Q: I have an Apple osx 10.6.8.   I am prompted to install Yosemite but advised I will lose Appleworks.  Would I have to buy an updated Appleworks?

LibreOffice will open an AW database in the form of a spreadsheet, but nothing else will open the document unless exported.

I thought I had read that but wasn't sure. You will note that I did not say only AppleWorks will open the databases.

Wisely. Of course though LibreOffice will at least access the data if you've put yourself in the position of not being able to run Appleworks, you lose all the formatting and calculations (it shows the result not the formula). Unfortunately the only way to get a close match to what AppleWorks does is to export as ASCII, then import into FileMaker Pro and remake all the formatting and calculations. This of course can be quite a job, plus there is a learning curve with FMPro and it's by no means cheap.

I used to maintain at least 3 databases in AppleWorks, 2 of which are in active use (my notes on my own software; and an "ideas" database for small chunks of text that don't need whole files to store them).  That isn't good b/c there doesn't seem to be any other program that can open AppleWorks databases.  Over the past year or so, I've moved the databases that I'm actively using to FileMaker.  FileMaker, of course, is expensive and complex, but also way more powerful than the database part of AppleWorks.  IIRC, I did this by carefully noting the field names, and doing a Save As.  That gave me text files with tabs between each field.  Then make a FileMaker database with similar fields & import the text file.  Then clean things up  -- for instance, I probably had some text formatted bold & I had to redo the bolding.