InnoDB : MySQL's ACID-compliant Storage Engine

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541 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 ...
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2answers
254 views

Which one to use? InnoDB Replication or MySQL Cluster?

I am building a url shortener and I use InnoDB as the storage engine for link data. I will start with a single VPS containing both application instance and MySQL database instance on the same Virtual ...
2
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1answer
4k views

Amazon RDS MySQL 5.5 Innodb Lock wait timeout exceeded

Ever since we've moved to Amazon RDS, we've had some pretty crazy performance issues, and today we started having locking issues. Because of that, I figured it was just a timeout issue, and went to ...
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1answer
54 views

how to recover .ibd and .frm files in mysql

so i am developing java application with mysql 5.6.13, few days before i purchased new laptop, from previous laptop i forgot to create dump of application instead i copied folder of my database(.ibd ...
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1answer
45 views

Slow queries with many self joins in variable-column database

I'm creating a table structure which needs to handle a variable number of columns. To handle that case the table structure is a listing of cells with a column and row number. To view the table a ...
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1answer
68 views

Delete Query takes a long time

I have a innodb table that counts circa 1 billion entries. I started a delete operation (with a small where condition on an indexed column) that should delete a lot entries, leaving circa 100 million. ...
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1answer
39 views

mysql directory grow to 246G after one query, which failed due to table is full

I was trying to run the following statement with the hope to create a join of two existing tables. create table CRS_PAIR select concat_ws(',', a.TESTING_ID, b.TRAINING_ID, a.TESTING_C) as k, ...
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1answer
28 views

How to calculate the space I need for the indexes?

CREATE TABLE info( home CHAR(10) CHARACTER SET latin1 NOT NULL, id TINYINT UNSIGNED NOT NULL, galaxy TINYINT UNSIGNED NOT NULL, galaxy_pos INT UNSIGNED NOT NULL, events TEXT NOT NULL, UNIQUE ...
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5answers
11k views

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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0answers
27 views

Converting UUID's from CHAR(32) to BIN(16)

I have a few questions relating to UUID's, but before I go on, let me explain our schema a bit, first, we're on MySQL 5.5 (Percona's version to be exact)... In each applicable table, we use a two ...
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1answer
44 views

MySQL not releasing memory

MySQL seems to want to keep an entire table in cache (table size = ~20GB) after any large inserts or select statements are performed on it. Right now my innodb buffer pool is 20GB. Total RAM is 32GB. ...
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2answers
780 views

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
176 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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2answers
2k views

Is the overhead of frequent query cache invalidation ever worth it?

I'm currently working on a MySQL database where we are seeing a large number of invalidations from the query cache, primarily because of the high number of INSERT, DELETE and UPDATE statements that ...
0
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1answer
82 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, ...
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2answers
156 views

Are MySQL transactions under-utilised?

I have a vague understanding of transactions that it means you can help the server understand that a series of queries are related. Scenario : Suppose I have a series of queries which creates a user ...
1
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1answer
47 views

Innodb buffer pool and multiple joins

assume we have 1 Billion records and want to store them in One or Three tables by post_type. post_id -> primary key post_type -> ( page, group, user ) user_id -> index date -> ...
2
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1answer
99 views

Strange things with Avg_row_length

The data from one tables is dumped to file and inserted into calls_old table with load data infile it shows Avg_row_length 7366. Later I dumped table with mysqldump, droped table, then created again ...
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2answers
49 views

Can CPU cores be separated for MySQL?

Is it possible to separate CPU cores in Mysql? I understand it is possible for Memory as we can tune it in innodb_buffer_pool_size or innodb_additional_mem_pool_size. How about CPU cores in ...
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1answer
132 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 ...
2
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0answers
43 views

RDS MYSQL instance rebooted and won't load INNODB table

So my production db in RDS apparently either crashed or was rebooted during a version update, and upon being restarted mysql couldn't load one of the innodb tables: as evidenced by the following error ...
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1answer
48 views

MySQL 5.1: Upgrade innodb plugin

My application is running on MySQL 5.1.58 community edition. As I studied on SO websites that After acquisition by Oracle, new InnoDB plugin has been released and MySQL 5.1 with InnoDB plugin is the ...
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1answer
93 views

invalidating query cache entries(key)

when I tried to delete some records from a MYSQL server (version 5.0.95-log) and checked the process list I got the result as follows mysql> show processlist \G *************************** 2. ...
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2answers
867 views

Optimizing mysql queries running on 50 million rows

Is there any technique/advice in order to optimize the performance of the queries below? According to my needs, my average db size will be approximately 30mill. rows per day, so every second less, ...
2
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1answer
7k views

MySQL: InnoDB keeps crashing - how to recover?

