All versions of MySQL (not Microsoft SQL Server). Please also add a version-specific tag like mysql-5.7 if that is relevant to the question.

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1answer
340 views

MySQL replication risks for the master

I have a production MySQL server, fairly heavily loaded with an INSERT-only load on one of its databases. I'd like to attach a non-production (sitting on my desk, more or less) replication slave to ...
5
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4answers
3k views

MySQL subquery slows down drastically, but they work fine independently

Query 1: select distinct email from mybigtable where account_id=345 takes 0.1s Query 2: Select count(*) as total from mybigtable where account_id=123 and email IN (<include all from above ...
2
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1answer
138 views

MySQL switch between data directories for individual databases

I'm in the middle of designing a solution to an issue we're currently experiencing while writing to certain large MyISAM tables. The database in question basically stores information regarding two '...
1
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1answer
525 views

use of signal for insert statement in mysql stored procedure

I want to create a procedure in which all types of possible errors can be handled using SIGNAL. Below is my stored procedure: DROP PROCEDURE IF EXISTS `spItem`$$ CREATE PROCEDURE `spItem`( IN ...
2
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1answer
214 views

Can not add list partitions

Following is the create table statement that is working as expected. But if I have a table without any partitions and if I try add partitions, it seems that I can not add more than 16 values in it. ...
2
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2answers
849 views

how to insert multiple columns(around 40) into my sql database using java

i have a program to read the content of an excel file to my-sql db. i have 40 columns in excel and i created a table of 40 fields. and i want to import the data from excel into corresponding table ...
3
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1answer
1k views

ACID-compliance of MySQL master-master replication?

I've created two MySQL 5.1 servers, replicating off each other (log-bin) in a low latency environment (different AZs within an EC2 region). All tables that are being replicated are using the InnoDB ...
3
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2answers
998 views

Rows already DELETEd on MySQL slave; How to DELETE on master?

I have a handful of rows that exist in my MySQL master but not in my slave. Replication is running ok and these rows are unlikely to ever be referenced as it is a store-and-forget type of table. ...
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2answers
1k views

Database Design - Employee Clocking In and Out System

I want to develop Employee Clocking In and Out System (website). I am concerned two things: If staff forgot to 'Clock Out' from yesterday and they have 'Clock In' today, it should flag to the ...
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0answers
2k views

stored procedure returns ERROR 1305 (42000): FUNCTION does not exist

I have a stored procedure and function as below CREATE PROCEDURE ProcName() begin .... DECLARE curs CURSOR FOR select A.PList, B.nid from persons A inner join articles B on A.aid=B.id; .... ...
2
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2answers
5k views

MySql - Read only on slave

I want to make my MySql slave read only, i've been looking and found the read_only option, but its says that users with super privalges can still write (if i understand the text correctly), here is ...
0
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1answer
156 views

getting error while installing memcached_function

now i am working with memcached with mysql cluster 7.2 for that i am installed libevent-1.4.14b-stable.tar.gz memcached-1.4.5.tar.gz libmemcached-0.8.tar.gz then memcached_functions_mysql-0.8....
2
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1answer
2k views

“Data truncated” vs “Incorrect string value”

I'm trying to figure out the difference between some warning messages related to data truncation. Consider the following table: CREATE TABLE `txttest` ( `mycol` text NOT NULL ) ENGINE=...
2
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1answer
3k views

alter table (mysql) adding column with default value of space (' ')

On my Mac, using 5.5.11 MySQL Community Server (GPL) alter table foobaz add column ( extendedTitle varchar(3000) DEFAULT NULL, clasindxIndent int, spacedash1 enum (' ', '-', '1') default ' ', ...
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2answers
5k views

How do I show warnings when loading data created from mysqldump?

I've got a large .sql file with large insert into ... values ... statements. Many of these statements are generating warnings during execution. How can I get mysql to print the warnings? If it hit ...
3
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1answer
10k views

Creating a table from variable names

Is it possible to create a table from a variable name? For example I have the following stored procedure that I'm trying to write but it will not compile past with the create statement. CREATE ...
4
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4answers
2k views

Help with Query. Finding records that have the same relationships (MySQL)

I have a table of Listings that has a many to many relationship with a Taxons table. The table structure looks like this: listings ---------------- id (int) name (varchar) listings_taxons -----------...
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1answer
74 views

How can this data be joined?

