MySQL : Open-Source, Relational Database Management System

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9
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3answers
13k views

How to get the most out of MySQL on a QuadCore machine with 16 GB of RAM?

I'm running a MySQL 5.5 server on my workstation for scientific data analysis and wonder how to configure MySQL in order to get the most out of it performance-wise. The types of query that I typically ...
0
votes
2answers
188 views

How to implement Draft functionality, with attached files?

Should allow for: User can save an entity as a draft, that would normally not be valid in its table (ie some missing values) User can attach files to the draft User can find, sort, and discard their ...
0
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2answers
86 views

Tiered permissions to generate conditional data access

I am working to improve the confidentiality and access level of the information presented within a program interface over top of a MySQL database. My goal is to create a two tier system: one based on ...
5
votes
3answers
25k views

How to display database structure in phpMyAdmin?

Is there any way to generate a report of my database structure using phpMyAdmin? What I would like is a table format like the following, and an Entity Relationship table. Table name: List ...
1
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2answers
884 views

Very slow performance from MySQL

I have the following procedure: drop procedure if exists deletebatches; create procedure deletebatches() BEGIN declare acount int default 0; declare done INT default 0; declare abatchno ...
0
votes
1answer
83 views

Redundant / partially duplicated data in a DB - how to structure?

I'm building a website for which a large amount of user generated data will be stored in a back end db and will be discoverable by all users. By its nature, a portion of the user entries will be ...
1
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2answers
434 views

Where can I find a good tutorial or book for various MySQL performance guidelines? [closed]

Can anyone refer me a good book or a small tutorial for various use cases for database design on MySQL for high load test/high availability scenarios. It should include the following: What are ...
3
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2answers
5k views

How to GROUP_CONCAT DISTINCT values in a MySQL query that gets number of records and min/max values?

I'm running MySQL 5.0.88 (Coldfusion8) I have a product search which I'm querying number-of-results as well as min/max prices/rebates across the product table. I also want to include a string of ...
3
votes
3answers
6k views

Test MySQL credentials from Linux command line?

How do you test MySQL credentials from the command line on a Linux server?
1
vote
1answer
2k views

How to design a table for storing news items?

I have a script that can get result from news websites and it will run every hour. The php script will get the title and content. The things I want to store in MySQL are: title content ...
2
votes
3answers
613 views

Tuning Question

Every so often our box is HAMMERED to a crawl %Wait goes to 40 or 50% and connections grows to 300 or so. i think its due to a query running, but i wanted to see if any of the settigns on the mysql ...
1
vote
1answer
360 views

Does this normalized model for artist music records make sense?

I want to make a database about one artist's music records... CD, Vinyl, Cassette, 8 Track, Singles, Ep, Lp, etc... I believe I have a good normalized model that will achieve my needs, however before ...
0
votes
1answer
676 views

InnoDB - Use combined index with primary key on GROUP BY

As far as I know, an InnoDB index always contains the primary index. I cannot get the following to work: SELECT t1.a FROM table_1 t1 LEFT JOIN table_2 t2 on t1.id = t2.refid WHERE t1.b = 99 GROUP ...
1
vote
2answers
104 views

Distributing MySQL database on n systems

I have a webserver in my application which talks to a single MySQL node. Instead of having just one MySQL node, I want to have a cluster of n nodes which form my database. Is it possible to do ...
-1
votes
1answer
302 views

Database for an application similar to Chatroulette

I am making an app that is similar to Chatroulette. When a user starts the app it finds someone that is not currently talking to anyone and have them talk to each other. At any point a user could ...
1
vote
1answer
950 views

How to change the display of an empty string in mysql command line tool?

I'm maintaining a database with InnoDB tables. These tables have some columns of type (from show create table): `val0` varchar(30) default NULL, `val1` varchar(30) default NULL, etc... From the ...
2
votes
1answer
1k views

foreign key constraints on same table

I have a table structure like this. tblquestion ( nQuestionId1 INT UNSIGNED PRIMARY KEY AUTO_INCREMENT NOT_NULL, nQuestionId2 INT UNSIGNED ALLOW NULL ); Here..nQuestionId2 has a foreign key ...
1
vote
1answer
228 views

What happens to existing MySQL databases when I upgrade my Ubuntu distro?

