I'm trying to import a mysqldump backup of a drupal database taken from a server running MySQL 5.0 (which will be upgraded to 5.5) onto my local machine running MySQL 5.5.23. The import fails with the below error:

ERROR 1100 (HY000) at line 11084: Table 'search_index' was not locked with LOCK TABLES

When I open up the backup at line 11084 here is what I get:

/*!40000 ALTER TABLE `sessions` DISABLE KEYS */;
INSERT INTO `sessions` VALUES ...
-- MySQL dump 10.11
-- Host: localhost    Database: drupal
-- ------------------------------------------------------
-- Server version       5.0.77-log

/*!40101 SET NAMES utf8 */;
/*!40103 SET TIME_ZONE='+00:00' */;

-- Table structure for table `search_index`

DROP TABLE IF EXISTS `search_index`;        <=== LINE 11084
SET @saved_cs_client     = @@character_set_client;
SET character_set_client = utf8;
CREATE TABLE `search_index` (
  `word` varchar(50) NOT NULL default '',
  `sid` int(10) unsigned NOT NULL default '0',
  `type` varchar(16) default NULL,
  `score` float default NULL,
  UNIQUE KEY `word_sid_type` (`word`,`sid`,`type`),
  KEY `sid_type` (`sid`,`type`),
  KEY `word` (`word`)
SET character_set_client = @saved_cs_client;

I checked the other statements and normally INSERT statements are followed by UNLOCK TABLES;. Accordingly if I make the below modifications to the mysqldump file the problem is fixed:

INSERT INTO `sessions` VALUES ...
UNLOCK TABLES;                   <=== ADDED LINE
-- MySQL dump 10.11
DROP TABLE IF EXISTS `search_index`;

I don't know what's wrong there but the whole comment block starting with -- MySQL dump 10.11 is the same as the one at the beginning of the mysqldump file, and it looks like mysqldump started a new dump while writing the INSERT INTO sessions statements which were not closed properly with UNLOCK TABLES;.

Does someone have any idea as to what's going on here?


My initial guess would be that when the mysqldump file was being created, the option single-transaction was not used.

According to MySQL Documentation on single-transaction

The --single-transaction option and the --lock-tables option are mutually exclusive because LOCK TABLES causes any pending transactions to be committed implicitly.

The fact that you embedded UNLOCK TABLES; into the dump manually shows that neither option was called when the mysqldump was first created. Thus, upon reload, this error reared its ugly head.

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  • 1
    Using --single-transaction did fix the issue :) Thanks for much. What's weird is that we never had this issue before, it only started occurring yesterday. – Max May 15 '12 at 11:03

Sometimes this error comes when you have the following command in your sql dump without any insert

LOCK TABLES `table_name` WRITE;

Just remove the above line and it will resolve the issue for you.

Hope it helps

Cheers S

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