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

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MySQL Master-Slave Replication Cross Database

I am setting up Replication for cross Database as i have set 2 variables in Slave' s my.cnf as replicate-do-db=database_name and Replicate-wild-do-table=database_name.% ,But i am not able to get ...
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1answer
60 views

Move databases on same Mac

I have just updated my MacBook to Mountain Lion. Since then, my MAMP installation does not work properly so I decided to use the build httpd/php stuff. For this, I have additionally installed a new ...
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0answers
88 views

How to profile individual queries using PERFORMANCE_SCHEMA

I've been looking at SHOW PROFILES, which seems ideal for what I am doing. However, I've noticed a warning that SHOW PROFILES is being deprecated and that PERFORMANCE_SCHEMA should be used instead. ...
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1answer
91 views

Count total where owner_user_id = some_value and deleted_by_owner = 0 or to_user_id = some_value and deleted_by_to = 0

I didn't know if this is possible using just a query or if I need some procedural logic on this one. I have this table: CREATE TABLE `default_messages_users` ( `id` int(11) NOT NULL ...
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2answers
11k views

innodb_flush_method=O_DIRECT vs O_DSYNC performance impact on ext3 with LVM disk partition

In one of my production environment, we have two instances running on a RedHat cluster, with one production instance associated with the cluster. We have 125G main memory with 24G InnoDB buffer pool ...
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0answers
87 views

MySQL replication backup

How to take MySQL Master-Master and Master-Slave replication backup?. I have setup Master-Master replication with a separate slave for each master on Ubuntu. What happens if, I issue or schedule ...
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1answer
5k 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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1answer
655 views

MySQL Replication Error, can't stop slave

When I run command SHOW SLAVE STATUS\G, I see Slave_IO_Running : 'Yes' Slave_SQL_Running : 'No' What I've usually done to fix this is to run STOP SLAVE; SET GLOBAL sql_slave_skip_counter = 1; ...
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1answer
3k views

Setting up MySQL Cluster on Two Systems

I am attempting to setup a MySQL Cluster. I have the folllowing setup one management node two data nodes another machine on which two more nodes reside Below is the config.ini file: [ndbd ...
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1answer
241 views

Compare MongoDB and MySQL

Can anyone help me to make right decision for choosing scalable and reliable database? I have to create 3-4 tables with around 200 columns each and these tables will have around 5000 data records. As ...
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73 views

memc_delete called from a MySQL trigger loop fails randomly

I'm calling memc_delete from a MySQL trigger's code. The call is inside a loop. Logging the results, I see that memc_delete sometimes returns 1 (ok, memcached entry deleted) and sometimes returns 0 ...
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3answers
352 views

Finding differences between a master and slave when pt-table-sync fails

I have a table that's showing some differences on a master and slave according to pt-table-checksum (PTC). I've found some verifying differences beyond that. Certain tables in the mix have composite ...
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1answer
167 views

Get and count all blog posts and all users that fits a LIKE condition (two sepparated queries)

I've this tables: -- -- Table structure for table `default_cmvblog` -- CREATE TABLE IF NOT EXISTS `default_cmvblog` ( `id` int(11) NOT NULL AUTO_INCREMENT, `title` varchar(100) COLLATE ...
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1answer
1k views

MySQL 5.5 not starting after master-master configuration

The following master-master configuration worked on MySQL Server 5.1.x(Ubuntu 10.04). Master1(192.168.2.80) ################################## #MySQL Replication ################################## ...
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2answers
508 views

MySQL - How much physical space will be reduced by changing the column type?

Lets say I have the following table: CREATE TABLE `my_table` ( `id` int(11) NOT NULL AUTO_INCREMENT, `user_id` int(11) NOT NULL, `relationship_status` varchar(48) CHARACTER SET utf8 COLLATE ...
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1answer
257 views

How to set unique columns combination

see this table: CREATE TABLE IF NOT EXISTS `default_messages_users` ( `id` int(11) NOT NULL AUTO_INCREMENT, `message_id` int(11) NOT NULL, `owner_user_id` int(11) NOT NULL, `to_user_id` ...
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1answer
896 views

MySQL INSERTs waiting for UPDATEs (MyISAM)?

