Correcting an over-design of my own. I had contacts given an identity in bulk
the first time synchronisation was switched on, and a full dedupe-key map of the
logbook rebuilt on every pass, both sized for 123 000 contacts.
Neither is needed, because the change log starts EMPTY. Contacts logged before
synchronisation was switched on are never in anyone's log and so are never
exchanged; an identity is stamped only on a contact that is actually logged,
edited or deleted from then on. Seeding a second machine with the existing
history is a one-time copy of the database or an ADIF import — not something
synchronisation should be doing, and not something it can do from a file that
starts empty.
One case survives, and it is why the dedupe key stays. Two machines can already
hold the SAME old contact, the second seeded by that copy or import, with
different row ids and no identity on either. The day one of them edits it, it
stamps an identity and sends a change naming it; the other has never seen that
identity and would insert a duplicate. Matching on the contact itself —
callsign, minute, band, mode, the importer's own key — recognises it.
So that became a targeted lookup through idx_qso_callsign, run only when an
identity is unknown, instead of a whole-table map rebuilt each pass. Rare work,
priced as rare work.
rouggy
c48294b0ca