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

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468 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 ...
3
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1answer
381 views

MySQL / Fusion IO Configuration Question

I need a little configuration optimization. I think what I have is pretty good but feel like there's still room for improvement. Current Config [mysqld] user=mysql datadir=/var/lib/mysql ...
6
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3answers
3k 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?
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1answer
57 views

Simple query hangs on a specific column condition

I have two servers, and I a dumped the database of the first to restore it on the second. Everything works great, except that on the second server, I can't do any selection based on a specific column ...
2
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1answer
115 views

Why does MySQL increment the auto_increment value when there's a constraint violation?

I have a table in a MySQL database with one column id, which has auto_increment and the Primary Key. There's also a Unique constraint in this table, on different columns. I noticed that when I try to ...
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1answer
12 views

MYSQL variable in function

Can anybody tell why the value of @URlID is always -1 even when i know the query will return a result? I have tried any possible type of variables and any possible way of inserting into the variable ...
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1answer
199 views

Mysqldump --flush-logs results in small backup files?

New to MySQL and just learning how to setup a daily full backup (binary logs enabled). My goal is to run a daily full backup of the databases/schemas and reset the binary log. I'm currently using an ...
1
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1answer
129 views

MySql - unique key not working

I have the following table: CREATE TABLE `timeline_lists` ( `id` int(11) NOT NULL AUTO_INCREMENT, `user_id` int(11) NOT NULL, `list_type` int(11) NOT NULL, `s_object_id` int(11) NOT NULL ...
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2answers
108 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 ...
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2answers
2k views

High MySQL “InnoDB Writes Per Second” - Can't see the queries?

On our live MySQL 5.5 database server, we use MySQL Workbench for running manual queries, checking running queries to see what's going on, etc. I noticed today that on the "Server Status" tab there's ...
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2answers
139 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 ...
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1answer
43 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 ...
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62 views

Best upgrade path for MySql 4.1 to 5.5?

Background Our production environment runs on a system that nobody wanted to update for a long period of time. With a new sherrif in town, we're going to update it. Production is MySql 4.1 with ...
3
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2answers
61 views

Fetch all words from column with like

I have a column with description and inside it can contain # value . what I want is all the words searched from that column with #tag This is my query SELECT description FROM photo where ...
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2answers
490 views

Using MySQL/PHP PDO, is there a 'simulate' or dry run option?

Does MySQL (or, ideally, PHP PDO) have some way of simulating transactions without actually committing them? (Can I get MySQL or PDO to act as if data is inserted/deleted/updated, without actually ...
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0answers
49 views

pt-online-schema-change with circular replication

So I have an alter table (adding 4 columns) to do on a fairly large table (74 million rows). The problem is this table has firstly to remain online and writable during the whole operation and ...
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0answers
9 views

Why pages not made young is zero?

In results of Show INNODB Status showed me very weird result: Pages made young 81821279, not young 0 The official statement says: Pages made young, not young: The number of old pages that were ...
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2answers
284 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 ...
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2answers
1k views

How to resolve: Specified key was too long; max key length is 767 bytes [duplicate]

Our server is creating a lot of tables and one of them is the Lock_ table. We are using MySQL 5.5 on Percona. Also we are using utf8_general_ci and utf8. It throws the following error when creating ...
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1answer
84 views

Is there any limit for MySQL database rows

I'm creating a database website which has a lot of data (Username,name,address,posts etc). Is there any limit to store database rows? (I have a table with more than 100,000 rows) How to host this ...
0
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1answer
63 views

What is wrong with this statement? 'Unknown column'? [duplicate]

I'm not used to the 'as' keyword and I thought it would be a nice idea to use it. So why do I get an 'unknown column' (eid) error? I use mysql... select t1.index as eid, t1.col1 as col1, t1.col2 as ...
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1answer
2k views

Add database to existing replication which uses binlog_do_db?

We have two MySQL 5.5 servers running on Ubuntu 12.04. We are successfully replicating 3 databases from server01 to server02, but need to add a 4th (new) database. Our my.cnf on the master has: ...
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1answer
656 views

Group by age range and gender with aggregation function on some columns

In Mysql, I have a patient table with id, birth_year and gender. Next table is transactions in which I have id, patient_id [FK from patient] and checkup_date. I need to select rows such that I get ...
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0answers
78 views

Soundex on a Large Table

I had a table of names, containing 200,000 rows. This has now been updated to include over 11 million rows. The table is queried using a SOUNDS LIKE 'str' and the result is then passed through ...
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22 views

Unaccounted for MySQL Processes

I am running a MySQL 5.5.38 on a VM running Ubuntu server 12.04. At certain times of the day around 12 mid day, CPU Utilization and loads spikes to over 90% with the MySQLD Process accounting for most ...
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2answers
94 views

Is this substring_index behaviour documented or a bug?

mysql> show variables like 'version'; +---------------+-------------------------+ | Variable_name | Value | +---------------+-------------------------+ | version | ...
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1answer
47 views

Importing Data with Single .ibd file

I have one ".ibd" file with me. I have configured my local Database server with FILE_PER_TABLE option. i have two question here. When i was trying to restore/import the IBD file, the engine expect ...
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2answers
1k 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 ...
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3answers
437 views

How to get “mysqlbinlog” utility for Ubuntu?

I can't find "mysqlbinlog" utility in my Ubuntu server, i can see mysql, mysqldump, mysqlshow etc... command line utilities but not mysqlbinlog utility. Can someone please help me from where I can ...
0
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1answer
390 views

MySQL my.cnf: innodb_log_file_size is missing

How to set innodb_log_file_size to MySQL database if there is no innodb_log_file_size in my.cnf configuration file? I'd like to backup via Percona Xtrabackup and the backup crashes at this point ...
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0answers
51 views

Mysql server stops responding quickly after +- 200 connections

We have a mysql instance, 5.5.28. Its working as intended, it has during normal operations perhaps around 200 to 300 connections on it. These connections are usually "idle" waiting for something to ...
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0answers
31 views

(libmysql): (filename not available): mysql_query

Hi everybody im running a game server connected to mysql and it crashes only because of mysql connection with the error in title.. when i dont use mysql and save data as files on harddrive it dont ...
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2answers
64 views

How do you update a large MySQL table that's on a server?

I have an application on a web server. The PHP front end for the application queries a MySQL database which has a table that contains 60 million taken domain names. My application queries this ...
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2answers
69 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
100 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 ...
2
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0answers
50 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
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1answer
764 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
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1answer
33 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 ...
3
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1answer
498 views

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: ...
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1answer
216 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` ( ...
2
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3answers
300 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
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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 ...
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0answers
108 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 ...
0
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1answer
2k 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 .
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1answer
189 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 ...
0
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1answer
35 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, ...
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17 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 ...
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2answers
7k 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 ...
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0answers
517 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 ...
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1answer
95 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 ...