In show processlist;, MySQL 5.5, we see that INSERTs tend to wait for UPDATEs to complete before they can proceed. This is on MyISAM tables. We tried INSERT HIGH_PRIORITY and UPDATE LOW_PRIORITY. ...
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1answer
77 views

Will these queries return the same results?

I have this simple query: SELECT friend_id FROM default_friend WHERE user_id = 1 And the results are below: +-----------+ | friend_id | +-----------+ | 2250 | | 4901 | | ...
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1answer
4k views

When to switch from MyISAM to InnoDB?

We have a MySQL 5.0 server running all tables as MyISAM. We have two slaves that, in the last month, we have upgraded to MySQL 5.5. Their tables are also still MyISAM. My original plan was to upgrade ...
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2answers
121 views

How to see what was executed in the database via binlogs for specific date?

I am trying figure out how to "query" binlogs to see what was exectued in the database for a specific date. For example, if I execute mysqlbinlog binlog then the thing just runs forever and it is had ...
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1answer
159 views

Need some help with this query get all status and their associated comments of me and all my friends

I've several days dealing with this query but can't get it to works as I want. This post is related to this one Several values from different tables in which I tough found the solution but I was ...
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1answer
121 views

Several values from different tables

I'm totally lost here and not know how to get this to work and hope any can help me here. I have several tables: default_users, default_profiles, default_status, default_comment and latest ...
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1answer
193 views

Is possible to optimize this query or it's already optimized?

I've three tables: default_users, default_profiles, default_friend. This are the SQL for each one: -- -- Table structure for table `default_users` -- CREATE TABLE IF NOT EXISTS `default_users` ( ...
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2answers
521 views

Tool to match mysql password encryption

I've created a user ... but forgotten the password mysql> create user 'blayo'@'%' identified by 'right'; Which Linux command line tool can encrypt the password the same way mysql does ? mysql> ...
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1answer
2k views

Slow insert performance in mysql innodb table for solr indexing

I have a Slave server (MySQL 5.5) having innodb tables. This server is being used for SOLR indexing. Few procedures used to fill 12 million data into 9 tables. The insertion speed is too slow. ...
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1answer
6k views

Deleting bin logs in replication environment

I have a question about deleting binary logs in the replication environment: We have an environment with 1 master and 2 slaves (running mysql 5.5). Sometimes, we run into a space issues during heavy ...
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1answer
348 views

Assertion failure from InnoDB while restoring using Innobackupex

I thought I would give back to all those people who help me when I have a problem. This might be something old, but I did not find it anywhere so here goes: We recently upgraded our production DBs ...
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2answers
881 views

Warnings: Why are statements with limit clause unsafe even if there isn't a limit?

I'm a bit irritated because of some warnings in mysql errorlog. Example 1: [Warning] Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT. The statement ...
2
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1answer
965 views

Extract some columns data from one table and insert into multiple tables

I have a table with 16,000 records and need to get out some columns and then insert values in multiples tables. For example, suppose I have the following tables tbl_1: id, name, lastname tbl_2: id, ...
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2answers
3k views

Scaling Percona datacenters: setup and replication

Since our startup has taken off nicely we are now meeting with some of those issues that you always assumed would NEVER effect you. We have already scaled alot of our application stack: we offloaded ...
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2answers
177 views

DELETE LOW_PRIORITY row visibility

I have a large MyISAM table on MySQL 5.5(Windows XP x64) on which I will have to run DELETE LOW_PRIORITY queries. Does DELETE LOW_PRIORITY make the rows invisible to SELECT statements immediately and ...
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1answer
530 views

Database Design - Creating Multiple databases to avoid the headache of limit on table size

I need to design database to store information contained in millions of log files generated by devices on trial on network. My first approach was storing all the information in tables contained in a ...
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1answer
2k views

mysql closing tables taking double the time of process

I have a delete query that is taking a long time. When I check in processlist that status is showing as closing table. It is taking a long time to close tables. ex: I run a query and the total time ...
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3answers
5k views

Maximum table size for MySQL database server running on Windows (NTFS) Table type InnoDB

I need to design database to store information contained in millions of log files generated by devices on trial on network. I have designed 5 different tables to store log file information. But, as ...
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2answers
2k views

Need suggestions for best way to archive MySQL (InnoDB) tables

Problem: I have two fairly large tables. A 'wall' table for messages between users with 9 million rows at 2 GB and a 'chapter' table at 2 million rows and 18 GB. I want to keep the number of active ...
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4answers
9k views

How to change a MySQL previous slave to be a master and remove slave status information?

