MySQL 5.6 : Latest Release of MySQL with improvements that enhance every functional area of the database kernel.

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10
votes
2answers
352 views

MySQL instance stalling “doing SYNC index”

Problem An instance of MySQL 5.6.20 running (mostly just) a database with InnoDB tables is exhibiting occasional stalls for all update operations for the duration of 1-4 minutes with all INSERT, ...
8
votes
4answers
15k views

Cannot open table mysql/innodb_index_stats

After a fresh install of XAMPP and import from my linux live db that is working to the windows Dev-stage, I started encountering problems with INSERT. Everything else seems to work well. The errors I ...
8
votes
2answers
13k views

InnoDB: Error: Table “mysql”.“innodb_table_stats” not found after upgrade to mysql 5.6

I upgraded to mysql 5.6 from 5.5, and now my logs are littered with such messages on startup I found a possible solution here, but it does not seem official. ...
5
votes
3answers
4k views

Why query_cache_type is disabled by default start from MySQL 5.6?

We've upgraded to MySQL 5.6 and start seeing the loading of db server increased significantly, and finally found out the query_cache_type is defaulted to off start from 5.6. We enabled it again and ...
5
votes
1answer
430 views

Why does InnoDB table by default uses the UNIQUE constraint instead of the PRIMARY KEY?

In my MySQL database I have a table with 4 columns, the PRIMRAY KEY, two columns with a FOREIGN KEY CONSTRAINT and one UNIQUE index on all fields except for the PRIMARY KEY. The SHOW CREATE TABLE: ...
4
votes
1answer
104 views

MySQL loading NULLs in numeric columns

MySQL 5.6.23, InnoDB I am loading tables from character delimited text files using the LOAD DATA INFILE commnd and I would like every field with a \N, which is the NULL character in this setting, to ...
4
votes
1answer
1k views

Slower queries after upgrade from mysql-5.5 to mysql-5.6

There is lots written about how MySql 5.6 is faster than MySql 5.5 (e.g. http://dev.mysql.com/tech-resources/articles/mysql-5.6.html) but we upgraded our Amazon RDS instance (using the new upgrade ...
3
votes
1answer
1k views

Best way to create materialized view in mysql

I am using mysql 5.6, I am not being able to create materialized view here like oracle. I got one or two solution like flexview and all... Can anybody tell me best way to create materialized view in ...
3
votes
2answers
105 views

SQL Question: Selecting different language versions based on availability

I have the following situation: I have a table that contains entries with language versions (German and English) as part of the key (the other part being a "name" field). However, not always both ...
3
votes
1answer
420 views

Is it mandatory to enable --log_slave_updates with MySQL Replication using GTID? [duplicate]

I'm setting up 5.6 Percona Mysql, in order to enable GTID should I have to enable log_slave_update on both Master and Slave ? If I should enable log_slave_update, then I'm counting this to CONS for ...
3
votes
3answers
1k views

Amazon RDS - and binary log rotation

New to RDS (used to having my own server in my own data center). We are on MySQL 5.6 on RDS. when a slave gets behind in replication lag, the master ceases to rotate out its binary logs. It is, ...
3
votes
1answer
270 views

How to upgrade MySQL (5.5) production DB to 5.6 with minimal downtime

Our existing Database size around 200GB. We want to use consistent, parallel backups methods. For testing, I migrated my Development DB from 5.5 to 5.6 by running mysqldump with option ...
3
votes
1answer
624 views

How to drop all scheduler events in MySQL 5.6?

In MySQL 5.6 is there a way to drop all scheduler events with an administrative command or do I have to go through them one by one with DROP EVENT [IF EXISTS] event_name?
3
votes
1answer
51 views

How can I copy the MySQL EXPLAIN result into a table?

I'd like to archive the results of a series of query EXPLAIN plans into a table for later analysis. I created a table that contains all the fields from an EXPLAIN result, but I can't figure out how ...
2
votes
2answers
247 views

Changing ORDER BY direction causes performance issue

I use MySQL 5.6, and I have two tables each with 16M rows: CREATE TABLE IF NOT EXISTS `newsstudios` ( `id` int(11) NOT NULL AUTO_INCREMENT, `title` varchar(255) COLLATE utf8_unicode_ci NOT NULL, ...
2
votes
2answers
3k 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. ...
2
votes
2answers
3k views

Master - Master replication Duplicate entry

I've got a Master - Master replication setup and it worked fine for a couple of days but I keep getting: Duplicate entry errors after a few days... My setup is as follow: One server in The ...
2
votes
3answers
359 views

Does MySQL 5.6 support fan-in replication?

