MySQL version 5.5 - please also tag with mysql for search purposes.

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Creating Archiving database for old data in MySQL

I Have a Master and Various Slave Servers. There is a huge amount of the data on all the servers and I wish to create an Archiving system for our Data. Scenario is : I want that only Last one year ...
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Listing rows with a WHERE condition

I am struggling with a SQL query that lists hosts that are offline. Problem The problem occurs when I need to list hosts that don't have any ports open (status = 0), so looking at the table at the ...
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innodb_buffer_pool_size not changed

I use MySQL 5.5.23-1~dotdeb.0 (Debian) and here is the relevant part of my.cnf default-storage-engine = innodb innodb_buffer_pool_size = 3G innodb_log_file_size = 256M innodb_thread_concurrency = 8 ...
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2answers
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Different behavior between MySQL 5.5 and 5.6

I have this schema with data: CREATE TABLE `ticket` ( `id` INT NOT NULL, `name` VARCHAR(45) NULL, `type` INT(11) NULL, PRIMARY KEY (`id`)); CREATE TABLE `task` ( `id` int(11) NOT NULL, `...
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2answers
920 views

Are there benefits to using more than 4 CPUs for MySQL?

We are running MySQL 5.5 on linux under VMWare, running on 2 CPUs. We are planning on increasing this to 4, but we have un-used CPUs available, and I'm wondering if there is any benefit to increasing ...
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3answers
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Why set up static data in views vs. using tables in mysql?

I get an LDAP feed nightly. I get it as a text file and dump/create my LDAPALL table. There are roughly 75K employees times about 50 fields. I have the following too: LDAPIMPORTANT - view that ...
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2answers
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What to use, CASCADE DELETE rule or ON DELETE trigger for one to many constraint?

I would like to ask about how to handle this relationship. For better view I've tried to simplify and convert my situation into how I think StackOverflow question voting has (sorry if not :-) I ...
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4answers
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How to Add Federated engine after installing Mysql

I have Mysql 5.5.18 and upon show engines: show engines; +--------------------+---------+------------------------------------------------------------+--------------+------+------------+ | Engine ...
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Inserting rows with WHERE condition

Structure 1 table named: scan 2 columns named: id, and date Problem I have two working queries, a SELECT and then an INSERT which I would like to merge together creating a INSERT where the ...
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1answer
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skip columns while using LOAD command mysql

I have a csv file having 5 columns and i want to load only one out of that, is there a way i can do it. I want to use LOAD statement of MySQL 5.5 Any pointers are welcomed, help would be much ...
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2answers
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How to split a string to and get info from another table in mysql

I have a system to assign score for each sentence stored in a column: TABLE 1: word_scores word score this 3 is 4 a 5 test 1 another 0 sentence 8 TABLE 2: ...
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1answer
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How to improve MySQL Server Performance..??

As a MySQL DBA most of the times we are supposed to optimize a poorly performing MySQL Servers. Now my question is where to start from like we will need to find out many things as 1.Find the ...
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2answers
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View with parameter IN

I'm creating a view in which I have a where with an in clause and I want it to be a parameter. Unfortunately views can't be created with parameters, so I tried replacing it with functions, but ...
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4answers
331 views

How to backup live mysql database?

I have 12 GB MySQL InnoDB Database with around 800 queries per second. No sooner I start 'mysqldump' over it to make backup I start getting '503' on my website. How do I make backup of my live ...
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2answers
518 views

Why wouldnt Mysql use index on the Primary query in a nested query

I have two tables: search_criteria and pricing. There is an index on search_id column in search_criteria table and on pricing_id column in pricing table. But running this nested query does not use ...
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1answer
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Mysql INSERT INTO .. ON DUPLICATE KEY UPDATE

I'm trying to do the following query in mysql 5.5 INSERT INTO countingTable( image_count, article_id ) SELECT COUNT( article_id ) AS sum, article_id FROM imageTable ON DUPLICATE KEY UPDATE ...
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1answer
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Mysql 5.5 InnoDB growing CPU - Going crazy

