Commit 140fc786 authored by serg@serg.mysql.com's avatar serg@serg.mysql.com

ALTER TABLE DISABLE/ENABLE KEYS section relocated

parent fc3e066f
...@@ -34541,15 +34541,6 @@ options, MySQL simply renames the files that correspond to the table ...@@ -34541,15 +34541,6 @@ options, MySQL simply renames the files that correspond to the table
@code{tbl_name}. There is no need to create the temporary table. @code{tbl_name}. There is no need to create the temporary table.
@xref{RENAME TABLE,, @code{RENAME TABLE}}. @xref{RENAME TABLE,, @code{RENAME TABLE}}.
@item
Since @strong{MySQL 4.0} the above feature can be activated explicitly.
@code{ALTER TABLE ... DISABLE KEYS} makes MySQL to stop updating
non-unique indexes for @code{MyISAM} table.
@code{ALTER TABLE ... ENABLE KEYS} then should be used to recreate missing
indexes. As MySQL does it with special algorithm which is much
faster then inserting keys one by one, disabling keys could give a
considerable speedup on bulk inserts.
@item @item
@code{create_definition} clauses use the same syntax for @code{ADD} and @code{create_definition} clauses use the same syntax for @code{ADD} and
@code{CHANGE} as for @code{CREATE TABLE}. Note that this syntax includes @code{CHANGE} as for @code{CREATE TABLE}. Note that this syntax includes
...@@ -34649,6 +34640,15 @@ If you use @code{ALTER TABLE} on a @code{MyISAM} table, all non-unique ...@@ -34649,6 +34640,15 @@ If you use @code{ALTER TABLE} on a @code{MyISAM} table, all non-unique
indexes are created in a separate batch (like in @code{REPAIR}). indexes are created in a separate batch (like in @code{REPAIR}).
This should make @code{ALTER TABLE} much faster when you have many indexes. This should make @code{ALTER TABLE} much faster when you have many indexes.
@item
Since @strong{MySQL 4.0} the above feature can be activated explicitly.
@code{ALTER TABLE ... DISABLE KEYS} makes MySQL to stop updating
non-unique indexes for @code{MyISAM} table.
@code{ALTER TABLE ... ENABLE KEYS} then should be used to recreate missing
indexes. As MySQL does it with special algorithm which is much
faster then inserting keys one by one, disabling keys could give a
considerable speedup on bulk inserts.
@item @item
@findex mysql_info() @findex mysql_info()
With the C API function @code{mysql_info()}, you can find out how many With the C API function @code{mysql_info()}, you can find out how many
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