should I make two separate tables for two similar objects

I want to store "Tweets" and "Facebook Status" in my app as part of "Status collection" so every status collection will have a bunch of Tweets or a bunch of Facebook Statuses. For Facebook I'm only interested in text so I won't store videos/photos for now.

I was wondering in terms of best practice for DB design. Is it better to have one table (put the max f开发者_运维知识库or status to 420 to include both Facebook and Twitter limit) with "Type" column that determines what status it is or is it better to have two separate tables? and Why?

Strictly speaking, a tweet is not the same thing as a FB update. You may be ignoring non-text for now, but you may change your mind later and be stuck with a model that doesn't work. As a general rule, objects should not be treated as interchangeable unless they really are. If they are merely similar, you should either use 2 separate tables or use additional columns as necessary.

All that said, if it's really just text, you can probably get away with a single table. But this is a matter of opinion and you'll probably get lots of answers.

I would put the messages into one table and have another that defines the type:

SocialMediaMessage
------------------
id
SocialMediaTypeId
Message

SocialMediaType
---------------
Id
Name

They seem similar enough that there is no point to separate them. It will also make your life easier if you want to query across both Social Networking sites.

Its probably easier to use on table and use type to identify them. You will only need one query/stored procedure to access the data instead of one query for each type when you have multiple tables.