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

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2
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1answer
33 views

WHERE attribute having two relation lines in the same SQL

I have a database designed with tree tables: checklist (id, name) tag (id, name) checklist_tag (checklist_id - FK, tag_id - FK) Running this SQL: SELECT cc.id as checklist_id, cc.name as ...
0
votes
2answers
69 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
1answer
241 views

Two different MYSQl instances on same machine?

I have MySQL 5.6 installed (Linux). /var/lib/mysql /etc/my.cnf I have a cold backup that I am recovering: /var/lib/mysql_backup /etc/mybackup.cnf In April I was able to get the backup started ...
0
votes
2answers
34 views

Mysql replication with c

I have huge database on MySql and It's become more and more huge. So, Now I am facing performance issues with my database. Some of tables has millions of records in it. like my login detail table ...
0
votes
1answer
160 views

Restrict access to rows by usename

In my database i store data of different users (e.g. addresses or invoices) in the corresponding tables. I want to make sure that a logged in user only has access to it's own data in the tables (so ...
3
votes
1answer
486 views

Convert Oracle Query for Date to Mysql queries

Need to convert the following oracle queries to MYSQL queries. 1) select to_char(to_date(?,'DD-MM-YY')) from dual; 2) select to_char(next_day(to_date(?,'DD-MM-YY'),'FRIDAY')) from dual; 3) ...
1
vote
2answers
38 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 ...
0
votes
1answer
111 views

Unable to run update_mysql in MySQL 5.5

I have recently taken over managing a MySQL database running on Windows Server 2008 R2 . It is running 5.5.37 Community Edition. When it is started, it includes the following lines: Thread, Type, ...
0
votes
1answer
395 views

Errors while creating multiple mysql-5.5 instances

I have installed 3rd mysql instance on my testing server. 2 instances already running without any issues. When I installed 3rd instance by mysql-5.5.30 zip source, it installed successfully but when ...
-1
votes
1answer
54 views

mysql server is not starting

mysql server is not starting after modifying configurations key_buffer = 16M max_allowed_packet = 16M thread_stack = 192K thread_cache_size = 8 query_cache_size = 16M after ...
0
votes
0answers
45 views

amazon small instance mysql query too slow

I have mysql database with 1.5 millions records with 2 million categories records. when i do query on categories and city where clause it takes 304989 milliseconds. on localhost it too fast. i tried ...
0
votes
1answer
24 views

How can I tell when InnoDB recovery is complete/check its progress?

I'm writing a process to bring up a new instance from our nightly database snapshots, and I want to watch its progress and perform some actions once the database is up. When mysql first comes up, it ...
0
votes
2answers
51 views

MYSQL: Join with many to many

I'm trying to create a view and trying to see what can be done, I have a main table a table I wanna join to and also a junction table. Event table (it's very big so it's just dummy data): ...
0
votes
2answers
38 views

query execution time in mysql

I have run the query in mysql which consists of approximately 33million records when i have executed the query select population1 < 200000 from city; it shows like this after execution ...
3
votes
2answers
5k views

How do I fix the definer problem The user specified as a definer ('fred'@'192.168.0.%') does not exist

I dumped an existing database from my web site into a new MySQL setup on my laptop. Everything works except pages that use a view, when the error message above appears. There is only one view on the ...
0
votes
1answer
34 views

installing mysql 5.1 alongside mysql 5.5

mysql 5.5 is installed. I need 5.1 to install an old website so it can be updated. The installer refuses to let me install onto the disk with 5.5. I don't have any other disks. I downloaded the ...
0
votes
1answer
19 views

change character set in mysql permanently

I want to change following parameters to utf8mb4 so that mysql can store emoji characters and special language characters. but when i try running following statements one by one SET ...
0
votes
2answers
104 views

How to autoincrement Prod_id based on Product_Name using trigger in mysql

Product_Details table : (Fields) Prod_id(Primary key), Product_Name, Prefix and Slno(Auto incremented) i need to increment Prod_Id based on the product name field and prefix field (Input will be ...
0
votes
1answer
311 views

Strange Locking issues while playing back logs via percona playback

Problem while replaying logs I am in the process of benchmarking a new DB node (specs at the end) and have run across some strange behavior: As described here i: Created a dump (innobackupex ftw) ...
1
vote
1answer
55 views

unable to import the file

Gone through the below link also but i am unable to import CSV file in mysql. Even i had tried by using > LOAD DATA LOCAL INFILE but same error persisting. Please help me in this. queries i tried had ...
0
votes
2answers
37 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 ...
0
votes
2answers
38 views

Using a join to return multiple values of the same column?

