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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2
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1answer
4k views

Delete data from huge InnoDB table from MySQL Master and Slaves

We have some huge tables in MySQL database, We have already archived/deleted data older than 2012 in 2013, Now we need to archive/delete data older than 2013 means we need to archive data for year ...
5
votes
1answer
5k views

MySQL 5.6 on OS X 10.8.2 disconnects on user creation?

Via Homebrew I just upgraded from MySQL 5.5.29 to 5.6.10 and all my queries and existing users are working fine, but whenever I try to modify permissions or create users now MySQL disconnects me. Are ...
3
votes
3answers
2k views

MySQL query extremely slow after server restart

I am managing a very large database for a custom application I wrote to keep track of visitors. The DB server was rebooted for the first time in over a year - not even to install any updates, but ...
2
votes
1answer
108 views

MySQL : Till when MySQL retains binary logs?

I have multiple queries : Till when does MySQL retain the binary logs ? What is the default setting ? When does it start logging ? What does the number of the binary log file name suggest for ...
0
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0answers
30 views

MySQL: why provide size of a datatype in table definition? [duplicate]

Below is an example table definition: CREATE TABLE IF NOT EXISTS `mytable` ( `id` MEDIUMINT(5) NOT NULL AUTO_INCREMENT, `title` varchar(255) DEFAULT NULL DEFAULT '', `content` text ...
2
votes
1answer
3k views

How to use LOW_PRIORITY for heavy queries?

I have scheduled heavy UPDATE queries at administrator level, and since they are heavy UPDATEs with multiple JOINs, consume a huge amount of resources. I do not want them to stop end users from ...
1
vote
1answer
5k views

column auto updated after 24 hours in mysql

i have a table T1 with column : Name State time mon 1 2014-01-09 11:23:00 tue 0 2014-01-07 14:40:00 wed 2 2014-01-08 09:23:00 thu ...
0
votes
1answer
6k views

Declare variable mysql

I am new to mysql, I have been using SQL in the past. I am trying to insert rows into a table via creating a loop. But struggling with it. Any help? DECLARE @minid INT = (SELECT MIN(Product_ID) FROM ...
0
votes
1answer
53 views

Retrieve column info from next column

I have a query that is working but I figure I could enlist some help to make it more efficient. However before I show the query I would like to get a few answer on how others would do this. What the ...
1
vote
1answer
231 views

How to do two actions in conditional UPDATE?

In a query as SET @x = 1 UPDATE table1 SET col2 = IF(col1 = 'y', @x:=0, @x:=@x+1) Every time reaching the value of y in col1, I want to SET the @x:=@x+1 and after that reset the x to 0. In other ...
0
votes
1answer
1k views

My database keeps crashing on startup how can i repair it without it running?

I've got some problems with my database. I hope somebody can help me out. Problem: The database keeps crashing on startup. In my log i see a couple off these errors: [ERROR] /usr/libexec/mysqld: ...
3
votes
4answers
5k views

Update column with the sum of column in previous rows in MySQL

We have a table, essentially: id, amount, end balance, account_id I now want to re-calculate the end balance values (because of possible corruption) End balance is basically "end balance of ...
3
votes
2answers
7k views

Select every n-th row, don't pull the entire table

In light of the Meta discussion on allowing basic SQL questions on dba.SE I present an issue that I'm having now, for which the answer on Stack Overflow is inadequate and naive. I hope that there is a ...
0
votes
2answers
142 views

I can't get an import to go past 1.1gig

I can't get an import to go past 1.1gig. I have a large 4gig InnoDB table/database I would like to get on my "tried and true" box. Current config on this box I want to work with = Dell PowerEdge ...
0
votes
1answer
4k views

MySQL auto increment problem with deleting rows / archive table

A hosted server is running "maintenance" each weekend. I am not privy to the details. In a database on this server there is a MyISAM table. This table never holds more than 1000 rows and usually much ...
1
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0answers
156 views

MySQL SSL Master-Slave replication not syncing

I have originally posted this thread on stackoverflow and after a comment I moved it here. The original post can be found here. I have setup a typical Master-Slave replication scheme for my MySQL ...
-2
votes
1answer
259 views

