Tagged Questions

InnoDB : MySQL's ACID-compliant Storage Engine

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0answers
34 views

innodb fulltext Table handler out of memory

I am running mariadb 10 and have a large innodb table with a fulltext index. When searching I am regularly getting this error ERROR 128 (HY000): Table handler out of memory Is there some way I ...
0
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2answers
62 views

MySQL thousands connections after convert MyISAM to InnoDB on fail-over structure

I've acquired a fail-over structure and I migrated my databases to new structure converting all tables of my database from MyISAM to InnoDB engine, but, after import all databases, I have a problem ...
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1answer
35 views

Joining a column from another table with InnoDB engine

I'm using MySQL with InnoDB and I want to join the location column from products table into a productStock table. I have this table 'products' mysql> select * from products; ...
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0answers
17 views

Does storing page views in my page table slow performance?

I am storing page views in a view_countcolumn on my page table. So every time the page gets loaded I increment the view count and update the entry. What affect can this have on the performance of my ...
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107 views

MySQL keeps crashing [on hold]

I've restored my vserver from a backup which was created by my host. After that my MySQL server is not starting anymore. I've tried several ways to recovery my tables, but it's still not working. ...
0
votes
1answer
29 views

Fastest way to alter column type in a 2-billion+ records innodb table

I have a MySQL table with 4 columns. The 1st column record_id is of type int, primary key, and auto-incremented. Now that I have added more than 2 billion records to this table I am finding that I ...
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1answer
41 views

innodb fulltext ibdata1 size

I am running mariadb 10 and have a large innodb table with a full text index. I have innodb_file_per_table=ON I've noticed though that the ibdata1 file grows at the same rate as my table file. I ...
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vote
1answer
86 views

Innodb issue is preventing MySQL from starting [closed]

For some reason mysqld refused to start after I rebooted my server. Now when I try to start it I will get the following error: [root@vps1 ~]# service mysqld restart ERROR! MySQL server PID file ...
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2answers
350 views

High MySQL “InnoDB Writes Per Second” - Can't see the queries?

On our live MySQL 5.5 database server, we use MySQL Workbench for running manual queries, checking running queries to see what's going on, etc. I noticed today that on the "Server Status" tab there's ...
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1answer
20 views

Automatic slave reconfiguration after updating master

I have development mysql master and slave servers and a prod server. I need to set up regular (once a week) syncronization of dev and prod databases. It would be easy for me to use prod# mysqldump > ...
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0answers
77 views

Very slow response even with a high number of available connections

I'm running this server for data mining purposes. It runs several compute-intensive data mining applications in parallel and does simultaneous access to the MySQL server. Here are the ...
0
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1answer
62 views

Appropriate use of mysql Optimize Table

I want to come up with some best practice for maintaining our mysql database. versions 5.5/6 and using InnoDB. i came across this artice - ...
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7 views

Why pages not made young is zero?

In results of Show INNODB Status showed me very weird result: Pages made young 81821279, not young 0 The official statement says: Pages made young, not young: The number of old pages that were ...
0
votes
1answer
41 views

MySQL InnoDB log files on different location

I am using MySQL version: 5.5.38 There are following parameters that can control InnoDB log files: innodb_log_files_in_group - amount of log files in the group, by default 2. Will create 2 files ...
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0answers
56 views

Too much IO to MySQL InnoDB log files

I am using MySQL version: 5.5.38 I have dedicated HDD to InnoDB log files using innodb-log-group-home-dir option. atopsar -d 30 shows big load (>50%) to this HDD The thing is that I have only 75 ...
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1answer
137 views

mysql - Recovering databases from ibdata1 , .frm and .idb

I have a server running a mysql instance which crashed today. Now there are a massive amounts of tables in multiple database exceeding over 200GB stored on disk. After the server crash mysql is ...
2
votes
1answer
155 views

MySqlDump's DISABLE KEYS have no effect on import

I have a follow up to my previous question regarding import speed with Inno-Tables (suprise!). Scenario I try to import some big* database dump on my local dev machine in reasonable time. We have a ...
1
vote
1answer
49 views

Fastest engine for Mass Updates (only updates done on table)

I have a table of 2 columns and 60 million rows. I want to update the table by incrementing one field by 1 on various different rows (This is the only type of operation that will ever be done on the ...
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0answers
16 views

Conversion to Barracuda/Compressed Rows Doesn't Free Disk Space

I'm currently converting large tables to the Barracuda file format. We are using file_per_table. I had one table that decreased from 4.3gb in size down to 1.8gb and we're very happy about this. ...
2
votes
1answer
59 views

Running a query on an improperly indexed, 600gb table

This is my first post on here and I'm really baffled by this. I have joined a team and somewhere in the past a horrific table was created which has been bloated to a point of 600+gb of data. ...
0
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1answer
62 views

MySQL Entity Relationship Problem - 3-way join table?

This is a db relationship question. I have a scenario which I believe I have come up with a solution - however, I can't be sure it's a manageable one, or even correct. The scenario is as follows: ...
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0answers
45 views

mysqldump with --single-transaction seems to be “fixing” InnoDB tables with page corruption - why?

I'm trying to find out what exactly is happening here. I've been intentionally corrupting index pages in InnoDB tables, changing bytes in user record areas that actually contain information (largest ...
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2answers
67 views

Should we enable innodb_file_per_table for single tenant SaaS app (thousands of databases)

We have a mySQL backed SaaS application where each customer has their own mySQL database. So think of it like a wordpress/magento etc. database for each client. Each database has ~200 table, and we ...
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0answers
47 views

Why is MySQL database is having irregular performance issues?

