InnoDB : MySQL's ACID-compliant Storage Engine

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7
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2answers
856 views

Investigate peak in MySQL throughput

Recently one of our servers has ran out of memory and crashed. After reviewing the munin graphs, it appears that the only metric (other than memory usage) that peaked just before the crash was the ...
6
votes
2answers
16k views

How do I shrink the innodb file ibdata1 without dumping all databases?

InnoDB stores all tables in one big file ibdata1. After dropping a big table, the file is keeping its size no matter how big the table was. How can I shrink that file without having to dump and ...
5
votes
1answer
555 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 ...
5
votes
1answer
2k views

Find out MySQL index size for a concrete index

In MySQL, for InnoDB engine, how do I find out the size of one of the indexes I have in the same table ? I know I can select the index_length from information_schema.tables, but this gives the total ...
4
votes
2answers
290 views

Using MyISAM for reading and InnoDB for writing data

I read many articles about comparisons of MyISAM and InnoDB from performance point of view and I decided to use MyISAM for reading data and InnoDB for writing data. I want to use two structure like ...
4
votes
3answers
3k views

Mysql backup strategies?

We have a innodb mysql database so we are lost with lots of different mysql backup strategies. Some talk about mysqldump some talk about third part tools. Some of the tables we also plan to run ...
4
votes
3answers
596 views

Is Oracle DB immune to the InnoDB deadlocks found in MySQL?

It seems odd to me that MySQL would not handle this internally: "Deadlock found when trying to get lock; try restarting transaction" Does Oracle DB work around this issue? After all, Oracle owns ...
3
votes
2answers
537 views

How to split a string to and get info from another table in mysql

I have a system to assign score for each sentence stored in a column: TABLE 1: word_scores word score this 3 is 4 a 5 test 1 another 0 sentence 8 TABLE 2: ...
3
votes
1answer
3k views

Is Percona xtrabackup the right choice for my 500GB MySQL backup?

I have a MySQL db with 500GB, consisting mainly of Innodb tables, and one big (200GB) MyISAM table. My current backup strategy is copying the db files to an external harddrive. This causes a downtime ...
3
votes
1answer
685 views

InnoDB “corruption”

I use: 5.1.63-0ubuntu0.11.10.1 Apache/2.2.20 (Ubuntu) MySQL client version: 5.1.63 The system is continuously displaying the following error during reading data from a MySQL database: ...
3
votes
1answer
3k views

How can I find who holds the lock based on the hex-dumped?

I've been reading the Diagnosing MySQL InnoDB Locks article. Karl E. Jørgensen writes on 2008 so I'm consfusing it is in effect. I would like to supply a snippet of the SHOW ENGINE INNODB STATUS: ...
3
votes
2answers
643 views

Should I move to InnoDB during a planned migration?

I'm shortly migrating a Debian Lenny webserver to another host and Debian Squeeze. The standard MySQL installation even on Squeeze is 5.1 and therefore would default to MyISAM - I'm inclined to stick ...
2
votes
2answers
64 views

How to monitor InnoDB Disk I/O using Server Status Variables?

This question is extension of my previous question "How to monitor InnoDB Disk I/O Required for MySQL? " As mention in my previous question i want to count total number of disk i/o per query, but ...
2
votes
1answer
129 views

AWS RDS showing large growth in Write Ops/sec, despite low # DB connections?

I have a Multi-AZ AWS RDS instance running MYSQL 5.5 I've noticed that my write ops/sec are growing fairly rapidly, despite low (and sometimes zero) DB connections - see charts for Avg write ops/sec ...
2
votes
2answers
3k 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 ...
2
votes
2answers
2k views

How to add column to big table in MySQL

I'm php developer so dont be strict. I have a big table ~5.5gb dump. Our PM decided to make new column in it to perform new feature. Table is InnoDB So what i tried: Alter table in screen with table ...
2
votes
1answer
313 views

Drupal 7 Uses InnoDB, so do I need other configs?

