InnoDB : MySQL's ACID-compliant Storage Engine

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MySQL - Slow InnoDB Write Speeds on Windows 10

I have Windows 10 bootcamped. I've installed the latest version of MySQL community server. I've also installed WordPress onto IIS. The MacBook has 16Gb of memory. Here is my config file [client] ...
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2answers
72 views

How to determine the best index on a table with 3 nullable columns?

I am examining a users table similar to this: CREATE TABLE `users` ( `id` int(11) NOT NULL AUTO_INCREMENT, `username` varchar(50) DEFAULT NULL, `email` varchar(255) DEFAULT NULL, `password` ...
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21 views

Columnar & Row Oriented DB

In a previous question, I discussed some challenges with a row-oriented table. I have two tables in this application. The first table is well-suited for row-oriented operation; the second is ...
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1answer
20 views

Get Master Server Information from Slave instance

We need to get Master server information such as server IP and Port, we know this information is dumped into master.info file by default but what if it required within MySQL prompt as we are using ...
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1answer
68 views

How to stop Mysql ibd files from continuously growing

I have a mysql 5.5.44-0ubuntu0.14.04.1-log DB that has 2 tables that get a lot of data written to them then deleted within 48 hours, it is for a Salt system. The my.cnf is specifying ...
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1answer
66 views

LAST_INSERT_ID without AUTO_INCREMENT

I have following table, which does have an UUID as primary key, which also acts as foreign key. CREATE TABLE `xxx` ( `guid` char(36) NOT NULL, .... PRIMARY KEY (`guid`) ) ENGINE=InnoDB ...
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Find the last record of group of overlapped records

I have a little dilemma with filtering out result. The result and what I want to achieve is not very trivial and I didn't find an answer anywhere after extensive search. So here is my problem: I ...
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1answer
52 views

Does InnoDB store row counts in secondary index B-Tree non-leaf nodes?

Does InnoDB store row counts of child nodes in secondary index B-Tree non-leaf nodes? If so, does MySQL use this information to speed up COUNT(*) queries with range constraint (assuming appropriate ...
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1answer
189 views

MySQL Write performance bottleneck

We are trying to diagnose a MySQL Bottleneck, specifically for data writes. Basically, we have a single process that picks files from a folder and load into a MySQL table X using LOAD DATA CONCURRENT ...
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2answers
69 views

Moving an ibd file temporarily to free up disk space

I want to optimize an InnoDB table but I do not have enough disk space. I have enabled innodb_file_per_table, so each table has *.ibd for each of their partitions. For example: 512MB ...
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1answer
28 views

MySQL 100+ instances on one Windows server

Please don't ask why I need 100+ instances on one server because I cannot say; suffice to say that I'm not impressed. They will be very small databases and not definitely not under any great load ...
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2answers
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Automatically set timestamps for “create” and “modified”?

I have currently following SQL table: CREATE TABLE IF NOT EXISTS `xyz` ( `id` bigint(20) NOT NULL, `guid` char(36) NOT NULL, `ts_created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, ...
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1answer
81 views

How do flush innodb table, copy files, then unlock tables from Windows bat file?

I can successfully execute "FLUSH TABLES myTable FOR EXPORT;" in MySql Workbench. Then I can copy the cfg and ibd files I need, and then I can go back to workbench and run "UNLOCK TABLES" and all is ...
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MySQL InnoDB over a Raw Device in an Active/Passive topology

We have an Active/Passive topology where there are two x86 complexes with a shared raw storage, where only one of the nodes in a given moment has an access to the shared storage (AKA the active node). ...
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25 views

Replication of MySQL databases, but only some of the data

I need to set up a system to do basically a partial backup/replication of a couple of MySQL databases (actually Percona XtraDB 5.5, all tables are InnoDB). There are a few hundred tables in one of ...
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2answers
42 views

innodb_flush_log_at_trx_commit=1 and flush-to-disk reality

I use the default settings of MySQL 5.5 on various servers and I have the following table: create table test._perf ( name varchar(255) not null ) engine=InnoDB; I have an .sql script which ...
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2answers
171 views

Where does InnoDB store transaction data before committing it?

