InnoDB : MySQL's ACID-compliant Storage Engine

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1answer
136 views

What if I want to keep using MyISAM

In my current use of MyISAM the databases are extremely small and kept for a few weeks after which time they are deleted and completely rebuilt with a clean slate. The script uses MYISAM tables and ...
3
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3answers
3k views

Issue after moving the ib_logfile1 and ib_logfile0 files

I wanted to increase the innodb_log_file_size for better performance. And I increased it from the default value to 256 MB. As usual I got the error saying InnoDB: Error: log file ./ib_logfile0 is of ...
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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 ...
2
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1answer
263 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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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 ...
1
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1answer
214 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 ...
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0answers
912 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' ...
4
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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 ...
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0answers
286 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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1answer
94 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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1answer
63 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 ...
2
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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 ...
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0answers
157 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 ...
6
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3answers
6k 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; +----+-------------+-----------+------+---------------+------+---------+------+-------+----------------+ | ...
0
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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 ...
1
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2answers
3k views

Which hot backup tools for MySQL InnoDB database : Percona XtraBackup, Zmanda Recovery Manager Enterprise or Community or…? [closed]

I manage a PHP/MySQL website : max 500 simultaneous users / average of 4000 per hour in update/read 1 MySQL Community Server (5.1) - (Xeon / 16 Go RAM) InnoDB Storage engine on 100 tables for 1.4 Go ...
3
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3answers
9k views

MySQL - fastest way to ALTER TABLE for InnoDB

I have an InnoDB table that I want to alter. The table has ~80M rows, and quit a few indices. I want to change the name of one of the columns and add a few more indices. What is the fastest way to ...
2
votes
1answer
224 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` ...
1
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1answer
121 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
171 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
515 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 ...
1
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1answer
695 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
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1answer
208 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 | ...
0
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0answers
194 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 ...
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2answers
3k views

Partitioning a table will boost the performance?

I have a very large table approx 28GB and that is continually increasing. I am thinking about partitioning my table. The table is InnoDB and The File Per Table is enabled I have a field name ...
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1answer
314 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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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 ...
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2answers
3k views

Unable to drop the table since its showing waiting for meta data lock

We are trying to drop one table but it's getting hanged, and when we see the 'SHOW PROCESSLIST' command it's showing as 'waiting for meta data lock'. Even we are unable to perform any operation on ...
0
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1answer
361 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 ...
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0answers
517 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 ...
7
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2answers
12k views

MySQL 5.1 InnoDB Configuration / 24GB RAM - bi-xeon high load

i'm running a facebook app which currently has 300 - 600 concurrent users (and growing). To get the hardware ready for growing i changed my i7 / 12gb ram / 2x 80gb intel x25 ssd's (debian 5.0 / mysql ...
2
votes
1answer
459 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
3k 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 ...
0
votes
1answer
98 views

Will Partitions and Indexes on the same table help in performace of Inserts and Selects?

I have a table containing the list of visitors and this table has the following information. Visitor Browser Information Visitor Location Information Visitor Time Information No of Visits I have a ...
2
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2answers
535 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 ...
4
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2answers
6k views

Dynamic change to innodb_flush_log_at_trx_commit

This is related to this question. It does help to get better performance for InnoDB tables. According to MySQL manual, innodb_flush_log_at_trx_commit is a global dynamic variable. Thus, I can change ...
0
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1answer
2k views

MySQL database drop insanely slow

I just installed MySQL 5.0.45-log Source distribution on my Debian 6.0.6 server. I installed it under my user home directory like I'm used to doing. But this time the queries are extremely slow to ...
3
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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 ...
2
votes
2answers
866 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 ...
2
votes
1answer
109 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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2answers
2k views

Where should I look for my.cnf?

I want to add innodb_file_per_table statement to my.cnf file. Where is my.cnf? Could I change this file when I have an online site?
0
votes
1answer
419 views

Converting a large SQL Server database to MySQL. Database corruption? Can't access data after transferring [closed]

I have gigabytes of tabular data stored in a SQL Server database. I've been trying to migrate it to MySQL using the Migration Toolkit from Oracle. I didn't have any mapping errors and fixed all the ...
3
votes
2answers
4k views

MySQL 5.5 High CPU Usage

I have been working with a client with high traffic website(500k visitors and 600-800 active users at any given time). This uses wordpress and the DB is using MyISAM engine. The problem we had was ...
0
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0answers
94 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 ...
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1answer
340 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.
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1answer
2k views

InnoDB tables inaccessible after reboot

After reboot each time, I can't see my InnoDB table. However, when use command mode I can see my tables, but cannot access to it. mysql> show tables; +----------------------+ | ...
2
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2answers
313 views

Can I use a foreign key index as a shortcut to getting a row count in an INNODB table?

I have a table that has a large number of rows in it. The primary key (an auto-incrementing integer) is, by default, indexed. While waiting for a row count to be returned I did an EXPLAIN in another ...
4
votes
2answers
2k views

“freeing items” taking forever on inserts, updates and deletes

Recently I migrated all my MySQL database tables from MyISAM engine to InnoDB. I'm using the DotCloud MySQL service as my server (http://docs.dotcloud.com/services/mysql/). After the migration, ...
1
vote
1answer
100 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, ...
0
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2answers
2k views

How to optimize MySQL for large BLOB updates

I have a table that holds large BLOBs (up to 10M), and is updated frequently. The problem is that UPDATE statements can take up to 1 second to execute, and due to app design this blocks UI. I need to ...