MySQL 5.5 brought many performance enhancements and expanded the feature set of the popular open-source RDBMS.

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1answer
904 views

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 ...
3
votes
1answer
2k views

What does the base64 BINLOG statements in mysqlbinlog output mean?

I have looked over the mysqlbinlog command as a candidate for rollback method from MySQL 5.5 to MySQL 5.0. When I ran the command on one of the bin-log files in the MySQL 5.5 server, I've noticed ...
3
votes
1answer
427 views

MySQL RDS Instance eating up memory and swapping

I have an issue with memory on a RDS instance which is of db.m2.4xlarge class. Below are the specifications of the RDS instance Instance Class: db.m2.4xlarge ( 68.4 GB of RAM ) Engine: ...
3
votes
1answer
782 views

How to modify `proxies_priv` in MySQL

I recently received a warning from MySQL that stated: [Warning] 'proxies_priv' entry '@ root@serverdomain' ignored in --skip-name-resolve mode. I looked in mysql.proxies_priv and there is ...
3
votes
1answer
240 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
648 views

Getting Random Sample from large database MYSQL (No Auto Inc Field)

You were so helpful with my last question, I thought id throw another one at you thats stumping me. Basically I got a table, requirements from company was it was all supposed to be 1 table so I got ...
3
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1answer
231 views

MySQL Stress testing issues?

I had gone through MySQL High Performance book Chapter 2 for MySQL Bench marking and Profiling,I have some questions about benchmarking How can we test an existing database and queries against it ...
3
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3answers
2k views

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 ...
3
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1answer
255 views

What's the most unsafe MySQL configuration?

I have MySQL 5.5.27-29.0-log instance running specifically for Jenkins. Since tests data is always recreated during setup, ACID is unnecessary and I'm hoping to sacrifice it to gain more performance. ...
3
votes
1answer
516 views

Do I need to index a key that I partition by?

I have an InnoDB table of customers, partitioned by KEY, with each partition being one US state. I have an index on phone number, and the performance is great. We also need to SELECT by last name in ...
3
votes
1answer
1k views

Configured MySQL replication but its not working

I have configured MySQL master and slave replication setup on 5.5.x. But for some reason data is not getting replicated properly. What might be the reason? At Master: /etc/my.cnf [mysqld] ...
3
votes
1answer
213 views

mysqld-multi with first DB as Slave and second DB as Master

Yesterday, I setup mysqld-multi in my.cnf. It works fantastic, but there is still a further Problem. The first DB on socket 1 running as Slave from a other server. The second one from socket 2 ...
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0answers
55 views

Is it a waste to set innodb_buffer_pool_instances greater than the # of CPUs?

I set the innodb_buffer_pool_size to 20GB on a server with 12 CPU cores. My full database is 11gb, however most of it is archived tables that are almost never used. The total queried data is around 3 ...
3
votes
5answers
678 views

MySQL runs out of memory when importing innodb database

I have a small VPS with 512MB RAM and no swap (can't have any). I am importing a 1.5GB innodb database with mysql -u -p < database.sql Before the operation can finish it says : Lost connection ...
3
votes
2answers
186 views

Problem in Fetching Result set in Desired Format

I have 2 tables having the following columns Person ------ person_id, first_name, middle_name, last_name Items ----- person_item_id, person_id, item_type, status, ordered_date The query is ...
3
votes
3answers
450 views

Finding differences between a master and slave when pt-table-sync fails

I have a table that's showing some differences on a master and slave according to pt-table-checksum (PTC). I've found some verifying differences beyond that. Certain tables in the mix have composite ...
3
votes
1answer
743 views

Convert Oracle Query for Date to Mysql queries

Need to convert the following oracle queries to MYSQL queries. 1) select to_char(to_date(?,'DD-MM-YY')) from dual; 2) select to_char(next_day(to_date(?,'DD-MM-YY'),'FRIDAY')) from dual; 3) ...
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4answers
4k views

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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2answers
8k views

MySQL Error Reading Communication Packets

In MySQL error logs, I see these quite few a warnings like these: 120611 16:12:30 [Warning] Aborted connection 2619503 to db: 'db_name' user: 'user_name' host: 'webapp_hostname' (Got an error reading ...
2
votes
2answers
567 views

Tool to match mysql password encryption

I've created a user ... but forgotten the password mysql> create user 'blayo'@'%' identified by 'right'; Which Linux command line tool can encrypt the password the same way mysql does ? mysql> ...
2
votes
2answers
157 views

How to store logs correctly?

(This is somewhat a follow up on my last question) I am using MySQL 5.5 with innodb. My Log table consists of two columns. One for user number, and the other for a string consisting of IP, request ...
2
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2answers
247 views

Tinyint structure is confusing

I am confused to see this tinyint(3) structure. If tinyint can store only 1 byte then what is the purpose of giving the size in brackets? Is there something special with this parameter in MySQL?
2
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2answers
870 views

How to GROUP_CONCAT between given rows?

I have a table as id diary 1 breakfast 2 walk 3 start 4 office works 5 office projects 6 end 7 taxi 8 start 9 preparing for meeting 10 doing the meeting 11 end 12 night I want ...
2
votes
4answers
332 views

Does my table violate normalization rules?

I am developing an emulator for a game. My item table looks like this: -- ---------------------------- -- Table structure for `items` -- ---------------------------- DROP TABLE IF EXISTS `items`; ...
2
votes
3answers
5k views

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 ...
2
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2answers
5k views

“Could NOT find Curses” error when installing MySQL from source

I am installing MySQL Server from the source distribution which I downloaded from: http://dev.mysql.com/downloads/mysql/#downloads. I have downloaded the file (mysql-5.5.19.tar.gz). I am using ...
2
votes
2answers
312 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 ...
2
votes
1answer
186 views

Is there a way to achieve Workload Management in MySQL?

