MySQL 5.1 : The Second Major Release of MySQL 5

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12
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4answers
5k views

Why use WHERE 1 or WHERE 1=1?

Usually, if conditions are not required in our query statements, we don't use a WHERE clause. But I see a WHERE 1 clause being used in many places, even where other conditions are not present. Why ...
6
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1answer
237 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 ...
6
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1answer
172 views

What is the expected performance impact when dropping a large table

I have a 100G+ innodb table that needs to be dropped in a production environment. I am trying to do this without interruption to service. The table is no longer being written to, and needs to be ...
5
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1answer
266 views

Migrating MySQL to new server

We have a MySQL 5.1 instance running on Windows Server 2008 R2 x64 (Server A) replicated to another MySQL 5.1 instance on Windows Server 2003 R2 (Server B). We have a new MySQL 5.5 instance on ...
4
votes
1answer
294 views

If MAX(id) != COUNT(id), does that mean rows have been deleted?

The question pretty much says it all. We're talking MySQL here, version 5.1. What I'm wondering is whether this would strictly means rows have been deleted, or if there are other possible scenarios ...
4
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1answer
250 views

Clarification about master slave configuration in mysql

We are planning to migrate an existing MySQL database to a new server using the MySQL replication master slave procedure. Unfortunately this will take a lot of time so we were thinking of doing a ...
4
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2answers
10k 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 ...
3
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1answer
5k views

How to solve “The table … is full” with “innodb_file_per_table”?

I have a MySQL database that holds a large amount of data (100-200GB - a bunch of scientific measurements). The vast majority of the data is stored in one table Sample. Now I'm creating a slave ...
3
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1answer
7k views

Change existing datadir path

I want to change the datadir path in the my.ini file. The existing datadir path is C:/ProgramData/MySQL/MySQL Server 5.1/Data/ The size of my C: drive is 30 GB and the MySQL data folder is occupying ...
3
votes
1answer
11k views

MySQL case sensitive table names on Linux

Moving a MySQL database from Windows to Linux I have the problem that on Linux the names of the tables are case sensitive. This is a problem, because the Java application that I am developing can't ...
3
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1answer
4k views

Mysql master-master replication auto flush old logs

I have mysql-5.1.41 master-master setup running on ubuntu machines and below is the configuration of a master: skip-host-cache skip-name-resolve event_scheduler = ON max_connections = 500 ...
3
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1answer
2k views

What memory should be given to the variables of my.cnf ?

Installing a MySQL server is quite easy. However, after installing, configuring the server is an important task for a DBA. Having 2GB of RAM and 250GB of disk space, how should I tune MySQL server so ...
3
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1answer
55 views

How to migrate from MySQL to MariaDB or Percona with minimum downtime?

I want to migrate my MySQL 5.1 database to one of these databases: MariaDB, PerconaDB or MySQL 5.6 Is there any way to do this operation with no downtime or with minimum downtime possible? How? The ...
3
votes
1answer
143 views

Merge difference MySQL DBs into a single new server

I have 4 servers which has it's own MySQL server along with databases and users. Now we have a new server dedicated only for MySQL and we would like to merge those MySQL servers into this new one. ...
3
votes
2answers
2k views

MySQL temporary column in SELECT statement

I'd like to do some calculations in a MySQL query. I've created some temporary columns which I'd like to use for the calculation. SQL fiddle for currently working (but discouraged) SQL query: ...
3
votes
1answer
84 views

How can I get this query to use it's index?

Queries matching this query below shows up in the slow log (with different contentVersionId & modifiedDateTime). As I don't really know what I'm doing I tried adding indexes to all columns in ...
3
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2answers
1k views

Can I do anything about a very long running KILL command?

I've got a table with 103M+ records in it and takes up 70GB on the disk. I decided to DELETE (in one statement) 70% of the records. As expected, this took an awfully long time to run. I decided to ...
3
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2answers
1k 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 ...
3
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1answer
1k views

Does `Seconds_Behind_Master` show exact Slave Lag from Master?

