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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254 views

Query takes over 200ms [closed]

So, im using symfony2 with doctrine running in local with WAMP. I have to select from my database : latest shop comments with shop & user informations latest liked shops with shop and user ...
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0answers
59 views

Multiple selects ordering desc from single table

I'm trying to do multiple selects to give multiple ordered columns. I'm struggling to get the below mysql query to achieve the output I want. SQLfiddle: http://www.sqlfiddle.com/#!2/a1002/3 ...
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1answer
39 views

Server down after PDO connection

I don't know is this off-topic for this site but I have site that run on PHP and MySQL. And I want to change my MySQL connection to PDO. This is my connection file that I include in every file at the ...
0
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0answers
34 views

Creating a table for indexing another table

We have a table with 350m rows and 12 columns, and around 1m rows adding everyday. We have crappy hardware and we cannot add an index on one of the 12 columns that we really really need to. (severe ...
2
votes
2answers
295 views

Whats row size in mysql?

i mean what does it mean ?, i have mysql db and table in myisam and it shows Space usage Type Usage Data 1.3 GiB Index 429.1 MiB Total 1.7 GiB Row Statistics Statements Value ...
4
votes
1answer
6k views

MySQL Innodb corruption

I recently inherited a Drupal site that has an Innodb corruption. MySQL will run for sometime--usually about 24-hours but will eventually need to be manually restarted(see log output below). I have ...
0
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1answer
36 views

Mysql functions for web apps

I have few questions about using functions in a MySQL database for plugins and extensions of web apps like Magento or Wordpress. Mostly this is for a few extensions I want to do for Magento. The ...
1
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1answer
444 views

Safely changing innodb_buffer_pool_size on MySQL replication master?

We have a MySQL server which is a replication master. We need to change the innodb_buffer_pool_size and innodb_flush_method to (hopefully) improve performance as the database has grown. What is the "...
0
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1answer
208 views

How to install TokuDB on MAMP

I'm by no means a DB admin. Just a hobbyist actually, and more of a programmer than a database person. I have MAMP 3.05, PHP 5.5.10, Mac OSX 10.9.3. I have a big suite of PHP applications and a ...
0
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1answer
43 views

Optimizing a query so MySQL will use the indexes for the joins

Some context: migrating some data from a 3rd party cloud MongoDB platform service into MySQL. Wrote a query but it's very slow. Here's the query: SELECT Table1.*, (long list of fields for each ...
6
votes
1answer
8k views

Product Attribute List Design Pattern

I am working on updating our website's product database. It’s built in MySQL but this is more of a general database design pattern question. I’m planning on switching to a Supertype/Subtype pattern. ...
2
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1answer
1k views

MySQL replication working fine, but still shows “Waiting for master to send event” at 280000 seconds

To repeat the title: MySQL replication working fine, but mytop still shows a thread "Waiting for master to send event". It has been like this for a few days, and is now at 280000 seconds. But ...
0
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1answer
55 views

What kind of data type to use for numbering in the Harmonized System?

The harmonized system uses a numbering that shows the hierarchy between different items. Similar to bookkeeping ledger numbers. Here is an example: 01 LIVE ANIMALS 0103 swine, live 010310 Purebred ...
4
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1answer
1k views

Is it possible for a MySQL database to have duplicate tables with the same name?

As in the question title - is it possible for a MySQL database to have duplicate tables with the same name? Is there a directive that can be used for a database to allow this? Normally, when trying ...
6
votes
2answers
3k views

MySQL hogging memory

An installation of MySQL 5.6.10 on a virtualized Ubuntu 12.04 is exhibiting massive memory hogging. The mysqld process claims the entire available memory within a couple of hours of uptime and forces ...
1
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1answer
3k views

