MySQL 5.5 brought many performance enhancements and expanded the feature set of the popular open-source RDBMS.

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8
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2answers
2k views

How do Application Like Yelp Retrieve distance information from data base efficiently

For example, say I have a table: Business(BusinessID, Lattitude, Longitude) All are indexed of course. Also there are 1 million records Say I want to find businesses closest to 106,5, for example, ...
3
votes
2answers
4k views

MySQL 5.5 High CPU Usage

I have been working with a client with high traffic website(500k visitors and 600-800 active users at any given time). This uses wordpress and the DB is using MyISAM engine. The problem we had was ...
3
votes
1answer
852 views

Keeping MySQL staging database on same server updated from production

I just migrated my MySQL 5.5.20 to Amazon RDS from MySQL on EC2. The one thing I'm having difficulty with is how to keep my staging database updated from production. Before, I just ran a nightly ...
2
votes
2answers
8k views

MySQL using too much CPU

I'm studying to be a DBA right now because I have a massive live database that is very sensitive that I manage. Here's the current system stats of my dedicated database server: CentOS 5.9 24gb Ram 8 ...
10
votes
1answer
5k views

MySQL transaction size - how big is too big?

I have an import process that runs every so often and I want it to be an 'all or nothing' kind of deal, aka: a transaction. There are many aspects, and the imports may yield anywhere between ...
6
votes
1answer
6k views

Deleting bin logs in replication environment

I have a question about deleting binary logs in the replication environment: We have an environment with 1 master and 2 slaves (running mysql 5.5). Sometimes, we run into a space issues during heavy ...
5
votes
1answer
1k views

Possibilities to speed up InnoDB INSERTs and UPDATEs

My website retains user sessions in an innodb table. This usually works well, but a few hundred times a day, the INSERT and particularly the UPDATE statements run slower. I'm monitoring when, and it ...
5
votes
2answers
25k views

Grant table privileges to a user connecting from any host

I have a user account - let's call it 'wordpress' - that I need to allow to access a few catalog tables in another e-commerce database on the same server. I've configured the user with three host ...
4
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2answers
2k views

Large files in wamp\bin\mysql\mysql5.5.24\data directory

I have discovered these files located in the wamp\bin\mysql\mysql5.5.24\data folder on my Windows 2008 server. They are consuming about 22 GB on a 40 GB drive. I am using a LMS called moodle, that ...
4
votes
1answer
442 views

How to Update same table on deletion in MYSQL?

In my Database I have a table: Employee with recursive association, an employee can be boss of other employee. Following is query I used to create table: CREATE TABLE IF NOT EXISTS `Employee` ...
3
votes
1answer
3k views

Recover the disk space after deleting rows from table

I deleted millions of rows from one of the table with innodb engine. I know that I need to run optimize table to recover the space. But running that will cause lock on the table, which will affect the ...
3
votes
2answers
768 views

How to split a string to and get info from another table in mysql

I have a system to assign score for each sentence stored in a column: TABLE 1: word_scores word score this 3 is 4 a 5 test 1 another 0 sentence 8 TABLE 2: ...
3
votes
1answer
2k 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
1answer
2k views

What does the base64 BINLOG statements in mysqlbinlog output mean?

I have looked over the mysqlbinlog command as a candidate for rollback method from MySQL 5.5 to MySQL 5.0. When I ran the command on one of the bin-log files in the MySQL 5.5 server, I've noticed ...
2
votes
2answers
290 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
363 views

Restriction on self referencing on insert in MYSQL?

How to restrict insert on adding self referencing rows in a recursive relation table (a table contains foreign key points itself). mysql> SELECT * FROM Employee; ...
2
votes
1answer
1k views

How to upgrade MySQL to a New version..?

I have installed mysql using the package management system.I am using ubuntu machine. After that i have very well configured the server for InnoDB and other server related parameters. I am using the ...
1
vote
2answers
175 views

Is there a way to get slow-query-log-like profiling information on a single query?

