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体验新版 GitCode,发现更多精彩内容 >>
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654f8f0b
编写于
5月 22, 1999
作者:
T
Thomas G. Lockhart
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差异文件
Finish initial markup of cvs.sgml, and include it in the programmer's guide
and the integrated doc. Clean up other markup.
上级
85170aa9
变更
9
展开全部
隐藏空白更改
内联
并排
Showing
9 changed file
with
1380 addition
and
1114 deletion
+1380
-1114
doc/src/sgml/cvs.sgml
doc/src/sgml/cvs.sgml
+611
-922
doc/src/sgml/datetime.sgml
doc/src/sgml/datetime.sgml
+697
-137
doc/src/sgml/pg_options.sgml
doc/src/sgml/pg_options.sgml
+1
-1
doc/src/sgml/postgres.sgml
doc/src/sgml/postgres.sgml
+10
-2
doc/src/sgml/programmer.sgml
doc/src/sgml/programmer.sgml
+7
-1
doc/src/sgml/query.sgml
doc/src/sgml/query.sgml
+0
-3
doc/src/sgml/sql.sgml
doc/src/sgml/sql.sgml
+3
-3
doc/src/sgml/user.sgml
doc/src/sgml/user.sgml
+8
-2
doc/src/sgml/xoper.sgml
doc/src/sgml/xoper.sgml
+43
-43
未找到文件。
doc/src/sgml/cvs.sgml
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654f8f0b
此差异已折叠。
点击以展开。
doc/src/sgml/datetime.sgml
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654f8f0b
此差异已折叠。
点击以展开。
doc/src/sgml/pg_options.sgml
浏览文件 @
654f8f0b
<
Chapter
Id
=
"pg-options"
>
<
Chapter
Id
=
"pg-options
-dev
"
>
<
DocInfo
>
<
AuthorGroup
>
<
Author
>
...
...
doc/src/sgml/postgres.sgml
浏览文件 @
654f8f0b
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/postgres.sgml,v 1.2
2 1999/05/20 05:39:27
thomas Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/postgres.sgml,v 1.2
3 1999/05/22 02:27:24
thomas Exp $
Postgres integrated documentation.
Other subset docs should be copied and shrunk from here.
thomas 1998-02-23
$Log: postgres.sgml,v $
Revision 1.23 1999/05/22 02:27:24 thomas
Finish initial markup of cvs.sgml, and include it in the programmer's guide
and the integrated doc. Clean up other markup.
Revision 1.22 1999/05/20 05:39:27 thomas
Rearrange and consolidate the Admin Guide.
Add reference pages for utilities and remove standalone chapters for same.
...
...
@@ -90,6 +94,7 @@ Move SQL reference pages up into the User's Guide.
<!entity advanced SYSTEM "advanced.sgml">
<!entity array SYSTEM "array.sgml">
<!entity datatype SYSTEM "datatype.sgml">
<!entity datetime SYSTEM "datetime.sgml">
<!entity environ SYSTEM "environ.sgml">
<!entity func SYSTEM "func.sgml">
<!entity inherit SYSTEM "inherit.sgml">
...
...
@@ -351,8 +356,11 @@ Your name here...
Additional related information.
</Para>
</PartIntro>
&docguide;
&datetime;
&docguide;
<!--
&contacts;
-->
&biblio;
</Part>
...
...
doc/src/sgml/programmer.sgml
浏览文件 @
654f8f0b
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/Attic/programmer.sgml,v 1.1
4 1999/05/20 05:39:27
thomas Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/Attic/programmer.sgml,v 1.1
5 1999/05/22 02:27:24
thomas Exp $
Postgres Programmer's Guide.
- thomas 1998-10-27
$Log: programmer.sgml,v $
Revision 1.15 1999/05/22 02:27:24 thomas
Finish initial markup of cvs.sgml, and include it in the programmer's guide
and the integrated doc. Clean up other markup.
Revision 1.14 1999/05/20 05:39:27 thomas
Rearrange and consolidate the Admin Guide.
Add reference pages for utilities and remove standalone chapters for same.
