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

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1
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1answer
173 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 ...
7
votes
2answers
22k views

How do you remove fragmentation from InnoDB tables?

I have a Database having number of tables. I want to delete some records from the tables say the no of records are more than 20K or 50K. The All the Tables are InnoDB. And file_per_table is off. ...
1
vote
1answer
927 views

I am getting an error while trying to download binary for mysql 5.5.11

I am trying to upgrade MySQL 5.1 to 5.5.11 on Ubuntu 10.10. Everytime I try the wget command I get this error: wget ...
2
votes
2answers
642 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 ...
1
vote
1answer
601 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` ...
6
votes
1answer
8k 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 ...
5
votes
3answers
6k 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 ...
5
votes
1answer
82 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 | | ...
2
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1answer
166 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 ...
2
votes
1answer
125 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 ...
2
votes
2answers
603 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> ...
5
votes
2answers
237 views

Is there a reason/benefit I am not aware of for this kind setup?

I now manage a MySQL database that was designed and created by another. I am confused about a certain setup that the original developer created.. He did not use auto increments for table IDs. ...
1
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2answers
1k 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 ...
1
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0answers
191 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 ...
2
votes
1answer
2k 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, ...
5
votes
2answers
195 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 ...
4
votes
3answers
2k 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?
2
votes
2answers
4k 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 ...
2
votes
2answers
3k views

How to improve MySQL Server Performance..??

As a MySQL DBA most of the times we are supposed to optimize a poorly performing MySQL Servers. Now my question is where to start from like we will need to find out many things as 1.Find the ...
2
votes
3answers
1k views

MySQL backup with no downtime [closed]

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 ...
1
vote
1answer
859 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 ...
3
votes
3answers
6k views

innodb_buffer_pool_size not changed

I use MySQL 5.5.23-1~dotdeb.0 (Debian) and here is the relevant part of my.cnf default-storage-engine = innodb innodb_buffer_pool_size = 3G innodb_log_file_size = 256M innodb_thread_concurrency = 8 ...
3
votes
1answer
60 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
votes
1answer
230 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 ...
1
vote
1answer
141 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 ...
4
votes
1answer
10k 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 ...
11
votes
1answer
4k 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 ...
-1
votes
1answer
1k 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 ...
6
votes
2answers
424 views

Less restrictive query return less result due to simple removing one additional constraint

Look at this query SELECT DISTINCT TB.ID, TB.Latitude, TB.Longitude, 111151.29341326*SQRT(pow(-6.185-TB.Latitude,2)+pow(106.773-TB.Longitude,2)*0.98839228980165) AS Distance FROM ...
1
vote
2answers
950 views

String comparison with integer is not working sometimes in MySQL 5.5

I have upgraded MySQL to version 5.5. Before upgrading when we used string comparison with integer, it was working. Code is "value = 1", here 'value' is declared as varchar(45) and its value can be ...
1
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1answer
798 views

How can I trigger this stored procedure on insert?

I have a table of error messages to which errors will be inserted. I also have a table defining interactions between errors. For example, when a "Power Restored" error occurs, it clears any previous ...
0
votes
1answer
57 views

2 Very similar queries return different number of result (one is null)

I want to find businesses near a point that contain a word that start with sea lat=-6.185068&long=106.773121&keyword=sea&distance=5000&startfrom=0&howmany=20&prominent=5 ...
0
votes
1answer
195 views

What database do most mobile start ups use? [closed]

mongodb? MySQL? PostgreSQL? If someone would add pluses and minus, let me know. Why I ask: I am a mobile startup. I need a database that supports spatial indexes. The spatial index must be able to ...
-2
votes
1answer
4k views

Why does MATCH (FullTextSearch) AGAINST ('*' IN BOOLEAN MODE) return nothing?

