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

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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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44 views

pt-online-schema-change with statement based replication in MYSQL

Is it possible/safe to use pt-online-schema-change in a Master slave environment where as the way replication is setup is statement based(SBR). What is the better way of doing it as currently I have ...
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3answers
114 views

Index optimization and cardinality

I'm by no means a DBA expert. Rather, a Magento developer having to troubleshoot some slow queries. I'll jump right in -- here's my attempt to EXPLAIN the troublesome query: EXPLAIN SELECT ...
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1answer
79 views

Non-Replicating commands from (master) Mysql 5.5.40 to (slave) MariaDB 10.0.19

CRUD replicates just fine. But we noticed that DB structure altering commands such as ALTER TABLE and/or adding/updating columns to a table and even creating new ones do not replicate to the slave at ...
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0answers
38 views

Index pages in innodb file when innodb_file_per_table = ON

I have MySQL 5.5, and innodb_file_per_table was always in config file. After some time of using MySQL DB was produced big ibdata1 file, but i don't know how explain why this file is so big, i try to ...
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0answers
121 views

Reclaim disk space after dropping table(innodb_file_per_table = ON), strange scenario

I know it is often asking question. But I can't find answer for my scenario with specific condition. We use MySQL 5.5 We have always(I am sure) innodb_file_per_table = ON option in our mysql ...
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2answers
49 views

Difference between Handler_write and Innodb_data_writes

Handler write is the number of requests to insert a row in a table. InnoDB data writes is the total number of data writes. Questions are Does inserting a row count as a disk write? If I do an ...
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2answers
56 views

Fixing MyISAM database without losing data

My old server was crashed but I was able to recover the databases from MySQL through testdrive. I'm trying to dump a database using mysqldump but it gives error for certain tables are crashed and ...
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40 views

MYSQL taking 17.5 GB of RAM

This is what top shows how MySQL is taking a large amount of memory. VIRT RES SHR S 3967 mysql 20 0 17.5g 1.4g 7008 S 41.2 2.3 17426:16 mysqld this is ...
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1answer
75 views

How to speed up query containing concat() in WHERE clause?

In my company we use a commercial software running with mysql 5.5 (MyISAM) that often executes a query of this form: SELECT table1.attrib1 FROM table2, table1 WHERE table2.status = 'Active' ...
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36 views

Got an error from unknown thread, /pb2/build/sb_0-13157587-1410170252.03/rpm/BUILD/mysql-5.5.40/mysql-5.5.40/storage/myisam/mi_write.c:226

I am using mysql 5.5.40-log and my default storage engine is Innodb, I found this error in my error log "[ERROR] Got an error from unknown thread, ...
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38 views

Does MySQL InnoDB locks multiple rows with READ_COMMITTED isolation level?

I am in trouble while resolving LOCK WAIT TIMEOUT EXCEED error with MySQL InnoDB. I have gone through this article and it says if we use isolation level READ_COMMITTED then my update query should ...
0
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1answer
56 views

Backup a huge database 200gb+

i have a mysql database where i need to take a backup of the log database. the problem is the log database i over 200gb and contains over 280 millions of rows, i need right now to remove a kind of ...
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1answer
79 views

“Remote” connection to a local MYSQL database on LAN

I have a mySQL (5.5.38) server running on my desktop (windows 7), I can connect just fine into any of the servers Users, and skip-networking is off when checked via show variables. I am trying to give ...
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1answer
30 views

MySQL Drop User Fails for Remote Host

We're clearing out some old MySQL users that connected from remote hosts during a database transfer. Why is this DROP USER query failing for the user asdfasdf_imac4? I'm logged in as root. mysql> ...
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1answer
31 views

Working with variables in stored proc

I want to create a meta table on the fly using a stored pdocedure and passing a table prefix as "in" parameter and then build the final table name somehow. My code looks like this: SET @table_ = ...
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0answers
40 views

MySQL - Get actual precision and scale of number

I would like to query the integer part and fractional part of all decimal(8,4) values in a column. By that I mean, I want to know the actual given values, and not the max allowed by the data type, ...
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1answer
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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0answers
26 views

get the min index of each group of consecutive records

I have a table of records. Each record has in index field. records are inserted sequentially and then individual records are deleted. think of a sequence 1 - 10 and randomly remove 4 numbers I need ...
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0answers
12 views

What does mysqltest's view-protocol option do?

The documentation on mysqltest lists this at the bottom of the list of options: --view-protocol Every SELECT statement is wrapped inside a view. What does this option do? Using mysqltest ...
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0answers
126 views

Plesk 12 Debian 7 MySQL CPU usage is too high

I have a problem with MySQL and MySQL CPU usage at Plesk. I have a news site with Joomla, and about 100-150 online user. CPU: AMD Opteron(tm) Processor 6366 HE 3 core Memory: 4GB HDD: 250 GB Plesk 12 ...
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2answers
66 views

MYSQL Row Count Limits?

