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Re: pervasiveness of surrogate (also called synthetic) keys

From: Misa Simic <misa(dot)simic(at)gmail(dot)com>
To: Merlin Moncure <mmoncure(at)gmail(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: pervasiveness of surrogate (also called synthetic) keys
Date: 2011-05-04 12:50:54
Message-ID: BANLkTinF0M9u_NojtRt0G98wiKhWT36v3w@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-general
2011/5/4 Merlin Moncure <mmoncure(at)gmail(dot)com>

> Most of the old school accounting systems maintained an invoice line
> number.
>
> > Invoice Line
> >     -Invoice Number
> >     -LineNo
> >     -ItemID
> >     -qty
> >     -Price
>
> The line number started from 1 (the first line on the invoice) on
> every unique invoice.  This has the added benefit of allowing the
> primary key index (invoice_no, line_no) allowing you to pull up the
> invoice line records in correct order without requiring an extra sort
> and, if you don't need any fields from the invoice, a join.
>
> Compare the two queries pulling up invoice lines over a range of
> invoice numbers.
>
> merlin
>


Thanks, merlin,

And in that case, what is "Natural" in LineNo? I would say, with adding
LineNo we are creating syntethic/surrogate Key (just instead of 1 surrogate
column - it will be Compound key with more columns...)? The same is with all
other tables what are "parts" of an Entity, Serial Numbers, Accounting
Distribution produced by Invoice...etc etc...

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Subject: Re: pervasiveness of surrogate (also called synthetic) keys
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Subject: Re: pervasiveness of surrogate (also called synthetic) keys

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