InnoDB : MySQL's ACID-compliant Storage Engine

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How can I determine which Innodb table is being written?

I am running Mysql 5.5. I have about 100 Innodb tables spread over 10 DB's (mostly wordpress sites) and I am recently seeing a lot more disk IO than I have been, without any increase in traffic. The ...
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How does mysql deal with queries that touches myisam and innodb tables?

In our mysql database, we use both myisam and innodb tables, though there are more myisam tables. QUESTIONS If a query involves both myisam and innodb tables, will the query use table lock or row ...
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whether a big (but not used) ibdata1 slow anything down

Hi I have an ibdata1 that is around 10 gig. I have gradually migrated to 'file per table' using the innodb_file_per_table=1 option such that there are no big tables in ibdata1 anymore. I recently ...
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2answers
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Problem with InnoDB “per table” file sizes

I Have configured the mysql server with innodb per table. There was a table watchdog having approximate 19GB of watchdog.ibd file. I have truncated the table now it has zero record. But the ...
2
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2answers
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Table compression in InnoDB?

I have read that table index compression happens just in MyISAM, but I came across an article in dev.mysql that said: InnoDB supports table and index compression! So now what is the pros of MyISAM? ...
2
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2answers
528 views

Any problem will all InnoDB and one MyISAM table?

I have a MySQL 5.5 DB with all InnoDB tables. For some reason, one of the developers decided to create a MyISAM table. It is a log table for user sessions. I don't see why we should mix in a MyISAM ...
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1answer
111 views

MySQL FullText search on string shorter than 3 chars returns no rows

I have a MySQL table with some addresses in it. Let's say I have the following 2 rows: "10 Fake Street" "101 Fake Street" I'm trying to use fulltext search with MATCH() AGAINST(). I have set ...
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5answers
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Why do MySQL threads often show “freeing items” status when the query cache is disabled?

When I run SHOW PROCESSLIST, there are often a large number of INSERT/UPDATE threads in the "freeing items" state. The MySQL manual suggests that at least part of the reason for a thread to be in ...
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1answer
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Mysql Innodb: InnoDB: ERROR: the age of the last checkpoint is InnoDB: which exceeds the log group capacity

I really need some mysql expertize. I am a newbi to mysql and I am seeing some server crash of my db in the past 1 week. I am using mysql 5.1.36 on Ubuntu. This is a dedicated mysql server with Dual ...
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3answers
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ALTER TABLE on a large table with an indexed column

I have a large table with a VARCHAR(20) column, and I need to modify that to become a VARCHAR(50) column. Typically, performing an ALTER TABLE (adding a TINYINT) on this particular table takes about ...
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2answers
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Why is MySQL is creating so many temporary tables on disk?

Can any configuration mistake lead to creating too many temp tables by mysql..mysql tuner shows Current max_heap_table_size = 200 M Current tmp_table_size = 200 M Of 17158 temp tables, 30% were ...
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2answers
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Percona vs MySQL

What is Percona? How does it differ from MySQL? When should we consider switching (or upgrading) from stock MySQL to Percona? To add some specifics in our situation we almost exclusively use ...
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4answers
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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 ...
5
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1answer
2k 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 ...
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3answers
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How to use insert delay with the InnoDB engine and use less connection for insert statements?

I'm working on an application which involves a lot of database writes, approximately ~70% inserts and 30% reads. This ratio would also include updates which I consider to be one read and one write. ...
4
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1answer
8k views

How To Optimize and Repair InnoDB tables? ALTER and OPTIMIZE table failed

I just switched my Wordpress databases to use the InnoDB engine. When using MyISAM, I used to run Optimize and Repair table. However, with InnoDB, these don't work. I manually ran OPTIMIZE TABLE ...
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3answers
753 views

InnoDB import performance

I'm struggling with bulk importing a quite big InnoDB-Table consisting of roughly 10 Million rows (or 7GB) (which for me is the biggest table I've worked with so far). I did some research how to ...
4
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1answer
340 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 ...
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2answers
372 views

MySQL InnoDB Index in swap

I can't find any info regarding my question. This is more theoretical question. For example, i have table keywords. CREATE TABLE IF NOT EXISTS `keywords` ( `kid` int(11) unsigned NOT NULL ...
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2answers
1k views

Why would increase in innodb_buffer_pool_size slow down MySQL?

5.1.68-cll - MySQL Community Server on CentOS The system has 32GB of RAM. I increased innodb_buffer_pool_size from 10240M to 15360M (10GB -> 15GB). Time taken for a series of identical operations ...
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1answer
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Is it possible to change ENUM() lists?

I wasn't sure if changing ENUM() list isn't possible so I made a test. In MySQL v5.1.58 I made a test InnoDB table that contains one field called 'bool' of type ENUM('yes', 'no'). Then I executed... ...
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2answers
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Amazon RDS I/O requests - 1 query = 1 billable I/O?