Does Seconds_Behind_Master show the correct result? I have also Implemented the mk-heartbeat replication monitoring. It was showing the other result in comparison with Seconds_Behind_Master. Which ...
3
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1answer
559 views

Is it possible to compare timestamps between rows?

I have a MySQL table reqs with (this is simplified from actual): | Field | Type | Null | Key | Default | Extra | ...
3
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1answer
5k views

MySQL : if server_id is not explicitly set, then get error `ERROR 1200 (HY000) at line 1: The server is not configured as slave;`

Our mysql version is "mysql Ver 14.14 Distrib 5.1.35, for portbld-freebsd7.2 (amd64) using 5.2" We have two database servers with replication, in a simple master/slave relationship. mysql2 is the ...
3
votes
2answers
147 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 ...
3
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1answer
1k views

Take individual MySQL database offline

MySQL does not have any SQL commands or internal mechanisms for making an individual database unavailable / offline moving an individual database Thtis being the case, how can you take an ...
2
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1answer
2k views

How soon after updating expire_logs_days param and restarting sql will old binlogs get deleted?

MySQL 5.1.x | InnoDB | Windows My mysql data directory is starting to fill up with bin logs. I currently have the following settings configured in my windows mysql server: [mysqld] log-bin ...
2
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3answers
1k views

Can I make sure two columns dont have the same value

If I have a table that looks like this CREATE TABLE foo ( id INT NOT NULL AUTO_INCREMENT, aa INT NOT NULL, bb INT NOT NULL, PRIMARY KEY (id), UNIQUE KEY (aa, bb), CONSTRAINT aa_ref ...
2
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1answer
80 views

Is there any difference between these two version of MySQL - 5.1.73-community-log Vs 5.1.73-community

I have installed MySQL 5.1.73 in Oracle LINUX 5 server. Just after RPM installation, I checked system variables and found that version is 5.1.73-community. When I copid ...
2
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1answer
367 views

Is it safe to kill ANALYZE TABLE query on a MyISAM table?

I have a huge MyISAM table that is blocking my application. I frequently find ANALYZE TABLE queries running on that table. I guess that's because a join is being performed on the table or at least an ...
2
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1answer
1k views

Innodb Slow queries since convert from MyISAM

a few days ago we converted some write intensive tables from MyISAM to InnoDB hoping to have a better performance due the better locking system of InnoDB, but instead of gain performance, we start to ...
2
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1answer
193 views

How can I disable utf8mb4 entirely on MySQL 5.5?

I know you're not supposed to do this, but I have a MySQL 5.5 master and a MySQL 5.1 replication slave. That's supposed to be okay, unless I do something stupid like use utf8mb4 that isn't supported ...
2
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1answer
2k views

log_warnings doesn't seem to work for aborted connections in MySQL 5.1

The docs for 5.1 say that I can set log_warnings = 2 to capture Aborted_connects in the error log. This bug report suggests that this was only merged into 5.5 and 6.0 (and maybe 5.2) but not into ...
2
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1answer
1k views

How to optimise read/write performance a MySQL table with many rows?

I am developing a django application where I use a MySQL database. In my application there is one table for domains information which has only 2 coloumns id domain_name but I have a problem when I ...
2
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1answer
3k views

Repairing Myisam Table when there was no additional Disk space & Table corrupted

I had a table which MyIsam as storage Engine contains million rows. There is a purging task and need to remove 35 days old data. i measured up the rows in following manner : mysql> select ...
2
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1answer
97 views

Do triggers affect DB performance

I have a database with 250 small and medium sized tables. These tables are related with both MyISAM and InnoDB storage engines. There are multiple triggers that have been created on different tables. ...
2
votes
3answers
95 views

How to update cust_id from Customer table to order table Cust_id field while inserting customer name using trigger

I have two tables 1. Customer_details and 2. Order_details. 1.Customer_details table -->fields--> Cust_Id(Primary Key) and Customer_Name, 2.Order_details table --> fields-- Ord_Id(Primary ...
2
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1answer
198 views

Why would one use the Innodb Plugin instead of the builtin Innodb in Mysql 5.1? (GPL)

Innodb works in Mysql 5.1 whether or not the innodb plugin, ha_innodb_plugin.so is loaded at startup or not. Configuration dependent of course. What are the advantages and disadvantages of either ...
2
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1answer
2k views

Is there a progress indicator for OPTIMIZE TABLE progress?