Definition: table_A table_B id,description id,description,id_table_A Column id_table_A is a foreign key to the primary key of table_A and is not mandatory. Sample data: ...
2
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1answer
235 views

Entries disappeared, auto_increment also reversed, web app security vulnerability or DB Error?

I am using Mediatemple's Grid Hosting (GS) platform to host a wordpress site. The DB tables are using the MyISAM engine. I had noticed that a previous article had disappeared from the site. At first ...
5
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2answers
719 views

Large accounting table, best way to partitioning by two dates

I need to create a log table to stores the connections to out network (last 3 years, after that the log will go into backup). The hardware/software used is proprietary, and for accounting it just call ...
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2answers
1k views

How to install MySQL server on Mac (OS X 10.6.8) from command line?

How to install MySQL server on Mac (OS X 10.6.8) from command line? If I donwload the .dmg file, is it possible to install it from command line?
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2answers
2k views

MySQL replication fails due to duplicate keys after master is restarted

I'm new to MySQL load balancing, I want to try the master-slave concept. Whenever I setup master-slave for the first time, and both have up-to-date fresh data, that works perfectly fine. However, ...
1
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1answer
2k views

Soft delete: Copy row data to archive table when deleting

How can I move data from my current table to an archive table when a delete is called on the table? My current table and archive table needs to be in sync in their schema too. Can someone help ...
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3answers
20k views

Calculating disk space usage per MySQL DB

I am currently using information_schema.TABLES to calculate the total disk space usage grouped by the database name, but it is running terribly slowly. On servers with hundreds of databases, it can ...
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2answers
1k views

How to backup a MySQL database without slowing the application?

I'm an application developer and wondering about our database backup strategy. Right now our sysadmins backup our database every 8 hours. I don't really know how the do it, but while the backup is ...
1
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1answer
683 views

Unable to connect to MySQL cluster database

I am unable to connect to mysql cluster database after starting my management node, data node, mysql node. I made the necessary changes by adding the loadbalance in the dbURL. But I am not able to ...
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2answers
27k views

How to log verbose output from mysqldump?

You typically save the verbose output of a Linux command like this: # command > output.txt But when you use a command like mysqldump, the > option outputs the dump of the database tables to ...
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3answers
10k views

InnoDB table SELECT returns ERROR 2006 (HY000): MySQL server has gone away (after power outage)

This server is a virtual machine running CentOS 6.0, MySQL 5.5.21 There is a database named devSystem. There are InnoDB tables within. Running the following commands causes error ERROR 2006 (HY000):...
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1answer
1k views

MySQL Cluster over WAN: Best Architecture Options?

My company is looking at a multi-data-centre solution for high-availability, fun, and profit. We have businesses across the planet, with the need for MySQL database clustering solutions that can keep ...
5
votes
1answer
7k views

How can I find who holds the lock based on the hex-dumped?

I've been reading the Diagnosing MySQL InnoDB Locks article. Karl E. Jørgensen writes on 2008 so I'm consfusing it is in effect. I would like to supply a snippet of the SHOW ENGINE INNODB STATUS: ---...
6
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1answer
7k views

How is INDEX on Composite Primary Key in mysql?

When making a composite primary key for two or more columns, e.g. PRIMARY KEY(col1, col2, col3); will the system INDEX each column individually? The reason that I am asking this question is that when ...
2
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1answer
2k views

Why can't I get a lock on an InnoDB table?

I have problem with lock table command: LOCK TABLE v3_cam_date WRITE; the command always running with state: "Waiting for table metadata lock". Try to find out which thread was hold the lock on ...
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2answers
535 views

How to model double relationships?

Background: I have designed a solution for Filemaker to input data into a Question Database. After we are done with inputting data into Filemaker, we will be exporting the data as excel and ...
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3answers
13k views

innodb_file_format Barracuda

I have a couple questions for those more familiar. Most of my instances have been running Antelope despite having support for Barracuda. I was looking to play around with some compresses innodb ...
3
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1answer
576 views

Is the “load data infile” command in MySQL unsafe in general, or just when using statement based replication?

