diff options
| -rw-r--r-- | doc/src/sgml/maintenance.sgml | 22 | ||||
| -rw-r--r-- | doc/src/sgml/ref/create_index.sgml | 2 |
2 files changed, 21 insertions, 3 deletions
diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml index ca1e82018f9..ae6456bc45e 100644 --- a/doc/src/sgml/maintenance.sgml +++ b/doc/src/sgml/maintenance.sgml @@ -750,8 +750,9 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu <para> In some situations it is worthwhile to rebuild indexes periodically - with the <xref linkend="sql-reindex"> - command. + with the <xref linkend="sql-reindex"> command or a series of individual + rebuilding steps. + </para> <para> @@ -777,6 +778,23 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu (This consideration does not apply to non-B-tree indexes.) It might be worthwhile to reindex periodically just to improve access speed. </para> + + <para> + <xref linkend="sql-reindex"> can be used safely and easily in all cases. + But since the command requires an exclusive table lock, it is + often preferable to execute an index rebuild with a sequence of + creation and replacement steps. Index types that support + <xref linkend="sql-createindex"> with the <literal>CONCURRENTLY</> + option can instead be recreated that way. If that is successful and the + resulting index is valid, the original index can then be replaced by + the newly built one using a combination of <xref linkend="sql-alterindex"> + and <xref linkend="sql-dropindex">. When an index is used to enforce + uniqueness or other constraints, <xref linkend="sql-altertable"> might + be necessary to swap the existing constraint with one enforced by + the new index. Review this alternate multi-step rebuild approach + carefully before using it as there are limitations on which + indexes can be reindexed this way, and errors must be handled. + </para> </sect1> diff --git a/doc/src/sgml/ref/create_index.sgml b/doc/src/sgml/ref/create_index.sgml index 01faa3afcf7..9a6a683e12d 100644 --- a/doc/src/sgml/ref/create_index.sgml +++ b/doc/src/sgml/ref/create_index.sgml @@ -405,7 +405,7 @@ CREATE [ UNIQUE ] INDEX [ CONCURRENTLY ] [ <replaceable class="parameter">name</ </para> <para> - If a problem arises while scanning the table, such as a + If a problem arises while scanning the table, such as a deadlock or a uniqueness violation in a unique index, the <command>CREATE INDEX</> command will fail but leave behind an <quote>invalid</> index. This index will be ignored for querying purposes because it might be incomplete; |