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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0
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1answer
167 views

How to index for multiple inequality WHERE search conditions?

I am thinking on the problem, if there is a multiple columns on which search must work as fast as possible. For example, see the table TEST(COL_A, COL_B) with a (tree) index TEST_IDX(COL_A, COL_B). ...
0
votes
2answers
22 views

Joining on 3 different keys as they're set

I have these tables: TABLE vessels ID int PK organization_id int FK fleet_id int FK name VARCHAR TABLE settings ID int PK organization_id int NULL FK fleet_id int NULL FK vessel_id int NULL FK ...
1
vote
1answer
197 views

Concurrency Issues when multiple users uses Portal (MySQL and PHP)

We have set up a portal using Yii Framework in Apache, PHP and MySQL. In the portal, there is a feature to export the data in dbf format, the extract takes around 7 minutes, but in those 7 minutes no ...
2
votes
1answer
449 views

MySQL with slow queries

I have a website running on Wordpress Multisite + Woocommerce with over 5700 users on a Nginx + Apache server. I recently experienced some down time but didn’t get any errors, just a blank page. I ...
0
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3answers
140 views

Add new admin user to MySQL

I have inherited a MySQL instance currently being used by an enterprise software suite. I have no idea what the credentials are for any account, but have full admin rights to the server that the ...
1
vote
2answers
2k views

Freeing up disk space in 'mysql\data'

I am trying to free up some space used by a MySQL instance, but I know pretty much nothing about MySQL. I notice that in the mysql\data folder there are lots of localhost-bin.0001** files, as ...
0
votes
1answer
79 views

How can I write queries as fast as possible in MySQL? [closed]

I'm looking for two things: Awesome manual about writing fast MySQL queries. Tool which will decompose my query into discrete steps, and give estimations of each step. I've seen the next tool, ...
2
votes
1answer
77 views

Peer review database design for various reports

I'm currently trying to redesign a poorly thought out database for a peer review system that we use internally at my workplace. Employees can log on and submit a review about another employee who ...
0
votes
1answer
111 views

MySQL TIMESTAMP isn't behaving as advertised

I'm using MySQL 5.5.34. The 5.5 Documentation says I can create a table like this: CREATE TABLE t1 ( ts1 TIMESTAMP DEFAULT 0, ts2 TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE ...
0
votes
1answer
52 views

Problem JOINing three tables

I want to show all the categories and the items inside that each category which should store in items_this_category. Note, I have created an associative table item_categories because one item can be ...
2
votes
1answer
480 views

inserting large quantity of data into mysql table

I need to insert about 400 000 000 rows of test data into the InnoDB table. Table is quite simple: CREATE TABLE IF NOT EXISTS `tgt` ( `id_1` int(10) unsigned NOT NULL, `id_2` int(10) unsigned NOT ...
0
votes
1answer
384 views

MySQL pivot table via a view

Suppose the following schema CREATE TABLE `log_apache` ( `date` datetime NOT NULL, `count` int(10) unsigned NOT NULL, `input` bigint(20) unsigned NOT NULL, `output` bigint(20) unsigned NOT ...
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0answers
274 views

Upgrade from mysql 4.1 to mysql 5.5

I was going through upgrade process of mysql server. It is mentioned that to upgrade from 4.1 to 5.5 we need to upgrade step by step like first to 5.0,5.1 ...5.4 and then 5.5. I have some questions : ...
1
vote
0answers
84 views

Querying number of tries since last successful log, checking IP as well as user

I asked this question before on stackoverflow, but it might fit better here, since it is mainly about database performance. The actual question With performance in mind, how would you go about ...
0
votes
0answers
319 views

How to set up MySQL 5.6 Master- Slave Replication step by step

I am new to Mysql replication. I want to have 2 MySQL servers, a Master and a Slave, running on two Ubuntu 14.04 Computers. Their IP addresses will be 10.0.0.1 (Master) and 1.0.0.02 (Slave). I need to ...
3
votes
2answers
5k views

“on duplicate key update” all the non-key fields mentioned in the insert

How can I update the field values mentioned in the insert portion without listing them again in the on duplicate key update portion? insert into tablename set keyname = 'keyvalue', fieldname = ...
1
vote
0answers
208 views

Migrate from Interbase to MySQL

I need to migrate a big database from Interbase to MySQL, I'd like to have suggestions about free and non-free tools to perform this task. I've found this one: ...
2
votes
0answers
21 views

MySQL slow query log not logging all slow queries [duplicate]

I am trying to analyze the hibernate query performance in our application. I tried logging all hibernate queries which take more than 100ms execution time from application side as well as using mysql ...
1
vote
2answers
5k views

MySQL on Windows or GNU/Linux?

