When I started pursuing my Slovak roots, oh so many years ago, there was the communist country of Czechoslovakia and dealing with them was difficult by mail. That was 1979. Twenty years and one velvet revolution later, the way to do Slovak genealogy was board a plane and get to Bratislava and go to the Archives. There were all the parish records from Slovakia. At that time some of the books were indexed some were not. Mostly the baptisms and marriages were indexed and deaths were not.
Then came the next leap. The Mormons microfilmed all the parish records. Suddenly you only needed to go to Salt Lake City to use these records. What's more they microfilmed the 1869 census as well. This led to many trips to Salt Lake City to use these records. I was the first to use them (and how do I know this? Because I had to recall each film from the vault which was off-site). It took me three separate trips to get all I needed.
But technology advanced again. These microfilmed records were placed on the Internet at www.familysearch.org/. So, now you could browse these records from your own home and save on the air fare to Bratislava (which I sadly paid in the 1990s).
Most recently I was on that site and noticed that they had begun indexing the records into a searchable database. From my many searches, I could see that baptisms have been indexed but not yet marriages or deaths. Of course, there's no control page to let you know what's going on. It's totally flying blind. I found that you had to search by surname alone since Slovak parish records are in multiple languages. George is listed in Latin as Georgius, in German as Georg and in Slovak as Juraj. And when you search, of course, they do a wide search and you retrieve thousands of hits. Your town may be first, but other towns follow. I tried to do an exact search and came up with nothing.
However, since I was pressed for time when I was doing my genealogy I only did my direct lines. Now I can search and retrieve all the siblings of my direct ancestors and see their families as well. It should make for a fuller tree in the end. It will be nice when all the records are indexed (and there is an obvious sign saying so).
But, for now, Slovak genealogy is taking another leap forward in convenience. You can search the parish records from home. Some are even now indexed.