I have two tables user Rank In the Rank table, I saved rank_id and supervisor_id. In the Rank table, I stored the rank name. The rank_id and supervisor_id are foreign keys from the Rank table. ...
-1
votes
1answer
39 views

Btree index and Bit Map Index [duplicate]

Please clarify the difference between BitMap Index and Btree index. I am using mysql version 5.5.37-0ubuntu0.12.04.1. I can able to create Btree index but unable to create the same, Please find the ...
2
votes
2answers
87 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 ...
0
votes
1answer
42 views

Could not access database

I have been trying to setup a local instance for a new application. I am new to MYSQL and I cannot understand how to actually connect this database to the actual web application sitting in the ...
0
votes
1answer
16 views

mysql fulltext query is very slow

I have one table for User detail in MySql with about 500000 records in it. I have also created fulltext index on firstname, lastname field on this table. but when I am trying to search any single ...
0
votes
1answer
73 views

Whether to use or not to use: DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP

In one Database table, created_at & updated_at are defined as: `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP `updated_at` timestamp NOT NULL DEFAULT ...
1
vote
2answers
26 views

getting one day timestamp in mysql

Please consider the following stored procedure I have: ORIGINAL Stored Procedure: -- -------------------------------------------------------------------------------- -- Routine DDL -- Note: comments ...
1
vote
1answer
40 views

How to log within a stored procedure that is encapsulated within a transaction

I have a stored procedure, let us call it sp_A which calls other stored procedures, let us call them sp_B and sp_C. For the sake of consistency an XA TRANSATCION is started within sp_A. What I ...
0
votes
1answer
22 views

MySQL Database Memory Consumption

i am newbie in mysql, just want to ask if what is the right formula in computing memory allocation for mysql, and how to check/query mysql memory consumption or we say where does memory consume by ...
0
votes
1answer
41 views

Setup mySQL in a chroot in Debian Wheezy

Sounds like a simple question, but the documentation is rare about what mySQL needs to run inside a chroot. I think I'm almost there, but I'm running into a permission problem that I can't solve, and ...
0
votes
1answer
53 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, ...
2
votes
2answers
164 views

Repeated values in group_concat

I have two tables, first the table food and Second is Activity: INSERT INTO food (`id`, `foodName`) VALUES (1, 'food1'), (2, 'food2'), (3, 'food3'), (4, 'food4'), (5, ...
1
vote
2answers
68 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 ...
0
votes
0answers
40 views

MySQL 5.5, Xubuntu 14.04 - INSERT and UPDATE bottleneck

DBAs: I have been developing and maintaining plugins for Moodle for the last ~2 years, and have recently decided to try using my local desktop again, rather than my institutions ESX VMs, as a ...
3
votes
3answers
307 views

Finding differences between a master and slave when pt-table-sync fails

I have a table that's showing some differences on a master and slave according to pt-table-checksum (PTC). I've found some verifying differences beyond that. Certain tables in the mix have composite ...
1
vote
1answer
45 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
votes
1answer
68 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 ...
-1
votes
1answer
71 views

How to Reclaim Data Free in InnoDB Tables?

I came up with an idea on how to shrink ibdata1 in mysql database then i got this solution on stackoverflow STEP 01) MySQLDump all databases into a SQL text file (call it SQLData.sql) STEP 02) Drop ...
1
vote
2answers
102 views

ALTER TABLE - Rename a column

This got me nuts! I want to rename a column from read-more to read_more in blog table Tried all this: ALTER TABLE blog RENAME COLUMN read-more to read_more; ALTER TABLE blog CHANGE COLUMN ...
0
votes
1answer
37 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 ...
3
votes
1answer
97 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 ...
1
vote
0answers
96 views

What to do with unused RAM on a MySQL database server?

For years I have been running dedicated servers with more or less limited ressources, resulting in unsatisfying performance of the web application (Drupal). Tools like Matthew Montgomery's MySQL ...
0
votes
0answers
24 views

output from mysqltuner.pl (from mariadb.service)

While running mysqltuner.pl script, I'm getting following message: [OK] Currently running supported MySQL version 5.5.35-MariaDB-log [OK] Operating on 64-bit architecture -------- Storage Engine ...
0
votes
0answers
46 views

mysql service failed to start when datadir changein ubuntu

I have dual Operating system on PC, windows 8 and ubuntu 14.0, and I am mostely using ubuntu because my MySql database is hosted on ubuntu. Recently when I am trying to restore my database, which is ...
0
votes
1answer
28 views

MySQL database configuration for fastening the select and insert queries

There are several DBEngines are available for MySQL DB. Currently I'm using InnoDB. My actual problem is, I have a table that consist of millions of data. Therefore the select queries that given to ...
-1
votes
1answer
13 views

What should I do if i forget password in MySQL?

I am using MySQL5.5. I trying to login in mysql from terminal by using "sudo -u root -p" But i could not remember password. How can i fix this problem?
0
votes
4answers
2k views

MySQL gives me:“Can't open and lock privilege tables: Table 'host' is read only”

I am facing problem restoring a MySQL database. My primary database was MySQL 5.1 and now I am trying to copy it to MySQL 5.5. The database was backed up by using Xtrabackup. I am using Ubuntu ...
0
votes
2answers
63 views

MySQL Community Edition Capacity

I am using MySQL Community Edition on Amazon RDS service. It is a very large database, 2/3 tables has about 10 millions records and 4-5 tables has 7-8 millions records. Questions How much capacity ...
0
votes
0answers
12 views

A connection is in sleep for long time in MySQL

When I am looking in process list, three to five sleeping connections are alive. I can kill them but except one connection that is first one in above image. A user connected with information_schema ...