Kouhei Sutou
null+****@clear*****
Mon Feb 10 11:20:08 JST 2014
Kouhei Sutou 2014-02-10 11:20:08 +0900 (Mon, 10 Feb 2014) New Revision: 98d64628d92da28c2ce34b14200f2e645e6899b6 https://github.com/groonga/groonga/commit/98d64628d92da28c2ce34b14200f2e645e6899b6 Message: doc column_rename: fix documentation Reported by nise_nabe. Thanks!!! Modified files: doc/source/reference/commands/column_rename.txt Modified: doc/source/reference/commands/column_rename.txt (+34 -13) =================================================================== --- doc/source/reference/commands/column_rename.txt 2014-02-07 19:26:15 +0900 (e17a10b) +++ doc/source/reference/commands/column_rename.txt 2014-02-10 11:20:08 +0900 (83fe764) @@ -11,16 +11,31 @@ Summary ------- -``column_rename`` command renames specified column name of table. +``column_rename`` command renames a column. + +It is a light operation. It just changes a relationship between name +and the column object. It doesn't copy column values. + +It is a dangerous operation. You must stop all operations including +read operations while you run ``column_rename``. If the following case +is occurred, Groonga process may be crashed: + + * Starts an operation (like ``select``) that accesses the column to + be renamed by the current column name. The current column name is + called as ``the old column name`` in the below because the column + name is renamed. + * Runs ``column_rename``. The ``select`` is still running. + * The ``select`` accesses the column to be renamed by the old column + name. But the ``select`` can't find the column by the old name + because the column has been renamed to the new column name. It may + crash the Groonga process. Syntax ------ -``column_rename`` command takes two parameters. - -The required parameter is ``table`` and ``column_name``:: +``column_rename`` command takes three parameters. All parameters are required:: - column_rename table column + column_rename table name new_name Usage ----- @@ -46,20 +61,26 @@ Parameters This section describes parameters of ``column_rename``. -Required parameter -^^^^^^^^^^^^^^^^^^ +Required parameters +^^^^^^^^^^^^^^^^^^^ -There are required parameters, ``table_name`` and ``column_name``. +All parameters are required. ``table_name`` """""""""""""" -It specifies the name of table. +It specifies the name of table that has the column to be renamed. + +``name`` +"""""""" + +It specifies the column name to be renamed. + +``new_name`` +"""""""""""" -``column_name`` -""""""""""""""" +It specifies the new column name. -It specifies the name of column. Return value ------------ @@ -75,5 +96,5 @@ Return value ``SUCCEEDED_OR_NOT`` - If command succeeded, it returns true, otherwise it returns false on error. + It is ``true`` on success, ``false`` otherwise. -------------- next part -------------- HTML����������������������������...Download