I've just read this article: http://dev.mysql.com/tech-resources/articles/move_from_microsoft_SQL_Server.html There it says that MySQL on Windows is a good choice. (or is what I've understood) In ...
0
votes
0answers
133 views

MYSQL backup options using mysqldump and mysqlbackup

I'm currently using mysqldump to backup mysql database. I heard that mysqlbackup offers a much much better performance. Unfortunately it requires MySQL enterprise version which is pricy. A few ...
-1
votes
1answer
1k views

My auto increment primary key is not automatically incrementing

I have the following database Whenever I try inserting values in the database I get the following error. Duplicate entry '0' for key 'PRIMARY' This means ID is not incrementing automatically. I ...
-1
votes
1answer
119 views

Lookup tables and performance

I am using 6 lookup tables in my mysql database. There will be frequent insert,update and delete queries in the db. Will that badly affect the performance. Do I need to save the data as it is without ...
0
votes
1answer
33 views

Privileges discrepancy

When I am logged in as rds_user and have following privileges: GRANT SELECT, INSERT, UPDATE, DROP ONnews.* TO 'rds_user'@'%' My code runs INSERT command just fine, but when it gives ProgrammingError ...
0
votes
1answer
537 views

How can I Automate MongoDB schema design from existing MySQL Database and Logs?

I am working on the project which will automatically generate sample MongoDB schema analyzing existing MySQL database and logs. I am looking for help regarding the below questions. Please, share your ...
0
votes
1answer
508 views

In MySQL Workbench 6.1 (OS X), can you make the Result Grid taller?

In MySQL Workbench 6.1 (OS X), can you make the Result Grid taller? I know the region expands to fill the space vacated by Action Output/Text Output/History, should you choose to hide that. But I'd ...
3
votes
2answers
2k views

MySQL encryption

I am thinking about encrypting some fields in MySQL database using MySQL's encryption functions. I can't find any good sources on how to properly implement it. Has anyone done this and have a good ...
-1
votes
1answer
346 views

Mysql Queries cause high load in server

I have problem in the database ,here is phpmyadmin status queries --------------------+ ...
1
vote
2answers
132 views

MySQL TEXT Disk Space

I have a plain text file with 3 million articles divided with \n. The file is 58G When I'm adding the articles to an InnoDB table one per row INT id TEXT article_content the .ibd file of this ...
1
vote
1answer
1k views

Fetch all parents from child id

I created a table with name "vegs" and inserted values just like this. id name parent -------------------------------------- 1 fruits 0 2 Apple 1 3 ...
1
vote
1answer
7k views

forcing innodb recovery of a corrupted database

A poorly designed script selected records from two existing tables and added records to a newly created table for 24 hours until I killed it by terminating the MySQL 5.6 command line client and ...
1
vote
1answer
454 views

User Table Design

I am designing for an ecommerce application, I need to know how to implement the following task. There are 2 options, Unregistered Users (Free Listing). Registered Users. In this the unregistered ...
1
vote
2answers
58 views

Is it possible to get the information of which user changed what in a database?

I'm trying to create a log of changes in a given table in a database. To do this, I'm going to get the info about all the fields in the original table and create a new one using a function. In ...
2
votes
2answers
234 views

Do Inactive MySQL Databases Consume Memory?

I have inactive databases that are on the server just for archive purposes. I know I can do mysqldump for all of them, but I am not 100% sure they are inactive. When I started my system I didn't ...
5
votes
2answers
7k views

ERROR - Function 'innodb' already exists

I'm looking to start converting some MyISAM tables to INNODB. Running Ubuntu 14.04 Server with MySQL 5.6 ( apt-get upgraded from 5.5 ), 32G ram on 4 core/ 8 thread cpu. Initially had trouble with... ...
0
votes
0answers
78 views

Mysql, performance problems with big database

I am running on Windows 7 64 bit with 4 GB RAM (used for Drupal based website). I have database dump of about 1.5 GB. After re-installing my XAMPP server, my MySQL server began working too slow. I ...
1
vote
0answers
163 views

Significant difference between duration for querys in SHOW PROFILE and SHOW PROFILES?

