diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ecpg.sgml | 4 | ||||
| -rw-r--r-- | doc/src/sgml/ref/declare.sgml | 49 |
2 files changed, 31 insertions, 22 deletions
diff --git a/doc/src/sgml/ecpg.sgml b/doc/src/sgml/ecpg.sgml index e2e757668a7..56f5d9b5db1 100644 --- a/doc/src/sgml/ecpg.sgml +++ b/doc/src/sgml/ecpg.sgml @@ -6792,8 +6792,8 @@ EXEC SQL DEALLOCATE DESCRIPTOR mydesc; <refsynopsisdiv> <synopsis> -DECLARE <replaceable class="parameter">cursor_name</replaceable> [ BINARY ] [ INSENSITIVE ] [ [ NO ] SCROLL ] CURSOR [ { WITH | WITHOUT } HOLD ] FOR <replaceable class="parameter">prepared_name</replaceable> -DECLARE <replaceable class="parameter">cursor_name</replaceable> [ BINARY ] [ INSENSITIVE ] [ [ NO ] SCROLL ] CURSOR [ { WITH | WITHOUT } HOLD ] FOR <replaceable class="parameter">query</replaceable> +DECLARE <replaceable class="parameter">cursor_name</replaceable> [ BINARY ] [ ASENSITIVE | INSENSITIVE ] [ [ NO ] SCROLL ] CURSOR [ { WITH | WITHOUT } HOLD ] FOR <replaceable class="parameter">prepared_name</replaceable> +DECLARE <replaceable class="parameter">cursor_name</replaceable> [ BINARY ] [ ASENSITIVE | INSENSITIVE ] [ [ NO ] SCROLL ] CURSOR [ { WITH | WITHOUT } HOLD ] FOR <replaceable class="parameter">query</replaceable> </synopsis> </refsynopsisdiv> diff --git a/doc/src/sgml/ref/declare.sgml b/doc/src/sgml/ref/declare.sgml index 2152134635e..8a2b8cc8929 100644 --- a/doc/src/sgml/ref/declare.sgml +++ b/doc/src/sgml/ref/declare.sgml @@ -26,7 +26,7 @@ PostgreSQL documentation <refsynopsisdiv> <synopsis> -DECLARE <replaceable class="parameter">name</replaceable> [ BINARY ] [ INSENSITIVE ] [ [ NO ] SCROLL ] +DECLARE <replaceable class="parameter">name</replaceable> [ BINARY ] [ ASENSITIVE | INSENSITIVE ] [ [ NO ] SCROLL ] CURSOR [ { WITH | WITHOUT } HOLD ] FOR <replaceable class="parameter">query</replaceable> </synopsis> </refsynopsisdiv> @@ -75,14 +75,25 @@ DECLARE <replaceable class="parameter">name</replaceable> [ BINARY ] [ INSENSITI </varlistentry> <varlistentry> + <term><literal>ASENSITIVE</literal></term> <term><literal>INSENSITIVE</literal></term> <listitem> <para> - Indicates that data retrieved from the cursor should be - unaffected by updates to the table(s) underlying the cursor that occur - after the cursor is created. In <productname>PostgreSQL</productname>, - this is the default behavior; so this key word has no - effect and is only accepted for compatibility with the SQL standard. + Cursor sensitivity determines whether changes to the data underlying the + cursor, done in the same transaction, after the cursor has been + declared, are visible in the cursor. <literal>INSENSITIVE</literal> + means they are not visible, <literal>ASENSITIVE</literal> means the + behavior is implementation-dependent. A third behavior, + <literal>SENSITIVE</literal>, meaning that such changes are visible in + the cursor, is not available in <productname>PostgreSQL</productname>. + In <productname>PostgreSQL</productname>, all cursors are insensitive; + so these key words have no effect and are only accepted for + compatibility with the SQL standard. + </para> + + <para> + Specifying <literal>INSENSITIVE</literal> together with <literal>FOR + UPDATE</literal> or <literal>FOR SHARE</literal> is an error. </para> </listitem> </varlistentry> @@ -133,7 +144,7 @@ DECLARE <replaceable class="parameter">name</replaceable> [ BINARY ] [ INSENSITI </variablelist> <para> - The key words <literal>BINARY</literal>, + The key words <literal>ASENSITIVE</literal>, <literal>BINARY</literal>, <literal>INSENSITIVE</literal>, and <literal>SCROLL</literal> can appear in any order. </para> @@ -246,10 +257,7 @@ DECLARE <replaceable class="parameter">name</replaceable> [ BINARY ] [ INSENSITI fetched, in the same way as for a regular <link linkend="sql-select"><command>SELECT</command></link> command with these options. - In addition, the returned rows will be the most up-to-date versions; - therefore these options provide the equivalent of what the SQL standard - calls a <quote>sensitive cursor</quote>. (Specifying <literal>INSENSITIVE</literal> - together with <literal>FOR UPDATE</literal> or <literal>FOR SHARE</literal> is an error.) + In addition, the returned rows will be the most up-to-date versions. </para> <caution> @@ -278,7 +286,7 @@ DECLARE <replaceable class="parameter">name</replaceable> [ BINARY ] [ INSENSITI <para> The main reason not to use <literal>FOR UPDATE</literal> with <literal>WHERE CURRENT OF</literal> is if you need the cursor to be scrollable, or to be - insensitive to the subsequent updates (that is, continue to show the old + isolated from concurrent updates (that is, continue to show the old data). If this is a requirement, pay close heed to the caveats shown above. </para> @@ -319,20 +327,21 @@ DECLARE liahona CURSOR FOR SELECT * FROM films; <title>Compatibility</title> <para> - The SQL standard says that it is implementation-dependent whether cursors - are sensitive to concurrent updates of the underlying data by default. In - <productname>PostgreSQL</productname>, cursors are insensitive by default, - and can be made sensitive by specifying <literal>FOR UPDATE</literal>. Other - products may work differently. - </para> - - <para> The SQL standard allows cursors only in embedded <acronym>SQL</acronym> and in modules. <productname>PostgreSQL</productname> permits cursors to be used interactively. </para> <para> + According to the SQL standard, changes made to insensitive cursors by + <literal>UPDATE ... WHERE CURRENT OF</literal> and <literal>DELETE + ... WHERE CURRENT OF</literal> statements are visibible in that same + cursor. <productname>PostgreSQL</productname> treats these statements like + all other data changing statements in that they are not visible in + insensitive cursors. + </para> + + <para> Binary cursors are a <productname>PostgreSQL</productname> extension. </para> |