InnoDB : MySQL's ACID-compliant Storage Engine

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2
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1answer
388 views

How mysql (innodb) handles auto increment column

I am working on a OLTP environment with multiple parallel write operation. I found this in documentation about auto increment locking but still i am interested to know much about it in details. Can ...
0
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3answers
85 views

Clustering MySQL with InnoDB engine

I have a MySQL single server setup with all tables using the InnoDB engine (because I need support for foreign keys). As response times are getting longer, I now believe I need to create a cluster of ...
-1
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1answer
139 views

Can we restore mysql db without .ibd & .frm files?

I have a data folder and the database folder with .frm & .ibd files is missing, any way to restore the database? Currently the data folder has: ibdata1 ib_logfile0 ib_logfile1
0
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1answer
2k views

Error 1067: The process terminated unexpectedly [InnoDB]

I am facing the following error when i try to restart the MySQL service after an unexpected shutdown of the database server last night. Could not start the MySQL service on Local Computer. Error 1067:...
2
votes
1answer
476 views

MySQL auto increment column increases after insertion error occurs

I was doing some insertion tests in my database and I realized that when the INSERT statement fails, due error 1452, causes the auto_increment value increase by 1. Even though, there wasn't any row ...
1
vote
3answers
6k views

Duplicating database on the same server without data loss

I want to duplicate an innodb database on my mysql server for testing another version of the software. Using tools for example phpmyadmin reduce the database around 20 MB and a "lot" of rows are ...
1
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0answers
927 views

MariaDB is ignoring /etc/my.cnf

The variable I am trying to change is innodb_buffer_pool_size. As you can see below the settings is 512M. But SELECT @@innodb_buffer_pool_size; returns 134217728. When I execute: /usr/libexec/mysqld -...
0
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0answers
72 views

what is causing Errors running from Localhost

wp_users: InnoDB: Tablespace is missing for table 'ftbw/wp_users' wp_usermeta: InnoDB: Tablespace is missing for table 'ftbw/wp_usermeta' wp_posts: InnoDB: Tablespace is missing for table 'ftbw/...
1
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2answers
93 views

Does InnoDB allow adding columns to a table with concurrent READ/WRITE of rows?

I have a large (3M rows) InnoDB table in MySQL 5.6.21 in production and I want to add some columns. From the MySQL Documentation on Overview of Online DDL I understand that, even if this is an ...
68
votes
4answers
110k views

Possible to make MySQL use more than one core?

I've been presented with some dedicated MySQL servers that never use more than a single core. I'm more developer then DBA for MySQL so need some help Setup The servers are quite hefty with an OLAP/...
0
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0answers
40 views

where does MySQL store data which is inserted into tables?

I have a small table named animals in database named test: mysql> select * from animals; +----+------------+-----------+ | ID | species | location | +----+------------+-----------+ | 1 | ...
1
vote
2answers
821 views

Mysql causing high load average with large amount of server resources left

I've have 2 servers running a application and the server that runs the mysql sgbd is with the load average around 3 times more than the webserver. I think that is something wrong because i have a lot ...
2
votes
1answer
480 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 ...
3
votes
1answer
524 views

Mysql HY000 the table table_name is full when adding new column

I can't add a new column innodb table which size's 16MB. when I try to add, mysql says HY000 the table table_name is full. I changed my tmp_table_size and heap_size but mysql still says same error. ...
1
vote
2answers
340 views

How to recover previous values in Mysql Table?

I have MySQL Innodb table of 14M rows. There was a column called is_disabled which had different values. By mistake I ran the query without the where clause: update url_queue set is_disabled=1 ...
3
votes
1answer
2k views

Getting duplicate primary key for auto increment column

I have a MySQL Innodb table with 'id' as auto increment primary key column. My Scripts are doing following operations: insert ignore into tablename set x='a', y='b' update ignore tablename set x='...
12
votes
6answers
28k 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 ...
6
votes
1answer
13k views

Error when dropping InnoDB database

I am trying to drop a database in mysql, but every time I get this error ERROR 2013 (HY000): Lost connection to MySQL server during query even logged in as root. Originally, I had a corrupted ...
0
votes
0answers
3k views

