Tagged Questions

InnoDB : MySQL's ACID-compliant Storage Engine

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Accessing Database from Slave server

I have an application running in one server eg: My Server's Ip is 192.168.10.10, and I have the MySQL database server in the same machine. The application connects database server as localhost. ...
2
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1answer
74 views

Is there any way to use different InnoDB settings for different databases on the same server?

From what i know, this is not possible but i'm surprised its not highly requested feature. I'd love to be able to have one db using InnoDB in ACID compliant mode and another db on the same server used ...
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2answers
2k views

The best MySQL Settings for 32GB RAM on a Dedicated Server

I am worrying about my memory usage as it is reaching more than 90% if I will not restart php-fpm. I have the following configuration on my MySQL: [client] port = 3306 socket = ...
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2answers
484 views

MySQL stores BLOB in innodb buffer pool (innodb_buffer_pool_size)?

I have several databases all in INNODB, 50GB are BLOB columns, only 700MB are not BLOB data. Tools as mysqltuner ask me to set innodb_buffer_pool_size = 51GB. Does MySQL store the BLOB in RAM? If ...
0
votes
1answer
37 views

MySQL innodb database creation…why do this? [closed]

I am new to administering MySQL databases but the company I work for has a number of servers set up with a physical "innoDB" schema in MySQL. Not sure why someone would do this and the schemas are ...
5
votes
1answer
830 views

Possibilities to speed up InnoDB INSERTs and UPDATEs

My website retains user sessions in an innodb table. This usually works well, but a few hundred times a day, the INSERT and particularly the UPDATE statements run slower. I'm monitoring when, and it ...
2
votes
1answer
226 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 ...
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2answers
52 views

Indexing a reference column

Say I have a reference table like languages with only 20 records. Is it worth indexing a field like language_code (e.g. en, es) that's frequently used in queries? I'm wondering if an efficient server ...
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1answer
2k views

Why should I use InnoDB and MySql instead of XtraDB and MariaDB? [closed]

Why should I use InnoDB and MySql instead of XtraDB and MariaDB, except that InnoDB and Mysql happen to be installed by default on my servers? Why isn't MariaDB and XtraDB installed by default ...
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0answers
168 views

invalidating query cache entries(key) [duplicate]

when I tried to delete some records from a MYSQL server (version 5.0.95-log) and checked the process list I got the result as follows mysql> show processlist \G *************************** 2. ...
2
votes
1answer
526 views

query cache hit value is not changing in my database

The query cache hit value is not changing in my database only for some queries.If I write select * from drugs_info limit 1000; the query cache hit has changed, but if I execute the following ...
2
votes
2answers
522 views

Can I move the undo log outside of ibdata1 in MySQL 5.6 on an existing server?

I've been growing concerned about the large size of ibdata1 that can never shrink even when using file-per-table on innodb Moving the undo log files outside seemed logical but this procedure seems ...
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1answer
2k views

Can I reset the ibdata1 and ib_logfile files when innodb_file_per_table is already in place

I am running into an issue where sensitive data was not encrypted properly at the application level of our production system. Even though the guilty records have been removed or corrected, scanning ...
1
vote
1answer
172 views

How to UPDATE a table for the level of parents in a column?

I have a table with internal parents as id parent parent_level 1 NULL 1 2 1 2 3 1 2 4 3 3 where parent has a FK to id. How can I update the table ...
0
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0answers
255 views

How to increase MySQL performance with joins

I have a MySQL database with InnoDB engine. Particularly one of my queries became very slow. The query is shown below: SELECT t1.`ARTREF1` FROM `lijnen` AS t3 INNER JOIN (`kortingen` AS t2, ...
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vote
1answer
80 views

MySQL command querying all MyISAM database

I would appreciate if anyone could help me of what's the proper command in MySQL to query all database for having "MyISAM" engine. I need to convert all DB & tables from MyISAM to InnoDB.
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vote
1answer
62 views

Do regular ALTERs weaken the performance?