I've known for quite awhile that Continuent's Tungsten Replicator supports fan-in replication (example). By fan-in replication I mean combining multiple datasources into a single instance (like a ...
2
votes
3answers
58 views

Updating/Inserting 2000 entries takes over 12 hours to complete

I have three tables of around 10 million rows each in MySQL on Amazon RDS and I am finding the insert/update performance to be VERY slow. Each table contains unrelated data. Each table is regularly ...
2
votes
1answer
38 views

Optimizing a 3 table join query

SELECT job.id_job, job.fk_company, job.fk_user, job.fk_job_category, job.fk_job_type, job.fk_place, job.job_identifier, job.external_job_id, job.title, job.short_description, job.status, ...
2
votes
3answers
82 views

Query 'optimizing' state is taking too long

I have a MySQL 5.6 on Amazon RDS that I'm using for testing some data archiving scripts. I'm removing oldest data based on a "updated_date" column and index. Curiously, after removing a few million ...
2
votes
1answer
3k views

Any known issues upgrading from MySQL 5.1.73 to 5.6.21?

I am planning my MySQL DB ver5.1.73 running on a CentOS 6.5 machine to MySQL 5.6.21. I understand the basic procedure for this based on what I have read on StackOverflow, but I was curious if anyone ...
2
votes
2answers
353 views

Can anyone offer an opinion on handlersocket vs memcached performance in MySQL 5.6

I must say I was a little mis(un)-informed about the MySQL Memcached plugin which offers the same NoSQL like access to InnoDB tables as HandlerSocket, I had only had experience with entirely ...
2
votes
2answers
783 views

Can I move the undo log outside of ibdata1 in MySQL 5.6 on an existing server?

I've been growing concerned about the large size of ibdata1 that can never shrink even when using file-per-table on innodb Moving the undo log files outside seemed logical but this procedure seems ...
2
votes
2answers
65 views

What are some known hazards with cyclical replication between two MySQL master servers?

If I were to set up cyclical replication between a MySQL 5.6 master server and a MySQL 5.1 master server, what are some things that could potentially go wrong? Also, the 5.6 MySQL does not have GTID ...
2
votes
1answer
322 views

InnoDB: “Only one log file found” after binary import

My first one on DBA... After successful upgrading a master MySQL server 5.5 to 5.6.17 (CentOS 6 VPS serer), I done and moved my binary backups to a slave server (same version 5.6.17 but different ...
2
votes
1answer
317 views

Why didn't MySQL keep the innodb_file_format after loading a mysqldump

I was loading a mysql dump today when I ran into ERROR 1118 (42000) at line 279: Row size too large (> 8126) Which I thought was weird because I know I had turned on row compression and was ...
2
votes
2answers
1k views

changing TEMPORARY TABLE default collation

when I use CREATE TEMPORARY TABLE to create a temporary table, the collation of this table is utf8_unicode_ci by default. why by default it is utf8_unicode_ci? How can I change the default?
2
votes
2answers
1k views

MySQL version confusion

How is this possible: I installed mysql-5.6.11-osx10.7-x86.dmg which is supposed to be version Mac OS X ver. 10.7 (x86, 32-bit), DMG Archive (32 bit!) But upon SHOW VARIABLES LIKE "%version%"; I get ...
2
votes
1answer
4k views

Issue on mysqldump in MySQL5.6

I did upgrade the MySQL server from 5.5 to 5.6 I am trying to take dump for a table like this mysqldump -uroot -p dba admin > D:\admin.sql But it gets following error mysqldump: Couldn't ...
2
votes
1answer
338 views

Can't query one view from another?

Okay, I'm moving a database from SQL Server (which I already miss) to MySql 5.6. I'm having a problem creating a list of valid dates. In SQL Server I just used CTEs to build up numbers, then months, ...
2
votes
2answers
89 views

MySQL Index Creation Internals

Right now there are two ways to build an index of a table in MySQL: Create the table structure first, then import the data and add indexes later. Create the table structure with indexes and then ...
2
votes
1answer
25 views

How do I change the config path for mysqld?

