How long are results kept?
Results for regular club sessions are typically kept for 4 weeks. After that, they are permanently removed. Results for the multi-session events are kept typically for about 6 months after the last session. After this, they are moved into an archive, and kept there indefinitely. Some details, like results for each board played, are stripped.
Can I have my regular session results kept longer?
You can. You must use web admin, find the result you want to keep, and mark it for "Archiving". When the default period of keeping expires, the result will be moved into the archive, where it will be kept indefinitely.
Bear in mind that results older than a week hardly attract any views, so the default holding period is very generous. This feature should be used only for special events that are played in one session only. It shouldn't be used for regular sessions (although nobody prevents that).