Show processlist / Max concurrent connections seem to max out at 131

When I put my database under a load test (basically just a basic write and basic read from our app), and run show processlist; in the middle of it, there is always 131 rows in the set and that's it. I'...
1
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2answers
78 views

mysqld is not producing binary log

I'm trying to understand why mysqld is not writing binary log anymore... [root@ip-10-179-155-214 mysql]# grep ^log-bin /etc/my.cnf log-bin=mysql-bin [root@ip-10-179-155-214 mysql]# ll mysql-bin.* -rw-...
1
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1answer
688 views

Dedicated mysql server slow response [closed]

I have server in Kimsufi with 2gb RAM but my server is very slow , with simple hosting in ovh it responds quickly ... With pingdom.com test i have for server: 10 sec and simple hosting: 2sec is ...
0
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0answers
123 views

Store both a city and its region?

I store various events (such as a search on the site) into a table (in fact I have two tables: one for the event and other (linking to the first) with characteristics of the event). Each city belongs ...
0
votes
1answer
188 views

Optimization for 100 GB Real-time info table

I have a table of device information feed which is filled by data from remote device units. There will be like 1000 units each sending an update per minute which will be stored as a row in that table....
21
votes
3answers
19k views

What are reasons *not* to use the MEMORY storage engine in MySQL?

I recently discovered that MySQL has a "memory" engine that I wasn't aware of (most of my database work is for hobby projects so I learn what I need as I go). It seems like this option should give me ...
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votes
1answer
38 views

60M+ InnoDB table simple query performance HELP

I know it is a repeated question but really need help here. What can I do to improve the performance of this query? Considering that I have no freedom to change system variables/configs :( Thanks in ...
1
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1answer
722 views

When tables are locked does MySQL queue queries?

I have a small production website, but it's live 24/7. When running the Optimize, Analyze or Repair commands, MySQL locks the table it is working on. QUESTIONS How would this effect users trying ...
0
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1answer
3k views

Plugin 'FEDERATED' is disabled

Im trying to start Mysql using easyPHP : the response is an alert window to a log file. The main error is <-- Plugin 'FEDERATED' is disabled -->. Through my research on internet i found that the ...
7
votes
3answers
2k views

Two tables with same name in MySQL

I got this weird issue today when I dropped a temporary table. I dropped the temporary table and desc the table just to verify. But, the table was not dropped. After some searching I found that: ...
6
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1answer
2k views

Benefits of Barracuda and Compression

I've been reading about MySQL's file formats Antelope and Barracuda a while ago, and I wonder if I could benefit with having Barracuda and Compression. My server is currently using Antelope, as it is ...
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0answers
54 views

Is there a MySQL setup for my use case?

I have multiple nodes that are mostly independent of each other, meaning 99% of traffic is reads to data contained inside themselves, plus some writes that need to be instantly available for the node ...
5
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1answer
1k views

ROW_FORMAT - COMPRESSED vs COMPACT vs DYNAMIC

In MySQL InnoDB, what is the difference between COMPRESSED, COMPACT and DYNAMIC for ROW_FORMAT? What are the benefits between each other?
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1answer
4k views

Innodb: Operating System Error number 5 in MySQL

I am trying to retrieve the data from MySQL ibd file but facing following error. 140601 17:00:45 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated ...
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1answer
212 views

how to link category, stock , purchase and sales tables in a erp

i have a database design like the following: i have a table for storing camera details and then different tables for stock, purchase_stock, purchase_order, delivery_challan and sales_invoice. The ...
1
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1answer
678 views

Personal and Global messaging database design

I am trying to implement a database design system that will be sending messages to a person(thus 1 to 1) or many persons (1 to many). table --users |u_id | Name | | ...
1
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1answer
688 views

How to store multiple values in a column in database?