Bulk Insert / Data Transformation [closed]

What techniques do people use to upload data from a flat file into a normalised database? We are planning on using MySQL or MariaDB. I have a number of large excel spreadsheets that I would like to ...
1
vote
1answer
116 views

Query result set

I've 1 query written in our legacy system. (using MySQL 5.5) Now, with growing data - the below mentioned query taking huge time. In our system, we've somewhat 2,000,000,000 (2 billion rows) approx ...
0
votes
1answer
2k views

Speeding up mysqldump / reload

Converting a large schema to file-per-table and I will be performing a mysqldump/reload with --all-databases. I have edited the my.cnf and changed "innod_flush_log_at_trx_commit=2" to speed up the ...
1
vote
1answer
92 views

Is an explicit KEY redundant if it is covered by a UNIQUE KEY?

I am auditing an application which I've been developing over the course of several weeks. I've noticed this in CREATE TABLE: UNIQUE KEY `baz_3` (`baz`,`foo`,`bar`), KEY `baz` (`baz`), Is the ...
0
votes
0answers
135 views

unexpected null returned from calculated columns

I'm working on a program that will calculate journey times based on bluetooth MAC addresses and i'm trying to nail down the mySQL commands I need before I get cracking on the software part of it. i ...
0
votes
2answers
71 views

Is it safe for me to switch from an 8GB server to a 4GB server? (Stats inside)

We are looking to cut some of our server costs and the only place I think it might be possible is our db server. We're currently running an 8GB rackspace cloud that houses a mysql instance and I ...
2
votes
1answer
2k views

How to call stored procedure inside trigger?

I have made stored procedure that will update product quantity as per product id. That works fine for me. Following is code : DELIMITER $$ CREATE DEFINER=`root`@`localhost` PROCEDURE `...
0
votes
2answers
447 views

Binary Log Format in MySQL

Reference manual for MySQL 5.6 states that " Some changes, however, still use the statement-based format. Examples include all DDL (data definition language) statements such as CREATE TABLE, ALTER ...
0
votes
1answer
198 views

multiple requests shut down mysql

I have some problems with my mysql database. I configured a server with the database and other services (apache, php) and put run multiple applications. There are two problems. Every day at the ...
1
vote
1answer
191 views

MySQL DB dynamic ranking or “static” separately saved

I have a table where I store the points with the connected categories and game-types of each user. There are different ways to get points. However everytime when the points need to get displayed in a ...
0
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0answers
9 views

Multiple requests shut down MySQL [duplicate]

I have some problems with my MySQL database. I configured a server with the database and other services (apache, php) and put run multiple applications. There are two problems: Every day at the ...
1
vote
1answer
808 views

MySQLdump on specific db date

I'm new in here and i don't really know where to start but here is my concern. I need to backyp a MySQL DB running under windows once a week. For e.g every friday i need to backup and transfer to ...
0
votes
0answers
66 views

Same table for real persons and fictional one

In my application stores both real and fictional persons (from movies, etc.) as well as stage names and alter egos. These entities have almost the same properties and are often referenced via foreign ...
1
vote
2answers
547 views

Idle connection plus schema-modifying query causing locked database

As part of our automated deployment process for a web app running on a LAMP stack, we drop all our triggers and stored procedures and recreate them from source control. It turns out there was a hidden ...
-1
votes
2answers
571 views

Mysql - Change name of Information_schema [closed]

I want to change the "Information_schema" database name to "some_thing_else". Is this possible? If so, how can I do so? As a developer knows about structure and a hacker also. How can we protect ...
2
votes
1answer
1k views

MySQL: What is the most optimized way to use datetime type field in query

I am working on optimization of some slow queries in my application. I found a query in which datetime comparison has been used. Below is the subquery: select * from jos_content c where c.visible = 1 ...
0
votes
2answers
727 views

Importing MySQL database using Linux Terminal

I have an existing database, named dlti.sql I want to transfer it to a Linux-based server. I tried using this code, however I get no response: mysql -u root -p Desktop < dlti.sql The .sql file ...
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2answers
2k views

Determining what algorithm MYSQL View is using

When creating a MySQL View, the algorithm is set to UNDEFINED. How do I see which algorithm MySQL is choosing for the query ? I tried using "EXPLAIN", but it is not obvious from the results what ...
0
votes
1answer
33 views

Primary key added automatially to seconday indexes on MySQL 5.5?