Good morning, I'm currently facing a problem where CPU usage keeps going up until the server crash. I've tried multiple best practices proposed in this forum and on Percona, reinstalled the server ...
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2answers
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MySQL 5.5 High CPU Usage

I have been working with a client with high traffic website(500k visitors and 600-800 active users at any given time). This uses wordpress and the DB is using MyISAM engine. The problem we had was ...
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1answer
953 views

Creating a partial unique constraint for MySQL

I have the same question as asked in a previous post: PostgreSQL multi-column unique constraint and NULL values. But the solution there is not applicable as I am using MySQL instead of PostgreSQL. My ...
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1answer
61 views

where varcharcol = 0 returns all rows

Suppose I have a table like this: create table mytable(cola int primary key, colb varchar(10)); Let's put some data in it: insert into mytable values(1, 'abc'); insert into mytable values(2, 'def')...
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MySQL replication to slave having VPN connection to Master

I am setting up an environment in which the Master and Slave are on different networks at different physical locations (both run on MySQL 5.5.20). I have set up a VPN connection from slave's network ...
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1answer
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how to “revoke” a “GRANT OPTION” from an mysql user/database?

i have a mysql installation with lots of users and grants. But one grant is unique, since its supposed to be a simple DB user and usually does not need GRANT privileges. However someone added it when ...
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2answers
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Is it possible to block a specific query, or return a static result?

Before you yell at me for doing it wrong, I know I'm doing it wrong. I'm using WHMCS (source code is not available), and we have a quarter of a million invoices. One particular query, which runs on ...
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2answers
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Fastest way to create local copy of live InnoDB MySQL database?

We have a MySQL database (InnoDB) on our live Ubuntu 12.04 server which has grown quite large (25gb+). Every month or so we need to copy this database to our development machines to work on locally. ...
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1answer
42k views

How to get only month from MySQL date/time?

In my MySQL server, I have rows that have the date of my created content. Example: 2013-03-17 02:53:47 For now, I am using: $date = $fetch[thedaterownamegoeshere]; <?php echo $date; ?> But ...
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1answer
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when will Innodb support activation of triggers on cascade foreign key? [closed]

The Manual says: http://dev.mysql.com/doc/refman/5.6/en/innodb-restrictions.html Currently, cascaded foreign key actions do not activate triggers. Any Idea when will this be implemented. Is ...
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1answer
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Keeping MySQL staging database on same server updated from production

I just migrated my MySQL 5.5.20 to Amazon RDS from MySQL on EC2. The one thing I'm having difficulty with is how to keep my staging database updated from production. Before, I just ran a nightly ...
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1answer
461 views

Implementing a one to one (1:1) relationship between Person and User

Scenario description I have this person table as super parent (or supertype), id firstname lastname email telephone ... ... and user table as a child (or subtype) id person_id (FK) password ...
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1answer
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MySQL 5.5 InnoDB = OFF?

We run a server with MySQL 5.5. 95% of the tables are set to the InnoDB engine. However whenever I look at the my.ini file (using the MySQL Workbench) under mysqld section innodb is unchecked and OFF ...
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1answer
20 views

mysql replication and GRANT that doesn't quite grant

I am trying to set up mysql replication. All's well, but I see an error 1045 for the slave: mysql> show slave status\G *************************** 1. row *************************** ...
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2answers
204 views

How to convert timezone in MySQL using the timezone name?

I want to convert date from one timezone to another timezone in MySQL, MySQL query which I am trying is SELECT DATE_FORMAT(CONVERT_TZ('2015-12-18 06:00:00', '+0:00', '-05:00' ),'%b %d %Y %h:%i %p') ...
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1answer
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mysqldump doesn't restore database. why not?

Why doesn't my restore operation work? I created a dumpfile for a database using: mysqldump -u root -p databasename > /home/databasename_bkup.sql I then opened the dumfile and confirmed ...
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1answer
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Why mysqldump is returning with error 1143: Couldn't execute 'show table status like

I ran the following command to create a mysqldump mysqldump -ubackup -psomething --single-transaction --quick somedatabase | gzip > 4_19.gz I got following error after 60% (estimating checking ...
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2answers
63 views

Fetch all words from column with like

I have a column with description and inside it can contain # value . what I want is all the words searched from that column with #tag This is my query SELECT description FROM photo where ...
3
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1answer
511 views

How to store static list of hashes in MySQL effectively?