If I'm optimizing a database that will be delivering multiple Drupal 7 websites, all using InnoDB, do I need to worry about [myisamchk] & [isamchk] sections, or can I just worry about the stuff ...
2
votes
1answer
1k views

How I prevent deadlock occurrence in my application?

I am developing an LMS application in PHP framework(Codeigniter 2.1.0). I am using MySQL database. All the tables in the database have innodb engine. I also created indexes on each tables. Now I am ...
2
votes
2answers
4k 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 ...
2
votes
1answer
2k views

MySQL / InnoDB: Does daily optimization improve performance?

Would performing daily optimizations of tables increase performance for MySQL and InnoDB? I have never did this before, but I have seen this module for Drupal http://drupal.org/project/db_maintenance, ...
2
votes
1answer
2k views

MySQL 5.5 Runs Out of Memory, Drops All Connections When Creating Many Databases

I'm running into a problem when I create a large number of databases consecutively on an Amazon RDS db.m1.large instance. The MySQL Engine Version is 5.5.23. At some point, the RDS instance drops all ...
1
vote
1answer
246 views

How to decide whether to enable MySQL query cache using InnoDB

How should the decision to enable / disable the MySQL query cache be made, on a server that uses just InnoDB tables. Say for example, if the cache is enabled, then how should the output of: SHOW ...
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2answers
5k views

MySQL using too much CPU

I'm studying to be a DBA right now because I have a massive live database that is very sensitive that I manage. Here's the current system stats of my dedicated database server: CentOS 5.9 24gb Ram 8 ...
1
vote
1answer
716 views

Can putting mysql DB into memory or having the innodb_buffer_pool_size match the size of DB increase performance?

We have a mysql database that has roughly 80 gigabytes (GB) of data using inno_db engine. We are looking to increase performance on the database (we looked at the slow log and gone through and ...
1
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1answer
1k views

MySQL 5.5 - determining correct write[read]_io_threads on high-end system?

Specifically dual-CPU 32 core - 128RAM - RAID 10 SSD . Ubuntu 64 server. Heavy Innodb load at times - ~ 2000+ queries per sec. Heavy read and write. Currently we are running on the default ...
1
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1answer
235 views

Fill ibdata1 With Zeros/Nulls/etc Or Change A Table's Tablespace

I have a MySQL 5.5 server running on CentOS 6. The MySQL package is a MySQL-released version (MySQL-server-5.5.28-1.el6.x86_64), not the stock CentOS one. I have moved an existing database over from a ...
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2answers
2k views

How to analyse innodb status on deadlock in insert Query?

I have a dead lock which i have posted here. I managed to get the innodb status from my server. Here is the Innodb status. OS WAIT ARRAY INFO: reservation count 247864, signal count 247470 Mutex ...
1
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1answer
2k views

What exactly are iblog files in mysql

I would like to understand these ibdata files as these play vital role in the crash recovery procedure. I could not find proper resources over the web for this.
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2answers
1k views

Similar function NOWAIT in MySQL

Select for update nowait doesn't work in MySQL 5x (innodb). Is there any function like NOWAIT in MySQL?
0
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2answers
1k 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 ...
5
votes
1answer
958 views

Slow InnoDB INSERT/UPDATE/DELETE

Background A couple of weeks ago all of my INSERT's/UPDATE's/DELETE's became overall slow (not SELECT's). Before that, everything was normal (mysql statements executed in <0,01 seconds). Now a ...
5
votes
1answer
2k views

Deleting MySQL table with pending transactions

Is there a way to delete an InnoDB table or database with pending transactions in MySQL (preferably on file system level)? What happened: I use MySQL 5.5.28 and ran LOAD DATA INFILE… to import a ...
5
votes
1answer
439 views

Dealing with temp tables when I have not control over db variables

I have no control over things like tmp_table_size and max_heap_table_size, and so as our tables grow the time taken by queries requiring temp tables is growing geometrically. I am wondering if there ...
4
votes
4answers
929 views

Is tuning the innodb_buffer_pool_size important on Solaris ZFS?

