Shit I wrote a long message but lost it when I clicked post 
Anyway, my main point is that whilst in principle I support this idea, in practice I question if it is practical.
It's so full of potential pitfalls that I just can't see how it can be implemented.
For example, who does the law regard as a "partner" and not just some random woman who's been on a date or even just someone with an axe to grind? So I meet a woman. We go on a couple of dates.....should she then be entitled to go to the police and apply for information? Six months? How does she prove we've been dating for 6 months? Or perhaps it's when we live together? Erm....isn't that a bit late? Again, how does someone prove she's living with him in a relationship and not just a houseshare? Or that the relationship is still going on? Perhaps she's just been dumped so she thinks "aha...I know...i'll see if I can dig up some mud...."
And which men do you provide information on? The guy who hit his wife/GF once during a major argument? Should he never be trusted and police be warning women forever for what may have been a very very uncharacteristic event or he may have been totally provoked? If we don't warn on first offence, then when? The second? The third? How many women must be abused before the law warns others?
And what's the definition of abuse? Physical (ie. fists & feet)? Or would emotional abuse be counted too? I have a friend who's been emotionally abused by her (now ex)husband for years and I can tell you the scars are just as real as being punched. If not worse. And over the twenty years, she's never once pressed charges on him even though he's hit her so....
...what about those who haven't been convicted? Perhaps allegations aplenty but no convictions. Are we going to ignore them?
Who decides when to release information? Would each individual officer reading the notes decide? Or would we set up a quango like the CRB office?
For me the whole online dating link is extremely misleading and just the newspapers sensationalising. Online dating is completely safe. It's just when you meet them it MAY get dangerous. That's no different than meeting a guy in the street/pub/club then agreeing to a date. You've no idea if the guy is going to be a bit handy with his hands in a few months or not.
Oh and lastly what about sexual equality? I know of two men who were beaten regularly by their wives. One was on the verge of divorce when she died, so that sorted that out. The other guy ended hanging himself as he couldn't face the shame of anyone knowing, nor the continued abuse by his wife. So it does happen. Should men be allowed to also apply?
Fuck it. Why don't we all submit to annual STD, CRB, genetic screening and store them with the government. They can then just give the information to whoever they see fit. What could possibly be the problem? After all, if you've nothing to hide..........