I first thought it was because of some bad queries, but it wasnt. It took 90 secs to execute a select statement on a table with two rows one column while during other times it executed within ms. ...
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vote
1answer
54 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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1answer
28 views

Importing Data with Single .ibd file

I have one ".ibd" file with me. I have configured my local Database server with FILE_PER_TABLE option. i have two question here. When i was trying to restore/import the IBD file, the engine expect ...
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0answers
48 views

InnoDB says I'm in Deadlock when it should not be

I'll do my best to explain the situation. I'm at a complete loss. Preliminaries I'm running a Java Web Application in Tomcat 7.0 using a JDBC Connector to communicate with my MySQL Database. The ...
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0answers
18 views

See indices implicitly created for foreign key constaints in MySQL

When I add a foreign key constraint to my table, SHOW INDEX doesn't show any new indices, but the overall space used by the indices in that table increases. Apparently, the index for the field I put a ...
0
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1answer
44 views

MySQL my.cnf: innodb_log_file_size is missing

How to set innodb_log_file_size to MySQL database if there is no innodb_log_file_size in my.cnf configuration file? I'd like to backup via Percona Xtrabackup and the backup crashes at this point ...
0
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0answers
36 views

innodb_buffer_pool & innodb_buffer_pool_instances

I have a database dedicated server with one quad-core cpu and 48GB Memory. Total database size is about 6GB and my ultimate goal is to get the maximum performance out of this system. At First, to ...
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vote
2answers
43 views

Is it safe to delete the innodb schema on a new Amazon RDS instance?

As per the title, I'm struggling to find out if it's safe to delete the innodb schema that's created on a fresh Amazon RDS instance. mysql> SHOW DATABASES; +--------------------+ | Database ...
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0answers
52 views

is this dead simple query too slow?

I have added and removed a few indexes from my user table and, while testing, didn't see the performance gains I had hoped. As a result, I removed the indexes and tried a simple query to see what my ...
2
votes
2answers
57 views

How do you update a large MySQL table that's on a server?

I have an application on a web server. The PHP front end for the application queries a MySQL database which has a table that contains 60 million taken domain names. My application queries this ...
2
votes
2answers
97 views

show table name + number of records for each table in a mysql innodb database

How to list all tables in the current database, together the number of rows of the table. In other words, can you think of a query to come up with something like this in mysql? ...
10
votes
2answers
189 views

MySQL instance stalling “doing SYNC index”

Problem An instance of MySQL 5.6.20 running (mostly just) a database with InnoDB tables is exhibiting occasional stalls for all update operations for the duration of 1-4 minutes with all INSERT, ...
0
votes
1answer
37 views

InnoDB compression: memory usage

InnoDB offers table compression for Barracuda-type tables and the recommendation seems to be to "adjust" buffer_pool_size. The documentation is rather vague about the definite impact of compression on ...
1
vote
1answer
40 views

How does subpartitioning actually work and what physical files are created?

I can't understand how the subpartitioning works in mysql. I am reading the following example: create table invoices ( customer_id int not null, product_id int not null, amount decimal ...
3
votes
1answer
606 views

Row size error with MySQL

I'm running a MySQL server on my Macbook (for testing). Version is 5.6.20 from Homebrew. I started running into "Row size too large" errors, and I've been able to reduce it down to this test case. ...
1
vote
1answer
57 views

Table is dropped but ibd file still exists

I was dropping some unwanted tables I have in the MySQL. When I run a drop table, its showing table doesnot exists. But when a check in the data directory, the .ibd file exists and its almost 1GB. How ...
8
votes
2answers
322 views

Why are simple SELECTs on InnoDB 100x slower than on MyISAM?

I have quite an annoying problem. I want to use INNODB as my main database engine and give up on MyISAM as I need the former for using galera-cluster for redundancy. I copied (description follows) ...
1
vote
1answer
64 views

InnoDB deadlock with INSERT .. SELECT

I am trying to understand why a deadlock occurs when two workers in parallel are running INSERT .. SELECT queries on a table which has both 1) auto incremented primary key, 2) a unique index on ...
2
votes
1answer
56 views

Innodb DB Consuming IO even when no operations are being done

I am currently doing some stress testing where I am pushing inserts to the database as fast as I can. The simulation inserts 10000 records per second. After inserting around 200 million records I ...
1
vote
1answer
46 views

MySQL Delete Rows from Slave

I want to truncate the majority of data on a slave such that it only has the most recent records. I'll eventually demote the current master, making it a read-only archive, and promote the truncated ...
0
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0answers
53 views

MySQL DATE vs DATETIME read/write performace

Did anyone perform accurate read/write performance comparisons of MySQL's DATE vs DATETIME column types? Please do not bother writing "It should be faster" or "I think it's faster". I am looking for ...
1
vote
1answer
102 views

Revoke write privileges vs setting database to readonly

I am planning to do a database migration to a new server. During the transition stage, I do not want Apache user to be able to write anything to the database. I have two options. Revoke write ...
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vote
2answers
174 views

Difference between On Delete Cascade & On Update Cascade in mysql

I have two tables in MySQL database- parent, child. I'm trying to add foreign key references to my child table based on the parent table. Is there any significant difference between ON UPDATE CASCADE ...
2
votes
2answers
54 views

Copying datadir directory enough for backing up a database with InnoDB tables?

I have an innodb table with 80 million rows and it's extremely slow with mysqldump so I'm thinking of copying the datadir directory for a backup / transfer. I used to copy database with only MyISAM ...
3
votes
4answers
136 views

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

TL;DR: Prove that in practice, the execution of the alter table table_name drop foreign key constraint_name statement does not corrupt existing data. The important consideration is the execution of ...
2
votes
1answer
66 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 | ...
3
votes
1answer
181 views

MySQL RDS 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: ...