We're running a moderate size (350GB) database with some fairly large tables (a few hundred million rows, 50GB) on a reasonably large server (2 x quad-core Xeons, 24GB RAM, 2.5" 10k disks in RAID10), ...
3
votes
1answer
320 views

Speeding up a NOT IN subquery

Good evening, I'm currently up to try to improve the performance of some of my queries. As far as I know, statements like "IN" or "NOT IN" are even faster with a large amount of values if a subquery ...
3
votes
3answers
2k views

InnoDB insertion faster

I'm a graduate school student researching OLAP with Mondrian OLAP. So I want to insert data into InnoDB (MySQL 5.5) faster at the initial loading. In this environment, the only user is me, so I think ...
3
votes
1answer
445 views

why is mysql still writing data two hours after all transactions have stopped

I have a mysql server used mostly as data warehouse. It loads about 4-5GB of data per day (actual database size, not the size of the source data). Lately, I noticed something peculiar. After I ...
2
votes
1answer
69 views

Optimize Percona MySQL InnoDB 3.2TB database

(Before you will call me an idiot or start laughing, please remember it's a real deal on my side and I cannot cancel this assignment as it is a part of a bigger project) I have a database server that ...
2
votes
2answers
81 views

How to monitor InnoDB Disk I/O Required for MySQL?

I am doing an estimate on how much i/o[disk read write] on Mysql 5.6 [innodb storage engine], for getting idea how to calculate total number of disk read write i have searched a lot on SO on DA and ...
2
votes
3answers
2k views

Purge old records from mysql ibdata1 file

Is it possible to purge old records from an ibdata1 file without taking down the database attached to it? Records that have been deleted from the database are still present when I scan ibdata1 for ...
2
votes
1answer
52 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 ...
2
votes
1answer
179 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
votes
1answer
283 views

Does the size of the primary key contribute to table size?

I have a table (InnoDB) with data length around 36G and index length 23G. It had a composite primary key across three columns. As an initial attempt to reduce the size of this table, I dropped the ...
2
votes
1answer
3k views

MySQL: Error reading communication packets

I get this warning in mysql, [Warning] Aborted connection 21 to db: 'MyDB' user: 'MyUser' host: 'localhost' (Got an error reading communication packets) I have been through few topics in google ...
2
votes
1answer
55 views

Do I need to reenter old data after adding an index to a table?

I want to add index to my tables. Some of my tables already have couple thousand rows. Do I need to reenter my stored data after adding index to columns (to make them aware of index/so the indexing ...
2
votes
1answer
2k views

Why does that query cause lock wait timeouts?

From time to time, I find a lot of these errors in my PHP error log: MYSQL.1213: Deadlock found when trying to get lock; try restarting transactionSQL The problem persists for about 2 or 3 minutes. ...
2
votes
2answers
3k views

Finding and fixing InnoDB index corruption

I encountered a new issue yesterday with one of my MySQL 5.5 slave DBs that runs on EC2 in AWS. The DB was created from a snapshot of another slave. The data is correct, but for at least one table a ...
2
votes
1answer
556 views

Number of locks exceeded when adding foreign key constraint

I'm adding a foreign key constraint to table a (17mil rows) that references table b (15mil rows): >ALTER TABLE a ADD FOREIGN KEY (b_id) REFERENCES b (id); ERROR 1206: The total number of locks ...
2
votes
2answers
2k views

Different MySQL Datafile Sizes After Restoration

I'm quite new in database administration. The database architecture of my current company is master-slave replication. We are using MySQL version 5.0.86. Some weeks ago, we upgraded the company's ...
1
vote
1answer
38 views

Adding new tables — memory usage increases

I added more tables to my mysql server. 20% increase in tables that are all innodb. I have 200 + databases that use the same schema. Does adding more tables increase memory usage? I am using about ...