Lakewright solutions / brief

Load mainframe fixed-width files into Apache Iceberg

Fixed-width mainframe extracts — no headers, no delimiters — become typed Iceberg tables. Lakewright infers the column layout from the data itself, and the layout is recorded in a reviewable plan before anything loads.

How can columns be inferred without a copybook?

Character-class transitions (digit runs, space gutters, date shapes) that hold across sampled lines mark column boundaries. Every inferred boundary is visible in the plan YAML — a human confirms the layout before the first row lands. If you have the copybook, you edit the plan to match; the plan is the contract either way.

The steps

lakewright scan  /transfer/legacy-extracts
lakewright plan  /transfer/legacy-extracts --out plans   # review layout
lakewright approve plans/policy_master.plan.yaml
lakewright load  plans/policy_master.plan.yaml --rest $CATALOG

FAQ