Is there a way to set up Workload Management in MySQL (in particular v5.5 on AWS RDS)? By Workload Management I mean the functionality implemented in e.g. Teradata, RedShift that allows ...
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2answers
1k views

Changing the mysql.proc table directly after upgrade

Our host upgraded our mysql install without us knowing from roughly 5.1 to 5.5. This caused a problem because the table definition of mysql.proc is different as discussed here: ...
2
votes
2answers
889 views

Does MySQL 5.5 support shared database with separate schema?

I am developing a SaaS based product using MySQL 5.5 as the backend database. I want to keep shared database for all the tenants, but separate a database schema of each tenant. There would be a single ...
2
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2answers
575 views

MySQL - How much physical space will be reduced by changing the column type?

Lets say I have the following table: CREATE TABLE `my_table` ( `id` int(11) NOT NULL AUTO_INCREMENT, `user_id` int(11) NOT NULL, `relationship_status` varchar(48) CHARACTER SET utf8 COLLATE ...
2
votes
1answer
161 views

Need some help with this query get all status and their associated comments of me and all my friends

I've several days dealing with this query but can't get it to works as I want. This post is related to this one Several values from different tables in which I tough found the solution but I was ...
2
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3answers
1k views

MySQL backup with no downtime [closed]

I'm running a M/S replication of MySQL 5.5 / innoDB (over ubuntu). My DB is pretty large: ~250GB. I'm looking for a backup tool/service that will do the following: full backup no downtime / locks ...
2
votes
2answers
3k views

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 ...
2
votes
2answers
4k views

MySQL Table level Replication

I have 3 servers, say A,B &C. All have the equivalent data(same data). Now what I want is to make A as the master and B,C the slaves. But the scenario is that I only want to replicate some of the ...
2
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4answers
260 views

Aggregate query optimization

Could you please help me to optimize this query - currently it takes ~4 minutes to run this query. It looks like keys: ip and timestamp are non-unique so shall I add some indexes? mysql> EXPLAIN ...
2
votes
1answer
663 views

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 ...
2
votes
1answer
411 views

MySQL with high CPU and memory usage

here we have a VPS with 3.2GHz quadcore processor with 2GB of RAM and 4GB of SWAP which need to work with a high intensive legacy system (read: bad coded). The main problem is that the CPU (~80 - ...
2
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1answer
2k views

Is it possible to force drop of mysql tables with FK?

For dropping a table in which a Foreign Key is used in other tables, it is necessary to drop all other tables having FK connection with the corresponding table. Is there a short way to drop a table, ...
2
votes
3answers
1k views

how to install mysql on mac?

My Mac runs Mac OS X, version 10.7.5., so it's a 64 bit system. First, I downloaded mysql-5.5.28-osx10.6-x86_64.dmg. Then I double clicked mysql-5.5.28-osx10.6-x86_64.dmg, it's mounted, and shows ...
2
votes
1answer
105 views

Why does MySQL increment the auto_increment value when there's a constraint violation?

I have a table in a MySQL database with one column id, which has auto_increment and the Primary Key. There's also a Unique constraint in this table, on different columns. I noticed that when I try to ...
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2answers
2k views

High MySQL “InnoDB Writes Per Second” - Can't see the queries?

On our live MySQL 5.5 database server, we use MySQL Workbench for running manual queries, checking running queries to see what's going on, etc. I noticed today that on the "Server Status" tab there's ...
2
votes
3answers
260 views

Rolling count of total transactions over time

I need to get a set of total transactions over time on a weekly interval. Essentially I need a total-transactions-to-date column. When I group by WEEK(Date) I get the amount of transactions for that ...
2
votes
2answers
899 views

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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2answers
773 views

How to SELECT rows with time duration stored in varchar column?

There is a column in table defined like this : duration varchar(10) It has value for duration of a MP3 file stored in it like : 52:19 (Minutes : Seconds) How can I create a SQL query, for ...
2
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1answer
4k views

Upgrading MySQL 5.1 to 5.5 on Centos 6 without removing dependencies

I'm trying to upgrade MySQL 5.1 to 5.5 using yum/rpm combo (yum to remove MySQL 5.1 and rpm to install MySQL 5.5). Most instructions I've found suggest to do first: yum remove mysql mysql-server ...
2
votes
1answer
109 views

Need to Rewrite/optimize Slow Query

I have a query with following explain plan EXPLAIN SELECT COUNT(applicant.id) as applicantCount, application.name,applicant.application_id,application.id FROM applicant LEFT JOIN application ...
2
votes
2answers
10k views

MySQL using too much CPU

I'm studying to be a DBA right now because I have a massive live database that is very sensitive that I manage. Here's the current system stats of my dedicated database server: CentOS 5.9 24gb Ram 8 ...
2
votes
1answer
1k views

Dealing with empty strings while loading a table from a CSV

I am trying to load a CSV file into a table. The CSV file contains some empty strings for example: 1,2,,4 I want to load the empty field as null. One way I know is to use \N i.e: 1,2,\N,4 but it ...
2
votes
2answers
4k views

Unable to drop the table since its showing waiting for meta data lock

We are trying to drop one table but it's getting hanged, and when we see the 'SHOW PROCESSLIST' command it's showing as 'waiting for meta data lock'. Even we are unable to perform any operation on ...