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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0answers
45 views

Normalization of irregular relations?

I have two tables in MySQL: The orders table CREATE TABLE `orders` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `transaction_id` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL, `task_id` ...
1
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2answers
680 views

Mysql Connection Pooling Similar To PostgreSQL's PgBouncer

I'm looking for a pooling solution for mysql that is independent of the language. I am using PGBouncer as an example because it Resides on the server the database is on Just change the connection ...
1
vote
1answer
3k views

What is the Best Way to detect if server is a Master inside a Stored Procedure?

I'm want to create a stored procedure/event to do some maintenance tasks. My setups are master/slave configured for failover scenarios (meaning the slave is not used for reporting, just might be ...
6
votes
2answers
4k views

MySQL Locks while CREATE TABLE AS SELECT

I am running the following (dummy) query CREATE TABLE large_temp_table AS SELECT a.*, b.*, c.* FROM a LEFT JOIN b ON a.foo = b.foo LEFT JOIN c ON a.bar = c.bar Suppose the query ...
3
votes
1answer
4k views

mysql table very large size although it doesn't have a lot of records

I have drupal website, one of the tables is cache_form. I have a cron to DELETE FROM cache_form where expire < UNIX_TIMESTAMP(NOW()); which works fine. The size of cache_form.myd is 4.9G ...
0
votes
1answer
426 views

Unable to migrate local database to RDS instance

I recently created an MySQL instance on Amazon RDS. Unfortunately, I'm not able to connect to the instance from the MySQL command line. I will brief you the details. 1) I want to move/migrate my ...
1
vote
2answers
547 views

MySQL Database replication for high availability

configuration: 1 balancer 2 Azure machines(4 gb ram, 2 cores), with MySQL master-master replication enabled. X users connecting to the balancer to sync data. test: i've tested the MySQL ...
2
votes
1answer
1k views

Is there a product to auto-build indexes based on slow queries?

I'm looking to either find, purchase, or write a script to identify slow queries, identify potential missing indexes, and when needed create the appropriate index within a reasonable amount of time of ...
0
votes
1answer
100 views

Column to Row and Vice Versa

I need to create a new table by combining the contents of two different tables. Is there any way to transform columns into rows and rows into columns in MySQL? I tried using JOIN but I can't seem to ...
0
votes
1answer
5k views

Find the size of each index in a MySQL table

I am trying to figure out size of each index of a table. SHOW TABLE STATUS gives "Index_length" is the summation of all the indices of the table. However if a table has multiple indices (e.g. in an ...
1
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0answers
4k views

getting SQL Error (1452): Cannot add or update a child row: a foreign key constraint fails (Unknown error code)

I am getting error with MySQL NDB Cluster 7.3.5 as described below: I have two tables: -User Profiles -User Services User services is a child table which contains foreign key constraint ...
2
votes
1answer
308 views

Why am I getting different results from a query vs. a view

The base problem I'm facing is that I need the latest record for each item. A little setup... MySQL 5.6.14. I need to create two views (because MySQL won't let me have a subquery in a view). My ...
2
votes
1answer
7k views

Aborted connection (Got an error reading communication packets) MySQL on Amazon RDS

I'm getting the following warning in MySQL: Aborted connection (Got an error reading communication packets) I'm using Amazon RDS for MySQL hosting. Both MyISAM and InnoDB storage engines are ...
0
votes
1answer
102 views

How To Prevent Replication Failure

If I become a MySQL DBA, will I had to deal all day with those kind of issues or do you have tips to prevent from breaking the whole replication? I received this message because I removed manually ...
1
vote
1answer
89 views

MySQL from table to table data transfer

I've got some problem with my MySQL. I have the database with many many data. Well, there is only one table actually with huge ammount of data, over 1 billion rows. For some reasons I need to create ...
1
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1answer
25 views

CREATE TABLE not issued on other masters

Database is created on all multi masters. Why CREATE TABLE doesn't being replicated to other masters. some explanations?
0
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0answers
154 views

CREATE VIEW joining two tables, only displaying rows from the first table with the most recent date in the second table

I have multiple tables. My main table has a composite key consisting of a phone number and an order number. I want to create a VIEW where only the subscriptions with the most recent order date are ...
1
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3answers
5k views

Is there a free software that can import excel into mysql on mac? [closed]

not csv format files, but .xls or .xlsx format excel files, is there any free software for mac, that can import data into mysql?
0
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1answer
93 views

MySQL - Bin folder [closed]

I'm trying to learn all the binary files inside the mysql bin folder,but unfortunately I couldn't able to find the detailed explanation of these.So please tell me the procedure to have good knowledge ...
0
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0answers
71 views

Upgrading MySql 5.1 to MySql 5.5

I followed a tutorial to update My MySql 5.1 to 5.5 (actually i wanted to upgrade to 5.6, but the tutorial mentioned that i should upgrade to 5.5 first and then to 5.6). However, after removing ...
1
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0answers
224 views

