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

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Alternative to using subqueries

Anyone please help me to optimize this query SELECT COUNT(csd.search_id) AS searches,count(distinct cd.cust_phone) as unique_searches, (SELECT COUNT(csd.product_type) FROM ...
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215 views

Centos 5.11 mysql-server 5.0.95 upgrade to mysql55w-server

Here's my thought process on my upgrade: mysqldump --all-databases > backup.sql service mysqld stop yum remove mysql mysql-server yum install mysql55w mysql55w-server service mysqld start ...
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2answers
13k views

Should I increase max_connections in AWS RDS t1-micro for MySQL?

I have an AWS RDS t1-micro running MySQL 5.5. It gives me too many connections error. I checked and it allows 34 maximum connections concurrently. What I have read is that i can increase this max ...
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1answer
26 views

MySQL - Is it possible to assign permission to count the number of tables in a database without permissions on individual tables?

As part of a script I am trying to count the number of tables that exist in a particular MySql schema. Using my own user I am using the query SELECT COUNT(*) FROM information_schema.tables WHERE ...
2
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1answer
1k views

Mysql 5.5.38 ERROR 1062 (23000): Duplicate entry '' for key 'anykey'

I dropped my UNIQUE KEY index 'myindex' on a table and I wanted to change the UNIQUE KEY to something else, so after dropping it I did: alter table mytable add unique key anykey (add1, city, state); ...
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0answers
24 views

Does creating an empty table in MySql have any effect(downtime) on production?

Disclaimer: I am, in all probability, paranoid about pushing a patch on a production server. The patch alters the schema, by creating a new table (which is empty), and changes some stored procedures ...
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2answers
770 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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3answers
2k views

MySQL information_schema doesn't update

I have a database, say abc, in mysql server. It has only one table named test. test uses innodb engine and I've set innodb_file_per_table to true. After I run the query delete from abc.test, I want ...
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1answer
2k views

MYSQL query to find records between two date range

I am working in a web application using PHP and MySQL. I have two tables Employee employee_id email_id 3 tl1@jasmine.com 4 agent1@jasmine.com 5 ...
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2answers
46 views

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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1answer
54 views

How to only display a variable in PHP inside a MySQL query when it has a content or when a condition is true?

How do I only display $mon or any variable when it has content? whenever i use this syntax and for example, monday must contain the number 1 and tuesday would contain number 2 and the other ones have ...
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1answer
45 views

Large query with subquery runs indefinitely after mysql update

We recently did a big server update, in the process migrating from mysql-5.0 to 5.5.40 Several of the queries, which had been running well on the old server, now grind everything to a screeching halt. ...
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1answer
85 views

Why are tiny Innodb row updates causing so much disk IO?

This is a followup question to my earlier How can I determine which Innodb table is being written? Using the accepted answer from the above-referenced question I was able to determine which (two) of ...
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0answers
38 views

Different Auto-increment values Mysql schema Replication

I have 6 Slave set up (EC-2, linux) and a Master ; 2 schemas getting replicated. Version info: mysql Ver 14.14 Distrib 5.5.34, for Linux (x86_64) using readline 5.1 Once in few months in one of the ...
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1answer
59 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 ...
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2answers
12k views

InnoDB: Error: Table “mysql”.“innodb_table_stats” not found after upgrade to mysql 5.6

I upgraded to mysql 5.6 from 5.5, and now my logs are littered with such messages on startup I found a possible solution here, but it does not seem official. ...
0
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1answer
142 views

MySQL always writes simple temporary/memory tables to disk (both tmp_table_size and max_heap_table_size are set to 8GB)

I'm struggling with this issue and just can't figure out why this is happening. CREATE TABLE sitecache._test ENGINE=MEMORY SELECT * FROM website.gallery_likes WHERE 1=0; Every time I execute this ...
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0answers
31 views

Use join to aggregate data from various normalized tables

I have a database as follows: tbl_clients (Primary Key: client_id, Foreign Keys:place_id,district_id,zone_id,country_id) tbl_places (Primary Key: place_id) tbl_districts (Primary key: district_id) ...
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1answer
37 views

Purge mysql log bins older than two weeks automatically

I have to manually write purge binary logs bin to "mysql-bin.somenumbers" ; Once in a while, I need to reduce the spaces that binlogs are taking on my web server. Is it possible to purge binary ...
0
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1answer
77 views

Add linked server from SQL-Server to MySQL: “Data source name not found” (Error:7303)

I'm trying to link my SQL-Server 2005 on Windows Server 2008 R2 with MySQL 5.5.40 on a different computer. I have followed this guide: ...
2
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2answers
301 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 ...
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1answer
46 views

MySQL Data Files Missing?

We are upgrading our website and I was checking on the size of the new database compared to the old one and was really surprised to find that in the /var/lib/mysql/ directory, the only files there ...
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1answer
44 views

Mysql Master-Slave replication catchup and bin_logs

I have set up MYSql Replication using 2x 128gig ram 24 core cloud servers. we have a massive live database that cannot experience down time due to the high volume of data input. I have found while ...
2
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0answers
4k views

Why does CAST(1 AS SIGNED INTEGER) return a BIGINT on MySQL?

If I do CAST(1 AS SIGNED INTEGER) I always end up getting a BIGINT returned, for example: $ mysql -u root -p --column-type-info Enter password: --- Copyright and help message snipped for brevity --- ...
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1answer
34 views

how to overcome these type of issues where null value inserted into primary key not null column in table

how to overcome these type of issues where null value inserted into primary key not null column in table
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2answers
173 views

How to batch multiple insert statements for database dump with MySQL?

