diff options
Diffstat (limited to 'doc/src/sgml/gin.sgml')
| -rw-r--r-- | doc/src/sgml/gin.sgml | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/doc/src/sgml/gin.sgml b/doc/src/sgml/gin.sgml index ca7641a8390..9ffa8be7bc3 100644 --- a/doc/src/sgml/gin.sgml +++ b/doc/src/sgml/gin.sgml @@ -105,7 +105,7 @@ Returns a palloc'd array of keys given an item to be indexed. The number of returned keys must be stored into <literal>*nkeys</>. If any of the keys can be null, also palloc an array of - <literal>*nkeys</> booleans, store its address at + <literal>*nkeys</> <type>bool</type> fields, store its address at <literal>*nullFlags</>, and set these null flags as needed. <literal>*nullFlags</> can be left <symbol>NULL</symbol> (its initial value) if all keys are non-null. @@ -130,11 +130,11 @@ <literal>query</> and the method it should use to extract key values. The number of returned keys must be stored into <literal>*nkeys</>. If any of the keys can be null, also palloc an array of - <literal>*nkeys</> booleans, store its address at + <literal>*nkeys</> <type>bool</type> fields, store its address at <literal>*nullFlags</>, and set these null flags as needed. - <literal>*nullFlags</> can be left NULL (its initial value) + <literal>*nullFlags</> can be left <symbol>NULL</symbol> (its initial value) if all keys are non-null. - The return value can be NULL if the <literal>query</> contains no keys. + The return value can be <symbol>NULL</symbol> if the <literal>query</> contains no keys. </para> <para> @@ -168,8 +168,8 @@ an array of <literal>*nkeys</> booleans and store its address at <literal>*pmatch</>. Each element of the array should be set to TRUE if the corresponding key requires partial match, FALSE if not. - If <literal>*pmatch</> is set to NULL then GIN assumes partial match - is not required. The variable is initialized to NULL before call, + If <literal>*pmatch</> is set to <symbol>NULL</symbol> then GIN assumes partial match + is not required. The variable is initialized to <symbol>NULL</symbol> before call, so this argument can simply be ignored by operator classes that do not support partial match. </para> @@ -181,7 +181,7 @@ To use it, <function>extractQuery</> must allocate an array of <literal>*nkeys</> Pointers and store its address at <literal>*extra_data</>, then store whatever it wants to into the - individual pointers. The variable is initialized to NULL before + individual pointers. The variable is initialized to <symbol>NULL</symbol> before call, so this argument can simply be ignored by operator classes that do not require extra data. If <literal>*extra_data</> is set, the whole array is passed to the <function>consistent</> method, and @@ -215,7 +215,7 @@ and so are the <literal>queryKeys[]</> and <literal>nullFlags[]</> arrays previously returned by <function>extractQuery</>. <literal>extra_data</> is the extra-data array returned by - <function>extractQuery</>, or NULL if none. + <function>extractQuery</>, or <symbol>NULL</symbol> if none. </para> <para> @@ -261,7 +261,7 @@ that generated the partial match query is provided, in case its semantics are needed to determine when to end the scan. Also, <literal>extra_data</> is the corresponding element of the extra-data - array made by <function>extractQuery</>, or NULL if none. + array made by <function>extractQuery</>, or <symbol>NULL</symbol> if none. Null keys are never passed to this function. </para> </listitem> @@ -305,9 +305,9 @@ </para> <para> - As of <productname>PostgreSQL</productname> 9.1, NULL key values can be - included in the index. Also, placeholder NULLs are included in the index - for indexed items that are NULL or contain no keys according to + As of <productname>PostgreSQL</productname> 9.1, null key values can be + included in the index. Also, placeholder nulls are included in the index + for indexed items that are null or contain no keys according to <function>extractValue</>. This allows searches that should find empty items to do so. </para> @@ -471,11 +471,11 @@ <para> <acronym>GIN</acronym> assumes that indexable operators are strict. This - means that <function>extractValue</> will not be called at all on a NULL + means that <function>extractValue</> will not be called at all on a null item value (instead, a placeholder index entry is created automatically), - and <function>extractQuery</function> will not be called on a NULL query + and <function>extractQuery</function> will not be called on a null query value either (instead, the query is presumed to be unsatisfiable). Note - however that NULL key values contained within a non-null composite item + however that null key values contained within a non-null composite item or query value are supported. </para> </sect1> |