Problem: I have a list of pairs (md5_hash, id). I want to store the data in MySQL and I want to make queries like this SELECT id FROM table WHERE md5_hash = <some_hash> The number of pairs ...
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MySQL gives me:“Can't open and lock privilege tables: Table 'host' is read only”

I am facing problem restoring a MySQL database. My primary database was MySQL 5.1 and now I am trying to copy it to MySQL 5.5. The database was backed up by using Xtrabackup. I am using Ubuntu 12.04....
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3answers
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MySQL information_schema doesn't update

I have a database, say abc, in mysql server. It has only one table named test. test uses innodb engine and I've set innodb_file_per_table to true. After I run the query delete from abc.test, I want ...
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1answer
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Backup and off-site restore setup

I've been reading a lot of threads about different backup options for MySQL and was hoping for some more insight so I can settle on one. Our current situation is ~100 GB of InnoDB and MySAM data in ...
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2answers
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How to COUNT number of rows with LIMIT?

I want to catch X rows, thus, I set LIMIT X; but how can I simultaneously count the total number of rows too? Currently, I use two separate queries to do so as SELECT COUNT(*) FROM col WHERE CLAUSE ...
3
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1answer
235 views

Get profiles values where message.sender_user_id = profile.user_id

I have this tables: default_messages CREATE TABLE IF NOT EXISTS `default_messages` ( `id` int(11) NOT NULL AUTO_INCREMENT, `subject` varchar(150) COLLATE utf8_unicode_ci NOT NULL, `message` text ...
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2answers
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Can we assign mysql Key_buffer_size value for particular table?

In some documents I found that we can assign key_buffer_size to myisam table. This also includes the following steps: SET GLOBAL myisam_table.key_buffer_size = 4194304; CACHE INDEX test.myisam_table ...
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1answer
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MySQL Killed by OOM after Corrupted Database

One of our web-app servers recently had an issue where MySQL was taking more memory than we have physical RAM. This server has 64GB of memory and 8GB in swap, and MySQL was OOM-ed because it was ...
3
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1answer
177 views

MySQL replication - invalidating query cache entries (table)

We lately moved to MySQL V5.5 on CentOS release 6.7 with master and 2 slaves. Since then the replication process lags a lot behind the master with the line in the process list of: invalidating ...
3
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1answer
161 views

Any risks in updating the system time on a mysql 5.5 server?

We just discovered one of our mysql systems has not been running ntp, with the result that the time has drifted a bit. If I enable ntp, and synchronize the time while the system is running are ...
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1answer
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View last several innodb deadlocks

I see that I can view the latest deadlock in mysql/innodb, but is there a way to view past deadlocks? We have two deadlock issues, one being important and the other not. The less important deadlock ...
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3answers
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Bulk Delete for Large Table in MySQL

I have a Notification table contains about 100 million rows host in Amazon RDS with 1000 IOPS, and I want to delete those rows older than one month. If I do DELETE FROM NOTIFICATION WHERE CreatedAt &...
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1answer
484 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 --single-...
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1answer
2k views

MySQL: Alter Table on very active table gives “Waiting for table metadata lock”

At my work, we've recently upgraded to MySQL 5.5 and since then, have been bitten a few times by the new (and intended) behavior of metadata locking. Basically, whenever we run an ALTER TABLE ...
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1answer
540 views

MySQL / Fusion IO Configuration Question

I need a little configuration optimization. I think what I have is pretty good but feel like there's still room for improvement. Current Config [mysqld] user=mysql datadir=/var/lib/mysql socket=/var/...
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1answer
184 views

MySQL Replication not proceeding

I have a weird replication problem I have not seen before. It's basic mysql replication with single master and two slaves. One of the slaves is not executing replication events and seems just stuck ...