I'm trying to make three tables in phpMyAdmin. The main columns here are named Campaign, Program and Asset. Under Campaign, there are different kinds of Programs. And under each Program, there are ...
0
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0answers
186 views

Performance: Interleaving several statement handles in MySQL

Does interleaving several statement handles slow the system down? Example (Perl): $sth1->execute(...); $sth2->execute(...); $sth1->execute(...); $sth2->execute(...); (interleaved) vs $...
8
votes
3answers
14k views

MySQL replication - slave is continuously lagging behind master

I am using MySQL-5.1.50 with a Master-slave replication setup. Most of the time the slave is lagging behind the master. When I run show processlist;, there is no query that's taking a long time. ...
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2answers
2k views

MySQL Slaves lag behind master

I have one master and four slaves. Sometimes all my slaves lag behind the master. I have implemented the heartbeat for monitoring replication lag. Now I am trying to find why the slaves are lagging ...
0
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1answer
37 views

SHOW INNODB STATUS averages calculated

I am reading to all tutorials/books that when running SHOW ENGINE INNODB STATUS the Per second averages calculated from the last X sec, the X should be 20 to 30 seconds. I have never manage to exceed ...
0
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1answer
278 views

Two MySQL requests at the same time - Performance issue [closed]

I have a MySQL server with many innodb tables. I have a background script that does A LOT a delete/insert with one request : it deletes many millions of rows from table 2, then insert many millions of ...
1
vote
1answer
54 views

Understanding how relationship sides works

So, I have this relations on my tables (see image) and I need to understand some things. I'll enumerate what I understand and what I need from yours is to say if I'm right or not and in case I'm not ...
1
vote
2answers
325 views

Any way to force “garbage collection” in TokuDB?

Playing around with TokuDB I'm finding even after "optimize table" for things such as changing row compression or other DDLs it takes a non deterministic amount of time for freed space to be reflected ...
0
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1answer
102 views

Sync MySQL 4.0 table to MySQL 5.6 server every few minutes

I am tasked with getting a copy of a table on a MySQL 4.0 server synced to a completely different database on a MySQL 5.6 server every few minutes for the purposes of having that table available ...
3
votes
1answer
483 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 --single-...
0
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0answers
20 views

Installing database

I have created database in my system using mysql.I tried to use in one of my friend's system.How can install the database in other system?
0
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2answers
91 views

SELECT query with referenced subqueries

How does one reference the currently-grouped by field in a subquery? Consider a table with the following data: Client Status Size 1 A 500 1 B 1500 2 ...
5
votes
2answers
1k views

Choosing MyISAM over InnoDB for these project requirements; and long term options

Sorry for the long post, but I had to give as much info as possible to make this very vague question more specific. My project's aim is to let users search a (huge) database of variety of products. ...
0
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2answers
271 views

MySQL: Moving Database from Windows to Linux

I have a Windows based dedicated server have below configuration: Windows edition: Windows Server 2008 R2 Standard Service Pack 1 Processor: Intel(R) Xeon(R) CPU X5460 @3.16GHZ 3.16 GHZ (2 Processors)...
8
votes
1answer
6k views

Qcache_free_memory not full yet I get alot of Qcache_lowmem_prunes

I just started dabbling with the query cache for our CMS. Can anyone tell me (or at least give a good guess) why I get a lot of Qcache_lowmem_prunes when more than half of Qcache_free_memory is free? ...
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0answers
732 views

Optimization Tips For MYSQL Tuner/Primer

So I have a site that has a crap ton of traffic. I see a decent amount of latency when the site has over 1,000 active visitors on it. I have new relic installed and it seems Im only using 10% of the ...
0
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1answer
33 views

Will my query pick up where it stopped due to connection timeout?

I am doing a rather large query that hits MySQL connection timeout. I know how to change the timeout parameter, but I'm also query from a laptop that can't be left running for long. The database ...
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1answer
176 views

Remove all duplicate data in mysql

I want remove all duplicate data from my table. anyone help me. my table : biblio one one two three three four five i want to get result like this biblio two four five
1
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2answers
818 views

How can I repair a TokuDB table?

I have a TokuDB table that works fine for most queries, but segfaults on others. I did a CHECK TABLE which indicated that the table had errors. However, TokuDB doesn't support REPAIR TABLE. How can I ...