I am in the midst of upgrading my Ubuntu distro from 10.4 to 12.4. Fearfully, it asked me for root password on MySQL when I was upgrading the distro. I used to have databases on that server, would ...
1
vote
1answer
1k views

mysql /dev/shm question

I have this in my.cnf: tmpdir = /dev/shm and I'm getting this in my error logs: [23-Apr-2011 10:22:08] WordPress database error Incorrect key file for table '/dev/shm/#sql_30f1_0.MYI'; try to ...
1
vote
1answer
57 views

Handling newsletter mail subscribers data

A simple data structure for subscribers is email, name, phone, building. Currently, Building is a VARCHAR field, however data contained in the field is actually mostly numeric. How can I change the ...
3
votes
1answer
110 views

MySQL - Partially restore binary log

I have restored a dump into MySQL. I also have a binary log, which I want to partially restore, let's say from position 10 - 2500. How can I do that?
2
votes
2answers
388 views

MySql Vs. Postgresql for a blog application

I am designing a blog application. Which of these fits better? In which use cases will mysql be good and for what use cases will postgresql be good?
1
vote
1answer
103 views

Select ``,* from table?

I'm trying to upgrade our database servers to MySQL 5.5. In doing so, I'd like to convert all of our tables to InnoDB to take advantage of several performance benefits. However, we use VARCHAR(50) ...
2
votes
2answers
166 views

Beginner problems administering users on mysql

Very new MySQL user here. Two questions for the community. I seem to have created an account that I can't delete/drop. I can't seem to get MySQL to actually require newly created accounts to require ...
2
votes
2answers
275 views

Database structure for a mailing list.

I am designing a database structure for a mailing list. The data I need to record is the mail recipient data: Since the mail recipient data is not predefined, it is causing a problem. For example, ...
2
votes
1answer
134 views

Reformatting master MySQL server and temporary solution

We have MySQL master and replication servers both running on different machines. We have noticed some system files showing integrity issues in the master machine. Temporarily we would like to make the ...
1
vote
1answer
726 views

MySQL Cluster: cannot start the management node

When I try to start the management node of MySQL Cluster on Windows platform, I get the following error: Could neither create or open key ...
2
votes
1answer
597 views

Safely promoting master to slave

Previously I've asked the similar question MySql Switching Masters During Failover with log-slave-updates. Let's say this is our current replication In addition, I have few application servers. ...
6
votes
2answers
2k views

Is DB2 more reliable and stable compared to PostgreSQL or MySQL?

Always i was using MySQL or PostgreSQL for my projects such as Web/Desktop apps. I had data loss few times and thanks to old backup i was always up and running. But for a recent project for Airport, ...
3
votes
1answer
3k views

PostgreSQL 9.1 vs MySQL 5.6 with InnoDB ? Which is better for scaling?

PostgreSQL 9.1 vs MySQL 5.6 with InnoDB. I do know that PostgreSQL offers better SQL features. I am currently using MySQL 5.6 lab release (the one with InnoDb full text search feature)(not in ...
3
votes
1answer
152 views

Distribute MySQL in different cities?

We have our main MySQL server in city A. We have the bulk of our customer service staff in city B. The staff are complaining that the connection is too slow to the server. The options are: Have them ...
1
vote
1answer
187 views

How export a database based in a primary key of a table?

So, I'm trying to export all the DB structure of my MySQL db. Attached is my DB structure, I have more then this, but I want these tables only. Basically Tools relate to Factsheets and Factsheets ...
2
votes
1answer
739 views

How do you verify that all InnoDB tables are in good shape?

Without using a script, Is there a way to get mysql to check all the tables at once to make sure they're not corrupted?
1
vote
1answer
533 views

how to avoid duplicated column in two different tables?