I've done some tests using READ_COMMITTED and READ_UNCOMMITTED at home, using the JDBC technology. I see that READ_UNCOMMITTED can actually read uncommitted data, e.g. data from some transaction not ...
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1answer
53 views

How does lock works when delete rows through secondary index in InnoDB?

step1: InnoDB Transaction Isolation Level Repeated Read. step2: Table schema CREATE TABLE `follows` ( `id` int(11) NOT NULL AUTO_INCREMENT, `followable_type` varchar(255) DEFAULT NULL, ...
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1answer
60 views

MySQL keep crashing over and over on reading ibd files

My MySQL instance keeps crashing over and over again, I am running it with innodb_force_recovery = 3 innodb_purge_threads=0 I have tried it with force_recovery = 1 as well. It has happened before but ...
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1answer
197 views

inno_db_buffer_pool_size and key efficiency

I have the following metrics from mysql workbench After I have set innodb-buffer-pool-size to 6G, according to this answer's query on how to determine the recommended size. While the used buffer ...
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1answer
270 views

Corrupted InnoDB table, mysqlcheck and mysqldump crash server

I manage a Percona XtraDB Cluster that uses a network storage with a flapping connection. Periodically we experience a high iowait with crashes and remount of the fs in read-only. Replacing the ...
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1answer
42 views

InnoDB: SELECT COUNT(*) using primary key 25 times slower on Windows

MySql 5.6, InnoDB. I have a table with 8 million records. It has an integer primary key, and a unique index u1 CHAR(40). It also has a few small fields and a VARCHAR(1000). SELECT COUNT(*) FROM ...
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1answer
93 views

Missing statement information from 'LATEST DETECTED DEADLOCK' InnoDB status output

I'm learning how to interpret the LATEST DETECTED DEADLOCK section in the output of SHOW ENGINE INNODB STATUS, and had a question about the output. Some sample output of SHOW ENGINE INNODB STATUS ...
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2answers
64 views

How can I defragment tables in MySQL?

I have a database named COUNTY. COUNTY has a fragmented table GEO. I executed OPTIMIZE TABLE GEO against the GEO table, but this returned the error "Table does not support optimize, doing ...
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1answer
103 views

What is the optimum way to store, update, and analyze integer data for 100+ attributes?

I need to store the count of all individual characters (A-Z, a-z, 0-9, spaces, punctuation marks, all symbols...) that occur in different texts which will be frequently changing. I will need to ...
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3answers
512 views

Lock mysql table to prevent select and insert at the same time

I know this question has been asked earlier and I have also read the documentation. But I guess I'm stupid not understand. I have a code that inserts a row and the row should be unique in several ...
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1answer
387 views

MySQL UPDATE query stuck on “Sending Data” State

I am having difficulty getting an UPDATE query to successfully execute, due to the process getting stuck on "Sending Data" state. I feel this differs from similar questions about the "Sending Data" ...
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2answers
28 views

MySQL Drive Storage Allocation

In our production servers for SQL Server, we usually split our drives by Software, Logs, Data, and Backups. I've been assigned to help with a MySQL installation (On Windows Server) and I'm not as ...
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1answer
109 views

Restore MySQL Database with only .frm files

One of our servers (running Ubuntu 12.04) recently crashed during a power outage, and MySQL refused to start back up. After a lot of trial and error, I decided to completely reinstall it. Since I ...
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2answers
59 views

How do you achieve a physically sorted table file organization?

Do I just declare an index on a column in the schema like ? ALTER TABLE `table` ADD INDEX `index_name` (`colDate`) I want the table records to be physically sorted not just when doing an ORDER BY ...
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1answer
69 views

Optimize slow query

I have this query that takes over half an hour to run on our Linux MySQL db... SELECT ls.emailaddress , lse.subscriberid , lse.eventtype , count(lse.eventtype) as total FROM ...
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Identifying table causing runaway rollback in MySQL 5.5 (InnoDB / Windows)

I have a large database (180 GB), running under Windows, with a runaway rollback that starts running as soon as the database is started up. I have started the database with innodb_force_recovery=3 ...
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1answer
467 views

Mysql Optimization suggessions

I have an InnoDB database table with more than 2 million rows. I am running efficienty indexed queries to reduce server load, but site becomes slower day by day. I ran Mysqltuner.pl to identify any ...
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2answers
430 views

