I need to put something together quickly that will take blog posts and place them on social media sites, the requirements are as follows:

• Blog Entries are independent records that already exist, they have a published date and a modified date, the blog entry application cannot be changed, at least not substantially
• A new blog entry, or update needs to be sent to social media sites
• I currently do not need to update or delete social media communications if the blog entry is edited, or deleted, though I may need to later

My design problems here are as follows:

• how do I know the status of each update
• how can I figure out what blog entry updates and postings have already been sent out?
• how can I quickly poll the blog entry table for postings that haven't yet been sent out? Avoiding looking at each Entry record from the DB as an object and asking if it's been sent already. That would be too slow.
• I cannot hook into any Blog Entry update code, my only option would be to create a trigger that an update queues something to be processed

I'm looking for general guiding principles here, the biggest problem I'm having is coming up with any reasonable way to figure out if a blog entry should be sent to our social media sites in the first place