I have a master -> slave configuration where the master failed. I've been able to reset the old-slave to be a master and the old-master to slave from it. Fine. What I can't seem to do is to remove ...
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2answers
20k views

way to prevent queries from waiting for table level lock

We've encountered a problem after moving the database of our customer to an extra server. This should have had positive effects on the site's performance, but there is a problem with table locking in ...
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1answer
58 views

where varcharcol = 0 returns all rows

Suppose I have a table like this: create table mytable(cola int primary key, colb varchar(10)); Let's put some data in it: insert into mytable values(1, 'abc'); insert into mytable values(2, ...
3
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1answer
222 views

Get profiles values where message.sender_user_id = profile.user_id

I have this tables: default_messages CREATE TABLE IF NOT EXISTS `default_messages` ( `id` int(11) NOT NULL AUTO_INCREMENT, `subject` varchar(150) COLLATE utf8_unicode_ci NOT NULL, `message` text ...
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1answer
617 views

Convert Oracle Query for Date to Mysql queries

Need to convert the following oracle queries to MYSQL queries. 1) select to_char(to_date(?,'DD-MM-YY')) from dual; 2) select to_char(next_day(to_date(?,'DD-MM-YY'),'FRIDAY')) from dual; 3) ...
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1answer
733 views

decreased performance of stored procedure when migrated from mysql server 5.0 to 5.5

i recently testing the move of our db from one server to another. as part of this process i copied all the data to the new db and started testing it. as a comparison i run a store procedure whose ...
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1answer
130 views

slave issue with load data

When I use "load data infile" on master, the data is properly transferred to slave. But when I use "load data local infile" from remote server to master, the data does not pass on to slave. Why does ...
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3answers
1k views

MySQL backup with no downtime

I'm running a M/S replication of MySQL 5.5 / innoDB (over ubuntu). My DB is pretty large: ~250GB. I'm looking for a backup tool/service that will do the following: full backup no downtime / locks ...
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2answers
172 views

Is there a way to get slow-query-log-like profiling information on a single query?

Specifically, I'm looking for this information: # Query_time: 0.011922 Lock_time: 0.000088 Rows_sent: 107 Rows_examined: 663 Rows_affected: 0 Rows_read: 107 # Bytes_sent: 4152 Tmp_tables: 3 ...
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3answers
1k views

What are the limits on the amount of slaves per master?

I currently have a Master with 2 slaves, all running MySql 5.5. What are the limitations on the amount of slaves I can connect to a single master? what parameters should be taken into affect?
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1answer
8k views

What can cause TRUNCATE TABLE to take a really long time?

I'm running MySQL5.5 with Master/Slave replication (1 master, 2 slaves). I have a process that runs once a week and truncate a specific table. The table is not large and only has a few thousands ...
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1answer
3k views

MySQL table with 100,000 records queried often

I have a single database of about 100 tables to store various kinds of information. The most important table is our order table which is used to store customers orders and is over 100000 records as ...
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1answer
894 views

What exactly is SOLR? [closed]

It seems like a magical technology that can Do spatial search do full text search The problem is, It doesn't say where does it store all the data. Does it have it's own proprietary database If it ...
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2answers
1k views

Some queries slower in MySQL 5.5 than 5.0?

We have an exceptionally inefficient process (1.3 million selects, 232k updates) that I'm now recoding to be 1 select and 50 updates. In the meantime, though, today's process ran. We recently updated ...
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185 views

How to speed up this query

MySQL doesn't have nearest neighbor search so. So I try to come up with a "distance" that's reasonable so the number of returned query is around 20-200. That way innodb doesn't have to compute ...