I imagine that this question has been raised before but I haven't found the answer so I'm posting it again.
I know that Jews were required to take last names starting around 1800 and that civil registrations of births, marriages and deaths came into use at the same time. I find it hard to imagine that births, marriages, and deaths weren't recorded before 1800 using patronymics but I've never seen any such records online. Are there any "synagogue" records that were kept (like the church records that were kept in Germany and Sweden (where the patronymic naming system continued until 1900))?
There's an interesting note by Warren Blatt on this question in one of the Jewishgen Infofiles (Polish-Jewish Genealogy — Questions and Answers) that says, in part:
"However, Jewish surnames do not appear until October 1821 throughout most of the Kingdom — so before that date you have to research based solely on given names and patronymics, since there were no surnames. This type of research is done by going though all of the civil registration documents for Jews in your town (you're lucky if it's a small town), and finding couples that match your characteristics: e.g. an Aron Moszkowicz (Aron son of Moszek), of a certain age and occupation, married to a Sara Jankielowna (Sara daughter of Jankiel) — that way you've got enough clues to be sure that you've got the right family — even without a surname. I've used this method in many towns, to trace most of my branches back to the mid-1700s."
It sounds like these records do exist but how does one locate them?