InnoDB : MySQL's ACID-compliant Storage Engine

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1answer
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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 | ...
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3answers
38 views

How do I prove that the act of removing foreign keys doesn't corrupt existing data?

My boss and I are having a difference of opinion about whether or not to use foreign keys in a MySQL/InnoDB database. I'm for using them for enforcing RI and taking advantage of ON DELETE CASCADE and ...
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0answers
18 views

RDS mysql instance eating up memory and swapping

I have an issue with memory on a RDS instance which is of db.m2.4xlarge class. Below are the specifications of the RDS instance Instance Class: db.m2.4xlarge ( 68.4 GB of RAM ) Engine: ...
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2answers
738 views

How much data is needed to show MySQL Cluster's performance scaling vs. InnoDB

I am evaluating MySQL Cluster as a possible replacement for an InnoDB schema. So far, I have tested it with 10s of MB of data, and found MySQL Cluster slower than InnoDB; however, I have been told ...
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0answers
8 views

MySQL: What are the pros and cons of running with engine=Memory vs on a memory-mapped filesystem?

What is the difference (in terms of read and write perf, alter tables, backup and recoverability and consistency) of running a MySQL database on a memory-mapped filesystem vs with ENGINE=MEMORY
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26 views

select where index + other field

Learning indexing I have made an index, consisting of usergroupid and birthdate I understand that queries will then benefit from indexing when searching usergroupid and/or birthdate But what ...
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1answer
32 views

mysql database performance issue [on hold]

I have a 2x Xeon Quad Core E5410 2.33 GHz with 24 GB of RAM. running 5.5.31 with the following my.cnf file. It supports lots of reads and writes and transactions(all INNODB). Are there any obvious ...
0
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1answer
1k views

What is the actual difference between innodb_autoinc_lock_mode 0,1,2

I would like to understand the differences between innodb_autoinc_lock_mode options 0,1 and 2 when parallel load data infiles are given. I see in "0" option, it locks the entire table and does the ...
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2answers
882 views

InnoDB Tablespace critical error in great need of a fix

Link to screenshot : http://www.nouvellesduquartier.com/i/1/p/Munin_%20Critical_MySql_InnoDB_.JPG (The value reported is outside the allowed range - Byte free, free, gauge, warn, critic) Question: ...
3
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1answer
492 views

Select * from statement execute very slowly, innodb io read speed is low

I have a very simple query " select * from ap_statistic " running in my servers. the servers have the same hardware and software configuration (CPU 8 core, mem :32G, OS: redhat 5.5, mysql version: ...
3
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3answers
181 views

MySQL buffer pool usage + high load

We've got a quite powerful server: HP ProLiant DL360p Gen8, 2xIntel Xeon E5-2630 2.30GHz, 128GB of RAM. The whole data set should fit in memory: mysql> SELECT ...
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2answers
822 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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2answers
215 views

MySQL runs out of memory when importing innodb database

I have a small VPS with 512MB RAM and no swap (can't have any). I am importing a 1.5GB innodb database with mysql -u -p < database.sql Before the operation can finish it says : Lost connection ...
0
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1answer
194 views

MySQL select by primary key against 100M of records within 30ms

I have no expirience with MySQL and database performance tuning in general. Wondering whether it is possible to perform a large number of selects against 100 millions of records by primary key within ...
0
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1answer
117 views

innodb completely crashed after interruption

I am having a major crash on mysql affecting a lot of websites. We had a crash on our SAN storage. Since that time, mysql refuse to start. I tried to reinstall mysql, but still no luck. I think ...
2
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1answer
31 views

MariaDB ALTER TABLE produced a separate .ibd file, how can I re-integrate the data into the shared table space?

We have a multi-GB InnoDB MariaDB (recently switched from MySQL). For some reason, the value of innodb_file_per_table changed to ON (we wanted only one innodb data file explicitely). So when I ran an ...
1
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1answer
26 views

MySQL: Merge Same Database on Several Location into Single Location

I have registration form, which exactly same for several location. Each of them has REG column, which this field is unique for each row. Basically each data input have different REG number for it, ...
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3answers
6k 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 ...
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1answer
137 views

Innodb buffer pool indexes versus data usage

The server has 128GB of RAM. The innodb_buffer_pool_size is set to 106GB. mysql> show global variables like 'innodb_buffer_pool_size'; +-------------------------+--------------+ | Variable_name ...
0
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1answer
263 views

The total number of locks exceeds the lock table size, even after increasing buffer pool size

I am trying to partition a table with 200 million records in it. This table already exists: CREATE TABLE linkmap_ntoken ( target_nToken varchar(200) NOT NULL, ntoken_hashcode int(15) NOT NULL, ...
0
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1answer
49 views

Restore InnoDB from .frm files

My database crashed and my PC and I now only have the .frm and .ibd files left. Is there any way to restore my database?
2
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1answer
41 views

Wordpress blog where pages are almost-always served from cache: SSD or more RAM?

I am working on the design of a Wordpress blog which when finished will almost-always serve pages from disk cache and this is because all posts will be published in batch and then cached, with at ...
0
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1answer
24 views

Consistent backup of large DB --single-transaction

I need to mysqldump a large DB (330 GB) in order to set up a slave for replication. Does --single-transaction allow me to dump the entire DB without shutting mysql down and keeping it down for the ...
0
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2answers
15 views

Restoring data from dumped sql file gives: mysql: unknown option '--innodb_file_per_table

I was trying to separate DB indexes from ibdata1 I took the steps in what-is-the-best-way-to-reduce-the-size-of-ibdata-in-mysql I dumped data, dropped databases, and started mysql service. I got the ...
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0answers
66 views

hot/live sql backup

please excuse my ignorant question as I am still fairly new to database things so I have a mysql database and a part of it has file with average size of 10M I store them in their own directory and ...
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1answer
790 views

MySQL SELECT query hangs - Opening Tables INNODB

On my server I have 6 MySQL databases. They all power Wordpress websites. For some reason, 2 of these databases are not accessible. To my knowledge they use INNODB, but I can't confirm it as even ...
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26 views

Previously inserted rows disappear at call of PHP script

I am developing a server-side portion of a sport manager application using MySQL (5.1.67), with InnoDB as storage engine, and PHP (5.3.3). When I try to execute a script containing any kind of query ...
0
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1answer
25 views

Is it possible to restore a database snapshot from a 64 bit system to a 32 bit one?

