the second table by throwing away
> columns whose hash is not in hash table and quickly finding the
> join target row otherwise.
>
> --
> Vladimir Zakharychev (bob_at_dpsp-yes.com)
http://www.dpsp-yes.com
> Dynamic PSP(tm) - the first true RAD toolkit for Oracle-based internet
applications.
> All opinions are mine and do not necessarily go in line with those of my
employer.
>
>
> "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message
> news:1016721483.26795.0.nnrp-10.9e984b29_at_news.demon.co.uk...
> >
> > A hash function or method is a function
> > that has a limited list of possible output
> > values. When supplied with a large list of
> > input values, a good hash function will distribute
> > the input randomly, evenly, and reproducibly
> > across its list of outputs.
> >
> > --
> > Jonathan Lewis
> > http://www.jlcomp.demon.co.uk
> >
> > Next Seminar - UK, April 3rd - 5th
> > http://www.jlcomp.demon.co.uk/seminar.html
> >
> > Host to The Co-Operative Oracle Users' FAQ
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> >
> > Author of:
> > Practical Oracle 8i: Building Efficient Databases
> >
> >
> >
> >
>
Received on Fri Mar 22 2002 - 10:32:14 CST