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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2answers
64 views

How to generate auto increment values for my duplicate column in my sql?

How to display when i was run to find duplicate values from my table at this time i want to add new column in select statement with auto increment values SELECT * FROM tutorials_tbl WHERE Lscno IN ...
1
vote
2answers
29 views

MySQL: How to sync on demand beetwen two database in the same server

I'll like to know if it's possible to have a systeme on synchronisation beetween two database in the same server. I have a production database in my server , i want a dev database (same database with ...
4
votes
2answers
92 views

Query only for the first n results of like

What I'm trying to accomplish is a huge speedup (read: incremental results) when searching a database with a like operator which is kind of a last resort, if everything else already failed, to come up ...
3
votes
2answers
146 views

Problem in Fetching Result set in Desired Format

I have 2 tables having the following columns Person ------ person_id, first_name, middle_name, last_name Items ----- person_item_id, person_id, item_type, status, ordered_date The query is ...
0
votes
1answer
52 views

Slow INSERT/UPDATE on InnoDB

I have a problem with the performance of my MySQL server, let me explain: I instaled a MySQL server, version 5.5.20 Server version: 5.5.20-log Source distribution SELECT queries runs fast on ...
2
votes
0answers
34 views

Emulating WITH clause in MySQL/query perfomance review

I have never really worked with MySQL queries till this last week. I was tasked with making a simple tool for my department that tracks contacts. Here are the 2 tables and the type of data they ...
1
vote
2answers
41 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
121 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, ...
1
vote
1answer
258 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
1answer
166 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 ...
0
votes
1answer
81 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 ...
0
votes
1answer
30 views

Simple Query optimization using ORDER BY

The following is a simple query that is taking more than 10 seconds to execute: select * from inventory.asset ass where ass.product_id=83 and ass.expiry_date > now() and ass.status=1 order by ...
2
votes
1answer
86 views
+50

MySQL RDS Instance eating up memory and swapping

I have an issue with memory on a RDS instance which is of db.m2.4xlarge class. Below are the specifications of the RDS instance Instance Class: db.m2.4xlarge ( 68.4 GB of RAM ) Engine: ...
3
votes
3answers
311 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 ...
0
votes
1answer
157 views

Data Analysis with MongoDB or MySQL

I have a need for processing some data in order to come up with some statistic. This is the scenario: Each user can answer several questions from the question list. They pick their answers from a ...
0
votes
1answer
64 views

Mysql improve Self join performance large table?

I have a task to help identify conflicting IP ranges , I want to highlight when one companies IP range falls within another's ... below is the sample table, I have converted the IP ranges from .dot ...
0
votes
1answer
36 views

MySQL JDBC does not behaves as the MySQL Workbench

I'm running the following from the MySQL Workbench, and from my local tomcat using jdbc. START TRANSACTION; CREATE SCHEMA IF NOT EXISTS `ROOT`; CREATE TABLE IF NOT EXISTS `ROOT`.`all_tables` ( ...
0
votes
2answers
79 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 ...
2
votes
3answers
40 views

Rolling count of total transactions over time

I need to get a set of total transactions over time on a weekly interval. Essentially I need a total-transactions-to-date column. When I group by WEEK(Date) I get the amount of transactions for that ...
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 ...
0
votes
2answers
55 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): ...
3
votes
1answer
498 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) ...
0
votes
2answers
2k views

MySQL 5.5 Fail start Fedora 16

I installed mysql and mysql-server from the repos (MySQL version 5.5). Then tried to start it, but got an error. [root@server]# service mysqld start Redirecting to /bin/systemctl start ...
0
votes
2answers
406 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 ...
0
votes
2answers
108 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
0answers
8 views

problem with localhost or path on xampp instalation

I have xampp installed on my E: drive, windows 7 system the control panel works fine, both apache and mysql start normally ports for apache are 81 and 444 port for mysql is 3306 My wordpress ...
1
vote
2answers
45 views

Difference between On Delete Cascade & On Update Cascade in mysql

I have two tables in MySQL database- parent, child. I'm trying to add foreign key references to my child table based on the parent table. Is there any significant difference between ON UPDATE CASCADE ...
0
votes
1answer
652 views

Restoring a single database from mysql enterprise full backup

I am having command to restore all databases from full dump taken by enterprise full backup .Can anyone help me how to restore single database from full dump .
1
vote
1answer
16 views

Error 2003: Setting up MySQL Replication

Trying to setup MySQL Replication using this guide here : http://wpguru.co.uk/2013/05/how-to-setup-mysql-masterslave-replication-with-existing-data/ I was able to do this on two random VMs running the ...
1
vote
1answer
304 views

How to removing or reduce the size of redo logs in MySQL cluster

Can anybody tell me that how can we reduce the redo log file size or can we remove the redo log file size in MySQL Cluster and also what will be the impact of it on performance of cluster.Also can we ...
0
votes
1answer
30 views

Why does mysql treat “<” like it was “<=”?