I have a table (purchaseorders) that has the following colums: PurchaseOrderID, PurchaseDate, CreatorID, TotalValue and a primary key consisting of the field PurchaseOrderID As I often have ...
0
votes
0answers
66 views

joining two tables and counting joined rows

table 1 : categories -------------------------------------------------------------- cat_id | cat_title -------------------------------------------------------------- 1 | sports 2 | news ...
1
vote
1answer
422 views

UUID in mysql database

I have a problem, I have two servers where I have to save my data. For persistent data I run mySql inno DB. I have a lot of entries, so I need fast (CRUD operations). For indexing I was thinking to ...
0
votes
1answer
736 views

InfoBright LOAD DATA INFILE Wrong data or column definition

I'm using BRIGHTHOUSE engine. I have a column defined as varchar(100). When loading data into the table, if the column data exceeds 100 characters, the engine will throw 'Wrong data or column ...
0
votes
1answer
2k views

Why “.my.cnf” file is empty?

I want to edit some of InnoDB variables ,I go to the .my.cnf which is located in home/.my.cnf I found the file just empty. And when I check SHOW VARIABLES in MySQL it gives me all the variables and ...
0
votes
1answer
544 views

Where does mysql write temporary tables?

MySQL 5.1.x | Windows Server 2008 Data Directory is on a different partition. I have an innodb database (innodb_file_per_table is set) that I'm trying to optimize and I don't appear to have enough ...
0
votes
1answer
94 views

Few Insert queries rollbacked due to system crash

Well, this problem occured to me first time. Yesterday, one of our mysql system server crashed and when it restarted last few inserts were completely rollbacked. I am sure that they were proper ...
0
votes
0answers
149 views

What are the steps to change tables engines from MyISAM to InnoDB?

I have a Datebase with 10MB size . The Tables' engines were MyISAM (table-lock level). So I deiced to change them to InnoDB (row-lock level). I used the sql query for each table : ALTER TABLE t ...
1
vote
1answer
76 views

Accessing Data after importing from file

I'm going to preface this with saying I'm a complete newbie at this database stuff before the rolling of the eyes happens, so please be patient with me. I have an sql dump that I am trying to import ...
2
votes
0answers
100 views

mysql vs mongodb cache/load balancing

I have a system where users can 'like' content. There will likely be many hundreds of these likes going on at once. I'd like it to be AJAX driven so you get an immediate response. At the moment I ...
0
votes
1answer
42 views

MySQL Database inside a VM on a high availablity cluster

I'm looking to do an infrastructure overhaul.Currently I have a ton of small databases scattered amongst our assets and I wish to consolidate them. Is consolidating all databases to 1 tuned database ...
0
votes
1answer
430 views

Incremental MySQL restore using binlogs

I've tried to restore a MySQL database using incremental binlogs and mysqlbinlog tool but I received the following message: ERROR 1666 (HY000) at line 30: Cannot execute statement: impossible to ...
0
votes
0answers
219 views

Cannot find /etc/init.d file in opensolaris

While installing MySQL , I noticed a point, I mean to start the MySQL server manually , use the command cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql The error shown is : cp: ...
2
votes
2answers
875 views

MySQL - INSERT … SELECT .. FROM .. - Single transaction or transaction per row?

Question: I am currently working on a data migration. I need to migrate 2.5 million rows from one InnoDB table to another InnoDB table (with a different setup). I am using the following syntax to do ...
2
votes
2answers
4k views

Difference between show status and show global status in mysql

When I execute "show status" and "show global status" in MySQL at interval of 5 seconds , I got set of 291 results each time. But, value of some parameters are different. Below are the list of those ...
1
vote
1answer
716 views

MySQL: Is it possible to have an IF subquery?

I'm attempting to run a subquery inside of an if statement used in the SELECT, but I'm getting an error. I've never needed to do something similar before so I've never tried this until now. Here is ...