MySQL : Open-Source, Relational Database Management System

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14
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3k views

MySQL 5.1.66 SSL connection error ERROR 2026 (HY000)

UPDATE2 Using WireShark I found out the problem string (I hope I did): 28 | 9.582638 | 192.168.18.128 | 192.168.18.129 | MySQL Response Error 1043 And the error is (according to docs): Error: ...
3
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241 views

“InnoDB: error clustered record for sec rec not found” MySQL 5.5.28

We have a high-end server, 128GB RAM, 32 Core , Xeon, SSD RAID 10 - running Ubuntu 12.04 with MySQL 5.5.28. During high load, randomly we got the below error. MySQLcheck, innochecksum shows no ...
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108 views

Once in a while synchronization of the independently updated mysql databases problem

I have a production database and a test database running on MySQL with MyISAM and InnoDB tables, which are updated independently. The Production database is updated by system and sometimes by a user. ...
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105 views

Mysql search matching multiple values in multiple columns

I need to speed up a search. Currently we let our users input a name: John Doe Then in Java we split that string to create multiple values (or "terms") ["John", "Doe"] and loop through the terms ...
2
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31 views

longitude lattitude performance

I have to store frequently (at least every min) the position (longitude, latitude) of animals in a DB, and perform for each update a search in order to determinate if ananother animal is near to it. ...
2
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90 views

Almost identical queries but large time difference in execution

Exhibit A SELECT SUM(value) FROM Credits RIGHT JOIN calendar ON datefield = DATE(FROM_UNIXTIME(created_at)) WHERE confirm = 1 && reason = 1 && country = 'it' && created_at ...
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55 views

Performance difference between two MariaDB slaves

I have a pool of MariaDB servers like this : master (5.5.38-MariaDB-log) slave1 (5.5.38-MariaDB-log) slave2 (5.5.38-MariaDB-log) The two slaves servers run on the exact same hardware (Dell ...
2
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38 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 ...
2
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38 views

Sample a Mysql table to increase performance

we are storing all our clients traffic data in a MySQL 5.1.73 database (MyISAM) and then we use it to generate user and internal statistics/graphs, always searchinng for a client id and a date/hour. ...
2
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63 views

Denormalizing to speed up inserts

I have a MySQL InnoDb table with approximately 40 million rows and the following columns: param1 (int), param2 (int), param3 (int), geo (char2), value1 (bigint), value2 (bigint) I have an ...
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47 views

Proper design of routes in Database MySQL

I'am trying to find out the best database design and try to stick with data integrity by using Foreign Keys. But I'm stuck right at the beginning because of limit relations between tables with FK to ...
2
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34 views

Difference of write authorization on file system with mySQL

On my local mySQL (on CentOS 6 VM) database I wanted to export some data from the DB to a file like this: SELECT html FROM mytable WHERE lang = 'en' and id='KEY01' INTO OUTFILE 'key01_en.html' By ...
2
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231 views

How can I connect to a network MySQL server using ODBC?

Somewhere on my company's network there's a (Oracle) MySQL server named FOO. I see FOO reference in SAS code written by my team's analysts, who use SAS's PROC SQL command to connect to it using ODBC. ...
2
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197 views

Recover innodb database from ibdata1 and *.frm files only

I have a problem on my server. I had a hard disk error on my server, and I restarted it. After that, I started wamp server software, but mysql services were not started. I checked all mysql data, ...
2
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61 views

Single database won't load MySQL

When I turned off my MySQL server, and turned it back on, it wouldn't read my database anymore. Just a single database, everything else in mySQL was fine. When I try looking at any of the tables it ...
2
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205 views

RDS MYSQL instance rebooted and won't load INNODB table

So my production db in RDS apparently either crashed or was rebooted during a version update, and upon being restarted mysql couldn't load one of the innodb tables: as evidenced by the following error ...
2
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1k views

MySQL - high CPU usage (MyISAM tables)

