InnoDB : MySQL's ACID-compliant Storage Engine

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3
votes
2answers
70 views

Should I normalise this database?

I have two database designs thought of for storing messages(instant messages) between users. It will be a group chat system. I have two table designs in mind. One is this: CREATE TABLE ...
4
votes
2answers
151 views

Integrate MySql Full Text searches in CMS

I'm developing my own CMS and using MySql v5.5 DB to save the content items records. Due to a technical limitations, I can't upgrade my database to a newer version that support Full-Text searches on ...
3
votes
0answers
63 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 ...
2
votes
1answer
230 views

MySQL Create Table with Partition Slow on server machine

Following create table statement with Partition runs in 10 Second on My Development Machine windows 7, i5 , 8GBRam, single disk runs in 16 Second on Virtual Machine windows server 2012 , xeon 2GHz ...
33
votes
1answer
58k views

What is the best way to reduce the size of ibdata in mysql?

I have some Production servers whose ibdata files increases in size day by day. It has already consumed 290GB of space. The tables in the servers are mostly InnoDB and there are high read and write ...
0
votes
1answer
95 views

RDS innodb_flush_log_at_trx_commit problem

I use Amazon RDS as mysql db backend for highload project and try to optimize insert performance for innodb tables. According to information from different sources - good candidate to speed up inserts ...
2
votes
2answers
552 views

MYSQL: How to improve performance of inserting over 1M rows to a table with over 100M indexed rows

I have this mysql table: CREATE TABLE `codes` ( `code` bigint(11) unsigned NOT NULL, `allocation` int(11) NOT NULL DEFAULT '0', `used` tinyint(1) NOT NULL DEFAULT '0', PRIMARY KEY (`code`), ...
1
vote
1answer
241 views

Slow database drop in mysql

Just installed a new 24 core server and it is noticeably slower when doing truncates and drops. Example: $ mysql -u root lmcdental_test2 Reading table information for completion of table and column ...
0
votes
1answer
676 views

mariadb won't start (InnoDB error: space header page consists of zero bytes in data file ./ibdata1)

The following messages are in /var/log/mariadb/mariadb.log when I try to start mariadb: 151103 13:42:01 [Note] InnoDB: Initializing buffer pool, size = 128.0M 151103 13:42:01 [Note] InnoDB: Completed ...
0
votes
1answer
65 views

mysql query taking differently long

I need some enlightenment on a MySQL query issue: I recently found out that a select query is taking differently long depending on how large ibdata1 is (at least that's how it seems to me). To be ...
2
votes
1answer
64 views

Split Mysql Table internally

How to split the huge mysql table (size around 200GB) internally? Is there any mechanism other than partition? The table size is daily growing. Table created using innodb with indices. Thanks in ...
1
vote
1answer
73 views

Small database size but very slow performance. What can I do?

We have this opencart installation with a database size of roughly 120 MB, 90MB of which is MyISAM and other is InnoDB. Most of the queries like : SELECT DISTINCT *, a.*, vd.seo, p.image, ...
2
votes
2answers
10k views

mysqldump --single-transaction, yet update queries are waiting for the backup

If I use mysqldump --single-transaction, according to the docs it should do flush tables with read lock to get a consistent state and then start a transaction and no writers should be waiting. ...
4
votes
1answer
82 views

Should a table be split if only a particular column gets updates?

I have a table in my MySQL 5.7 database, which has 9 columns. One column is an AUTO INCREMENT PRIMARY KEY, where as the other 6 contain some data, which isn't going to be updated in a year. Now, the ...
2
votes
1answer
183 views

“Unknown table engine 'innodb'” error after changing my.cnf

I am getting "Unknown table engine 'innodb'" for some query after changing my my.cnf. I have reverted the old my.cnf and restarted mysql and now I can see innodb. Could you please help me figure out ...
0
votes
0answers
26 views

Syntax error or access violation: 1286 Unknown storage engine 'InnoDB'

MySQL won't start after I changed the my.cnf file. After a lot of use on my site, MySQL crashes and I get this error: Syntax error or access violation: 1286 Unknown storage engine 'InnoDB' I ...
0
votes
0answers
11 views

Mtop - How to reset ID numbers?

