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Marc-André Bombeck
d8196d5208
The weekly pass built the whole account in memory, serialised it whole, encrypted the string whole, and handed the result to the database whole. That is four full copies of the record at the same moment — the object graph, the JSON, the base64 ciphertext at 1.33x the JSON, and the copy the driver makes of that parameter. Measured against a seeded account of 445 000 readings, the JSON alone is 242 MB and the run dies of heap exhaustion; under a modest heap it never reaches the insert. The pass was not slow, it could not finish. A health record's JSON is extremely repetitive, so gzip takes that 242 MB to 14 MB and every copy after it shrinks with it. The same run completes in about twenty seconds with a peak heap of 434 MB and a stored row of 25 MB instead of 322 MB — which also matters because the copy lives inside the database it would be needed to restore. Both backup jobs now hand the serialised form back from a frame of its own, so the payload graph is released before the compress step allocates anything. The marker sits inside the ciphertext, so the stored column keeps the one shape `decrypt()` already understands and rows written before this still restore. The off-host object gets the same treatment through the version byte its envelope always carried; version 1 objects still read back, which both the restore drill and the restore script depend on. The obvious saving — dropping soft-deleted readings, four rows in five on a real record — is not taken, and the round-trip test now seeds a tombstone and asserts it makes the journey. A tombstone inside the retention window is what tells a synced client the row is gone and what makes a re-sent sample a no-op; a restore without them brings back every measurement the account ever deleted on the next device sync.