I have a MySQL database with some large tables. In particular, the largest table (by far) currently has ~11,000,000 rows. According to the a query I ran, the table clocks in at around 1.7GB, but it's ...
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1answer
103 views

Why does this ALTER TABLE ADD FOREIGN KEY query create two foreign key constraints

I am attempting to add a foreign key constraint to existing tables via an ALTER TABLE statement: CREATE TABLE `blog` ( `blogid` int(11) NOT NULL AUTO_INCREMENT, `deptid` int(11) NOT NULL DEFAULT ...
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0answers
77 views

MySQL Dynamic columns duplicate value workaround

As the title suggests i have the following code which transposes certain row values into field names, however the problem im having is that the values "closed" & "reopened" may appear in several ...
2
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4answers
894 views

Getting 0KB of size file while backup mysql database using mysql dump [closed]

I am using below code to backup my database using php script but I am getting 0KB size file. How can I backup my full database with all routines and functions? $dbhost = 'localhost'; $dbuser = ...
10
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2answers
150 views

Find total duration of each consecutive series of rows

MySQL Version The code will run in MySQL 5.5 Background I have a table like the following one CREATE TABLE t ( id INT NOT NULL AUTO_INCREMENT , patient_id INT NOT NULL , bed_id INT NOT NULL , ...
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0answers
184 views

Are there any caveats to installing MySQL 5.5 on CentOS 5?

I need to install MySQL 5.5 in CentOS 5. As CentOS 5 is a little bit old is there any odd behavior when you want to install MySQL 5.5 on CentOS 5?
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1answer
71 views

How can I determine which Innodb table is being written?

I am running Mysql 5.5. I have about 100 Innodb tables spread over 10 DB's (mostly wordpress sites) and I am recently seeing a lot more disk IO than I have been, without any increase in traffic. The ...
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2answers
95 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 want to join to and also a junction table. Event table (it's very big so it's just dummy data): ...
5
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2answers
132 views

Is there a (non-binary) MySQL collation that doesn't treat different mathematical symbols as the same character?

I've run into a real headache with MySQL's collations and non-BMP characters (ones with Unicode codepoints above U+FFFF). Basically, given a table and data like: CREATE TABLE `math` ( `id` int(11) ...
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0answers
70 views

How to use a subquery that returns multiple rows?

I am getting Error 1242 : Subquery returns more than 1 row. Basically, I have to do this : select data from my database based on a time criterion (between 2 dates) and then apply a filter on the ...
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1answer
43 views

Unique constraint for new values only

I have a large table with a column that contains duplicates. I want to add a unique constraint on this column for future entries only (not the old data). Is this possible?
2
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1answer
125 views

MySQL - Get Minimum Value, Data From Multiple Tables

Good evening all, first post on the DBA forums. I am having real issues working out how to accomplish a seemingly simple task within MySQL as a model for PHP code later on. I am not exactly a MySQL ...
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0answers
586 views

Combine and display multiple row data with same column data in MySQL

I have a menu, from where every item ordered is stored in a row. For a single order, there can be multiple rows.What I want is that when I display it, for same order_number ( number) all rows data is ...
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1answer
102 views

MySQL Workbench - “deploying” schema into a real database

a noob here, finding my way around. So, how can I "transfer, deploy or whatever the right term is" the database tables, fields, etc. that I have created with Workbench into a real database? The dB I ...
0
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1answer
54 views

import text file getting command is not allowed with this MySQL version

here is my table CREATE TABLE cities ( country CHAR(2), city_ascii VARCHAR(100), city VARCHAR(255), region CHAR(2), population INT UNSIGNED, ...
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2answers
233 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
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1answer
83 views

Is it possble to replicate MySQL server on Azure virtual machines

I have two Windows Server 2012 R2 virtual machines on Azure. I need to replicate the database on each of the windows servers. I have followed this link but I am not getting the connection between the ...
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0answers
315 views

Server version (5.5.40-MariaDB) does not match with the version of the server (10.0.15-MariaDB) with which this program was built/distributed

I just upgrade MariaDB (Mysql) 5.5.40 to MariaDB 10.0.15 by following this step by step. I have failed to enable the mysql and also mysql_upgrade with the following errors mysql_upgrade -u root -p ...
0
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0answers
46 views

Access Denied to users after upgrading mysql to 5.5.40

I recently upgraded mysql from 5.1.0 to 5.5.40 but suddenly some users seem to have lost the previlages. All the projects are live and those with issues are showing database connection error. How can ...
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1answer
47 views

Hierarcy Query Mysql

I have a table like this... ========================================================================== UID || PARENT ID || SPONSOR ID ...
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1answer
111 views

When try to do Mysqldump Backup from console then getting such as error [closed]

mysqldump: Got error: 2003: Can't connect to MySQL server on 'localhost' (10061) when trying to connect when i am tring to do MySQLDump backup from console then getting such as above error. I am ...
2
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1answer
97 views

View last several innodb deadlocks

I see that I can view the latest deadlock in mysql/innodb, but is there a way to view past deadlocks? We have two deadlock issues, one being important and the other not. The less important deadlock ...
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0answers
34 views

MySQL JDBC Driver puts transaction in read only. Why?

Using the MySQL JDBC connector with a MySQL 5.6.22 data source defaults the transaction mode to read only. Anyone know why?
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1answer
46 views

Finding out the exact size of the database after inserting records?

I have this query: SELECT table_schema "db.name" , Round(Sum(data_length + index_length) / 1024 / 1024, 1) "DB Size in MB" FROM information_schema.tables GROUP BY table_schema; Does this ...
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0answers
24 views

Can MySQL Index Merge an Composite index with a single column index?

I am tuning a query and currently have an index as following : Index 1 : (col1, col2) An example query would be : SELECT * FROM t1 WHERE col1 = '1' AND col3 = '2'; I have created an index on ...