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

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getting one day timestamp in mysql

Please consider the following stored procedure I have: ORIGINAL Stored Procedure: -- -------------------------------------------------------------------------------- -- Routine DDL -- Note: comments ...
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311 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 ...
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113 views

Migrating MyISAM tables from 5.5 => 5.6

I was wondering if anyone had any pointers on migrating MyIASM tables from mysql 5.5 to 5.6, specifically using Percona builds, via an rsync? Is this safe? I know we need to do a full ...
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209 views

What is the difference between uniqe index/unique/unique key/unique constraint keywords?

I am using mysql 5.5.16 What is the difference between the following DDL statements? 1) create table sql_query ( id int not null , query_text varchar(21826) not null , query_md5 ...
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962 views

Can I disable an account in mysql after x failed login attempts?

The question is in the title. I would like to disable accounts after x failed login attempts. Is it possible? Thank you
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153 views

Indexes slowing Insertions(Can't use Explain Insert to Analyse)

I have a MySQL database, I am parsing files from a log and inputting it inside. So far including a simple 4MB file in the database could take me about 4 minutes to insert ! and i have about 10,000 ...
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379 views

char vs varchar in mysql

I was reading the book MySQL high performance, it has mentioned that : CHAR is also better than VARCHAR for data that’s changed frequently, because a fixed-length row is not prone to ...
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1k views

Timeout on ALTER TABLE table ENGINE=InnoDB - is table still converted?

I'm converting tables in an old MYISAM database to InnoDB to increase robustness in case of power loss etc. I'm using Mysql 5.5.x Before doing the production system, I am doing a trial run on a copy ...
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3k views

MySQL - Server collation utf8_unicode_ci vs table collation utf8_bin: compatibility and performance

I'm not sure whether this belongs to SE DBA, but it sounds more logical ... Our MySQL 5.5.32 on Ubuntu 12.04 64 uses utf8_unicode_ci for the Server collation and some tables, like phpBB3, uses ...
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273 views

Squeezing Maximum Out Of My Server

I have a dedicated server only built to hold MySQL databases. Currently I have a database that has 173 million records and increasing by 5-15+ million records very day. My question is what and why I ...
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4k views

ESCAPED BY clause in LOAD DATA INFILE

Can somebody please help me understand what is ESCAPED BY clause means in LOAD DATA LOCAL INFILE statement MySQL 5.5. I am a newbie to MySQL so please bear with me.
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652 views

Large table delete in mysql

I want to delete a table with 10,000,000 records. Due to some restrictions I can't do truncate on that table (I don't have the DROP privilege), I can think of two options: DELETE QUICK To set some ...
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Multiple table rows in one row

I have a table from where want to get such classes where 3rd position candidate got more marks than difference of 1st and 2nd. class position name total_marks 10 1 a 100 10 2 ...
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516 views

Is there a way to find the least recently used tables in a schema?

Is there a way to find the least recently used tables in a MySQL schema? Besides going into data directories? I was hoping there was a metadata or status trick-- but Update_Time in STATUS and ...
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375 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 ...
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61 views

Identical subquery optimisation in an update

update activitybooking set `submitted`='1' where id='958' and (select SUM(pool1_count) from (select pool1_count from `activitybooking` where `abt`='12' and (id='958' or ...
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620 views

Creating a partial unique constraint for MySQL

I have the same question as asked in a previous post: PostgreSQL multi-column unique constraint and NULL values. But the solution there is not applicable as I am using MySQL instead of PostgreSQL. My ...
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607 views

Limit Access To mysql information_schema

In case of mysql attacks, many times user extracts information from information_schema. can i do something in mysql that can restricts user to xtracts information from information_schema while all ...
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168 views

Data usage increases initially when reorganize partition mysql cluster

In my MySQL cluster, the data usage of 4 data nodes is approximately 77%. I added a new data node online, and attempted to reorganize partition to redistribute data among all data nodes. But before ...
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Database and query optimizacion

I have a database containing three tables: tbl_database (main table is the primary), tbl_cmdatabase and tbl_blacklist. The three tables share the same structure but differ in the number of records ...
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4k views

MySQL Table not repairing

Table info: Database name: user_motiva Table name: wp_options.frm wp_options.MYD wp_options.MYI wp_options.TMD when I do a mysqlcheck -r --all-databases it gets hung on that table even if you ...
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7k views

Error 1044 Access denied to user

This is driving me crazy. When I try to create a few tables from my Workbench model I get this error 1044. I've been trying to find a solution but nothing works for me. Curiously when I run ...
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8k 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); ...
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411 views

mysql session logging tables

I've been building a session logging system for our sites. We get around ~15m hits a year and at the moment we're really only interested in stats about people who logon to our sites. Our table ...
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1k views

`show procedure status` doesn't list all of the procedures?

mysql-server-5.5.28-1.el5.remi I'm pulling my hair with this problem: only EMS SQL Manager can list all of my store procedures (1763). mysql client, mysql-workbench, Navicat, ... only see some of ...
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1k views

Does TRANSACTION/COMMIT/ROLLBACK only work on certain MySQL engines such as InnoDB?

Are transaction functions only relevant for particular database engines on MySQL, or are transactions supported under all MySQL engines, including MyISAM and InnoDB? someone says here that ...
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7k 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 ...
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184 views

How we can enable index_condition_pushdown in MySQL..?