# free -m total used free shared buffers cached Mem: 48289 35288 13000 0 347 30399 -/+ buffers/cache: 4541 43747 ...
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2answers
933 views

The best MySQL Settings for 32GB RAM on a Dedicated Server

I am worrying about my memory usage as it is reaching more than 90% if I will not restart php-fpm. I have the following configuration on my MySQL: [client] port = 3306 socket = ...
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0answers
19 views

MariaDB : Larger innodb_buffer_pool_size causing SQL updates to be slower

Has anyone here encountered such scenario before where and update statement took longer time to run when innodb_buffer_pool_size is bigger. I've run a few tests using the same statements on around ...
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1answer
20 views

Immigrate to file-per-table mode in MySQL

I have 20 MySQL databases and in each there are about 20 tables. All the data is saved in a file called ibData1. Now I discovered about the file per table mode but if I change the value in the my.ini ...
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4answers
2k views

Prevent reset of auto_increment id in Innodb database after server restart

I recently read that because of how InnoDB recalculates the AUTO_INCREMENT value when the server restarts, any records on the high end of the ID list may have their IDs reused. Normally, this isn't a ...
1
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1answer
23 views

creating table result in errno 150

I'm trying to create the following schema, but I'm getting errors when I'm trying to create project and staffphone tables. Not sure what is it complaining about. mysql> CREATE TABLE staff( ...
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2answers
27 views

Mysql used key changes between two consecutive EXPLAINs

I have a huge unmaintained innodb table (~1.5billion rows), I just started to try to query it. I write && instead of AND once; and surprise! it uses different key! EXPLAIN EXTENDED SELECT * ...
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1answer
45 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 ...
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1answer
444 views

How can Innodb ibdata1 file grows by 5X even with innodb_file_per_table set?

I have innodb_file_per_table set and just today my ibdata1 file jumped from 59M to 323M after I made several changes to an 800M table to reduce it to about 600M. That particular table's .ibd file was ...
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3answers
17k views

How large should be mysql innodb_buffer_pool_size?

I have a busy database with solely InnoDB tables which is about 5GB in size. The database runs on a Debian server using SSD disks and I've set max connections = 800 which sometimes saturate and grind ...
3
votes
1answer
18 views

Is the innodb_lazy_drop_table problem solved?

I'm researching database configuration for MySQL/MariaDB. I've been reading the configuration chapter in "High Performance MySQL". In there, it suggests that innodb_lazy_drop_table can be used to ...
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3answers
63 views

Verify mysqldump backup is corruption free

We've got a cron task backing up our Database using mysqldump - my main concern is corruption, short of manually importing and checking the backups each time whats the best way to check / verify a ...
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2answers
42 views

Recovering mysql innodb table from table.ibd backup file

Just practising DB disaster recovery. As per our back up policy, we do complete disk image back ups every half an hour (on our slave server). Now for a scenario, where some how a table has been ...
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2answers
54 views

Transaction basics. What is the result of 2 transactions running concurrently?

I have a rather basic question on transactions. Assume a table Account with a column amount. Now we have the following code: BEGIN $amount = SELECT amount FROM ACCOUNT WHERE id = 123; $amount = ...
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2answers
68 views

What variable(s) to look to maintain MySQL speed of scanning through all database tables while it starts?

We have few thousand small databases with total .ibd files of about 800000. We noticed that MySQL takes couple of minutes to stop but about two hours to start. For e.g. while MySQL is starting and ...
0
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2answers
573 views

Percona Xtradb Cluster : How to speed up insert?

I recently installed a 3 full master node cluster based on Percona Xtradb (very easy install). But now i need to make some tuning to increase INSERT/UPDATE requests. Actually, i made around 100 ...
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3answers
554 views

Backup / Export data from MySQL 5.5 attachments table keeps failing!

Can anyone please help! - I have a large table in a MySQL 5.5 database. It is a table which holds a mixture of blobs/binary data and just data rows with links to file paths. It has just over a million ...
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1answer
69 views

Why does auto increment jumps by more than the number of rows inserted?

I am very perturbed by this weird behaviour I am seeing in the auto_increment value recorded in the bidID of a Bids table after performing bulk insertion using a stored procedure: INSERT INTO Bids ...
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3answers
97 views

What does “InnoDB stores its tables and indexes in a tablespace” mean? [duplicate]

Was reading the mysql engine innoDB tutorial, I came across this sentence "InnoDB stores its tables and indexes in a tablespace" Can any body explain me this what does it means. Thank you :)
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0answers
40 views

MariaDB Galera Cluster

I have two mariadb servers in cluster that is working galera and xtradb. it is my primary server configuration: [mysqld] datadir=/var/lib/mysql query_cache_size=0 binlog_format=ROW ...
0
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1answer
47 views

Is there a table size above which SELECT performance degrades significantly?

In MySQL, does SELECT performance degrade significantly after a certain table size? I have a table with about 107 million rows and some queries seem stuck in "Sending data" for a long time. Of course, ...
9
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1answer
6k views

InnoDB create table error: “Row size too large”

We have some engineers that flatten a normalized db structure into a temporary table for the purposes of generating a report. The columns are specified as TEXT NOT NULL (I know "why are they doing ...
10
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3answers
4k views

MySQL InnoDB crash post-mortem

MySQL crashed on me this morning. With the exception of the standard MySQL included databases everything I use is InnoDB. I attempted to restart the MySQL daemon but it failed twice. I then ...
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1answer
38 views

The most efficient method to obtain the total entries into a mysql table

I have a table that has a very high usage (insert/update/select) - one of the operations is to obtain a count of the number of rows. So far I've been using the classic select count(pk) from table but ...
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1answer
403 views

InnoDB - How to get top locked tables and rows which are locked

I was searching for a tool OR query which can give me top locked tables and which particular row is locked, Is it possible to get ?
0
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1answer
23 views

Check whether MySQL Innodb Rows are compressed

After setting the various variables to enable compression on the Innodb Barracuda tables, what query will you use to check that those tables are indeed compressed?