...
...
@@ -94,6 +98,7 @@ Bigger updates to the installation instructions (install and config).
<!entity bki SYSTEM "bki.sgml">
<!entity compiler SYSTEM "compiler.sgml">
<!entity contacts SYSTEM "contacts.sgml">
<!entity cvs SYSTEM "cvs.sgml">
<!entity docguide SYSTEM "docguide.sgml">
<!entity geqo SYSTEM "geqo.sgml">
<!entity options SYSTEM "pg_options.sgml">
...
...
@@ -216,6 +221,7 @@ Disable it until we put in some info.
<!-- appendices -->
&cvs;
&docguide;
<!--
&contacts;
...
...
doc/src/sgml/query.sgml
浏览文件 @
654f8f0b
...
...
@@ -158,9 +158,6 @@ COPY INTO weather FROM '/home/user/weather.txt'
</para>
</sect1>
</Para>
</sect1>
<Sect1>
<Title>Querying a Class</Title>
...
...
doc/src/sgml/sql.sgml
浏览文件 @
654f8f0b
...
...
@@ -288,7 +288,7 @@ attributes are taken from. We often write a relation scheme as
<parameter>D<subscript>i</subscript></parameter>,
for each attribute
<parameter>A<subscript>i</subscript></parameter>,
1 <&equal
; <literal>i</literal> <&equal
; <literal>k</literal>,
1 <&equal
s; <literal>i</literal> <&equals
; <literal>k</literal>,
where the values of the attributes are taken from. We often write
a relation scheme as
<literal>R(<parameter>A<subscript>1</subscript></parameter>,
...
...
@@ -325,11 +325,11 @@ attributes are taken from. We often write a relation scheme as
integers. We define this by assigning a data type to each
attribute. The type of <classname>SNAME</classname> will be
<type>VARCHAR(20)</type> (this is the <acronym>SQL</acronym> type
for character strings of length <&equal; 20),
for character strings of length <&equal
s
; 20),
the type of <classname>SNO</classname> will be
<type>INTEGER</type>. With the assignment of a data type we also have selected
a domain for an attribute. The domain of <classname>SNAME</classname> is the set of all
character strings of length <&equal; 20,
character strings of length <&equal
s
; 20,
the domain of <classname>SNO</classname> is the set of
all integer numbers.
</para>
...
...
doc/src/sgml/user.sgml
浏览文件 @
654f8f0b
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/Attic/user.sgml,v 1.
9 1999/05/20 05:39:29
thomas Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/Attic/user.sgml,v 1.
10 1999/05/22 02:27:25
thomas Exp $
Postgres User's Manual.
Derived from postgres.sgml.
thomas 1998-02-24
$Log: user.sgml,v $
Revision 1.10 1999/05/22 02:27:25 thomas
Finish initial markup of cvs.sgml, and include it in the programmer's guide
and the integrated doc. Clean up other markup.
Revision 1.9 1999/05/20 05:39:29 thomas
Rearrange and consolidate the Admin Guide.
Add reference pages for utilities and remove standalone chapters for same.
...
...
@@ -49,6 +53,7 @@ Move SQL reference pages up into the User's Guide.
<!entity array SYSTEM "array.sgml">
<!entity biblio SYSTEM "biblio.sgml">
<!entity datatype SYSTEM "datatype.sgml">
<!entity datetime SYSTEM "datetime.sgml">
<!entity environ SYSTEM "environ.sgml">
<!entity func SYSTEM "func.sgml">
<!entity inherit SYSTEM "inherit.sgml">
...
...
@@ -149,7 +154,8 @@ Your name here...
&manage;
&storage;
&commands;
&datetime;
<!--
&contacts;
-->
...
...
doc/src/sgml/xoper.sgml
浏览文件 @
654f8f0b
...
...
@@ -186,7 +186,7 @@ SELECT (a + b) AS c FROM test_complex;
<para>
Providing NEGATOR is very helpful to the query optimizer since
it allows expressions like NOT (x = y) to be simplified into
x
<>
y. This comes up more often than you might think, because
x
<>
y. This comes up more often than you might think, because
NOTs can be inserted as a consequence of other rearrangements.
