InnoDB : MySQL's ACID-compliant Storage Engine

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7
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108 views

Avoid MySQL self-crashing on long semaphore waits

I run heavy queries on my InnoDB databases every night, and sometimes it causes long semaphore waits. More background in this question. What I have observed is that if the data is stored on an SSD, ...
4
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347 views

RDS MYSQL instance rebooted and won't load INNODB table

So my production db in RDS apparently either crashed or was rebooted during a version update, and upon being restarted mysql couldn't load one of the innodb tables: as evidenced by the following error ...
3
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78 views

MySQL process stuck on “cleaning up”, locking table forever

It was suggested I post here as opposed to StackOverflow. I'm new to debugging mysql/innodb issues so here is the best I have: I'm trying to run an integration test so these results are near ...
3
votes
0answers
49 views

How does mysql(innoDB) handle same foreign key for join

I have a table called X and another called Y. There is a primary key on Y that is a foreign key on X. Now, my data is such that there will be many rows in X that will have the exact same foreign key ...
3
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0answers
428 views

Which is the right way to fix “Error: 1205 Lock wait timeout exceeded; try restarting transaction”

I have a PHP script that sync a local DB against external datasource. Each time the script runs I perform some triggers on the DB where INSERT or UPDATE happen. These are the the triggers for that ...
3
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0answers
76 views

Flexible and robust way to cull older data?

I am no DBA and that is becoming more apparent daily, as such I am having trouble keeping my query times reasonable. I have about 3.57 Million records ( at about 3.43 GB ) and it takes about 2 minutes ...
3
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0answers
2k views

Query getting periodically stuck in 'copying to tmp table' state, never completes

I am running Wordpress on a dedicated server with a MySQL backend. I have a query that usually takes <1 second to execute, but periodically, this query will get stuck in a 'copying to tmp table' ...
3
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0answers
407 views

“InnoDB: error clustered record for sec rec not found” MySQL 5.5.28

We have a high-end server, 128GB RAM, 32 Core , Xeon, SSD RAID 10 - running Ubuntu 12.04 with MySQL 5.5.28. During high load, randomly we got the below error. MySQLcheck, innochecksum shows no ...
2
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47 views

MySQL: Is the read committed isolation level safe with mixed binary log format?

When using the MIXED format with the READ COMMITTED isolation level, am I safe? The docs state (http://dev.mysql.com/doc/refman/5.5/en/set-transaction.html#isolevel_read-committed) If you use ...
2
votes
0answers
55 views

Identifying table causing runaway rollback in MySQL 5.5 (InnoDB / Windows)

I have a large database (180 GB), running under Windows, with a runaway rollback that starts running as soon as the database is started up. I have started the database with innodb_force_recovery=3 ...
2
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0answers
32 views

FullText search using only some of columns in index

I have a full text index on (name,category,description) as shown below. mysql> show create table phppos_items; ...
2
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109 views

Two queries usually run fast but get slow when joined

There are those 2 tables CREATE TABLE IF NOT EXISTS `media` ( `mid` int(11) NOT NULL AUTO_INCREMENT, `user` int(11) NOT NULL, `order_type` int(11) NOT NULL, `media_id` varchar(50) COLLATE ...
2
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0answers
75 views

Mysql Match…against query performance in InnoDB Mysql 5.6

I need to search records in the table which contains millions of records. I have recently updated Mysql version from 5.1 to 5.6. I was using like in query which was taking around 15 sec to 30 sec. ...
2
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0answers
109 views

innodb update with limit locks all matching (ignores limit)

For a query similar to this: UPDATE myinnotable1 SET value=5,updated=now(),status=1 WHERE status>10 AND message="match msg" LIMIT 1; I found that innodb engine locks ALL rows matching criteria ...
2
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0answers
40 views

See indices implicitly created for foreign key constaints in MySQL

When I add a foreign key constraint to my table, SHOW INDEX doesn't show any new indices, but the overall space used by the indices in that table increases. Apparently, the index for the field I put a ...
2
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0answers
74 views

Denormalizing to speed up inserts

I have a MySQL InnoDb table with approximately 40 million rows and the following columns: param1 (int), param2 (int), param3 (int), geo (char2), value1 (bigint), value2 (bigint) I have an ...
2
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0answers
580 views

