Query a column you never stored
A lot of enterprise columns are exact functions of other columns — total = qty×price, VAT, day-buckets, keys, running indexes, denormalized joins. AT-1 GenDerive discovers the function, verifies it on every row, and stores the column as a ~20-byte formula instead of data. Then it answers predicates on that column by running the formula — an index or aggregate query reads zero bytes.
Discover, store as a formula, query scan-free
at1 genderive build orders.csv -o orders.at1gd # 200,000 rows, 4 derived col(s) stored as formulas, 3 stored # total = qty*price (queryable, ~0 B) # vat = (total*15)//100 # seq = 1*i+0 at1 genderive query orders.at1gd "SUM total" # 6,967,314,136 [scan-free: computed from base, 0 B stored/scanned] at1 genderive query orders.at1gd "COUNT seq BETWEEN 50000 150000" # 100,001 [ZERO bytes read (index formula)] at1 genderive verify orders.at1gd # OK: reconstructed byte-exact (every formula-regenerated column matches)
Discovered, not declared
Finds product / affine / bucket / percentage / index dependencies — and composedones (a column derived from a derived column). Each is verified exact on every row before it’s trusted.
Scan-free answers
Aggregates compute from the base columns; index- function columns answer from pure arithmetic. The derived column is never stored and never scanned. Honest limit: a genuinely independent column can’t be beaten — it’s stored.
Byte-exact
Every eliminated column regenerates byte-for-byte on demand, verified against the original table’s hash. Storage shrinks; nothing is lost.
The general form of GenQuery: it works on any column that is an exact function of other stored columns — the union of generator-recovery and functional-dependency discovery. Pay-as-you-go: first 100 builds/month free, then metered per build. Query and verify are always free.