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
376 views

Speeding up a simple select query on Mariadb

I have a 100k rows table with the following structure: +----------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | ...
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0answers
36 views

Slow MySQL query with Group by

I have a query that is taking a long time to execute minutes and more. The two tables orders and tickets have around 150k records. This is the query: SELECT orders.id, count(distinct tickets.id) ...
2
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1answer
241 views

Mysql: How can i make a host show up by hostname in 'show processlist' rather than by IP address

THought this might be something controlled via rdns but updated that and still getting connections for a couple machines showing in 'show processlist' as the ip address (and port) rather than hostname ...
0
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1answer
123 views

Not all MySQL processes are killed when restarting

We have a MySQL 5.6 server running on Ubuntu 12.04 using the MySQL 5.6 PPA. The service comes up fine when rebooting the box, but whenever we restart the MySQL process via /etc/init.d/mysql restart, ...
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1answer
969 views

Filtering records not present with specific conditions in another table

I have a table (let's call it extra_info) in MySQL that has various extra information/labels on user accounts: account_id / data_key 11 / 'test' 11 / 'blah' 12 / 'coupon a' 12 / 'coupon b' 15 / ...
10
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1answer
139 views

How to estimate the I/O operations performed by MySQL queries?

On Amazon's RDS, you pay about $0.10 per 1 million I/O requests. I've noticed a very high number (in hundreds of thousands) of I/O requests for a very low traffic database. On seeing this, I did some ...
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1answer
1k views

ClearDB Granting Created User Access

I added the ClearDB addon to Heroku, but upon using the created username to create a new database, the error appeared: Executing: CREATE SCHEMA `androidchatterdatabase` DEFAULT CHARACTER SET utf8 ; ...
1
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1answer
26 views

MySQL -> Loop through a table, running a stored procedure on each entry

I have a database with 'books' (short stories for children) and it would be extremely informative to have word counts of each word in the books. I figured out how to get the word count for each word ...
2
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2answers
291 views

MYSQL joining 3 tables with left join

I have these tables: pupils: (id_pupil, name, surname, email, user, pass, level, class) incidents: (id_incidents, date, time, type_incident, comments, id_pupil, id_user, subject, id_trimester) ...
3
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5answers
28k views

Remote MySQL connection fails (10060) - “Can't connect to MySQL server on domainname.com(10060)”

I have developed an application in VB6, and am using an online MySQL database server for storing my application's data. The first time I try to connect to my database server is successful, but after ...
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2answers
52 views

How to improve performance of a query with an IN subquery

Get the count of other users having the x tag with order_id in order_id of users having the y tag table: MyCustomTable (200K rows) order_id user_id type ('x' and 'y') my custom tags and the ...
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1answer
166 views

How do you remove reported non existing tables from mysql?

I was trying to export a mysqldump --all-databases and noted errors. A subsequent mysqlcheck --all-databases revealed several non existent tables like the following Error : Table ...
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2answers
719 views

Percona XtraDB - Random deadlock

Randomly my database gets locked completely and queries hang and they pile up until it gets "Too many connections". Below is my mysql log file, I couldn't find anything related to the error system ...
0
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1answer
349 views

Large long-running reporting queries are causing very slow new mysql connections

Usually, mysql's connecton time is in the 0.001 second range. However, when I run a large reporting query (that spans multiple tables with aggregates), I get tons of warnings saying that new mysql ...
1
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1answer
145 views

Why do innodb tables get corrupted so easily?

I'm upgrading a legacy system running MySQL 5.1 all the way to MariaDB 10. We're on a brand new Windows server, running XAMPP. I've done plenty of DB migrations in my time but this one has just been ...
0
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1answer
32 views

Display the error message returned form Mysql

I need to get the whole error message returned from MySQL and assign it to @error_string : DECLARE CONTINUE HANDLER FOR SQLEXCEPTION BEGIN SET @error_string = ...
1
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1answer
179 views

Index to fix this query MySQL

We have an extremely large forum running lots of third party software (Most of which doesn't run all that well) and we're starting to optimize things as time allows. This query keeps popping up in the ...
2
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2answers
688 views

InnoDB not enabled

I have a mysql database that when I run SHOW ENGINES; innodb does not show up as an engine. This seems strange as I have an identical server setup where innodb is enabled and in use. I have checked ...
0
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2answers
119 views

Which files in the “MySQL-5.0.27-win32” folder do i need to backup?

