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Update "Conflicting lock modes" to show as conflict, add

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current/requested headings, add link to table from text.
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Bruce Momjian 2007-02-18 01:21:49 +00:00
parent 49451ae03e
commit 9b9cd9c205
1 changed files with 93 additions and 93 deletions
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186
doc/src/sgml/mvcc.sgml
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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/mvcc.sgml,v 2.68 2007/02/16 03:50:29 momjian Exp $ --> <!-- $PostgreSQL: pgsql/doc/src/sgml/mvcc.sgml,v 2.69 2007/02/18 01:21:49 momjian Exp $ -->
<chapter id="mvcc"> <chapter id="mvcc">
<title>Concurrency Control</title> <title>Concurrency Control</title>
@ -536,7 +536,8 @@ SELECT SUM(value) FROM mytab WHERE class = 2;
To some extent the names reflect the typical usage of each lock To some extent the names reflect the typical usage of each lock
mode &mdash; but the semantics are all the same. The only real difference mode &mdash; but the semantics are all the same. The only real difference
between one lock mode and another is the set of lock modes with between one lock mode and another is the set of lock modes with
which each conflicts. Two transactions cannot hold locks of conflicting which each conflicts (see <xref linkend="table-lock-compatibility">).
. Two transactions cannot hold locks of conflicting
modes on the same table at the same time. (However, a transaction modes on the same table at the same time. (However, a transaction
never conflicts with itself. For example, it might acquire never conflicts with itself. For example, it might acquire
<literal>ACCESS EXCLUSIVE</literal> lock and later acquire <literal>ACCESS EXCLUSIVE</literal> lock and later acquire
@ -741,119 +742,118 @@ SELECT SUM(value) FROM mytab WHERE class = 2;
releases locks acquired within it. releases locks acquired within it.
</para> </para>
<table tocentry="1" id="table-lock-compatibility"> <table tocentry="1" id="table-lock-compatibility">
<title> Compatibility of lock modes</title> <title> Conflicting lock modes</title>
<tgroup cols="9"> <tgroup cols="9">
<colspec colnum="1" colwidth="1*"> <colspec colnum="2" colname="lockst">
<colspec colnum="2" colwidth="1*"> <colspec colnum="9" colname="lockend">
<colspec colnum="3" colwidth="1*"> <spanspec namest="lockst" nameend="lockend" spanname="lockreq">
<colspec colnum="4" colwidth="1*">
<colspec colnum="5" colwidth="1*">
<colspec colnum="6" colwidth="1*">
<colspec colnum="7" colwidth="1*">
<colspec colnum="8" colwidth="1*">
<colspec colnum="9" colwidth="1*">
<thead> <thead>
<row> <row>
<entry>Modes</entry> <entry morerows="1">Requested Lock Mode</entry>
<entry>AS</entry> <entry spanname="lockreq">Current Lock Mode</entry>
<entry>RS</entry> </row>
<entry>RE</entry> <row>
<entry>SUE</entry> <entry>ACCESS SHARE</entry>
<entry>S</entry> <entry>ROW SHARE</entry>
<entry>SRE</entry> <entry>ROW EXCLUSIVE</entry>
<entry>E</entry> <entry>SHARE UPDATE EXCLUSIVE</entry>
<entry>AE</entry> <entry>SHARE</entry>
<entry>SHARE ROW EXCLUSIVE</entry>
<entry>EXCLUSIVE</entry>
<entry>ACCESS EXCLUSIVE</entry>
</row> </row>
</thead> </thead>
<tbody> <tbody>
<row> <row>
<entry>AS</entry> <entry>ACCESS SHARE</entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">N</entry> <entry align="center">X</entry>
</row> </row>
<row> <row>
<entry>RS</entry> <entry>ROW SHARE</entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
</row> </row>
<row> <row>
<entry>RE</entry> <entry>ROW EXCLUSIVE</entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
</row> </row>
<row> <row>
<entry>SUE</entry> <entry>SHARE UPDATE EXCLUSIVE</entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
</row> </row>
<row> <row>
<entry>S</entry> <entry>SHARE</entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
</row> </row>
<row> <row>
<entry>SRE</entry> <entry>SHARE ROW EXCLUSIVE</entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
</row> </row>
<row> <row>
<entry>E</entry> <entry>EXCLUSIVE</entry>
<entry align="center">Y</entry> <entry align="center"></entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
</row> </row>
<row> <row>
<entry>AE</entry> <entry>ACCESS EXCLUSIVE</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
<entry align="center">N</entry> <entry align="center">X</entry>
</row> </row>
</tbody> </tbody>
</tgroup> </tgroup>