I want to change configuration file path from C:\ to E:\, but I can't find the way to do this. Alternatively, is there a way to start a new instance with the config file I want? I've done something ...
2
votes
3answers
365 views

How can I make MySQL client read password from mylogin.cnf?

I'm trying to make the mysql client connect to a mysql server without requiring the password to be given interactively. Steps taken: 1) First create a mylogin.cnf file $ mysql_config_editor set ...
2
votes
2answers
958 views

What is default MySQL binlog retention in AWS RDS?

I tried to retrieve my MySQL RDS binlogs in order to run manual "rollback" for some SQLs. Unfortunately, I noticed that only 2 binlogs for the last 30 minutes are available. "call ...
2
votes
1answer
1k views

How to do While Loops?

How can we use while loops in MySQL? My test script: BEGIN SELECT 0 INTO @n; WHILE @n < 10 DO SELECT @n; SET @n := @n +1; END WHILE; END; But it has syntax errors. I've also ...
2
votes
1answer
421 views

Optimize table and query, aggregate by date or date-hour

I have a table storing sensor data (100M rows currently) from stations from different sites. In my case, sites may have many stations. Create table statement is as follows: CREATE TABLE sensor_data ( ...
1
vote
1answer
55 views

How to select second last row from table?

Table Name :- ModelParam_EMS Primary Key :- ParameterID No of Rows :- 500 want to select 499th row from table only. Note :- No. of rows can be less or more but not fixed. Create Table :- ...
1
vote
1answer
684 views

How performance schema in mysql 5.6 improve performance?

Since MySQL 5.5 performance_schema database has been added likewise information_schema. As we know that tables in information_schema contains statistical information like tables, plugins, partitions, ...
1
vote
1answer
51 views

What is the difference between Com_xxx and handler_xxx?

Initially my com_delete variable and handler_xxx variables are nil. | Com_delete | 0 |+ | Handler_delete | 0 | +----------------+-------+ then I issued a delete query delete from gt ...
1
vote
1answer
143 views

How to include a semicolon (“;”) in a MySQL pager command

I've just discovered the pager command in the MySQL command-line client, and I'm having a tonne of fun. This blog post is great: ...
1
vote
2answers
40 views

mysql master slave replication scenario

We are creating a new mysql slave, but for dump we are taking from a backup server which is a slave of current master. Now to enable replication we want to connect it with the master so should I take ...
1
vote
2answers
38 views

MySQL connection timeout on connection spike

I have a little bit difficult problem, whenever a spike of connection occurs our MySQL server, connecting from all sources to the MySQL is practically impossible, the max_connections setting is not ...
1
vote
2answers
34 views

How to define partition according to Date?

I am currently using MySQL 5.6. In my database, I have a log table called paramlog_ems. It has 2M rows I want like to partition this log table according to Date. Here is the table structure: ...
1
vote
1answer
54 views

MySQL replication slave of slave not receiving updates

I have 4 servers: A, B, C and D. A and B are in a master-master setup. C is a slave to B and D is a slave to C. Changes on A or B get to all nodes other than D. I need them to get to D Changes ...
1
vote
1answer
31 views

returning the number of columns in a row that are zero in mysql

I have a table that contains amongst other things a datetime column, and 4 other columns that contain either a zero or a number. I would like to return how many columns in a row contain a zero in ...
1
vote
2answers
5k views

MySQL does not start - Ubuntu 14.04 LTS after migration to new disk

I have installed in a Virtualbox VM a 64-bit desktop version of Ubuntu 14.04 LTS and MySQL Server 5.6. I had some databases in the machine's main virtual hard disk but then I was going to open a SQL ...
1
vote
1answer
114 views

optimize the query with big and low cardinality

I have big enough dataset and few joins to get them all with help next query: SELECT DISTINCT c.c_id FROM c_active z1 INNER JOIN cs c ON (z1.cv_id=c.cv_id) INNER JOIN indi i ON (c.m_id=i.m_id) INNER ...
1
vote
1answer
778 views

MySQL crashes frequently on a Windows server

I have been facing an issue with MySQL crashes since last week. I don't know what exactly is happening. When I look at the Windows logs, I see the following error message: Faulting application name: ...
1
vote
1answer
104 views

Migrating MyISAM tables from 5.5 => 5.6

I was wondering if anyone had any pointers on migrating MyIASM tables from mysql 5.5 to 5.6, specifically using Percona builds, via an rsync? Is this safe? I know we need to do a full ...