Bulk initial load - drop :db-before, etc.?

[denew]

Loading ~3000 records, each of about 8KB, using :local: file. Started reasonably quickly, but 2/3 in, now nearly 2 minutes per record. I assume this is because of the state/transaction data preservation as indicated by the deref of d/transact, i.e. the :db-before, :db-after, :tx-data, :tempids (which I'll refer to as metadata) and their associated processing. I am converting from an old mongo db, so statements are being executed as...

@(d/transact conn {:tx-data [(hash-map :db/ident (:id ex-mongo)...]})

...in a loop. The resulting asami db works fine, but I wonder if there is an 'override' for initial loads, as the metadata/history is irrelevant at this point. (If I drop the @/deref, insertion speed is near enough to instant, but the record can't be queried for some time without throwing an exception, presumably while the metadata catches up.

I could try importing from EDN after another conversion exercise, but I'm not clear if that bypasses the issue. Am I doing it wrong?