Recover innodb database from ibdata1 and *.frm files only

I have a problem on my server. I had a hard disk error on my server, and I restarted it. After that, I started wamp server software, but mysql services were not started. I checked all mysql data, ...
2
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0answers
819 views

using Aria vs InnoDB vs MyISAM

I was wondering (if anyone knows) if Aria database is crash safe . I had some tables with MyISAM which were getting corrupted very often and switch them to InnoDB . However innodb is a bit slower and ...
2
votes
0answers
78 views

Count how many locks required for a MySQL (InnoDB) query

I'm performance tuning a very data-heavy mysql application. It has a purge system that often seems to cause lock timeout errors for users. Based on my research I have a few adjustments to the query to ...
2
votes
0answers
253 views

Sleeping connections

I have a dedicated MySQL server(8GB) with following configuration. [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql lower_case_table_names = 1 ...
2
votes
0answers
2k views

How to prevent “ibdata files do not match the log sequence number”?

I am dealing with a very large set of databases that are all innodb. I've enountered this on mysql restart too many times for my comfort: ibdata files do not match the log sequence number But I've ...
1
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0answers
32 views

Disable/Remove Table Index for INSERT Performance

I am doing a database maintenance where I have to add new fields to a table with over 10GB of data about (20 million rows). To solve that I renamed tableA to be old_tableA and created a new table ...
1
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0answers
61 views

MySQL 5.6 Performance Tuning Issue

I have read and try lots of things about MySQL optimization and tuning. I tried most of them one by one according to our needs but nearly I got nothing. I am doing my test using some simulation ...
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0answers
36 views

InnoDB AUTO_INCREMENT resetting itself without MySQL restart

We've recently noticed the following scenario happening in many of our databases: A record is inserted, and receives an AUTO_INCREMENT primary key. The record is deleted. Another record is inserted, ...
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14 views

How to restore InnoDB from files

here is the situation I fu*d up my mysql setup, before I did that I copied entire /var/lib/mysql directory to another location. Now fresh installation of mysql is back and I cannot restore my files. ...
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0answers
36 views

How to resolve Innodb lock

I am trying to run a sitemap generator job for Magento and here is what I get as Innodb status after the query has failed to complete even after several hours. I do not know much about DBA stuff and ...
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0answers
40 views

mysql innodb - strange data loss

I am running a mysql database on linux with several InnoDB tables. At some point, the ibdata1 file got quite big and I wanted to delete it. So I made a dump, deleted the file and restarted the server. ...
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0answers
41 views

Moving to innodb_file_per_table?

I have just noticed (unfortunately while trying to restore from backup), that on my production server there is a 35GB ibdata1 file! As I understand I can reduce its size by moving to ...
1
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0answers
46 views

Optimizing a group by/where in/min() query in MySQL

Assume I have a table that looks like such (The actual column names of my real table would only make things harder to explain, so I have created a mimic that behaves similarly). id | cond1 | cond2 ...
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0answers
34 views

Find the last record of group of overlapped records

I have a little dilemma with filtering out result. The result and what I want to achieve is not very trivial and I didn't find an answer anywhere after extensive search. So here is my problem: I ...
1
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0answers
100 views

How to configure correctly Mysql heavy used server to prevent it from write IO huge spikes?

I have mysql 5.6 server which handles thousands of users online. All tables are Innodb. The problem is, that once or twice a day it writes huge amount of data to disk, or it slows down a lot. Than ...
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63 views

Update queries randomly slow on INNODB Mysql

I have been struggling with a slow update query. Have already tried using indexes and other query optimization techniques. I have been using MYSQL database with INNODB engine. The issue is that, ...
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0answers
41 views

Migrated servers… Innodb tables stayed innodb, but database is showns as MyISAM. Problem?

I moved servers. I exported DB on old, imported to new. Kept getting syntax error on import until I tried no compression. Weird, but it worked. I was skeptical so I compared the two carefully and ...
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0answers
55 views

Mariadb support rtree index on innodb soon?