</para>
...
...
@@ -225,21 +225,21 @@ SELECT (a + b) AS c FROM test_complex;
These are the standard restriction estimators:
<ProgramListing>
eqsel for =
neqsel for
<>
intltsel for
< or <
=
intgtsel for
> or >
=
neqsel for
<>
intltsel for
< or <
=
intgtsel for
> or >
=
</ProgramListing>
It might seem a little odd that these are the categories, but they
make sense if you think about it. '=' will typically accept only
a small fraction of the rows in a table; '
<>
' will typically reject
only a small fraction. '
<
' will accept a fraction that depends on
a small fraction of the rows in a table; '
<>
' will typically reject
only a small fraction. '
<
' will accept a fraction that depends on
where the given constant falls in the range of values for that table
column (which, it just so happens, is information collected by
VACUUM ANALYZE and made available to the selectivity estimator).
'
<=' will accept a slightly larger fraction than '<
' for the same
'
<=' will accept a slightly larger fraction than '<
' for the same
comparison constant, but they're close enough to not be worth
distinguishing, especially since we're not likely to do better than a
rough guess anyhow. Similar remarks apply to '
>' and '>
='.
rough guess anyhow. Similar remarks apply to '
>' and '>
='.
</para>
<para>
...
...
@@ -249,48 +249,48 @@ SELECT (a + b) AS c FROM test_complex;
matching operators (~, ~*, etc) use eqsel on the assumption that they'll
usually only match a small fraction of the entries in a table.
</para>
</sect2>
<sect2>
<title>JOIN</title>
<sect2>
<title>JOIN</title>
<para>
The JOIN clause, if provided, names a join selectivity
estimation function for the operator (note that this is a function
name, not an operator name). JOIN clauses only make sense for
binary operators that return boolean. The idea behind a join
selectivity estimator is to guess what fraction of the rows in a
pair of tables will satisfy a WHERE-clause condition of the form
<ProgramListing>
<para>
The JOIN clause, if provided, names a join selectivity
estimation function for the operator (note that this is a function
name, not an operator name). JOIN clauses only make sense for
binary operators that return boolean. The idea behind a join
selectivity estimator is to guess what fraction of the rows in a
pair of tables will satisfy a WHERE-clause condition of the form
<ProgramListing>
table1.field1 OP table2.field2
</ProgramListing>
for the current operator. As with the RESTRICT clause, this helps
the optimizer very substantially by letting it figure out which
of several possible join sequences is likely to take the least work.
</para>
</ProgramListing>
for the current operator. As with the RESTRICT clause, this helps
the optimizer very substantially by letting it figure out which
of several possible join sequences is likely to take the least work.
</para>
<para>
As before, this chapter will make no attempt to explain how to write
a join selectivity estimator function, but will just suggest that
you use one of the standard estimators if one is applicable:
<ProgramListing>
<para>
As before, this chapter will make no attempt to explain how to write
a join selectivity estimator function, but will just suggest that
you use one of the standard estimators if one is applicable:
<ProgramListing>
eqjoinsel for =
neqjoinsel for <>
intltjoinsel for < or <=
intgtjoinsel for > or >=
</ProgramListing>
</para>
neqjoinsel for <>
intltjoinsel for < or <=
intgtjoinsel for > or >=
</ProgramListing>
</para>
</sect2>
</sect2>
<sect2>
<title>HASHES</title>
<sect2>
<title>HASHES</title>
<para>
The HASHES clause, if present, tells the system that it is OK to
use the hash join method for a join based on this operator. HASHES
only makes sense for binary operators that return boolean --- and
in practice, the operator had better be equality for some data type.
</para>
<para>
The HASHES clause, if present, tells the system that it is OK to
use the hash join method for a join based on this operator. HASHES
only makes sense for binary operators that return boolean --- and
in practice, the operator had better be equality for some data type.
</para>
<para>
The assumption underlying hash join is that the join operator can
...
...
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