We have a server running LAMP stack on CentOS release 5.6 (Final) MySQL is having high CPU usage constantly which causes server to lag as shown top - 13:50:47 up 80 days, 13:53, 1 user, load ...
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201 views

How to model (a many to many) to many relationship

Hello i am facing the following scenario. I have a student table with the following structure. Student id(PK), matriculation number, first_name, last_name, email A student can have more than one ...
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52 views

Count how many locks required for a MySQL (InnoDB) query

I'm performance tuning a very data-heavy mysql application. It has a purge system that often seems to cause lock timeout errors for users. Based on my research I have a few adjustments to the query to ...
2
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1k views

MySQL Queries taking too long to execute

I have a database table, with 300,000 rows and 113.7 MB in size. I have my database running on Ubuntu 13.10 with 8 Cores and 8GB of RAM. As things are now, the MySQL server uses up an average of 750% ...
2
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0answers
94 views

Understanding Indexes and using them better

I've been spending some time trying to optimise our MySQL queries that we use which essentially joins one table with 2 million rows onto another which has 1-2 million. I know MySQL is able to easily ...
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88 views

Does it make a difference to add the DEFAULT keyword in CREATE TABLE?

The MySQL manual says: CREATE DATABASE db_name [[DEFAULT] CHARACTER SET charset_name] [[DEFAULT] COLLATE collation_name] ALTER DATABASE db_name [[DEFAULT] CHARACTER SET charset_name] ...
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732 views

Mysql slow writes

i have a strange problem with mysql. My selects goes fast. My insert/create/delete/drop/update go very slow. I have done some tests on 2 machines. My old machine and my new machine. Old is worst ...
2
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102 views

Why does MySQL force the tradeoff between swallowing errors and leaking commits in transactions?

Referring specifically to the choice of whether to use DECLARE EXIT HANDLER FOR SQLEXCEPTION. If you use it, you swallow errors and there doesn't seem to be any way to access them programmatically, ...
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827 views

Query getting periodically stuck in 'copying to tmp table' state, never completes

I am running Wordpress on a dedicated server with a MySQL backend. I have a query that usually takes <1 second to execute, but periodically, this query will get stuck in a 'copying to tmp table' ...
2
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1k views

How to prevent “ibdata files do not match the log sequence number”?

I am dealing with a very large set of databases that are all innodb. I've enountered this on mysql restart too many times for my comfort: ibdata files do not match the log sequence number But I've ...
2
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473 views

Insert Speeds for large batches

In my application, my INSERTs seem to be taking a major chunk of the time. I have a large number of objects in memory (~40-50,000) which i want to insert into a table. Lets take a sample table ...
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500 views

The nature of the relationship between two tables in MySQL

Good day. I'm designing a database for a research project where we're predicting whether or not young female athletes will rupture their ACL(s) based on the nature of a test jump recorded with a ...
2
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214 views

InnoDB forum DB design and Composite Primary Key (Cluster Primary Key)

I am designing forum database using InnoDB and got few questions , Could any one please help me to clarify them? Posts and Comments table design below CREATE TABLE `my_posts` ( `forum_id` ...
2
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85 views

MySQL Partitioning Performance

I have a MyISAM table with billions of rows that is still causing me problems because the indexes, even after I shortened them as much as possible, do not fit in my 64GB of RAM. I am unable to index ...
2
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250 views

Storing history of full/partial tables

I'm building a web-application with Django and MySQL (InnoDB) and am currently pondering over how to manage historical changes on various tables. I wonder if it's efficient to store a lot of rows ...
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114 views

Changing Charset to utf8 for all the fields and tables in mysql

How should I use the mysql and awk to change the charset for all the fields and tables for a specific database? I did not include username or password, so for sure it will not work. Should I run it ...
2
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65 views

How can one improve the performance of a query that selects on a low cardinality column in MySQL?

