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

learn more… | top users | synonyms

1
vote
0answers
250 views

How do I recover from MySQL InnoDB table/index corruption?

While trying to upgrade a database (in place) I got the following error. The server starts up and everything seems to be fine, except that the table mentioned in the message is no longer accessible. ...
1
vote
1answer
41 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 ?
0
votes
1answer
29 views

How to Upgrade Master Slave MySQL on AWS RDS?

I already have Master Slave configuration on AWS RDS. We want to upgrade 5.5 to 5.6.23. ..What should be correct sequence to Upgrade ? 1. Upgrade Master ( Using Modify Instance ) --> Upgrade Slave 2. ...
1
vote
1answer
305 views

mysql fulltext query is very slow

I have one table for User detail in MySql with about 500000 records in it. I have also created fulltext index on firstname, lastname field on this table. but when I am trying to search any single ...
2
votes
2answers
608 views

Errors while creating multiple mysql-5.5 instances

I have installed 3rd mysql instance on my testing server. 2 instances already running without any issues. When I installed 3rd instance by mysql-5.5.30 zip source, it installed successfully but when ...
2
votes
3answers
52 views

How to show multiple names for one record but not duplicate the record?

I have a database structure like so: Car - id - carname - image - category - status Parts - partid - partname CarParts - carpartid - carid(fk) - partid(fk) - amountid(fk) Category - ...
1
vote
2answers
3k views

Hyperthreading & MySQL InnoDB Thread Concurrency Performance

I have a dedicated DB Server with the following specs" Ubuntu 12.04 LTS Server Intel(R) Xeon(R) CPU X5670 @ 2.93GHz 12 Cores MySQL 5.5.29 64 GB RAM RAID10 We are currently doing Hyperthreading ...
1
vote
1answer
31 views

MySQL Read/Write Benchmark

I'm trying to benchmark Read/Write speed in MySQL 5.5. Currently I have a stored procedure that insert rows with random numbers to a table and I'm measuring time of execution before and after ...
4
votes
2answers
199 views

Problem in Fetching Result set in Desired Format

I have 2 tables having the following columns Person ------ person_id, first_name, middle_name, last_name Items ----- person_item_id, person_id, item_type, status, ordered_date The query is ...
4
votes
5answers
854 views

MySQL runs out of memory when importing innodb database

I have a small VPS with 512MB RAM and no swap (can't have any). I am importing a 1.5GB innodb database with mysql -u -p < database.sql Before the operation can finish it says : Lost connection ...
0
votes
1answer
67 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 ...
1
vote
2answers
59 views

mysql master slave replication scenario

We are creating a new mysql slave, but for dump we are taking from a backup server which is a slave of current master. Now to enable replication we want to connect it with the master so should I take ...
3
votes
3answers
12k views

MySQL using too much CPU

I'm studying to be a DBA right now because I have a massive live database that is very sensitive that I manage. Here's the current system stats of my dedicated database server: CentOS 5.9 24gb Ram 8 ...
0
votes
1answer
47 views

what could cause a mysql process to close (clean)

We are using mysql master-master (version 5.5.32) for an API manager called Layer7. The 2 hosts holding the instances are in the same ESX From time to time we have mysql doing a clean shutdown for ...
0
votes
2answers
48 views

Killing a process without login to MySQL

Here is the situation: I was running a very complex query on a database which was expected to execute within a few hours over night(server configuration is not good and data set is large). This ...
2
votes
2answers
934 views

How to GROUP_CONCAT between given rows?

I have a table as id diary 1 breakfast 2 walk 3 start 4 office works 5 office projects 6 end 7 taxi 8 start 9 preparing for meeting 10 doing the meeting 11 end 12 night I want ...
0
votes
0answers
38 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, ...
2
votes
3answers
5k views

How to import table's data in MySql from Sql Server?

I am trying to export table from SQL Server 2008 R2 TO MySql 5.5. For this I am using SQL Server Import and Export Wizard of Sql Server 2008, but it is giving this error. Here this error may be ...
3
votes
2answers
1k views

How to split a string to and get info from another table in mysql

I have a system to assign score for each sentence stored in a column: TABLE 1: word_scores word score this 3 is 4 a 5 test 1 another 0 sentence 8 TABLE 2: ...
1
vote
2answers
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); ...
0
votes
1answer
25k views

How to get only month from MySQL date/time?

In my MySQL server, I have rows that have the date of my created content. Example: 2013-03-17 02:53:47 For now, I am using: $date = $fetch[thedaterownamegoeshere]; <?php echo $date; ?> But ...
1
vote
3answers
76 views

Mysql Master Offline

In a unidirectional Master-Slave setup, should the slave be manually stopped in cases where the Master is offline due to Maintenance, Crash etc. ? Or should one just leave it so that it keeps trying ...
0
votes
1answer
44 views

Mysql Master - Master Replication

i have established a master A and master B replication between two servers.Both are getting replicated.But it is limited with only one database. My questions 1.How to create a new database in ...
1
vote
0answers
29 views

Delete using join or using sub-query?

I need to delete rows from a table based on what is present in a temporary table. For me, both of these statements work : DELETE from main_table where `id` in (select `deletable_id` from ...
1
vote
1answer
28 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 ...
0
votes
0answers
36 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 ...
1
vote
3answers
102 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 ...
1
vote
2answers
47 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 ...
11
votes
1answer
7k views

MySQL transaction size - how big is too big?

I have an import process that runs every so often and I want it to be an 'all or nothing' kind of deal, aka: a transaction. There are many aspects, and the imports may yield anywhere between ...
0
votes
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 ...
0
votes
0answers
73 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 ...
0
votes
2answers
44 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 ...
1
vote
2answers
192 views

insert row if table is empty, else update row (mysql)

i have 2 tables "table1" and "table2" both have TIMESTAMP cols for starttime and endtime. i want something like if (table2 is empty) insert into table2 (table2.starttime, table2.endtime) value ...
0
votes
1answer
97 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 ...
0
votes
0answers
37 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 ...
1
vote
1answer
70 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' ...
1
vote
0answers
807 views

MySQL server: Unable to connect with root because of skip-name-resolve option

We had our MySQL server on an old server. We decided to move all of the databases to our new server. Old MySQL Server engine 5.5.31 New MySQL Server engine 5.5.38 We created one general dump file ...
0
votes
0answers
32 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, ...
1
vote
2answers
189 views

about giving same column name in every table of database

I have a database with 5 tables. In every table there is a column for checking status. If i give the name to that column which is same in all the 5 tables; What will happen? Is it correct according ...
0
votes
0answers
37 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
votes
1answer
53 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 ...
1
vote
1answer
62 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 ...
1
vote
1answer
23 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> ...
0
votes
1answer
25 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_ = ...
0
votes
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 ...
1
vote
1answer
44 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 . ...
0
votes
0answers
25 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 ...
0
votes
0answers
96 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 ...
0
votes
2answers
45 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 ...
1
vote
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 ...