I have an InnoDB database that I'd like to migrate onto Amazon RDS. My current implementation, hosted on my own server, shows roughly 8M queries per month. The RDS site say that I/O Rate $0.10 ...
5
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3answers
12k views

Error 'Unknown table engine 'InnoDB'' on query. after restarting mysql

I have mysql DB on server S1 (mysql version 5.1.41-3ubuntu12.7-log). I have created master-slave for this DB on server S2 (mysql version 5.1.54-1ubuntu4-log). The DB on S1 was using one data file ...
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3answers
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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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1answer
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MySQL Index creation failing on table is full

UPDATE: tl;dr: The problem was MySQL uses the TMPDIR when creating indexes. And my TMPDIR was the one running out of disk space. Original Q: I'm trying to add an index to an InnoDB table, and ...
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2answers
222 views

Are there implicit indexes in InnoDB like MyISAM?

If you have (id, a, b, c, d) table with primary key (id) and another key (a, b, c), in MyISAM that means that you also have the following implicit keys: (a) (a, b) (a, b, c, id) Is this valid for ...
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2answers
1k views

Cannot update certain rows in innodb tables

I found the following on http://dev.mysql.com/doc/refman/5.1/en/innodb-deadlock-detection.html When InnoDB performs a complete rollback of a transaction, all locks set by the transaction are ...
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3answers
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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
108 views

Why is there no data loss with mysql innodb_flush_log_at_trx_commit set to 0?

Here is the MySQL info: mysql> show variables like 'innodb%flush%log%'; +--------------------------------+-------+ | Variable_name | Value | ...
2
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2answers
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ib_logfile opened with O_SYNC when innodb_flush_method=O_DSYNC

mysql will open and flush data/log files as below when innodb_flush_method=O_DSYNC Open log Flush log Open datafile Flush data O_SYNC NONE NONE fsync () ...
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2answers
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How to tune mysql to be inmemory-like

I've given MySQL 5GB of memory (I use innodb), but when I insert lots of data (dumpfile is 1GB), hard drive I/O is still a bottleneck (CPU is not busy and hard drive is). Is it possible to force ...
2
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1answer
2k 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 ...
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1answer
382 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 ...
6
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1answer
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Tuning dedicated Percona Server with XtraDB for OLTP

Hardware specs for an OLTP DB dual quad core xeon with hyperthreading 24GB ram Hardware RAID10 BBU Software specs Standard install of Ubuntu 10.04LTS with default LVM partitioning Installed ...
5
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1answer
3k 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 ...
4
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1answer
3k 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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5answers
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TokuDB not much faster than MySQL

I have converted a MySQL database with 80.000.000 rows to TokuDB. Now when I run: select count(id) from xxx where active=1 it takes 90% of the time of the normal MySQL request. What do I have to ...
4
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2answers
5k views

Internal reason for killing process taking up long time in mysql

I copied a big table's structure with (it is an InnoDB table btw) CREATE TABLE tempTbl LIKE realTbl Then I changed an index, and filled it up so I could run some test. Filling it was done using: ...
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2answers
3k views

Using MySQL triggers or transactions?

I want to ask your opinion in using MySQL triggers or transactions in a website. Actually I have a history payment table with - UserId | OperationId | Comment | Credits | Sign (debit or credit). So ...
3
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1answer
150 views

Migrate from innodb_file_per_table to off in MySQL

We have a large number (2,500+) of databases and users in MySQL 5.6 on a single virtualized server (4 cpus and 8GB of memory). All the tables are using InnoDB. The actual data size is not very large ...
3
votes
2answers
908 views

Database space doesn't match ibdata1 size

I'm using InnoDB database with a single file configuration (in /var), so no innodb_file_per_table. In the MySql workbench, when I query for the databases used space, with this query SELECT ...
3
votes
1answer
4k views

Move ibdata1, set innodb_data_file_path

I am in a bit of an awkward situation right now. I have a database with a few large InnoDB tables, one of which is about 145 GiB. I have been running a lot of maintenance on this table in particular, ...
3
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1answer
4k views

When are InnoDB table index statistics updated?

In a vanilla build of MySQL 5.5.20, when are InnoDB table index statistics updated? What events trigger such updates? I've seen comments suggesting that the following might trigger it: table is ...
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2answers
1k views

MySql replication with Raw Data and InnoDB tables

I want to start replication on DB that has many InnoDB tables and MyISAM tables. I did everything according to manual Creating a Data Snapshot Using Raw Data Files. Firstly, I tried copied all ...
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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 ...
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3answers
70 views

Drop Tables with Bigger size

We have a mysql database with a size of 2 TB, in which we have for to five big tables ranging from 110GB to 350GB. When we try to drop these tables the mysql goes to the defunct mode and hangs in that ...
2
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1answer
568 views

Database Design - Creating Multiple databases to avoid the headache of limit on table size

I need to design database to store information contained in millions of log files generated by devices on trial on network. My first approach was storing all the information in tables contained in a ...
2
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1answer
1k views

Transaction Lock Timeouts When Updating a Row

I'm trying to determine the cause of an InnoDB transaction lock timeout. This one is very strange in that it appears to be a deadlock error instead - nonetheless, here's the output of my slow log ...
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2answers
1k views

Is there any performance difference among MariaDB (xtradb plugin) and XtraDB Server for InnoDB?

Title says it all. However i have to enter at least 30 characters.
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1answer
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temp table (#sql-7a87_230c32.ibd along with its .frm) still exists on slave

I executed some alter statements on my master server, which have been successfully executed on master (now there is no temp table on master) and all alter also have been replicated on slave server ...