I have optimizer_switch variable as mysql> show variables like 'optimizer_switch'; +------------------+-------------------------------------------------------------------------------------------+ ...
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984 views

String comparison with integer is not working sometimes in MySQL 5.5

I have upgraded MySQL to version 5.5. Before upgrading when we used string comparison with integer, it was working. Code is "value = 1", here 'value' is declared as varchar(45) and its value can be ...
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3k views

Sudden MySQL error: Unable to connect to any of the MySQL Hosts

I am using MySQL Community Server 5.5.18 on Windows 7. My application was running absolutely fine without any troubles but since morning it is giving strange messages while opening reports. Reports ...
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6k views

Function returning “No data - zero rows fetched, selected, or processed” in MySQL 5.5

I have upgraded MySQL version to 5.5.16 After upgrading, some of the functions are giving warning as No data - zero rows fetched, selected, or processed. In those functions, cursors are there, but ...
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49 views

Mysql error “#1030 - Got error -1 from storage engine” when doing insert/update queries

I am starting to learn manipulating some long list of data from datalogs in mysql, around 300k entries, and it is being added by about 1k off entries everyday, it was working fine in a week then ...
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39 views

Diffrences between master and slave replication in mysql?

In a database named asterisk, there is a table named cdr which was partitioned on the time field. mysql> show create table cdr; Create Table: CREATE TABLE `cdr` ( `gid` bigint(20) NOT NULL ...
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Set sql_mode “blank” after upgrading to MySQL 5.6

After upgrading MySQL from 5.5 to 5.6, some our app face to problem and need set sql_mode to blank to solve this issue. I added sql_mode = '' to my.cnf but there was no effect on the mysql setting. ...
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50 views

MySQL SELECT blocking an INSERT?

Is it possible for a SELECT query to block INSERT / ALTER queries? I have the following (taken from ENGINE INNODB STATUS) on my slave database: ---TRANSACTION 26DA7060, not started mysql tables in ...
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59 views

mysqldump error on common_schema

I tried to take the backup of common_schema in Server version: 5.5.44 MySQL Community Server (GPL). mysqldump -u root -p common_schema > common_schema_bkup.sql I got the following error: ...
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Windows crashes on doing sql dump [closed]

Windows simply crashes and opens the blue screen for dumping physical memory on trying to import sql dump. Blue screen error: IRQL_NOT_LESS_OR_EQUAL So far I have tried 4 methods: Through workbench ...
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34 views

Mysql can't start?

Mysql can't start, here is the log : 150708 06:28:36 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql 150708 6:28:36 [Warning] Using unique option prefix key_buffer instead of ...
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43 views

mysql replication and innodb_file_per_table

Is it possible for the master (5.1) to have innodb_file_per_table = 0 and for the slave (5.1 or 5.5) to have innodb_file_per_table = 1 ?
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29 views

MySQL: Incorrect binary log format - OFF.000

I have a Percona MySQL 5.5.30 as a master(Debian 6.0.7). I got a weird issue that all my binary logs started saving in format OFF.00* instead of the specified format in .cnf file. mysql> show ...
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50 views

Unknown sticky Problem after MySQL upgrade

few weeks ago we upgraded mysql server from 5.5 to 5.6 on 1st server few days ago (5May) I reboot mysql server , after this customer reported that some database data table not load to their site . ...
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Why is restoration from binary logs so slow?

We have a MySQL 5.5 server with binary logging enabled and a backup script that collects the binary logs and, once a day, generates a complete database dump with mysqldump. In testing database ...
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157 views

Mysql causing high load average with large amount of server resources left

I've have 2 servers running a application and the server that runs the mysql sgbd is with the load average around 3 times more than the webserver. I think that is something wrong because i have a lot ...
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Awful execution plans after migrating from MySQL 5.5.11 to MariaDB 5.5.41

We just migrated our web site database from a server running MySQL 5.5.11 to one running MariaDB 5.5.41. Everything is working mostly fine, except there's at least one query from our storefront that's ...
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81 views

phpMyAdmin and mysql not showing the same database

I have setup WAMP which I managed by using a tutorial and everything seems fine... I am logging into mysql as the root user with full privileges granted and I am able to create databases in mysql and ...
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34 views

Installed Percona-Toolkit, but no sign of xtrabackup

I've installed Percona-Toolkit on my Debian (Wheezy) test Server, using dpkg -i percona-toolkit.deb apt-get install --fix-missing -f dpkg -i percona-toolkit.deb However, there is no sign of ...
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218 views

How to turn Event Scheduler On permenantly in mysql

How do i turn on the event scheduler in mysql permanently. I'm using phpmyadmin and i have scheduled an event to copy records from one table to another everyday at a specific time, but the records are ...
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339 views

Table Design for Student Attendance hourly for each day

I have created a table (attendance_details) for storing every day attendance of Students in MySQL. Need to capture attendance for hourly (1-8hrs) every day. I have the student details in separate ...
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Need to convert date to word using trigger

I have created a datetoword function in Mysql. Checked the function working fine. Now using this function need to convert the date from field1 (date-datetype) to field2 (Varchar-datatype) within the ...
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70 views

Can MySQL log lock waits?

Is it possible to have MySQL log queries or transactions where lock waits occur? One can debug specific application errors generated from lock wait timeout errors from the DB but without the ability ...