In a project, we need to frequently ALTER the tables to delete or add columns. I wonder if this weakens the database performance in long term. If it has a considerable negative impact, what is the ...
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vote
1answer
1k views

MySQL: sysbench test - InnoDB vs Memory tables

I've done some tests in order to investigate performance issue on the new HP Gen8 server (Intel(R) Xeon(R) CPU E5-2630 0 @ 2.30GHz) I've created two tables, first one is using InnoDB storage engine ...
2
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0answers
145 views

Sleeping connections

I have a dedicated MySQL server(8GB) with following configuration. [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql lower_case_table_names = 1 ...
2
votes
0answers
807 views

Query getting periodically stuck in 'copying to tmp table' state, never completes

I am running Wordpress on a dedicated server with a MySQL backend. I have a query that usually takes <1 second to execute, but periodically, this query will get stuck in a 'copying to tmp table' ...
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2answers
2k views

bulk_insert_buffer_size and InnoDB

I read the following on this page http://dev.mysql.com/doc/mysql/en/server-system-variables.html bulk_insert_buffer_size MyISAM uses a special tree-like cache to make bulk inserts faster for ...
2
votes
1answer
189 views

Deleting 200M+ rows from InnoDB table

Basically, we have a table with the following structure: CREATE TABLE `reqs` ( `id` INT(10) NOT NULL AUTO_INCREMENT, `reqid` BIGINT(20) NOT NULL, `from` BIGINT(20) NOT NULL, `to` ...
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2answers
1k views

Percona Xtradb Cluster : How to speed up insert?

I recently installed a 3 full master node cluster based on Percona Xtradb (very easy install). But now i need to make some tuning to increase INSERT/UPDATE requests. Actually, i made around 100 ...
2
votes
1answer
684 views

mysql innodb space x did not exist in memory

Into my innodb log I got the errors below. How to fix? What did it mean? Some tables are corrupted but not all. InnoDB: space id 1753 did not exist in memory. Retrying an open. 130906 16:31:27 ...
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1answer
115 views

MySQL failures after changing innodb_flush_method to O_DIRECT and innodb_log_file_size

We changed innodb_flush_method to O_DIRECT, innodb_log_file_size to a bigger value, and 3 other things (innodb_buffer_pool_size, innodb_additional_mem_pool_size, innodb_log_buffer_size) while MySQL ...
1
vote
1answer
635 views

Spatial Index on an InnoDB table

I have a database which is in InnoDB, because I wanted consistency (cascading delete). Now, I want to use spatial indexes for selecting rows ordered by geometric distance. However, spatial indexes ...
1
vote
1answer
174 views

MySQL looking up more rows than needed (indexing issue)

In our MySQL 5.5 database, we have following InnoDB table with 30M+ rows: +----------------+-------------+-----------------+--------+ | participant_id | question_id | given_answer_id | status | ...
1
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1answer
149 views

Combining multiple left join for one single line

We have a query as below. SELECT tblSData.header, tblEAlert.eMessage FROM tblSData LEFT JOIN tblEAlert ON tblSData.sDataID=tblEAlert.sDataID Where tblSData.aID=".$aID." Order By tblSData.dateTimer ...
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0answers
188 views

Drupal database doesn't work after MySQL restart

I've installed Drupal 7x on my local XAMPP 1.8.3 Server. Everything went fine but after adding some modules, changing the drupal theme and restarting the MySQL Server, the MySQL Server is dropping ...
1
vote
1answer
293 views

MyISAM vs InnoDB for Forums [closed]

I want to design a forum script with MySql. Which database engine would have better performance? MyISAM or InnoDB ?
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votes
0answers
1k views

How to prevent “ibdata files do not match the log sequence number”?

I am dealing with a very large set of databases that are all innodb. I've enountered this on mysql restart too many times for my comfort: ibdata files do not match the log sequence number But I've ...
0
votes
1answer
313 views

Deadlock from mysqldump --single-transaction, is it possible?

Is it possible to get a deadlock if you ran mysqldump with the argument --single-transaction ? or any other complication ? If it is used to backup a live site with many other querys running at the ...
1
vote
0answers
396 views

Incorrect information in .frm file after a power outage?

CentOS release 6.3 (Final) x86_64 mysql Ver 14.14 Distrib 5.5.31, for Linux (x86_64) using readline 5.1 SHOW SLAVE STATUS\G: Slave_IO_Running: Yes Slave_SQL_Running: No ...
0
votes
1answer
8k views

What is causing Waiting for table level lock errors?