Specifically, I'm looking for this information: # Query_time: 0.011922 Lock_time: 0.000088 Rows_sent: 107 Rows_examined: 663 Rows_affected: 0 Rows_read: 107 # Bytes_sent: 4152 Tmp_tables: 3 ...
0
votes
0answers
70 views

Too much IO to MySQL InnoDB log files

I am using MySQL version: 5.5.38 I have dedicated HDD to InnoDB log files using innodb-log-group-home-dir option. atopsar -d 30 shows big load (>50%) to this HDD The thing is that I have only 75 ...
0
votes
1answer
111 views

Select post and concatenating all categories it belongs to

I have 3 DB tables POSTS +----------+----------+----------+ | id | title | content | +----------+----------+----------+ CATEGORIES +----------+----------+ | id | title | ...
0
votes
1answer
2k views

In place upgrade from MySQL 5.5 to 5.6.11 removes all users from user table

On Windows, I upgraded from 5.1 to 5.5 no problem. Copied my 5.1 data folder into my 5.5 instance Started mysqld skipping grants Ran mysql_upgrade All good, but going from 5.5 to 5.6: Copied ...
5
votes
2answers
227 views

Is there a reason/benefit I am not aware of for this kind setup?

I now manage a MySQL database that was designed and created by another. I am confused about a certain setup that the original developer created.. He did not use auto increments for table IDs. ...
3
votes
3answers
3k views

InnoDB insertion faster

I'm a graduate school student researching OLAP with Mondrian OLAP. So I want to insert data into InnoDB (MySQL 5.5) faster at the initial loading. In this environment, the only user is me, so I think ...
3
votes
3answers
2k views

MySQL optimization - year column grouping - using temporary table, filesort

I have a transactions table which is having 600,000 records, I need to list the count for the dashboard on financial year basis. The table used is MyISAM. I tried adding index for the transaction date ...
3
votes
2answers
2k views

MySQL replication to slave having VPN connection to Master

I am setting up an environment in which the Master and Slave are on different networks at different physical locations (both run on MySQL 5.5.20). I have set up a VPN connection from slave's network ...
2
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1answer
1k views

Is it possible to force drop of mysql tables with FK?

For dropping a table in which a Foreign Key is used in other tables, it is necessary to drop all other tables having FK connection with the corresponding table. Is there a short way to drop a table, ...
2
votes
1answer
232 views

How can I disable utf8mb4 entirely on MySQL 5.5?

I know you're not supposed to do this, but I have a MySQL 5.5 master and a MySQL 5.1 replication slave. That's supposed to be okay, unless I do something stupid like use utf8mb4 that isn't supported ...
2
votes
3answers
3k views

Automatic MySQL Replication Fail-over Strategy

I want to know that if replication is down due to some reason as if master is down then what strategy should be followed so that the replication is up instantly without manually intervening the ...
2
votes
2answers
824 views

How to GROUP_CONCAT between given rows?

I have a table as id diary 1 breakfast 2 walk 3 start 4 office works 5 office projects 6 end 7 taxi 8 start 9 preparing for meeting 10 doing the meeting 11 end 12 night I want ...
2
votes
2answers
125 views

How to see what was executed in the database via binlogs for specific date?

I am trying figure out how to "query" binlogs to see what was exectued in the database for a specific date. For example, if I execute mysqlbinlog binlog then the thing just runs forever and it is had ...
2
votes
2answers
2k views

mysql 5.5 corrupt - missing temporary table

One of our mysql instances crashed and failed to start: 120422 10:04:13 InnoDB: Error: trying to open a table, but could not InnoDB: open the tablespace file './databasename/#sql-29f6_45.ibd'! ...
1
vote
2answers
94 views

Monthly report by time [closed]

I work in a parking company. We need a report of monthly vehicle exits by time. select hour(datetimeout) as 'dateout',count(*) from to_leaveveh where datetimeout between '2014-09-01' and ...
1
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2answers
152 views

MySQL user without SUPER privilege

This may be a simple question and may not be the right place to ask but I couldn't find any useful information from Google. Here is my question. When creating users in mysql using grant all ...
1
vote
1answer
92 views

Slow queries InnoDB occasionaly

I have the next table: CREATE TABLE `sessions` ( `session_id` char(32) COLLATE utf8_unicode_ci NOT NULL, `session_expires` int(11) NOT NULL DEFAULT '0', `session_data` varchar(10000) COLLATE ...
1
vote
1answer
26 views

Is there any value in adding an already indexed column to a composite index?