Using Mtop for slow queries logging in our InnoDB. Since there is actually high database usage, the log IDs in front when using the mtop command are increasing rapidly and I would like to reset them, ...
1
vote
0answers
46 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. ...
1
vote
1answer
77 views

Decrease Query Execution Time

I have been having issues with 2 queries with query execution times up to 250 seconds for each query. The tables joined have each less than 10,000 rows, with exception to 2 tables that have around 60k ...
2
votes
1answer
84 views

Cannot access MySQL database after moving files in data directory

I am using Xampp locally and I recently did a computer upgrade where I went from XP to Windows 7 and also got a new drive to install Windows on. I have all my old Xampp files in: G:\xampp I installed ...
1
vote
1answer
36 views

automatic innodb redo log archiving

We have an option to do recovery through bin-logs, but we thought recovery through bin-logs is not 99% consistent because there is no LSN(Log Sequence Number)/SCN (System Change Number) in bin-logs ...
3
votes
2answers
167 views

Release MySQL Memory and Performance Tunning

I am new to the MySQL database. I have recently installed MySQL 5.7 and configured the my.ini file. Please find the below copy of the file. The server is a dedicated server for MySQL database and the ...
0
votes
1answer
36 views

Prefix index length impact for VARCHAR?

I have a VARCHAR(255) primary field field in an InnoDB database table. I only store values of length 32 bytes in it (32 ASCII characters). My primary key has a prefix length of 767 bytes. Clearly, ...
0
votes
0answers
110 views

how to recover everything from ibdata in mysql

I lost all my databases files after my hard disk was broken, In a way or another I got ibdata files the size for the file is 4GB.After replacing log files and files and type innodb_force_recovery=6 in ...
1
vote
2answers
122 views

DB randomly locks up when innodb_buffer_pool_size is set high

I have been struggling to work out what could be happening here but for many months, since upgrading to mysql 5.6 we seem to be experiencing random lag spikes in page loads which has been tracked back ...
1
vote
1answer
329 views

How can i import 150GB database after deleting ibdata1,logfile in MYSQL?

I have a 150GB database and my ibdata1 file size is 240GB so I want to shrink the ibdata1 file because I have to export the DB and then drop the tables and then stop mysql, delete the ibdata1 file and ...
6
votes
4answers
17k views

How to increase fast backup and restore of 500GB database using mysqldump?

There is a database A size of 500GB. Tables in database A contains both MyISAM and INNODB tables. MyISAM tables are master tables and Innodb tables are main transaction tables. Backup and restore ...
2
votes
2answers
32 views

MySQL Database Archive

We have 300 databases in our environment mixed of MyISAM and Innodb(innodb_file_per_table has been enabled) tables.Using MySQL 5.5.19 version. I we are planning archive inactive database.Is there any ...
0
votes
1answer
16 views

First Insert is skipped by the trigger

I am facing a very strange issue as i have implemented a trigger on tableA which does encrypt data and insert data to another tableB and update column to 4 digit. The issue is First insert is somehow ...
3
votes
1answer
59 views

How we can recover MySQL database (Innodb,myisam)

I have found some recovery tool innodb-recovery but it works only on linux machine, I would like to know how to recover innodb tables on windows. Transaction ID based recovery Cancel based, Change ...
0
votes
1answer
50 views

How to ORDER a big table?

I have a simple but big table (tens of millions of rows). The performance is quite good except when I need to order the table by the column with format datetime. A simple SELECT query to fetch the ...
0
votes
0answers
78 views

After recovering full backup with innobackupex, innodb system tablespace appears to be corrupt

I've a full backup of a database. From time to time, I recover those full backups on a recovery machine. This process has worked fine always, until today. The backup went OK, zero warnings, nor ...
7
votes
2answers
12k views

How can I configure MySQL Innodb to handle 1000s of inserts per hour?