I was looking through mariadb bug list online (https://mariadb.atlassian.net/secure/RapidBoard.jspa?rapidView=24&projectKey=MDEV), but I am unfamiliar with JIRA so I am not sure exactly what I am ...
1
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0answers
492 views

Reclaim disk space after dropping table(innodb_file_per_table = ON), strange scenario

I know it is often asking question. But I can't find answer for my scenario with specific condition. We use MySQL 5.5 We have always(I am sure) innodb_file_per_table = ON option in our mysql ...
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0answers
521 views

MariaDB is ignoring /etc/my.cnf

The variable I am trying to change is innodb_buffer_pool_size. As you can see below the settings is 512M. But SELECT @@innodb_buffer_pool_size; returns 134217728. When I execute: /usr/libexec/mysqld ...
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0answers
10 views

How “relatively safe” is the data which was salvaged from corrupted MySQL InnoDB database?

I encountered the corruption like the following. 150208 14:27:52 InnoDB: Error: page 443375 log sequence number 8941 870477908 InnoDB: is in the future! Current system log sequence number 5968 ...
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72 views

InnoDB Deadlocks Involving Currency Transactions

We're dealing with InnoDB deadlocks that are affecting our virtual transaction system. LATEST DETECTED DEADLOCK 150210 20:51:03 *** (1) TRANSACTION: TRANSACTION 0 4240405649, ACTIVE 0 sec, process no ...
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0answers
143 views

MySQL InnoDB Configuration with 60Gb of Memory

I'm running a large MySQL Database, in the range of 30Gb in size. The MySQL 5.5 server is running on a dedicated server with 60GB of RAM, with no other processes installed apart from monitoring tools, ...
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0answers
121 views

25.000+ rows - MySQL SELECT consecutive numbers performance issue

I have tried to be as explicit as I could. Below you have the query explained in details What I want to obtain? - I want to SELECT start_number and end_number from a set of consecutive numbers from ...
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0answers
395 views

How do I recover from MySQL InnoDB table/index corruption?

While trying to upgrade a database (in place) I got the following error. The server starts up and everything seems to be fine, except that the table mentioned in the message is no longer accessible. ...
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0answers
22 views

Need advice on optimizing database on a recurring basis

I have a search engine with approx 3.5 million rows in the searchable table. There are many suppliers that feed into the table each day, so primary keys are constantly being removed and added and the ...
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0answers
43 views

Can't seem to optimize joined select query

Can't seem to figure this one out. Query is taking upwards of 7-8 seconds which is just not acceptable and seems as though it will get worse as the table(s) get larger. Without going into a ton of ...
1
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0answers
25 views

Conversion to Barracuda/Compressed Rows Doesn't Free Disk Space

I'm currently converting large tables to the Barracuda file format. We are using file_per_table. I had one table that decreased from 4.3gb in size down to 1.8gb and we're very happy about this. ...
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0answers
198 views

mysqldump with --single-transaction seems to be “fixing” InnoDB tables with page corruption - why?

I'm trying to find out what exactly is happening here. I've been intentionally corrupting index pages in InnoDB tables, changing bytes in user record areas that actually contain information (largest ...
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0answers
775 views

How to generate data for News Feed efficiently like facebook , googleplus , twitter e.t.c?

I have created table as post ( post_id int(15) auto_increment primary key , user_id int(11) , post_text varchar(2000) , post_type int(1), ...
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0answers
70 views

Move all InnoDB databases into one subdirectory (innodb_file_per_table is ON)

First of all, excuse my English. I want to run a MySQL 5.6 on ZFS volume, and need to move all InnoDB databases to one subdirectory (which in fact will be a different ZFS filesystem). For example, by ...
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0answers
258 views

What do spikes in InnoDB lock structures indicate?

I co-maintain a high traffic site similar to StackExchange. It runs MySQL 5.1 (working on replacing it with MySQL 5.5 or MariaDB). All our tables are InnoDB. MySQL goes down a couple of times a day. ...
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0answers
242 views

MariaDB Galera Cluster

I have two mariadb servers in cluster that is working galera and xtradb. it is my primary server configuration: [mysqld] datadir=/var/lib/mysql query_cache_size=0 binlog_format=ROW ...
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0answers
54 views

Does union all have an enforced ordering

I know that a union does a de-duplication so can jumble the results, but I can't find a definitive answer for union all Example query select id from ( select id from table where id = 1 union all ...