I've tried the following command: SELECT * FROM `mi_schedule` WHERE `day`<=(DATE_ADD(NOW(),INTERVAL 7 DAY)) AND `day`>=NOW() Got 8 rows. Then I changed the <= to <, and nothing changed, ...
0
votes
0answers
11 views

Recovery database from masters

I have a multi master setup with 3 mysql nodes with Tungsten, Unfortunately replication has broke between 3 servers. Now the data is inconsistent say 100 users data is in node1, 100 users data in node ...
0
votes
2answers
87 views

How to verify data dumps between two MS SQL and MySQL

I'm trying to verify data exported from MSSQL and imported into MySQL is 100% accurate using MD5 hash. On Linux, I'm using md5sum and WinMD5 on Windows. The encoding is the same: UTF8. I tried both ...
2
votes
2answers
66 views

Cannot configure nor start MySQL

On a brand new Kubuntu 14.04 install, I ran sudo aptitude install mysql-server-core-5.6. The install could not complete due to dependencies of some KDE packages on mysql-server-core-5.5, which would ...
1
vote
1answer
263 views

MySQL users corrupt

I have a strange situation here: From time to time I cannot log in with any of my mysql users. I even cannot make a mysql dump. So I started searching in mysql files and I found that users.MYD and ...
0
votes
0answers
32 views

Moving datadir OK start, but socket error for mysql client

I'm trying to move my MySQL datadir from /var/lib/mysql over to /home/mysql (an ssd drive as I'm having iowait issues on /var/lib/mysql when MySQL is running on that drive). The OS is CentOS 5.6 ...
3
votes
2answers
228 views

MySQL runs out of memory when importing innodb database

I have a small VPS with 512MB RAM and no swap (can't have any). I am importing a 1.5GB innodb database with mysql -u -p < database.sql Before the operation can finish it says : Lost connection ...
5
votes
3answers
2k views

How costly is opening and closing of a DB connection?

How CPU intensive is opening and closing of a DB connection (for a web app) in MySQL ... when the DB software is on localhost? ... when the DB software is on another machine?
0
votes
1answer
25 views

Altering a table to add a New Column vs Create table with New Column

I have Table A which i'm tasked to add a new column is_fully_complete bit(1), and i'm thinking: Would it be better to a.) Create a new table Table_A_new like Table_A and add the new column there ...
0
votes
1answer
38 views

Migrating database with views trough phpMyAdmin causes error in second host

I'm trying to migrate a database which contains some views and I'm doing trough phpMyAdmin export feature. MySQL version on servers are: Server to migrate: Server version: 5.5.34-0ubuntu0.12.04.1 ...
1
vote
2answers
1k views

MySQL equivalent of WITH in oracle

I need the mysql equivalent of the WITH clause in Oracle. Please help. Thank You
0
votes
0answers
38 views

Show single value of one column for multiple rows of other columns

I have a SQL query which displays my data results like this. date emp_id emp_name spent_hours 19-08-2013 1024 jack 10 19-08-2013 1024 jack 11 19-08-2013 1024 jack ...
0
votes
0answers
8 views

MYSQL Incomplete trigger

BEGIN IF (NEW.chik_updates = 'y') THEN UPDATE chik_subscriptions SET sub_additions = sub_additions + 1; ELSE UPDATE chik_subscriptions SET sub_removals = sub_removals + 1; END IF; END I have ...
0
votes
1answer
19 views

How to access another Connect server table in my Local server in SQLyog 7.01?

In same server name using same database select * from area;(Working Good) Same Servername but Different Database select * from mysql.event(Working Good) Now i am connection TWO Different server ...
5
votes
1answer
281 views

Is it Possible to Recover Data from a BLACKHOLE table? [closed]

I had created table with engine BLACKHOLE basically the BLACKHOLE storage engine acts as a “black hole” that accepts data but throws it away and does not store it. Retrievals always return an empty ...
0
votes
1answer
22 views

How to restore data after MySQL Upgrade?

I upgraded from MySQL 5.5 to 5.6 by uninstalling 5.5 and then installing MySQL 5.6. Now that MySQL 5.6 is running, none of my DBs or data is present/visible in MySQL Workbench. I also see that I ...
0
votes
1answer
26 views

Is it possible to restore a database snapshot from a 64 bit system to a 32 bit one?

I would like to perform a restoration test on a snapshot backup of my MariaDB database using a test server running on a 32-bit OS. My production server is a 64-bit system. I would like to know if the ...
2
votes
1answer
185 views

innobackupex is failing while exporting backup

I am using perl script which is working fine in one of my other box which used to take individual schema backups & finally take all schema together using percona innobackupex. I have following ...
0
votes
0answers
18 views

self join of single table to find time difference of adjacent rows of a single column which are not in sequence

I want to find the time difference between two adjacent rows of a single table which are not in sequence.i made a self join of table and tried but i did not achieve what i need .can anyone please help ...
1
vote
1answer
55 views

Count/Statistic for number of SHOW INDEX queries in MySQL/MariaDB 5.5 [closed]

We have a lot of SHOW INDEX FROM queries coming from our ORM layer. Usually there is a mechanism to prevent this but it doesn't seem to work at the moment. To better analyze the problem it would be ...