MySQL 5.1.4x (Windows) | Innodb I recently purged data from a mySQL DB (a few hundred thousand rows) and I'm planning to use OPTIMIZE TABLE LOGTABLEFOO1,LOGTABLEFOO2,LOGTABLEFOO3; to reduce the ...
2
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1answer
480 views

MySQL proxy and SHOW PROCESSLIST query time

I have MySQL replication currently occurring between two masters bidirectionally, one in a data center locally, another over at Amazon EC2. Everything seems to function normally replication wise, no ...
2
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1answer
2k views

Mysql Forcing close of thread 946 user

My mysql box keeping shutting down and up. Below is snippet of the log file. There is quite a number of places I notice this Forcing close of thread 946 user: 130426 12:36:28 [Note] Event Scheduler: ...
2
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0answers
502 views

mysql pre-start process (23901) terminated with status 1 [closed]

I installed a new Mysql server version 5.1 on machine which was running on 5.0. Now when I try to start the mysql server using command service mysql start it gives me an error start: Job failed to ...
1
vote
1answer
124 views

Help Optimizing Query

For the following table structure in MySQL 5.1.49: CREATE TABLE `leads` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `institution_id` int(10) unsigned NOT NULL, `lender_id` int(10) unsigned ...
1
vote
2answers
609 views

Mysql master-master permission replication issue

I came to know it's safe to replicate mysql database to have the users and permissions replicated, from a post in ServerFault is-it-ok-to-replicate-mysql-db. I have setup master-master replication ...
1
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3answers
287 views

Is there any command to optimize all MySQL tables one by one automatically?

I execute below command line statement to optimize a table: optimize table tablename; Is there any command or statement which can optimize all the tables one by one of the selected database?
1
vote
1answer
52 views

Conditional Counting

I'm analyzing a database of login records for a university and I'm trying to write a query that will give me an idea as to how many users are using the labs for short bursts, verse a more extended ...
1
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3answers
225 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 ...
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2answers
320 views

MySQL views and table locking (5.1 MyISAM)

I have a large (160 million rows, 50GB) table in MySQL 5.1 using MyISAM. If I were to construct a view defined by a fairly complicated query, would a SELECT on the view lock the underlying table?
1
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2answers
124 views

Mysql select ends with 'killed'

Okay, I'm sure this will turn out to be something dumb, but then I'm a dumb n00b DBA. I've got a largish table, about 163 million rows and something like 44 GiB. After some experiments with ...
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2answers
884 views

Difference between show status and show global status in mysql

When I execute "show status" and "show global status" in MySQL at interval of 5 seconds , I got set of 291 results each time. But, value of some parameters are different. Below are the list of those ...
1
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1answer
397 views

My SQL server showing different result with same query execution at different time

When I execute below query from MySQL server, it shows me different output for each time even though database is stable and not used by anyone except me. SELECT TABLE_NAME , table_rows FROM ...
1
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1answer
3k views

Why does max_used_connections status not get refreshed automatically once it reaches max_connections, even though the Threads_connected falls down

I always wonder, why does the max_used_connections value not come down, once it reaches the peak value of max_connections? I always flush the status and bring down this value to avoid DB connection ...
1
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1answer
11k views

Error Code: 1205 Lock wait timeout exceeded in MySQL

I have set InnoDB lock wait time-out to 120 seconds. When I run the query below for first time, it works fine. However, the second time, the same query with a different value gives me: Error ...