MySQL Bugs: #46160: ha_innobase::check_if_incompatible_data may be wrong when used for 5.1.36

Bug #46160	ha_innobase::check_if_incompatible_data may be wrong when used for 5.1.36
Submitted:	14 Jul 2009 5:59	Modified:	30 Sep 2009 19:59
Reporter:	Yasufumi Kinoshita	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: InnoDB Plugin storage engine	Severity:	S3 (Non-critical)
Version:	5.1.36 + 1.0.3	OS:	Any
Assigned to:	Vasil Dimov	CPU Architecture:	Any
Tags:	Contribution

Description:
When 1.0.3 with 5.1.36, without the following patch, some mysql-test scripts result in fail.
Plugin may need to be fixed along with http://lists.mysql.com/commits/75258

How to repeat:
executing some mysql-test scripts

main.innodb
main.innodb_mysql
main.innodb-index
etc...

(all scripts should be patched by .patch files in the Plugin source)

Suggested fix:
diff -ru innodb_plugin-1.0.3_orig/handler/ha_innodb.cc innodb_plugin-1.0.3_tmp/handler/ha_innodb.cc
--- innodb_plugin-1.0.3_orig/handler/ha_innodb.cc       2009-07-14 13:51:44.000000000 +0900
+++ innodb_plugin-1.0.3_tmp/handler/ha_innodb.cc        2009-07-14 14:46:54.000000000 +0900
@@ -9319,7 +9319,8 @@

        /* Check that row format didn't change */
        if ((info->used_fields & HA_CREATE_USED_ROW_FORMAT) &&
-           get_row_type() != info->row_type) {
+           get_row_type() != ((info->row_type == ROW_TYPE_DEFAULT)
+                               ? ROW_TYPE_COMPACT : info->row_type)) {

                return(COMPATIBLE_DATA_NO);
        }

Thank you for the report.

Verified as described.

Failed tests in my case are:  main.innodb main.innodb_mysql main.innodb_bug42101-nonzero main.innodb-semi-consistent main.innodb_bug21704 main.innodb_bug42101

Yasufumi,

The tests do not fail for me with the latest version of the plugin that is not published yet, Marko committed this change recently:

------------------------------------------------------------------------
r5392 | marko | 2009-06-22 14:58:20 +0300 (Mon, 22 Jun 2009) | 4 lines
Changed paths:
   M /branches/zip/handler/ha_innodb.cc

branches/zip: ha_innobase::check_if_incompatible_data(): When
ROW_FORMAT=DEFAULT, do not compare to get_row_type().
Without this change, fast index creation will be disabled
in recent versions of MySQL 5.1.
------------------------------------------------------------------------

--- cut ---
Index: handler/ha_innodb.cc
===================================================================
--- handler/ha_innodb.cc	(revision 5391)
+++ handler/ha_innodb.cc	(revision 5392)
@@ -9183,14 +9183,15 @@ ha_innobase::check_if_incompatible_data(
 		info->auto_increment_value != 0) {
 
 		return(COMPATIBLE_DATA_NO);
 	}
 
 	/* Check that row format didn't change */
-	if ((info->used_fields & HA_CREATE_USED_ROW_FORMAT) &&
-	    get_row_type() != info->row_type) {
+	if ((info->used_fields & HA_CREATE_USED_ROW_FORMAT)
+	    && info->row_type != ROW_TYPE_DEFAULT
+	    && info->row_type != get_row_type()) {
 
 		return(COMPATIBLE_DATA_NO);
 	}
 
 	/* Specifying KEY_BLOCK_SIZE requests a rebuild of the table. */
 	if (info->used_fields & HA_CREATE_USED_KEY_BLOCK_SIZE) {
--- cut ---

Yasufumi,

I think your patch is unnecessary restrictive, please verify my analysis:

If the newly specified row format (info->row_type) is ROW_TYPE_DEFAULT, then your patch will check whether the current format (get_row_type()) is ROW_TYPE_COMPACT and will return COMPATIBLE_DATA_NO if it is not. I think this is unnecessary and COMPATIBLE_DATA_YES should be returned in this case because if info->row_type==ROW_TYPE_DEFAULT this means that no ROW_FORMAT= has been specified in the SQL and so the format remains whatever it has been and the new and the old table definitions are compatible.

What do you think?

This has been fixed in r5392 and has been released in InnoDB Plugin 1.0.4.

Noted in 5.4.2 changelog.

For InnoDB tables, an unnecessary table rebuild for ALTER TABLE could
sometimes occur if ROW_FORMAT was specified.