Match unique id's on import- csv to sql

I have a csv file that I would like to import into a phpMyAdmin database (Wordpress). The CSV file is formatted as shown below: list-id | post_title | slider | ...
0
votes
0answers
245 views

Upgrading MySql 5.1 to MySql 5.5

I followed a tutorial to update My MySql 5.1 to 5.5 (actually i wanted to upgrade to 5.6, but the tutorial mentioned that i should upgrade to 5.5 first and then to 5.6). However, after removing ...
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0answers
41 views

Need help in optimizing a Slow Query

I am using userpoints module to provide points for different actions that they do on my site. mysql> desc userpoints; +-------------+---------+------+-----+---------+----------------+ | Field ...
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0answers
2k views

mysql takes too long on “checking permissions”

We have about 20 databases with about 8000 tables each. Modifying the software is not an option (it is bought), and it seems most of the cpu is consumed by "checking permissions". While the s/w ...
0
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0answers
30 views

MySql cannot get started after increasing buffer_pool_size and log_file_size in my.ini

I try to change buffer_pool_size to 256 MB and log_file_size to 64 MB in my configuration file. After the changes made, I was unable to start MySQL service. System RAM size is (1.99 GB usable)4 GB. ...
0
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0answers
294 views

Huge load on CPU because of mysql process [closed]

I am getting a huge load on my linux servers because of this query. CPU is on 500% load & this query is causing load. /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql ...
2
votes
2answers
1k views

MySQL-NT is crashing frequently

MySQL is crashing frequently and there is no error in the err log file. The following error message was found in the event viewer: faulting application mysqld-nt.exe, version 0.0.0.0, faulting ...
4
votes
2answers
17k views

How are auto_increment keys handled in INSERT (SELECT * FROM…)

I have table1 and table2 in MySQL. Both have a primary auto_increment key id. If the table schemas match and I do INSERT INTO table1 (SELECT * FROM table2) what happens with regards to the new rows ...
-6
votes
2answers
117 views

MySQL stores 0.00 as 0? [closed]

How can we store 0.00. The column is of float datatype. It automatically converts 0.00 to 0
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2answers
3k views

How to maintain MySQL performance at high concurrency

The following has been observed using "mysqlslap". mysqlslap -u root -p --create-schema=matrix --query=monthly_kpi.sql --iterations=1 --concurrency=1 --delimiter=";" Benchmark Average number ...
3
votes
1answer
3k views

MySQL crashes frequently

I am facing frequent MySQL crash problem. Not sure how to fix the problem. Attaching the mysql error log. Suggest me a solution. Server Config Digitalocean SSD server 1GB RAM CentOS 6.5 64-bit ...
3
votes
1answer
5k views

Getting unique names when the IDs are different (DISTINCT ?)

I've got this table: id | name 1 | John 2 | John 3 | Peter 4 | Mike 5 | Mike And I want to get the unique names, getting the latest one in the list. I could go for: SELECT DISTINCT name ...
0
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0answers
22 views

MySQL crashes frequently [duplicate]

I am facing frequent MySQL crash problem. Not sure how to fix the problem. Attaching the mysql error log. How can I improve the performance? Suggest me a solution. Server Config Digitalocean SSD ...
0
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0answers
201 views

Mysql DB recovery

Mistakenly I have deleted "ibdata1" file in mysql server. Now my database is not working. All the tables are corrupted. But still I have "ib_logfile0" and "ib_logfile1" files.Also I have a recent ...
0
votes
0answers
243 views

MySQL SSL encryption

Does setting MASTER_SSL to 1 in change master ensure encryption without specifying options MASTER_SSL_CA, MASTER_SSL_CAPATH, MASTER_SSL_CERT, MASTER_SSL_KEY ? After setting MASTER_SSL to 1, show ...
2
votes
2answers
18k views

Declaring and using variables in triggers

I have been testing something with triggers today, but I am stuck with it and I do not have any idea what is causing my problem. DELIMITER $$ USE `pucko`$$ CREATE TRIGGER `after_delete_Alien` AFTER ...
0
votes
2answers
83 views

Which database for survey app [closed]

I need to build a very simple mobile survey app. The app will ask for different questions where people can give one of 3 possible answers, which will be always "yes", "no" or "maybe". To save ...
0
votes
0answers
225 views

MySQL: after query optimization the CPU is still over 100%

my first time here! First of all I want to say that I'm not a DBA and I have a very little experience with MySQL but I like to study and understand what I'm doing. I have a virtual machine (2gb RAM, ...
1
vote
1answer
139 views

Performance issues when extracting scatter plot data

First off: Sorry for the title, couldn't think of anything better. Feel free to change it though. Ok, assume I have the following table: ...
0
votes
1answer
168 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
198 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
450 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
votes
3answers
141 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
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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
481 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 ...