Ok, I am using a pretty old MYSQL "mysql-5.0.27-win32" and the file and the structure maybe different from the latest Mysql (mysql 7). Here is the current structure of of mysql-5.0.27-win32: In ...
0
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1answer
131 views

error 2013 (hy000) lost connection to mysql server during query while load of mysqldump

I'm trying to load mysqldump and I keep getting following error: ERROR 2013 (HY000) at line X: Lost connection to MySQL server during query /etc/my.cnf: [mysqld] max_allowed_packet = 16M ...
0
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1answer
141 views

Difficulty with nested query order & grouping

I'm trying to identify the count of objects a user updated during a given day, but only where the user was the final update. Each object can have multiple updates in a day from any user, but the ...
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1answer
2k views

MySQL SELECT query hangs - Opening Tables INNODB

On my server I have 6 MySQL databases. They all power Wordpress websites. For some reason, 2 of these databases are not accessible. To my knowledge they use INNODB, but I can't confirm it as even ...
0
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1answer
1k views

Deadlock caused by INSERT trigger - thread looking for lock it already has?

Using MySQL 5.6.17. I have a table with an INSERT trigger that reads values from that table and 4 other tables, combines the results and writes that to a sixth table. Ever since I added this trigger, ...
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2answers
271 views

Avoiding Multiple Queries when Searching for Records Associated with a Set of Records

So, I am sure I have done something really stupid while designing this, and I'm open to schema changes if they'll really help me out. On to the problem: I have a custom shopping cart system (backed ...
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2answers
216 views

How to change mysql password

I am on OS X 10.9.5 and I did a reinstall of mysql2 and I provided a password during installation but it is not working when I run the command mysql -uroot -p. The result I get is: ERROR 1045 (28000): ...
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1answer
47 views

REGEXP does not show the right result?

I have in the name column: 3 boxes of frogs 7 boxes of frogs 48 boxes of frogs When I execute: SELECT name FROM items WHERE name REGEXP "[^1-5] boxes" ...the result is: 7 boxes of frogs 48 ...
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2answers
5k views

Error Querying MySQL server linked to SQL Server 2008

I've created a linked server in MS SQL Server 2008 to a remote MySQL server. When I try to query any tables, I get an error: .tablename. contains no columns that can be selected or the current user ...
0
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1answer
142 views

Hash index for InnoDB

I saw a database schema that looked like this CREATE TABLE foo ( name_hash bigint, name varachar(500), a varchar(500), b varchar(500), ... PRIMARY KEY (name_hash), KEY ... ...
20
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3answers
9k views

How Does Table Partitioning Help?

I am having difficulty to grab the idea of pros and cons of table partitioning. I am about to start work on a project which would have 8 tables and one of them will be the main data table which will ...
0
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1answer
116 views

Laggy slave OK to have only one system user in processlist?

In all the examples of a processlist on a mysql slave I've seen, there are two system users. I have a slave that is very far behind the master. When I do show a processlist, there is only one system ...
2
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2answers
49 views

Migrate SQL Server backup to MySQL for a Wordpress site

I have a client with an old .Net site that used SQL Server. For lots of reasons they decided to switch to Wordpress. They had a bunch of news articles on that old site that they want turned into posts ...
2
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1answer
162 views

MySQL running fine while data files (disk) are not present. Data folder nowhere to be found

I'm running MySQL server 5.6 on Windows 2012 R2, and since the installation didn't go as planned, I had to re-install it to change the data directory path. The installer for some reasons never gave ...
7
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1answer
19k views

How to set up multiple fields as primary key in MySQL?

