diff options
| author | Bruce Momjian | 2004-04-20 04:25:47 +0000 |
|---|---|---|
| committer | Bruce Momjian | 2004-04-20 04:25:47 +0000 |
| commit | bb18b4739001cfbfb38584f467d53d97666cc114 (patch) | |
| tree | 32367982b4e4c47ae91a915586893e2f57d4d0b3 /doc | |
| parent | 2f2a3439a54263b82e4a0c74e3269f09884d65df (diff) | |
Document partial indexes for IS NULL lookups.
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/src/sgml/ref/create_index.sgml | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/doc/src/sgml/ref/create_index.sgml b/doc/src/sgml/ref/create_index.sgml index 34e12c6a5d2..43583df54d5 100644 --- a/doc/src/sgml/ref/create_index.sgml +++ b/doc/src/sgml/ref/create_index.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/create_index.sgml,v 1.45 2004/04/20 01:00:26 momjian Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/create_index.sgml,v 1.46 2004/04/20 04:25:47 momjian Exp $ PostgreSQL documentation --> @@ -77,11 +77,9 @@ CREATE [ UNIQUE ] INDEX <replaceable class="parameter">name</replaceable> ON <re </para> <para> - <literal>NULL</> values are not indexed by default. The best way - to index <literal>NULL</> values is to create a partial index using - an <literal>IS NULL</> comparison. <literal>IS NULL</> is more - of a function call than a value comparison, and this is why a partial - index works. + Indexes can not be used with <literal>IS NULL</> clauses by default. + The best way to use indexes in such cases is to create a partial index + using an <literal>IS NULL</> comparison. </para> <para> |