Re: CHECKSUM() question

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Hi Eric Isaacs,

Thanks for your reply.

Basically I am creating a hash tables in a separate database, and speed is
crucial, since that database will be used for web based where users will
perform a search based on First, Last, Address, State , Zip etc... After I
find the required records in the hash tables then I join the temp table into
the source database where I grab the full records. I hope that clarifies a
bit more.

Thanks,

Eric

"Eric Isaacs" <eisaacs@xxxxxxxxx> wrote in message
news:3662b581-9f59-4584-911a-512333796984@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
You're also going to want to take into account the speed. Depending
on how you store the hashbyte value (as a calculated field or an
indexed view) I think you'll find that checking the value for
uniqueness will happen much faster if the value is stored and
indexed. If it's a calculated field and you add an index to it, it
will be stored twice. If you add it as an indexed view on the
hashbytes, I think it will store the hashbyte value only once. If you
add a unique constraint to the last and first names, it will store the
names twice (once in the table and once in the index.)

Diskspace is cheap, but getting this wrong could be expensive and
slow. You didn't mention speed as a criteria, but speed could be
exactly what you give up by finding a solution that doesn't index the
two names properly.

-Eric Isaacs


.

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