I would like to perform a restoration test on a snapshot backup of my MariaDB database using a test server running on a 32-bit OS. My production server is a 64-bit system. I would like to know if the ...
0
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1answer
98 views

InnoDB Failure of some kind

I have MySQL 5.5 installed. I tried to install Joolma but it failed. I went into their sql and replace EGNINE=InnoDB with MyISAM and the install worked. InnoDB is listed under SHOW ENGINES; Any idea ...
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2answers
620 views

MySql InnoDB tables are missing after restarting

I had a MySql database with a few InnoDB tables. After restarting the server, and starting MySql Server again, I connected to the MySql Server using MySql Workbench, and couldn't see the database at ...
0
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1answer
64 views

MySQL - Indexes deleted, reduced column size but table size increases

Here is the original table definition which contains 107547934 (~107.5M) rows CREATE TABLE `twitter_tweets` ( `id_str` varchar(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL ...
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2answers
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MySQL information_schema doesn't update

I have a database, say abc, in mysql server. It has only one table named test. test uses innodb engine and I've set innodb_file_per_table to true. After I run the query delete from abc.test, I want ...
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1answer
31 views

MySQL consistent nonlocking reads vs. INSERT … SELECT

So, from my reading of the MySQL 5.5 documentation and some experiments I did with colleagues, I understand that the following is the case: With InnoDB tables, a simple SELECT statement (one that ...
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0answers
53 views

Finding the right MariaDB configuration

I’ve read several articles about how to configure MySQL/MariaDB, but now I’m kind of confused how to find the right values. Some articles suggest not choosing to high values, others recommend adapting ...
0
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1answer
33 views

How to start mysqld with read-only data directory?

I'm trying to start MariaDB in a docker container, using a data directory from the host mounted read-only. MySQLd is of course shut down on the host. Unfortunately, even with adding the read_only flag ...
1
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1answer
28 views

Change column without interrupting service

We need to change the data type of a column in a large table (~1.7 GiB) from VARCHAR(1024) to VARCHAR(512) in order to be able to create a secondary index over two columns. We're using MySQL 5.6 with ...
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1answer
272 views

Mysql Deadlock on update query on same row

My server is experiencing occasional deadlocks on two update queries on same row both using index (primary key). The conflicting queries are: UPDATE auth_user SET rep_score=185 WHERE ...
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1answer
21 views

MySQL InnoDB table accepts Non-Existent Foreign Key

Using EasyPHP 14.1 VC11 and phpMyAdmin (4.1.4) to create a website project in my home computer. The MySQL version is 5.6.15 according to the EasyPHP administration page. Working on Windows 7 64-bit. ...
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2answers
634 views

How to run a cold backup with Linux/tar without shutting down MySQL slave?

I run the following before tar-ing up the data directory: STOP SLAVE; FLUSH TABLES WITH READ LOCK; FLUSH LOGS; However, tar will sometimes complain that the ibdata* and ib_logfiles* files are ...
3
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2answers
143 views

MySQL 1264 warning from libmysql

I'm using the libmysql.dll library to connect to my database from a 3rd party application (metatrader). I managed to connect and things are going almost fine. I use mysql_real_connect and ...
0
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1answer
76 views

Recovering from removal of ibdata1 [duplicate]

I just upgraded from Debian Squeeze to Wheezy and mysql stopped working. Blindly following some advice without any understanding of what I was doing, I removed ibdata1 in an attempt to solve the ...
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1answer
335 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 ...
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3answers
10k views

Fastest way to check if InnoDB table has changed

My application is very database intensive. Currently, I'm running MySQL 5.5.19 and using MyISAM, but I'm in the process of migrating to InnoDB. The only problem left is checksum performance. My ...
0
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2answers
48 views

Is it safe to copy DB files directly from an LVM snapshot?

I saw two different approaches for backing up database with LVM snapshot. This article suggests spawning another MySQL instance to do an SQL dump. MYSQL Performance Blog suggests that it is safe to ...
0
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1answer
114 views

DB disk space requirements comparision between MySQL versions

I have 2 labs where MySQL is installed. DataBases are created and deleted dynamically by certain internal processes. InnoDB is the Engine used. In one lab, MySQL version 5.0.77 is installed. The DB ...
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1answer
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Change table from InnoDB to ARCHIVE in MySQL

I try change my table from InnoDB to ARCHIVE with SQL command: ALTER TABLE data_obook ENGINE = ARCHIVE; But it always show me only error: #1005 - Can't create table 'coincity.#sql-1350_8a' (errno: ...
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3answers
128 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 ...
0
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2answers
50 views

Restore InnoDB to different machine

It was pointed to me from serverfault that the following question would be a better fit here so this is basically my original question from there. I currently have backups that were taken with ...
0
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1answer
607 views

consequences of using “innodb_flush_method = O_DIRECT” without having a battery backed write cache? or on a KVM guest?

Mysql 5.5.29 Innodb- 128GB Ram - 32 cores - Raid 10 SSD. Our server which is a dedicated KVM guest on a 'baremetal' is hosting our heavy read-write DB server. Everything is file-per-table. ...
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2answers
45 views

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 () ...