OK, I'm inexperienced in terms of database design, so hopefully my question isn't too silly. I have 2 tables users and user_profiles these two tables has one-to-one relation between them. ...
3
votes
1answer
3k views

Slow insert performance in mysql innodb table for solr indexing

I have a Slave server (MySQL 5.5) having innodb tables. This server is being used for SOLR indexing. Few procedures used to fill 12 million data into 9 tables. The insertion speed is too slow. ...
3
votes
2answers
1k views

Errors after installing mysql

After installing mysql I get the following errors: > 120105 6:02:49 [Warning] Setting lower_case_table_names=2 because > file system for /usr/local/var/mysql/ is case insensitive mysqld: > ...
2
votes
1answer
1k views

How can you output UPDATE / INSERT query results when using MySQL -e,--execute?

When using MySQL to run an UPDATE or INSERT, I get query result info: Query OK, 0 rows affected (0.00 sec) Rows matched: 1 Changed: 0 Warnings: 0 When using MySQL from the command line (eg: mysql ...
1
vote
1answer
402 views

Why is Mysqlcheck on 5.1.41 still showing as Innodb table corrupted after a table dump and restore?

I had a very large corrupt innodb table. mysqld would crash whenever I did a check table on it. I did a innodb-force-recovery=1 and did a dump of the table. No errors showed up. I dropped the table ...
2
votes
1answer
514 views

How can I restore a MySQL database after formatting my hard drive

I recently formatted my PC which had MySQL running on it. As a result, I lost the databases on my hard drive. I tried to restore the databases by re-installing the MySQL Server and putting the ...
2
votes
0answers
664 views

Index usage for database server

How can i fix the Index usage on one of our database server? It says from our Nagios control panel that: Service: DB Index Usage Host: MySQL Cluster Address: ( our IP ) State: CRITICAL Additional ...
2
votes
1answer
91 views

Change-set SQL optimization

I'm trying to clean up a change-set query that returns rows from a table that have changed since a given time and also do not exist in a known list of already previously returned results. select ID, ...
2
votes
2answers
1k views

MySQL general log

Is there away to have MySQL dump its log to a remote MySQL server? I would like to audit MySQL connections but I don't want the server to store all the information local on its own hardware.
2
votes
0answers
95 views

Can't connect to MySQL Cluster Storage (data) nodes

I've deployed a MySQL Cluster with a few nodes, and I want to access the storage nodes directly from another machine using NDBAPI. When I tried to connect from the same host it worked, but when I try ...
1
vote
1answer
158 views

Optimizing table and choosing storage engine

Having the follow MyISAM table: +----------------------+-----------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | ...
4
votes
2answers
1k views

Could running ANALYZE on all databases on large InnoDB tables show some performance increase?

So we have an old database that was fragmented until we ran OPTIMIZE on all tables. The database/tables are about 100GB in size. Tables are InnoDB with heavy read/write activity. There are so many ...
4
votes
2answers
1k views

How to copy a MySQL database which is a mixture of InnoDB and MyISAM to the same server?

Because mysqldump takes forever, we decided to just move around the files. Because the 2 databases are on the same server, a cp will be fast. The problem is, from research, MyISAM is okay with being ...
2
votes
1answer
390 views

MySQL table locks solution -> InnoDb / Partitions

I'm experiencing many table locks in a MyISAM MySQL table that is pretty big (Constx10xGB and 15M rows). It's mainly caused due many heavy inserts. My current thoughts to optimize: Changing to ...
1
vote
1answer
106 views

MySQL Database Temporarily Compromised?

Two days ago, I had connected to my ClearDB test server with MySQL workbench. I had left this workbench open and when I had checked it today, there were two new schemas named "test_justin" and ...
2
votes
1answer
2k views

Why can't I get a lock on an InnoDB table?

I have problem with lock table command: LOCK TABLE v3_cam_date WRITE; the command always running with state: "Waiting for table metadata lock". Try to find out which thread was hold the lock on ...
9
votes
3answers
6k views

MySQL status variable Handler_read_rnd_next is growing a lot

In MYSQL status, Handler_read_rnd_next value is very high. I am aware that, this value will be incremented when a query is executed which is not having proper indexes. But, even when we execute ...