tags:

views:

480

answers:

1
+1  Q: 

What do "Internal Relations" do in phpMyAdmin for MyISAM tables?

In phpMyAdmin v2.8.2.4 for MyISAM tables, the "Relation View" appears under the Structure tab. It shows a list of Internal Relations. But what do these do, given that MyISAM does not support foreign key constraints or relational integrity?

By phpMyAdmin version 3.2.0.1 this page ("Relation View") no longer appears for MyISAM tables. So does this mean that it wasn't doing anything in the first place?

Any explanations much appreciated. Justin

A: 

Foreign keys in MyISAM are for advisory purposes only. You can look at them to see where the referential integrity would be, if there were any. It's easier to understand the schema that way than to guess relations by looking at the indexes created as a side-effect.

I don't know why it'd disappear in phpMyAdmin, unless it's a config issue (I believe the view can be disabled)?

bobince  2009-11-12 12:40:37
Thanks for your response - so there are no performance benefits from specifying the Internal Relation in MyISAM? (Yes, it may well be my config that is hiding the page for me in the latest version of phpMyAdmin, have not checked).
JS London  2009-11-12 12:58:23
No, the potential to affect performance comes from adding indexes, which is a side-effect of adding a foreign key (as well as something that can be done on its own of course).
bobince  2009-11-12 16:51:14

related questions

Remove Quotes and Commas from a String in MySQL
What's the best way of converting a mysql database to a sqlite one?
How do you manage databases in development, test, and production?
Multiple foreign keys?
Add 1 to a field (MySQL)
Issues using MS Access as a front-end to a MySQL database back-end?
Bigger than a char but smaller than a blob
How do I retrieve my MySQL username and password?
Long-time LAMP Developer moving to VB.NET
How do I Concatenate entire result sets in MySQL?
Full complete MySQL database replication? Ideas? What do people do?
SQL: Distribution of table in time
SQLite vs MySQL
How do I create a new Ruby on Rails application using MySQL instead of SQLite?
Multiple Updates in MySQL
MySQL/Apache Error in PHP MySQL query
What all do I need to escape when sending a (My)SQL query?
Auto Generate Database Diagram MySQL
Mechanisms for tracking DB schema changes
How big can a MySQL database get before performance starts to degrade.
Python and MySQL
SQL Server 2005 implementation of MySQL REPLACE INTO?
How to export data from SQL Server 2005 to MySQL
Throw Error In MySQL Trigger
Binary Data in MySQL