ERROR Error reading packet from server: Lost connection to MySQL server during query ( server_errno=2013)

We are facing the issue in replication that we are not getting any error in Show slave status\G output rather facing the following issue in Error Log File [ERROR] Error reading packet from server: ...
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3answers
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Very slow Insert and update on 20 core 250 Gb RAM dedicated MYSQL 5.5 server on Ubuntu [closed]

Most of the data is in tbl_user_ads. Its a huge table. Many concurrent processes (over 1000) try to select, insert or update this table. The CPU utilization is just around 2%. As I increase the ...
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1answer
45 views

Mysql stop working woocommerce

I have a WooCommerce website hosted on an Amazon EC2 centOS server with 4GB RAM and 4GB swap. My problem is that sometimes MySQL stops working due to failure to allocate memory and also the website ...
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3answers
911 views

Optimal Number of MySQL InnoDB Buffer Pool Instances

Server Characteristics Total system RAM: 8GB (running MySQL + other stuff than MySQL on it i.e. not dedicated to MySQL) Number of CPU Cores: 6 I have data in the db amounting to about 2GB I have ...
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1answer
54 views

MySQL Query causing high CPU and taking forever to execute

this below query takes a long time to execute in excess of 120 seconds, upon checking the explain plan it seems to be using using where, using temporary; using filesort. Since the application is a ...
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1answer
53 views

when do i usually optimize an innodb table?

I have a table that's always used 24/7. There is always a stream of update and/or insert of 10-20 rows per 30 to 60 seconds. As stated on the MYSQL documentation: "After doing substantial insert, ...
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How to configure correctly Mysql heavy used server to prevent it from write IO huge spikes?

I have mysql 5.6 server which handles thousands of users online. All tables are Innodb. The problem is, that once or twice a day it writes huge amount of data to disk, or it slows down a lot. Than ...
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1answer
68 views

Multi-Column PK or Auto-Increment PK?

In another question I mentioned that I have a table where, in order to ensure uniqueness, I need to use multiple columns as the PK. However, lookups are usually only done using the first of those ...
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1answer
137 views

Two updates cause a deadlock

I have a mysql queue with the following sheme: CREATE TABLE IF NOT EXISTS `media` ( `mid` int(11) NOT NULL AUTO_INCREMENT, `order_type` int(11) NOT NULL, `media_id` varchar(50) COLLATE ...
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Discard tablespace of temporary innodb table in MySQL

I have following problem, i need to discard tablespace of temporary table(file is present, i want to delete this file too) or somehow completely remove this table. This table can't be shown with ...
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4answers
1k views

Calculate row size and max row size for a table

Problem: Is there any way of calculating number of bytes occupied by the table creation, i know that you can get some information from information_schema.tables but that information is not accurate ...
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1answer
354 views

MariaDB/InnoDB: Temp file write failure

When attempting to alter a table to enable compression by modifying the KEY_BLOCK_SIZE I received the error: ERROR 1296 (HY000): Got error 64 'Temp file write failure' from InnoDB The command ...
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What storage engine do I need - Mysql?

I have designed a database and came to the point of actually deciding which storage engine is better for my case. I estimate that during the first few years I would have around 100,000 - 500,000 ...
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Update queries randomly slow on INNODB Mysql

I have been struggling with a slow update query. Have already tried using indexes and other query optimization techniques. I have been using MYSQL database with INNODB engine. The issue is that, ...
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1answer
1k views

InnoDB: Error: Table “mysql”.“innodb_table_stats” not found

I've got the same error, although I'm running galera cluster with 3 nodes. I tried following the instructions from InnoDB: Error: Table "mysql"."innodb_table_stats" not found after ...
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0answers
49 views

Percona: Innobackupex failing when taking incremental backup

I have been trying to take incremental backup as below and its getting error all the time. Innobackupex 2.1.8 Linux x86_64 Mysql 5.5.45 Step1: innobackupex -uxxx --stream=xbstream datadir > ...
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1answer
49 views

How can i write a stored procedure which will perform a calculation and store the result in a table?

I have two tables: CREATE TABLE `siteArea` ( `length` decimal(6,2) NOT NULL, `breadth` decimal(6,2) NOT NULL, `Area` decimal(6,2) NOT NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1; CREATE TABLE ...