The title says it all. Does the query optimizer see composite indexes where each column is already indexed as redundant? Or, is it used when each of the composite index's columns are in the WHERE ...
1
vote
3answers
431 views

What happens when we take a timediff between timestamp and datetime

Say I have following table in mysql (5.5+): CREATE TABLE IF NOT EXISTS `test` ( `id` int(11) NOT NULL, `x_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, ...
1
vote
2answers
110 views

Is column order reliable in UPDATE?

Can we reply on the order of columns in an UPDATE? SET @x = 0 UPDATE table1 SET col1=IF(col1 IS NULL, NULL, @x:=@x+col1), col2=IF(col2 IS NULL, NULL, @x:=@x+col2), col3=IF(col3 IS NULL, NULL, @x:=0) ...
1
vote
3answers
807 views

Converting live MyISAM table to InnoDB

I have a table that tracks web traffic. The table is constantly written and read from. Since table is pretty big in size I have to make sure the application will not "freeze" in the process of ...
1
vote
2answers
66 views

Need some support on MySQL Query

I have a query SELECT leads.id, sfav.id is_favorite FROM leads INNER JOIN teams tst ON tst.team_set_id = leads.team_set_id INNER JOIN members members ON tst.team_id = ...
1
vote
1answer
6k views

BEFORE INSERT trigger in MySQL

I am new to MySQL and I'm having problems creating a BEFORE INSERT trigger. I get an unexpected END error. I have a table named verlof_aanvragen with a column datum (and 6 more columns). What I ...
1
vote
1answer
293 views

MySQL localhost vs Amazon RDS instance

I am seeing unexpected behavior with some MySQL performance. When I run a simple query SELECT 1; on my local host (MySQL 5.6.x) using workbench, it executes in 0.000s, but the same query run on ...
1
vote
2answers
171 views

Breaking Semisynchronous Replication in MySQL 5.5

I've set up Semisynchronous Replication between two MySQL 5.5 servers running on Windows 7. My application is running and updating the database of the master server and same is being updated in the ...
1
vote
2answers
296 views

Should master and slave have same mysql version?

I have a master database running mysql 5.5.11, and I am planning to setup a new slave. I am planning to use the 5.5.30 as it is the latest version. For setting up new slave, I am copying files from ...
1
vote
2answers
6k views

MySQL Installation error: Unable to update security settings

I tried to configure MySQL server 5.5 on Windows and this is what I get mysql-server-5.5-winx64:56 - Attempting to update security settings. mysql-server-5.5-winx64:100 - Unable to update security ...
1
vote
1answer
5k views

Connect Error (2054) - mysql_old_password issue still not solved

i use php 5.4.3 and i want to connect to a MySQL DB remotely (php script resides on a different server than the db) with normal oop way: $mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME); ...
1
vote
1answer
5k views

Some MySQL slave errors?

Master version: mysql-server-5.5.14-1.el5.remi Slave version: Percona-XtraDB-Cluster-server-5.5.24-23.6.340 Binlog format: ROW based I'm using PRM to setup HA for MySQL. Sometime, MySQL slave ...
1
vote
1answer
121 views

Several values from different tables

I'm totally lost here and not know how to get this to work and hope any can help me here. I have several tables: default_users, default_profiles, default_status, default_comment and latest ...
1
vote
1answer
896 views

I am getting an error while trying to download binary for mysql 5.5.11

I am trying to upgrade MySQL 5.1 to 5.5.11 on Ubuntu 10.10. Everytime I try the wget command I get this error: wget ...
0
votes
2answers
186 views

Database Design Help: MySql/PostgreSQL Single Database/Multiple Databases

We are planning to build a web based custom business analytics tool using PHP and MySQL/PostgreSQL. In our application, we are planning to upload customer’s data using a Excel sheet and these data ...
0
votes
2answers
53 views

MySQL query performance question

I have a MySQL database where I would like to return results based on multiple rows. id | key | value | selector --------------------------------------------------------- 1 | username ...