MySQL : Open-Source, Relational Database Management System

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primary_key problem in MySql view

I have 3 tables. and I want to create a view. There is no problem about generating SQL qeury and creating a view. but when I want to use this view in my web app it says me (LIKE THIS): "your view's ...
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1answer
35 views

How to join 3 tables together given 2 many-to-many relationships tables in between?

I have 3 main tables: Person, Publication and Conference and 2 many-to-many link tables in between: person_publication and person_conference I want to join all 3 main tables together (showing me all ...
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2answers
43 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 ...
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1answer
20 views

Which file in “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 ...
1
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1answer
21 views

how to change mysql table auto_increment primary key

Now i have a table with Auto_increment id as Pri key, and exchange_id as key, How could I change the primary key to field [ticker]..?
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1answer
71 views

Optimizing large MySQL SELECT WHERE IN clauses

How can the following SELECT WHERE IN case be optimized? I have a table with over 100 million rows with only 3 columns. The primary key (col1) is a 127 varchar. I am performing a SELECT col1 WHERE ...
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0answers
27 views

mysqlcheck --repair a specific table?

I logged in my server via SSH and committed a "repair table xxx" query on a MyISAM table with 34 million rows and 69GB of data. Unfortunately the SSH connection was lost. When I logged back in I found ...
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2answers
49 views

Mysql LEFT JOINing same table twice

mysql> SELECT * FROM customers; +----+------+ | id | name | +----+------+ | 1 | Matt | | 3 | John | +----+------+ mysql> SELECT * FROM purchases; +----------+------+-------+ | owner_id | type ...
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27 views

Mysql table with only two columns, nothing unique: Will an index increase search performance?

If my table only has two columns (username, groupname) and a million or so rows, will an index improve performance at all? Wouldn't it take just as long to search the index file as it would to search ...
1
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1answer
28 views

table exists on 'show tables' - can't query

Anybody know why this his happening? mysql> show tables; +-------------------+ | Tables_in_photos | +-------------------+ | captions_images | | image_meta | | mentions_images | ...
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1answer
23 views

Can I generate binary logs if they weren't turned on?

Ok, so here's the scenario: Our master went down, boom! gone (Call this one DB1) We switched our backup replica server. Ok, life is good, sort of (Call this DB2) Binary logs were not turned on for ...
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1answer
31 views

Varchar indexing

I am very rusty with MySQL and I'd like some advice. I have several software tools that are deployed throughout the company and I am writing a DLL to keep track of the usage, errors and stuff of some ...
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1answer
37 views

How performance schema in mysql 5.6 improve performance?

Since MySQL 5.5 performance_schema database has been added likewise information_schema. As we know that tables in information_schema contains statistical information like tables, plugins, partitions, ...
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0answers
17 views

Insert XML remote data into MYSQL [migrated]

I have this code i am using to insert data into a mysql database. <?php $xmlDoc = new DOMDocument(); $xmlDoc->load(".....url"); $mysql_hostname = "localhost"; $mysql_user = "root"; ...
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0answers
9 views

How could I prevent the mysql cli-/terminal client from converting/altering multiline-statements (in the process of logging)?

Is there a way to prevent the default mysql client from ?: 'removing newlines' a.k.a. 'converting newlines to spaces' a.k.a. 'mapping newlines to spaces' Being more specific, with 'default mysql ...
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0answers
22 views

Select groups mysql

How do I select a separate category by category groups, for example: column1, column 2, column 3 category 1, category 2, category 3 pineapple, strawberry, watermelon lemon, grape, ...
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1answer
44 views

A single, simple update takes 10+ seconds

We are running MySQL 5.1.71-log and have a table with 2.7 million rows. Simple updates to it are regularly taking more than 10 seconds to execute. The table structure is: CREATE TABLE `person` ( ...
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1answer
26 views

Large NOT IN Statement vs Creating/Populating Temp Table

I have a large daily data feed which can contain up to around 5,000 ID's. I need to delete all pre-existing records in the DB that are not referenced in the new feed. Should I create a temporary table ...
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14 views

set error message on out variable in mysql stored procedure

I have a stored procedure: fill_DATA (serial varchar(20), OUT oError) I am doing an Insert operation here. so what I want is to SET value of oError for any error message in case the query fails to ...
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0answers
20 views

Help with MySQL query which is only occasionally slow? Temp tables/Disc caching?