I have a "State" column that has a low cardinality (three possible value), on which most of my queries perform an equality selection (WHERE col = 'blah') AFAIK you need something like a bitmap index ...
2
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466 views

MySQL: Improve performance for one row insert into table with unique constraint

I have a table with ~ 40 mil records, with a unique index on the url collumn, of type varchar(255). Now the insert speed is about 30/s, is this expected? how could I improve it? I can't use bulk ...
2
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288 views

Dynamic MySQL partitioning based on UnixTime

My DB design includes multiple MYISAM tables with measurements collected online, Each row record contains auto-incremented id, some data and an integer representing unixtime. I am designing an aging ...
2
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385 views

Incorrect data when we using the CONVERT_TZ function on DST boundaries

We have a problem in converting time zone from "America/New_York" to "UTC". This problem occurs only on times representing 2.00 AM during the daylight saving. Timezone conversion with correct output ...
2
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0answers
2k views

'Access Denied' in MySQL on AWS RDS

I'm trying to use an ETL (in my current case, the free version of Talend). I've successfully set up a MySQL on Amazon RDS, logged in through the MySQL Workbench for Mac, and uploaded my company's ...
2
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587 views

SQL set profiling

I'm setting up an automatic database backup for a website. When I try to do a backup it comes up with the error" MySQL error: The 'SHOW PROFILE' feature is disabled; you need MySQL built with ...
2
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0answers
886 views

MySQL Server hitting 100% unexpectedly (Amazon AWS RDS)

We've been struggling with this issue for months. This week we upped our RDS instance to the highest performing instance and although the occurrences have reduced, we're still seeing our database ...
2
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0answers
67 views

MySQL Partioning: Is there a performance tradeoff between number of partitions and size of each partition?

I have a large table (several 100 million rows) that I would like to efficiently partition. My question is whether there is a tradeoff between partition size and number of partitions. As far as I ...
2
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1k views

MySQL re-install fails under Mountain Lion

I have problems to reinstall MySQL on Mac OS X after it was running on my system. I uninstalled it because the PreferencePane wasn't working as expected, using the procedure described here: ...
2
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0answers
2k views

mysql taking too long to send data

I have a simple table with million of records (14,000,000) and for a simple query it is spending too much time "sending data". The table CREATE TABLE IF NOT EXISTS details ( id int(11) NOT NULL, ...
2
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0answers
572 views

Index usage for database server

How can i fix the Index usage on one of our database server? It says from our Nagios control panel that: Service: DB Index Usage Host: MySQL Cluster Address: ( our IP ) State: CRITICAL Additional ...
2
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0answers
93 views

Can't connect to MySQL Cluster Storage (data) nodes

I've deployed a MySQL Cluster with a few nodes, and I want to access the storage nodes directly from another machine using NDBAPI. When I tried to connect from the same host it worked, but when I try ...
2
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0answers
287 views

MYSQL & Access ODBC

I am trying to connect mysql with access, i am settings up the ODBC correctly from the data sources, however i get a driver error. I am using access 2010 and the driver version of the ODBC conector ...
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15 views

Multilanguage category structure - standard vs. normalization?

I'm building a multilingual application and I need some advice on how to structure the table. Basically I have a category table based on nested set. There are 4 languages and I plan to enlarge this ...
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14 views

Sysbench insert data between a given range

I was trying to insert 1000000 records of data into 1000 tables in sysbench. But after installing about 278, sybench just crashed with the following error: FATAL: failed to execute function ...
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21 views

Migration error: “Invalid date literal detected” when reading decimal

I'm attempting a migration from MSSQL to MySQL and keep coming across a "Invalid date literal detected" error when reading certain decimal columns. I'm running the following (all up-to-date as of ...
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23 views

Migrate from SQLite to MySQL (then back)

For various reasons, I must use a SQLite database with a local application. However, I wrote a Flask app that enables users to more easily classify items in the database, and it runs very slow on ...
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21 views

Need advice on optimizing database on a recurring basis

I have a search engine with approx 3.5 million rows in the searchable table. There are many suppliers that feed into the table each day, so primary keys are constantly being removed and added and the ...