diff options
Diffstat (limited to 'doc/src/sgml/maintenance.sgml')
| -rw-r--r-- | doc/src/sgml/maintenance.sgml | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml index d7d2eec623..76225bd2f9 100644 --- a/doc/src/sgml/maintenance.sgml +++ b/doc/src/sgml/maintenance.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/maintenance.sgml,v 1.9 2001/11/21 05:53:41 thomas Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/maintenance.sgml,v 1.10 2001/11/28 20:49:10 petere Exp $ --> <chapter id="maintenance"> @@ -100,8 +100,8 @@ $Header: /cvsroot/pgsql/doc/src/sgml/maintenance.sgml,v 1.9 2001/11/21 05:53:41 </indexterm> <para> - In normal <productname>PostgreSQL</productname> operation, an UPDATE or - DELETE of a row does not immediately remove the old <firstterm>tuple</> + In normal <productname>PostgreSQL</productname> operation, an <command>UPDATE</> or + <command>DELETE</> of a row does not immediately remove the old <firstterm>tuple</> (version of the row). This approach is necessary to gain the benefits of multiversion concurrency control (see the <citetitle>User's Guide</>): the tuple must not be deleted while @@ -268,7 +268,7 @@ $Header: /cvsroot/pgsql/doc/src/sgml/maintenance.sgml,v 1.9 2001/11/21 05:53:41 The new approach to XID comparison distinguishes two special XIDs, numbers 1 and 2 (<literal>BootstrapXID</> and <literal>FrozenXID</>). These two XIDs are always considered older than every normal XID. Normal XIDs (those - greater than 2) are compared using modulo-2^31 arithmetic. This means + greater than 2) are compared using modulo-2<superscript>31</> arithmetic. This means that for every normal XID, there are two billion XIDs that are <quote>older</> and two billion that are <quote>newer</>; another way to say it is that the normal XID space is circular with no endpoint. |