Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

how much data can mysql handle, really

Posted on 2010-11-17
11
Medium Priority
?
728 Views
Last Modified: 2012-05-10
Hi

Is mysql capable of handling joins on really large tables?

I am having a problem working with large amounts of data. I tried to join a table with 1 million records to a table with 100,000 records and the join 'ate up' all the memory in the machine so that everything just died.

Mysql is an enterprise database but I have no idea if it can handle database joins on these types of scale.

Is there a way to help it out in these situations? I'm sure indexing will help but is there anyway of breaking a join down into blocks or steps

thanks
0
Comment
Question by:andieje
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 6
  • 5
11 Comments
 
LVL 143

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 34154230
table structure is?
indexes on the tables are?
query is?
explain plan of the query is?

configuration/tuning tips are here:
http://www.mysqlperformanceblog.com/2006/09/29/what-to-tune-in-mysql-server-after-installation/
0
 

Author Comment

by:andieje
ID: 34154291
I don't have a specific example, this is an exploratoty question

Simple one to many relationship
Lets say i have table A and table B. A contains a million records and table B contains a 100,000 records. There is a one to many relationship between table A and B. They have a common field which is the prinary key in table A and is a foreign key in table B. This field is indexed.

select * from table a, table b inner join on a.pk = b.fk

0
 
LVL 143

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 34154305
the correct syntax, in MySQL, would be either:
select * from table a join table b on a.pk = b.fk

Open in new window

or
select * from table a , table b where a.pk = b.fk

Open in new window


and when you say both pk and fk fields are indexes, the join should use the indexes to perform the join... eventually.
it does depend on the configuration of the memory assigned to mysql (see link above)
0
Learn how to optimize MySQL for your business need

With the increasing importance of apps & networks in both business & personal interconnections, perfor. has become one of the key metrics of successful communication. This ebook is a hands-on business-case-driven guide to understanding MySQL query parameter tuning & database perf

 

Author Comment

by:andieje
ID: 34154308
I am asking this question because i have been told mysql won't handle the type of data I want it to handle because when someone else tried it, mysql simply 'died.' I'm hoping not to waste my time if I can avoid it

0
 
LVL 143

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 34154313
I have to presume that the "someone else" did not know about the configuration you have to do with MySQL to allow it to take more RAM than it does by default... which is usually much too low, by default ...
0
 

Author Comment

by:andieje
ID: 34154320
what do you mean the 'join should use the indexes to perform the join eventually'

I apologise for getting the syntax wrong. My question isn't about the syntax though its simple, should mysql be able to handle a simple query like that with that much data or would i really have to fine tune the configuration?
0
 
LVL 143

Accepted Solution

by:
Guy Hengel [angelIII / a3] earned 2000 total points
ID: 34154321
Mysql is able to handle a join between tables having millions of records, espacially if there are appropriate indexes.
0
 

Author Comment

by:andieje
ID: 34154337
this is what i thought but i've been warned by someone not to do what I was planning to do, but as you say they might have left the innodb_buffer_pool_size at 1M

I don't suppose youve ran mysql on the cloud have you? I was wondering how much memory they would let you assign to mysql. I'm not the 'cloud person' in my team. I'm not even the computer person :)
0
 
LVL 143

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 34154368
>I don't suppose youve ran mysql on the cloud have you?
no. only a couple of distinct instances, each for a very specific task each.
the largest installation has some 200 tables, each 4GB each table (1 table = 1 day of data, actually)
0
 

Author Comment

by:andieje
ID: 34154383
you've answered many of my questions before which i really appreciate so I know you know your stuff inside out!

I would really appreciate it if you could look at this question for me if you have any time
http://www.experts-exchange.com/Database/MySQL/Q_26619565.html

many thanks
0
 

Author Closing Comment

by:andieje
ID: 34201327
thanks
0

Featured Post

Moving data to the cloud? Find out if you’re ready

Before moving to the cloud, it is important to carefully define your db needs, plan for the migration & understand prod. environment. This wp explains how to define what you need from a cloud provider, plan for the migration & what putting a cloud solution into practice entails.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction Since I wrote the original article about Handling Date and Time in PHP and MySQL several years ago, it seemed like now was a good time to update it for object-oriented PHP.  This article does that, replacing as much as possible the pr…
Creating and Managing Databases with phpMyAdmin in cPanel.
In this video, Percona Solution Engineer Dimitri Vanoverbeke discusses why you want to use at least three nodes in a database cluster. To discuss how Percona Consulting can help with your design and architecture needs for your database and infras…
In this video, Percona Solutions Engineer Barrett Chambers discusses some of the basic syntax differences between MySQL and MongoDB. To learn more check out our webinar on MongoDB administration for MySQL DBA: https://www.percona.com/resources/we…
Suggested Courses

688 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question