MariaDB MySQL server does not start

My MariaDB mysql server doesn't start with error 1067 This is the error log: 140222 0:43:44 InnoDB: The InnoDB memory heap is disabled 140222 0:43:44 InnoDB: Mutexes and rw_locks use ...
1
vote
1answer
134 views

Very weird Innodb Corruption Issue

I'll try to keep this to the point. System: OPenVZ VPS, debian 6, 512 MB RAM, 50 GB HDD (25GB free) I have a mysqldump dump file (3GB), that was created when the innodb database was working fine. ...
1
vote
2answers
519 views

MariaDB/InnoDB: What to do on “Locks in Status-Log but no locked table found”

We migrated lately from MySQL to MariaDB. SELECT VERSION() 10.0.13-MariaDB-log When executing this: SHOW ENGINE INNODB STATUS I get (shortened): ... ---TRANSACTION 279257007, ACTIVE 23981 ...
2
votes
1answer
813 views

Is it possible to restore a MySql database only using files from Data directory?

I have a mysql installed inside a windows virtual machine. The hard drive was crashed and the system is not able to restore all again. But I can have access to entire c: ROOT. So I went to c:/...
1
vote
1answer
135 views

Is it safe to disable InnoDB doublewrite buffering when setting Innodb_page_size = filesystem page size?

As I understand, doublewrite buffering is needed to avoid partial write, because Innodb_page_size default is 16K, while filesystem page size normallly is 4K; I wonder if I set "Innodb_page_size = ...
2
votes
2answers
336 views

Need to make MySQL's LOAD DATA LOCAL INFILE load large data faster

I need to load 4 million rows of data into a MySQL InnoDB table using LOAD DATA INFILE and would like to know if there are server configuration options I can tweak to get faster load. It took me 15 ...
1
vote
1answer
723 views

MySQL InnoDB 5.6.23 cannot start segmentation fault 11

I have a Linux Gentoo server which has OwnCloud application installed. It works for about 2 months with out any problems, and sudden this morning MySQL died. I have tried to restart mysql server and ...
1
vote
1answer
38 views

if set global transaction, how can I commit?

I found that MySQL can set a global transaction, but can I commit in another session? refer: http://dev.mysql.com/doc/refman/5.6/en/set-transaction.html
0
votes
1answer
251 views

MySQL: check max chracter length (ERROR 1118 (42000): Row size too large)

I'm trying to convert/copy MyISAM to InnoDB table and I'm getting the following error message: mysql> INSERT INTO test.innodb_table SELECT * FROM test.myisam_table ERROR 1118 (42000): Row size ...
112
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9answers
99k views
2
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2answers
684 views

Can anyone offer an opinion on handlersocket vs memcached performance in MySQL 5.6

I must say I was a little mis(un)-informed about the MySQL Memcached plugin which offers the same NoSQL like access to InnoDB tables as HandlerSocket, I had only had experience with entirely ...
0
votes
1answer
64 views

Query perfomance with multiple JOINs on MyISAM-based DB

I'm working with Enron Email Dataset in MySQL database. After I executed data import from the dump file into MyISAM-based DB, I got the set of tables without any connections between them via foreign ...
0
votes
1answer
90 views

Rolling update to all rows in innodb table (no rollback if aborted)

I have the following table, which stores the Social Security Death Master File database (~86M rows): CREATE TABLE `death_master_files` ( `id` int(11) NOT NULL AUTO_INCREMENT, `ssn_an` smallint(5) ...
0
votes
1answer
53 views

InnoDB index concurrent inserts

I have an InnoDB table with an index on it. I have a few million rows to insert, so I thought I might take advantage of the row-level locking and do it in parallel. I'm inserting in batches of 10000, ...
1
vote
2answers
438 views

Speeding Inserts of longtext or longblob columns

i'm currently migrating a DB2 database to MySQL, using SQL WORKBENCH Tool It basically does a select from DB2 and Insert to DB2. It works fine, but on the tables with longblob or longtext columns (...
1
vote
1answer
986 views