We got the database hanging twice already and trying to find a cause. show processlist Waiting for global read lock | INSERT INTO {myisam_table} ... In here the disk space was full so we thought ...
1
vote
0answers
484 views

MySQL InnoDB slow inserts

I'm currently struggling with an MySQL Community Server 5.5.27 when inserting large numbers of rows into a table. We're running a 24 core Intel Xeon machine with an SSD software raid array. I did some ...
2
votes
1answer
403 views

MySQL Performance Issues

Over the past 3 weeks we have been having bottle-necking issues at our MySQL server. I have been using MonYOG to watch the processlist in an attempt to get a grasp on the issues. We are aware that ...
3
votes
1answer
2k views

Recover the disk space after deleting rows from table

I deleted millions of rows from one of the table with innodb engine. I know that I need to run optimize table to recover the space. But running that will cause lock on the table, which will affect the ...
3
votes
1answer
306 views

MySQL / Fusion IO Configuration Question

I need a little configuration optimization. I think what I have is pretty good but feel like there's still room for improvement. Current Config [mysqld] user=mysql datadir=/var/lib/mysql ...
3
votes
1answer
457 views

Finding swap causes of MySQL

In my centos 6.3 server I have a MySQL 5.5.33 database. It has 17 tables (15 InnoDB, 2 MyISAM) and total records 6.7M rows. I refactored my schemas and added indexes for my slow logs. My average query ...
2
votes
2answers
504 views

Setting innodb_buffer_pool_size in for Mysql

We have a dedicated DB box with with 8 GB of RAM and running Redhat linux 64 bit OS. Our MySQL Data + Index size almost 7.8 GB. About setting innodb_buffer_pool_size, I have read 2 suggestions Set ...
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votes
4answers
8k views

Cannot open table mysql/innodb_index_stats

After a fresh install of XAMPP and import from my linux live db that is working to the windows Dev-stage, I started encountering problems with INSERT. Everything else seems to work well. The errors I ...
2
votes
1answer
2k views

What happens if the mysql database's innodb log files are lost?

What I did was /etc/init.d/mysql stop then removed the files: ib_logfile0, ib_logfile1 then modified my.cnf file, variable: innodb_log_file_size and then: /etc/init.d/mysql start and allowed ...
6
votes
3answers
5k views

Why does MySQL ignore the index even on force for this order by?

I run an EXPLAIN: mysql> explain select last_name from employees order by last_name; +----+-------------+-----------+------+---------------+------+---------+------+-------+----------------+ | ...
2
votes
1answer
97 views

Why isn't the rows of an EXPLAIN accurate?

I have the following table: mysql> select count(*) from employees; +----------+ | count(*) | +----------+ | 10000 | +----------+ 1 row in set (0.03 sec) I do an EXPLAIN: ...
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votes
2answers
732 views

How do I determine how much data is being written per day through insert, update and delete operations?

The longevity of SSDs is largely determined by the amount of bytes written by insert, update and delete operations. What is the best way to accurately determine how much data is being written by ...
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vote
3answers
925 views

Backup / Export data from MySQL 5.5 attachments table keeps failing!

Can anyone please help! - I have a large table in a MySQL 5.5 database. It is a table which holds a mixture of blobs/binary data and just data rows with links to file paths. It has just over a million ...
0
votes
0answers
90 views

Any drawback to lots of creating and renaming tables at InnoDB?

I'm trying to optimize an important cronjob for my program, and what it basically does is generate a long list of user ids with their score points. I have a table called user_ranks and it will bulk ...
1
vote
1answer
300 views

TokuDB database size unknown in phpmyadmin

In mysql server, I installed the TokuDB storage engine. I converted database engine InnoDB to TokuDB, but my table sizes show unknown in phpmyadmin.
1
vote
1answer
84 views

Increased server load after InnoDB deadlock

I am using InnoDB instead of MyISAM for a couple of months right now, and it has really optimized my game database-wise. I was aware of the danger of deadlocks, but hadn't had any problems with it, ...
2
votes
1answer
998 views

InnoDB: Error: pthread_create returned 12

have installed MySQL in a particular folder. I was able to run the server and create accounts, databases etc. However, now whenever I try to start the server, I get an error: $ mysqld_safe ...