We have an issue with one particular query whch runs regularly on our MySQL database, though I am not necessarily sure it is a problem with the query itself. 90% of the time it runs perfectly fine ...
0
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1answer
63 views

Help optimizing very slow mySQL query

I have a query which takes about 6 secs to execute. SELECT * FROM (SELECT ord.ID, op.name AS prodName, op.code, ord.date, ord.email, op.total, stat.ID AS statusID, stat.value AS status, ...
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31 views

MySQL Table with 568 columns: 1118, 'Row size too large…'

I'm currently migrating a database from Oracle to MySQL5.6. One table consists of 568 columns. When atempting to create the table I received this Error 1118, 'Row size too large..' I already ...
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1answer
37 views

What is the meaning of different roles available(DB Admin etc.)

I have recently installed MySQL and also created the basic user as scott but my doubt is regarding the roles. I don't understand different roles available for the user which I have created. I want ...
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3answers
74 views

Slow DELETE in MySQL with a subquery

I am running the following DELETE SQL on a MySQL database on a MyISAM/utf8 table. The SQL is called in a loop, once time per Users (in this case):- DELETE FROM regulatory WHERE documentid IN ( ...
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2answers
62 views

Are there benefits to using more than 4 CPUs for MySQL?

We are running MySQL 5.5 on linux under VMWare, running on 2 CPUs. We are planning on increasing this to 4, but we have un-used CPUs available, and I'm wondering if there is any benefit to increasing ...
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1answer
36 views

How to do the complex nested select SQL?

I have two tables, table1 is as following, id is primary key, table2_id is foreign key id date aid table2_id message 1 2014-03-19 16:21:02 121 1 login from xxxx 2 ...
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1answer
106 views

slow writes on percona / mariadb server only when replication is running

Hi I am trying to migrate to percona server from mysql 5.6 on windows. In my development machine for percona is running of centos 6.5 which is installed on vmware 5.5 sphere. Our business ...
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2answers
58 views

How to monitor InnoDB Disk I/O using Server Status Variables?

This question is extension of my previous question "How to monitor InnoDB Disk I/O Required for MySQL? " As mention in my previous question i want to count total number of disk i/o per query, but ...
2
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1answer
46 views

Need scalable database solution for very big automated data entry database

I've been working on MySQL database in simple web applications for a long time and i now have a project which should maintain about 1,000 up to 10,000 query per minute (it is some logging database ...
0
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2answers
55 views

What is the best choice for MySQL high availability (zero downtime)? [closed]

As I know there are many solutions for MySQL HA, but most of them are congenitally not zero downtime solution, like MHA, AWS RDS... That said, if zero downtime is "must have", the only choice is ...
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2answers
46 views

SQL - query multiplying records returned - Cartesian Product

I am using the following query which is returning a huge number of multiplied records - i.e. a cartesian product: SELECT * FROM specimen, topography_index, morphology, functions WHERE ...
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1answer
18 views

Omitting [INTO] in the INSERT … SELECT statement

Does the INTO keyword only makes the query more readable, or does it bring another benefits as well? The queries beneath both seem to run equivalently . insert ignore tbl (type, details) values ('1', ...
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1answer
35 views

Access Sharing database over Network vs Mysql multiple users [closed]

Something no one mentions and I find important to stress is that Access has a file locking mechanism for sharing the database on a network share which is orders of magnitude more efficient than any ...
2
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1answer
64 views

Optimize Percona MySQL InnoDB 3.2TB database

(Before you will call me an idiot or start laughing, please remember it's a real deal on my side and I cannot cancel this assignment as it is a part of a bigger project) I have a database server that ...
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0answers
14 views

Disable procedures for data load in MySql using Innodb engine

I have a database with an integrated ledger for a multi-unit company. As we bring new units into the database we load their existing ledger data into ours. Unfortunately the existing procedures on the ...
0
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1answer
65 views

MySQL: How to clean MySQL from RHEL5?