Server stuck in INTERNAL DDL LOG RECOVERY IN PROGRESS

Recently, one of my servers had a crash. I had alot of trouble but managed to restore everything. But, Now, the first background thread upon startup is locked on "INTERNAL DDL LOG RECOVERY IN ...
8
votes
2answers
3k views

COUNT(*) on InnoDB whenever phpMyAdmin loads

It's a known issue that innodb is slow in SELECT count(*) FROM Table Hence I avoided that. But I notice that whenever I login to phpmyadmin, it will automatically execute a count(*) for my innodb ...
3
votes
2answers
485 views

Inner Join and Right Join same query

I'm using MySQL and InnoDB, I have a table reserver with 2 columns : idReservation and idChambre I have a table reservation and a table chambre Now I want my query to return every "chambre.id" who is ...
6
votes
4answers
9k views

Mysql innoDB write operations are extremely slow

I'm having serious performance problems with MySQL and the InnoDB engine. Even the simplest table makes writing operations (creating the table, inserting, updating and deleting) horribly slow, as you ...
0
votes
2answers
323 views

MySQL - Changing from system tablespace to file per table

The MySQL database I am working on has the InnoDB tables and indexes stored in the system tablespace which is now > 20Gb. Some years ago I managed a MySQL database that made use of a file per table ...
0
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0answers
169 views

Cannot open table slave_master_info

I have a dabatase working on InnoDB engine Now it is damaged. I can´t open any table, it shows error 1146 Table 'database.tablefromdatabase' doesn't exist I tried innodb_force_recovery with all ...
0
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0answers
99 views

CPU jumps massively and stays high, under very light load

We had two separate RDS instances exhibit the same pattern today. This was both during low load times, one during the lowest load time for that server. They both started at almost the same time. No ...
0
votes
1answer
74 views

MYSQL any way to improve this query's performance?

MYSQL version 5.6.23 CENTOS 7 Hi, I have the following query that is coming from an application that I am hoping to make more efficient from the mysql side of things. I have an index built on ...
0
votes
1answer
63 views

InnoDB Table has backed up INSERT and UPDATE queries, high CPU

I am running an MySQL DB with all InnoDB tables. I often have many queries backed up for the same table when I run SHOW PROCESSLIST; Basically, I keep a table of every logged in customer and update ...
0
votes
1answer
47 views

What is the performance benefit when using a temporary table to update a regular table?

I'm trying to understand what the performance benefit between two different methods of updating multiple table rows. For the first method we have an explicit update statement for each line to be ...
0
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0answers
90 views

MySQL is pretty slow after 50-100k rows whats happen?

i have trying now a lots of time, and i try to find a way there make sense to find out of my problem, but this problem stil make a lot perfumes issues. i testing it of on a developer server ( 2 cores,...
1
vote
2answers
713 views

Large ibdata file in MySQL

I am having MySQL database with all my tables as InnoDB with file_per_table config on. But Still I m seeing huge ibdata file ( ~50GB). All tables are having .ibd file as well. This is a machine I have ...
0
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0answers
520 views

Why is MySQL not saving inserted data?

So I have the following insert statement that I run through MySQL Workbench: INSERT INTO PeakOnlineCount (time_stamp, LocationId, Count) values ('2015-03-26', 0, 1) If I run the following query: ...
0
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0answers
1k views

How to restore mysql database in XAMPP using backup of mysql folder?

I have a backup of the entire xampp/mysql folder. How can I use it to recover my old db on a fresh installation of XAMPP? Simply copying the old xampp/mysql folder to new xampp leads to mysql errors ...
0
votes
1answer
116 views

I have a DB that is locking up from numerous updates to a table: Should I convert it from MyISAM to InnoDB?

FYI: I don't believe this is a duplicate question, I've looked and most are general questions with vague answers. See more specifics below: Currently a database I am in charge of locks up every once ...
0
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0answers
74 views

Percona Master-Master lag issues

I have 2 servers with master-master replication using Percona MySQL 5.6 and I am having replication lag in the second server: db-02, however db-01 never had a lag situation. What could be causing ...
5
votes
1answer
337 views

Does MySQL exectution plan depend on available indexes?

Does MySQL choose an execution plan for a given query taking into account what indexes are available, or does it first choose an execution plan and then uses indexes if they are available? Motivation:...