MATCH (FullTextSearch) AGAINST ('k*' IN BOOLEAN MODE) return something Namely anything with a word that start with k MATCH (FullTextSearch) AGAINST ('ku*' IN BOOLEAN MODE) return less MATCH ...
8
votes
2answers
2k views

How do Application Like Yelp Retrieve distance information from data base efficiently

For example, say I have a table: Business(BusinessID, Lattitude, Longitude) All are indexed of course. Also there are 1 million records Say I want to find businesses closest to 106,5, for example, ...
3
votes
1answer
2k views

Configured MySQL replication but its not working

I have configured MySQL master and slave replication setup on 5.5.x. But for some reason data is not getting replicated properly. What might be the reason? At Master: /etc/my.cnf [mysqld] ...
1
vote
1answer
126 views

How to Archive Only MySQL Master not the Slave.?

Currently I have a Master and Slave. Both of them have same set of data(Can Say are in Sync).The Replication is running fine. What i need to accomplish is that... Need to Archive the Master(Say I ...
0
votes
1answer
103 views

Can MySQL be patched

I just saw a note about a security issue in MySQL so thought that I'd better patch my test server just in case. The MySQL site is not very helpful and a quick google revealed lots of people asking how ...
3
votes
2answers
2k views

Can we assign mysql Key_buffer_size value for particular table?

In some documents I found that we can assign key_buffer_size to myisam table. This also includes the following steps: SET GLOBAL myisam_table.key_buffer_size = 4194304; CACHE INDEX test.myisam_table ...
2
votes
1answer
588 views

“set-variable = innodb_thread_concurrency=4” or “innodb_thread_concurrency=4”

Based on this question, the asker wrote: set-variable = innodb_buffer_pool_size=2M set-variable = innodb_additional_mem_pool_size=500K set-variable = innodb_log_buffer_size=500K set-variable = ...
5
votes
1answer
4k views

Can I safely kill OPTIMIZE TABLE on an InnoDB table?

MySQL's documentation for kill warns: Warning Killing a REPAIR TABLE or OPTIMIZE TABLE operation on a MyISAM table results in a table that is corrupted and unusable. Any reads or writes to ...
6
votes
2answers
3k views

Insert-heavy InnoDB table won't use all my CPU

I have a packet log database, which is almost never queried. It just needs to be fast on inserts. I'm using InnoDB because I'd like to maintain ACID compliance, since even losing a single packet could ...
1
vote
1answer
803 views

Change root password of mysql database

This could be a Rookie problem , but it seems that i am not able to solve it. I have MySQL server installed on my windows machine(MySQL 5.5) under the Admin username root. Some How i lost the ...
0
votes
1answer
2k views

MySql 5.5 in ubuntu repository

Sorry for duplicate question. I am looking for the best way to install mysql 5.5 on ubuntu. So far, there are few options: Installing from tar.gz Installing from PPA. Alien on RPM. All of them ...
2
votes
2answers
4k views

MySQL Table level Replication

I have 3 servers, say A,B &C. All have the equivalent data(same data). Now what I want is to make A as the master and B,C the slaves. But the scenario is that I only want to replicate some of the ...
2
votes
3answers
1k views

InnoDB UPDATE slow need a better option

I'm using MySQL 5.5 with a table in InnoDB running: deleteme tinyint NOT NULL DEFAULT 0;` UPDATE `import` SET `deleteme` = 1; -- Set the delete field LOAD DATA LOW_PRIORITY LOCAL INFILE ...
3
votes
2answers
6k views

What to use, CASCADE DELETE rule or ON DELETE trigger for one to many constraint?

I would like to ask about how to handle this relationship. For better view I've tried to simplify and convert my situation into how I think StackOverflow question voting has (sorry if not :-) I ...
1
vote
3answers
253 views

getting error while starting memecached service with ndb engine

i am installed memcached library by following the steps in the internet. now there is a binary file created in bin folder of mysql now i exicuting the command memcached i am getting error like this ...
6
votes
1answer
247 views

Why does Oracle keep working on MySQL 5.1

2 years ago the first version of Mysql 5.5 was released. What is the reason to continue working on MySQL 5.1 - the current release is Mysql 5.1.62 It looks like there are should be fundamental ...
2
votes
1answer
3k views

What is the optimal way to select the parent and child rows on a table with a self-relationship?

Sample data from the genres table: id | genre_name | genre | parent_id --------------------------------------------- 2 | Blues | MAIN | NULL 6 | Folk | MAIN ...