I have a table with fields EmployeeID blahblah blahblah2 ..... RecordMonth RecodrdYear so each employee should only have a matching entry for a month, year, Emp#. How do I set up a table. ...
0
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3answers
3k views

Migrate Jira to MySql - Unknown system variable 'storage_engine'

I'm migrating JIRA in Windows from HSQL to MySQL and I got stuck with the message Unknown system variable 'storage_engine'. Though I created a backup, installed MySQL and copied J connector to libs ...
0
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2answers
130 views

What is making MySQL stay in strict mode

New Mac El Capitan 10.11.2 mysql-5.7.10-osx10.10-x86_64.dmg I have to work with a database that has default dates "0000-00-00" but MySQL is in strict mode and chokes on them. I can't find a way to ...
4
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2answers
107 views

find the beginning and ending values of sequential runs

This article does the inverse of what I need: Find which numbers in [1, 161] are not in the result set? Given the sample data they used: mysql> CREATE TABLE wp_blogs -> ( -> ...
0
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1answer
116 views

replication filtering replicate-rewrite and do-table Mysql 5.6 (innodb engine )

I have a master/slave replication setup based on statement based replication. On master database named DB1, I have 5 tables and I want to replicate only two table on slave's database named DB2. Also, ...
1
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1answer
25 views

Get previous and next row from result set help

I have to get "relevant" results from a table by joining it on another table and filtering the results on parent id and current id, this all goes fine until your current id is either the first or the ...
4
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2answers
2k views

How much data is needed to show MySQL Cluster's performance scaling vs. InnoDB

I am evaluating MySQL Cluster as a possible replacement for an InnoDB schema. So far, I have tested it with 10s of MB of data, and found MySQL Cluster slower than InnoDB; however, I have been told ...
0
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2answers
20 views

check when last password changed in my user db/table

i have radius billing system with mysql as DB. I want to know which user 'password' was changed in last 5 minutes So that I can fetch such user mobile number from the DB and send SMS Alert about the ...
1
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1answer
163 views

federated tables? synchronization? replication? [mysql]

I have a REMOTE suppliers table with, lets say, a code and a name, and several client databases will be creating new suppliers. Server database code | name ______________ 1 | Mark 2 | ...
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2answers
113 views

Select highest id of each type in mysql

I am creating a database that keeps track of backups on our various servers. The query that I am using actually seems to work for the most part. The only issue is that it isn't getting the highest ...
2
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1answer
161 views

MySQL stored procedure updates twice

I have this stored procedure: DELIMITER $$ CREATE PROCEDURE updateTrendContentStats(IN mongoid VARCHAR(255),IN numericid INT,IN points INT,IN ctype INT,IN activity INT,IN created INT) BEGIN DECLARE ...
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1answer
203 views

Slave Waiting to reconnect

I have added new slave host to master for replication, but missing some of the parameters. mysql> show slave status\G *************************** 1. row *************************** ...
1
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1answer
251 views

What's the approach to figure out reason for mysql crash?

The database I'm using crashes a lot recently. And I can't find a decent way to dig into the issue. I looked into mysql error log, but don't know how to start. I know there was a "load data infile" ...
1
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1answer
157 views

MySQL Workbench can either Dump or Restore - How Do I Configure To Do Both?

I have previously posted this question on Stack Overflow, but have not solved the problem. Hopefully it is not incorrect to post it here in the hope that it will be seen by a some different ...
0
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1answer
11 views

MySQL Proxy on Current User

I'm trying to grant permissions to the current user logged in depending on their role, but it doesn't seem possible to have a select statement at the end of the GRANT PROXY # TO # command The code I ...
0
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1answer
123 views

MySQL very long-running queries

I have a quite large db (800+Mb dump file) that I imported to my local server. It's a Wordpress db from witch I need to extract certain posts. There are around 160,000 posts inside. Currently I'm ...
3
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2answers
236 views

MySQL indexes maintenance

I made a lot of research about how to maintain indexes in MySQL to prevent fragmentation and to optimize somehow the execution of some queries. I am familiar with that formula that calculates the ...
0
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1answer
30 views

Writing a query to COUNT all the services involving a particular

Learning PHP and SQL on an online MOOC, this is a homework that I've got to do. I need to write a query in SQL to count all the services which involve a particular person in my database. The ...