I have a very high traffic website where it is possible that 1000s of new records are inserted every hour. This one error is crippling the site: PDOException: SQLSTATE[40001]: Serialization failure: ...
1
vote
2answers
1k views

ERROR Error reading packet from server: Lost connection to MySQL server during query ( server_errno=2013)

We are facing the issue in replication that we are not getting any error in Show slave status\G output rather facing the following issue in Error Log File [ERROR] Error reading packet from server: ...
2
votes
2answers
56 views

Mysql hand machine due to high load average and CPU

Mysql is used by only one application which only fire query periodically. When i restart server,It run smooth for period of time. and then crash the whole server. My my.cnf file [mysqld] ...
3
votes
4answers
323 views

What architecture is best to store a large 3 dimensional array in MySQL?

I am looking to create a large 3 dimensional database in MySQL. The structure will basically be a standard MySQL table, with a time component / dimension added. See the following analogy: { x, y, ...
3
votes
2answers
75 views

MySQL for Oracle DBA

I am a newbie to MySQL, but understand Oracle databases well. I need a quick help to understand the architectural differences. Currently I am working on a Windows platform. 1) In Oracle we have to ...
16
votes
3answers
10k views

Why are simple SELECTs on InnoDB 100x slower than on MyISAM?

I have quite an annoying problem. I want to use INNODB as my main database engine and give up on MyISAM as I need the former for using galera-cluster for redundancy. I copied (description follows) ...
2
votes
2answers
74 views

what is the difference between UPDATE … LIMIT and SELECT … FOR UPDATE?

I have read an article, there is one sentence about MySql: As one might expect, lock contention is an issue and we use several strategies to mitigate it including a separate table for each ...
1
vote
1answer
123 views

Slow MySQL InnoDB performance of table with 100 million rows

I have the database in this format. CREATE TABLE `dna` ( `p_id` bigint(20) NOT NULL AUTO_INCREMENT, `dna_bits` bit(32) NOT NULL, `user_id` int(11) NOT NULL, PRIMARY KEY (`p_id`), KEY `dna_bits` ...
0
votes
0answers
57 views

Simple InnoDB update query locks transaction - why?

I have the following lines in my error log (often repeating after a recent code update): *** (1) TRANSACTION: TRANSACTION 2959776709, ACTIVE 0 sec starting index read mysql tables in use 1, locked ...
1
vote
1answer
48 views

How to make a unique datetime without seconds?

I need to build a table accepting one row for each minute. If I set the type of primary key to datetime, 60 records can be added for each minute. Is there any trick to design a table to keep ...
1
vote
1answer
28 views

Theory of indexes for query with joins

I found the following talk by Zardosht Kasheff enlightening: http://www.infoq.com/presentations/Index-SQL but it only covers the case of simple queries on a single table. Is there something similar ...
10
votes
3answers
12k views

Why does MySQL ignore the index even on force for this order by?

I run an EXPLAIN: mysql> explain select last_name from employees order by last_name; +----+-------------+-----------+------+---------------+------+---------+------+-------+----------------+ | ...
0
votes
1answer
51 views

Restored database copy larger than original

I've created a copy of a database for testing. It's on the same server as the original. However, tables are listed as being larger on the restored copy than on the original. My original database is ...
0
votes
0answers
120 views

“mysqld got signal 11” error

I have a MySQL 5.6.22 InnoDB database and just now, suddenly out of nowhere, when I try to start it up using /etc/init.d/mysqld start, I see this error in the error log and the server won't start up : ...
2
votes
1answer
126 views

Is it ok to have 'view count' column in the same table?

Let's say I have a website similar to YouTube where I'm storing and displaying the 'view counts' for each video. It is ok if I'm storing the view count column in the same table as the actual view ...
2
votes
3answers
141 views

UPDATE query periodically is slower by factor of 5000x

I run a site (Magento) which have a problem with a specific UPDATE query. Under heavy load, this query runs ~200 times/minute, and takes in average 1 ms (stdev 0.2 ms). However, at intervals of 1-2 ...
0
votes
2answers
3k views

MySQL 5.5 Fail start Fedora 16

I installed mysql and mysql-server from the repos (MySQL version 5.5). Then tried to start it, but got an error. [root@server]# service mysqld start Redirecting to /bin/systemctl start ...
0
votes
1answer
59 views

Optimizing slow query

For a few days now, i'm trying to optimize this query. But still I haven't found the right solution in how to fix this. The contents table contains about 20 million records. As the connect table ...