I have use mysql profiler to optimize an opencart query which takes more than 10 seconds to executes. mysql> SHOW PROFILES; ...
1
vote
1answer
3k views

update an id to max+1 in current table? (MySQL)

I've got a 'jobs' table where each row has a 'worker_id' that is either zero (job is not being worked on) or some unique ID that needs to be incremental. Basically, when assigning this worker_id, I ...
0
votes
0answers
1k views

Why is InnoDB waiting for table metadata lock in simple INSERT/DELETE + SELECT?

I've started using a new MySQL server and moved an InnoDB table there. I'm seeing a weird behavior that when I have a long running INSERT / DELETE, any SELECT from the same table is locked which is ...
2
votes
3answers
1k views

Whats the difference between information_schema.user_privileges and mysql.user?

I have the notion that privileges set in mysql.user should reflect in information_schema.user_privileges but when I try to alter some privileges in mysql.user and queried ...
3
votes
2answers
131 views

SQL Question: Selecting different language versions based on availability

I have the following situation: I have a table that contains entries with language versions (German and English) as part of the key (the other part being a "name" field). However, not always both ...
2
votes
1answer
12k views

Why does mysql adds a default timestamp on insert/update even if I did not specify anything?

I have a table that is as follows: CREATE TABLE SomeTable ( id int unsigned NOT NULL AUTO_INCREMENT, status enum('broken','repaired') NOT NULL, from datetime NOT NULL, until ...
0
votes
0answers
36 views

Analize Query in MySQL Server 5.1

I try use MySQL Workbench 6 to analyze the cost, but they don't show the cost of query. How i get this costs?
2
votes
1answer
250 views

Why does IN (subquery) perform bad when = (subquery) is blazing fast?

Have a look at these two queries: Simple: mysql> SELECT * FROM omgbatch JOIN omgoutput ON (idomgbatch=omgbatch) WHERE idomgoutput = (SELECT DISTINCT lastoutput FROM omgenvelope WHERE ...
9
votes
3answers
15k views

How do you re-sync the Master MySQL DB with Slave DB changes if the Master goes offline?

MySQL Server 1 is running as Master. MySQL Server 2 is running as Slave. With both DBs online, they are in "perfect sync". If Slave goes offline, there's no problem if Master still online; they will ...
1
vote
1answer
162 views

Syncing updates to master in master/slave setup [semi-sync replication]

Background info I have two MySQL 5.5 servers set up in a Master/Slave configuration with Semi-synchronous replication. The database is being used for a high-profile WordPress site. Problem It ...
2
votes
1answer
726 views

MySQL Seconds behind Master fluctuation

I have two servers set up in Master-Master with one additional Slave connected to the first master. Lately I've started getting alerts from monyog that Master 1 has a seconds_behind_master value of ...
1
vote
1answer
212 views

Mysql sequential numbering based on MAX of another column

I've a table lp_pictures which have these fields: [id | plate_uid] [1 | aaa] [1 | aaa] [1 | aaa] [1 | bbb] [1 | bbb] [1 | bbb] and i need to UPDATE the field id to becomes: [id | plate_uid] ...
3
votes
2answers
13k views

Execution of a Java program by a trigger.

I want to make an update trigger execute a Java program. I have a table T1 with a column named Flag. Whenever Flag changes, I want to run a trigger that results in an execution of a Java program. ...
2
votes
1answer
53 views

Will composite indexes or unique indexes help with query performance?

I need help with identifying indexes to increase performance of the following query. I'm currently using v5.5 with InnoDB. I cannot modify the query. However, I can add indexes as needed. The ...
0
votes
0answers
37 views

Optimise complex query

The previous developer has left an utter query inside our Joomla to search for companies or whatever that has somewhere the keyword. Here is the query SELECT DISTINCT con.id, con.title FROM ...