What is the maximum row count for a table in MYSQL? I have a system with around 600,000,000 rows in three tables. Average Data Length (from data_length column) for these tables is 58,000,000,000 ...
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1answer
17 views

'mysql' database in fresh MySQL installation

I installed MySQL database and according to show databases command I have a database named 'mysql'. Is this database used for holding some internal values for MySQL? In addition, is it possible to ...
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1answer
102 views

InnoDB Index Doesn't Fit in Memory

I am using InnoDB tables in my database and total index_size is 250 GB and my data size is 500 GB. Server has 128 GB RAM, and innodb_buffer_pool_size is set to 64 GB. Data size is increasing every day ...
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0answers
72 views

ERROR 1644 (HY000) at line 1852: Unexpected content found in the performance_schema database

I was upgrading MySQL from 5.1 to MySQL 5.6 on a Linux server installed with RHEL6. I already have 5.1 installed and running with about 300GB of database data, so I want to do a in-place upgrade to ...
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2answers
50 views

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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2answers
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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1answer
44 views

MySQL, can't find MYD files on OS X, MAMP

Try as I may I can't find the data files for my MAMP installation! FRM files are here: /Applications/MAMP/db/mysql/database_name/ but, there are no corresponding MYD or MYI files anywhere. The ...
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1answer
41 views

In slow_log tables, sql_text column showing “throttle: index not used' warning(s) suppressed” instead of exact query

I'm trying to find the slow running queries from slow_log table (as I don't have direct access to server to check slow log file). In sql_text column instead of query it is showing "throttle: index not ...
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1answer
25 views

Indexed varchar column efficiency

On a table with several million rows, with an index on the only column in the where clause (varchar 100, full length indexed), would there be performance gains in making sure that the differences ...
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1answer
81 views

'USE db_name' takes too long to change when login remotely

I gave SELECT privilege to a user on a particular database, Now whenever I try to connect remotely $ mysql -h ip-of-remote -u username -p with that user credentials and try to change the database ...
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2answers
70 views

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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2answers
466 views

grant select on all databases except one mysql

I have user called test_user created under MySQL 5.5.17 under MS Windows 2008R2, I want to grant this user select privileges on all databases except MySQL database, note I have around 200 database ...
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0answers
115 views

how can i connect from yahoo small business webhosting domain to remote mysql server

so far I have done these: set up remote access using Remote Mysql.Added the yahoo website's domain ip and yahoo nameservers. went on to my website on yahoo small business and set up an Aname and ...
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0answers
35 views

Unsafe statement written to the binary log using statement format

In MySQL error log I am getting this warning message: [Warning] Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT. Statement is unsafe because it ...
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1answer
34 views

Is there an easy way to update a mysqldump file from version 9.11 to 10.11? [closed]

We have a client that has had their servers for soo long, they were still running MySQL 4.0.24. Now that they are refreshing their servers, we took a mysqldump of their current database to put into ...
5
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1answer
176 views

MySQL overhead of calling a Stored Procedure

Within Java, we access MySQL (v5.5.40) via JDBC -- a prepare statement, setting parameters then calling the stored procedure. It appears that every execute() has the overhead of 4 meta-calls (per ...
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0answers
22 views

How to make an indexed search over a list (set)?

A follow-up question for How to most efficiently store possible combinations of categories? An answer pointed to SET datatype. As far as I know, the default search option for it, FIND_IN_SET, doesn't ...
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1answer
27 views

manual transfer fails with table does not exist

I performed a manual transfer of data manually (zip up the dir and rsync'ed it over. I moved the members.ibd (the only .ibd file) to a save place, extracted and then replaced members.ibd with the ...
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2answers
964 views

Why are mysql password hashes internally saved with a star (asterisk)?

I was reading upon some mysql internals, when going through the mysql.user table in the my mysql shell, I get mysql> select * from mysql.user limit 1 \G *************************** 1. row ...
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2answers
74 views

How to most efficiently store possible combinations of categories?

I have a table of categories (currently with 14 rows, not likely to change). A need to cache combinations of categories emerged, so I'm creating a table of allowed combinations (only few hundreds of ...
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1answer
15 views

Import lots of mysqldumps with missing CREATE DATABASE

I have a bunch of mysqldumps of my old server with one database each. Unfortunately we forgot to add CREATE DATABASE ... in all those dumps. How can I import those files in one batch?
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1answer
73 views

Error: Incorrect usage of UNION and ORDER BY

I have this query: SELECT DISTINCT CONCAT (MONTH(`Date`),'-',YEAR(`Date`)) from wp_result_plugin WHERE Bet=2 AND month(`Date`) = EXTRACT(month FROM (NOW())) ORDER BY MONTH(`Date`) ASC UNION ...
0
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1answer
121 views

mysql database under symlinked directory: ERROR 1018 (HY000): Can't read dir of './<dbname>/' (errno: 13)

I'm using mysql 5.5 on an ubuntu linux server. I need to move a database from its current location (under /var/lib/mysql) to a disk with more space, so I attempted to move the directory and create a ...
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1answer
22 views

Can combine five mysql statements into just one statement?

Can I combine all the five statements into just one statement? update mytable set myfield1 = replace(myfield1, '…' ,'-') ; update mytable set myfield1 = replace(myfield1, '‖' ,'|') ; update mytable ...
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0answers
37 views

IF statement inside stored procedure, seems to cause locks by side effects

We are running a MySQL 5.5. server with READ-COMMITTED transaction level to store and process a large time series dataset. We have a large time-series-table, into which we write batch updates every ...
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0answers
19 views

Optimizing MySQL for write throughput ceiling

We have a large MySQL database on AWS RDS, with a huge table around ~1.8TB with massive write workload. We recently hit a write throughput bottleneck, which caps our provisioned IOPS way below the ...
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0answers
15 views

creating best results from two tables

I have two tables, one is the results of an assessment from users(per row) and column starting with 819....X1 represents the qid. The other table holds the score for the answers (A1,A2,A3), both are ...
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0answers
65 views

Tunning MySQL Variables

we have a dedicated mysql server with 10 CPU and 32G of memory After doing some readings came up with those configs : # This was formally known as [safe_mysqld]. Both versions are currently parsed. ...
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2answers
60 views

Get rows where lastLoginTimestamp is in last 7 days

I'm trying to get the rows from a table where lastLoginTimestamp is in last 7 days and I'm doing as follow: SELECT * FROM representative WHERE DATE_SUB(lastLoginTimestamp, INTERVAL 7 DAY) ...