I have installed MySQL 5.1.73 community edition through RPM. It was working fine. I uninstalled this version by using yum remove mysql-server command. I wanted to upgrade MySQL from 5.1.73 to 5.6.19 ...
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0answers
41 views

Question on MySQL insert race condition

I'm using MySQL 5.1, PHP 5.3 and the table is MyISAM. Here's the DTD of this very fake table: CREATE TABLE `temp1` ( `value` varchar(10) DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 This ...
2
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2answers
81 views

How to monitor InnoDB Disk I/O Required for MySQL?

I am doing an estimate on how much i/o[disk read write] on Mysql 5.6 [innodb storage engine], for getting idea how to calculate total number of disk read write i have searched a lot on SO on DA and ...
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1answer
33 views

MySQL ON DUPLICATE KEY UPDATE performance issue

We have a table with over 200k rows. Every row belongs to a category, there are almost 50k rows per category. What is the best way to update all rows of that category? We are using a script like ...
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1answer
40 views

Can I install MySql and Oracle 10g both Databases in same machine? [closed]

I have MySql Installed in my windows 7 machine and PHP on IIS. Now i need Oracle 10g anyway.I'm having king of dilemma to install Oracle 10g. If i can do so please suggest necessary steps and ...
0
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1answer
33 views

Good configuration for 2gb (my.cnf) [duplicate]

I'm little newbie in configuring mysql and i seek a good configuration for mysql i have one site in ajax with many query and very slowly with VPS Iam in kimsufi 2gb i run only mysql in vps not apache ...
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1answer
23 views

How to make MySQL join one-to-many with lowest value?

I have following database structure Domain has many URL which has many positions which belongs to phrase which belongs to user which belongs to subscription. In subscriptions table I have period ...
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1answer
21 views

Want to create partitions of a MySQL table and change the charset of new partitions

I have a database table which contains large amount of data. I have written a script to create new partitions every week and drop old partitions (which are of no use). Currently, I have a column in ...
0
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1answer
21 views

How can I perform this database backup/sanitization task?

I have a 3-node MariaDB/Galera cluster. I need to do two things: Back up the database regularly (multiple gigs in size) for a normal, in-case-everything-crashes-I-can-restore-from-this backup. Have ...
1
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1answer
19 views

MRG_MyISAM with myisampack tables blocking inserts

I'm using INSERT_METHOD=FIRST and compressing all tables that are members of the union but when I try to insert into the MRG_MyISAM table it tries to insert into the second one (instead of the first). ...
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0answers
34 views

Optimization mysql very slowly [duplicate]

Hello I have a server in kimsufi 2gb RAM and 500gb storage but the query with php mysql is very slowly I have change innodb buffer pool size to 500M but i have error too many connections, i add max ...
0
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1answer
30 views

InnoDB issue after power outage a few weeks ago - no backup

A few weeks ago we had a power outage on one of our web servers that hosts several websites, we didn't think it affected anything and everything came back up as normal as far as we were aware. I have ...
2
votes
2answers
74 views

Why is this simple join taking so long?

I'm trying to run some reporting queries on a MySQL database, and I'm running into serious performance issues for some reason. One table, page_views, is extremely large (~70 million records), so some ...
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0answers
27 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 ...
0
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2answers
111 views

Parent/child relationship or not if the name of the field implies the relationship?

I am working with the harmonized system and try to catalog this in a MySQL database. This works for example like this: 01 LIVE ANIMALS 0101 horses, asses, mules and hinnies, live 0102 bovine ...