Subject | Low Selective Index |
---|---|
Author | chee hee |
Post date | 2006-09-01T03:16:28Z |
Hi All,
I have a transaction table which has about 5 million records (and growing) and has a foreign key column to a table called Company. The Company table only has 3 records. I understand that a foreign key will have an index created automatically. So this would be a very low selective index and from the book theory, low selective index is not good for performance.
So in general, should we create foreign key from very huge table (> million records) to very small table (< 10 records) ?
Thanks in advance.
regards,
CM
[Non-text portions of this message have been removed]
I have a transaction table which has about 5 million records (and growing) and has a foreign key column to a table called Company. The Company table only has 3 records. I understand that a foreign key will have an index created automatically. So this would be a very low selective index and from the book theory, low selective index is not good for performance.
So in general, should we create foreign key from very huge table (> million records) to very small table (< 10 records) ?
Thanks in advance.
regards,
CM
[Non-text portions of this message have been removed]