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mirror of https://github.com/postgres/postgres.git synced 2025-07-07 00:36:50 +03:00

Fixups in content and markup for 7.0 release.

This commit is contained in:
Thomas G. Lockhart
2000-05-02 20:02:03 +00:00
parent a6894eb81a
commit 45f79cae14
57 changed files with 3130 additions and 2380 deletions

View File

@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.8 2000/04/07 13:30:58 thomas Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.9 2000/05/02 20:01:52 thomas Exp $
-->
<chapter id="sql">
@ -24,7 +24,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.8 2000/04/07 13:30:58 thomas E
<para>
<acronym>SQL</acronym> has become the most popular relational query
language.
The name <quote><acronym>SQL</acronym></quote> is an abbreviation for
The name "<acronym>SQL</acronym>" is an abbreviation for
<firstterm>Structured Query Language</firstterm>.
In 1974 Donald Chamberlin and others defined the
language SEQUEL (<firstterm>Structured English Query
@ -759,8 +759,8 @@ t<subscript>r</subscript>(A,B)=t&and;t<subscript>r</subscript>(C,D)=t<subscript>
can be formulated using relational algebra can also be formulated
using the relational calculus and vice versa.
This was first proved by E. F. Codd in
1972. This proof is based on an algorithm (<quote>Codd's reduction
algorithm</quote>) by which an arbitrary expression of the relational
1972. This proof is based on an algorithm ("Codd's reduction
algorithm") by which an arbitrary expression of the relational
calculus can be reduced to a semantically equivalent expression of
relational algebra. For a more detailed discussion on that refer to
<xref linkend="DATE94" endterm="DATE94">