I'm also trying to understand why MySQL considers "load data infile" unsafe and switches to RBR if running in mixed mode, does that mean it is only unsafe when using SBR?
3
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1answer
3k views

How do I diagnose missing rows on a MySQL slave?

I'm running traditional master/slave replication on MySQL 5.1.52, my master is set for statement based replication. A few tables are missing rows on the slave (differing row counts), these tables are ...
2
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1answer
2k views

how do I limit the characters in selected row and con-cat with '…'

I have a query which return a column named comment. I want to limit the number of characters returned by select statement to 50 and if the comment row contain more than 50 characters, I want to append ...
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3answers
42k views

How can I move a MySQL database to another drive?

I'm using MySQL 5.5 on a local machine to analyze a large amount of government data. I've created a local database that resides on my default drive (Win7 C: drive). I'd like to store the data on my E: ...
3
votes
2answers
6k views

mysql out of available memory

We have a dedicated MySQL server with 16GB of RAM that's serving 8 web workers with relatively high traffic (over 1000 requests per second at peak traffic) At peak we're seeing the following errors ...
3
votes
1answer
2k views

Getting duplicate primary key for auto increment column

I have a MySQL Innodb table with 'id' as auto increment primary key column. My Scripts are doing following operations: insert ignore into tablename set x='a', y='b' update ignore tablename set x='...
1
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1answer
3k views

strategy for enabling a general query log on MySQL 5.0.95 with no restart?

I would like to configure a general query log for a busy MySQL 5.0.95 production server without effecting the availability. Obviously I can set the "log" option in the my.cnf file and restart the ...
3
votes
2answers
11k views

How to use RESTRICT for Foreign Key in mysql?

In the database structure of CREATE TABLE Country ( name varchar(40) NOT NULL, PRIMARY KEY (name) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; CREATE TABLE City ( name varchar(40) NOT NULL, ...
5
votes
3answers
772 views

how do I model this in database?

I am using mysql as my backend database. Here is the use case; A HolidayPackage is configured with some default offerings. These default offerings can be up/downgraded based on the options provided. ...
3
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3answers
746 views

Need help configuring Memcached to store values in MySQL Cluster

I am working on a Memcached implementation with MySQL Cluster 7.2. I have installed and configured memcached with following parameters: PORT="11211" USER="mysql" MAXCONN="1024" CACHESIZE="1024" ...
1
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1answer
345 views

Installing Sphinx on Mac OS with XAMPP

We have: Sphinx 2.0.3 Mac OS 10.6.8 XAMPP 1.7.3 (with MySQL 5.1.44) Here is PATH: user:sphinx-2.0.3-release user$ echo $PATH /Applications/xampp/xamppfiles/bin:/opt/local/bin:/opt/local/sbin:/...
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1answer
1k views

MySQL hang in load data infile command

From the link: LOAD DATA (400k rows) INFILE takes about 7 minutes, cannot kill the "logging slow query" process? I had changed the command order (unlock before commit + replace some ...
3
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5answers
3k views

Two-sided UNIQUE INDEX for two columns

Creating a table with composite PRIMARY KEY or using UNIQUE INDEX for two columns guarantee uniqueness of col1, col2. Is there a tricky approach to make the reverse order of two columns UNIQUE too (...
1
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1answer
1k views

Usefulness of Foreign Key WITHOUT reference option

Sorry, if this is naive question, but I searched a lot and did not get a vivid answers. Consider a simple InnoDB FOREIGN KEY without ON DELETE or ON UPDATE I think this will avoid INSERT of a value ...
4
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1answer
2k views

How can I prevent gaps in a MySQL table AUTO_INCREMENT field?

For example, I have a table for user registration: CREATE TABLE IF NOT EXISTS test_user ( user_id int(10) unsigned NOT NULL AUTO_INCREMENT, user_name varchar(50) NOT NULL, PRIMARY KEY (...
2
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1answer
1k views

MySQL using trigger instead of check

Is there any way that I could use trigger instead of check? like I have CREATE /*!50017 DEFINER = 'root'@'localhost' */ TRIGGER test BEFORE UPDATE ON apply FOR EACH ROW BEGIN ...