Sheetbysheet

Sheetbysheet is a term used in data processing to describe the practice of handling the individual worksheets of a multi-sheet spreadsheet file one sheet at a time, then integrating the results into a unified dataset. The approach treats each sheet as a modular data source, allowing sheet-specific cleaning, transformation, and validation before any consolidation.

The concept emerged in data engineering and spreadsheet governance as a pragmatic response to real-world files that contain heterogeneous data sections within a single workbook. Rather than attempting to force a single schema across all sheets, sheetbysheet emphasizes per-sheet processing followed by reconciliation during the merge phase.

A typical sheetbysheet workflow involves loading a workbook, iterating over its sheets, applying cleaning rules and type conversions appropriate to each sheet, and mapping each sheet to a canonical schema. Metadata such as sheet name and last modified timestamps are preserved to aid auditing. After per-sheet processing, results are concatenated or joined into a master dataset, with conflict resolution and provenance information recorded. The process is often parallelizable, as sheets are independent until the final merge.

Advantages include modularity, easier handling of varying data quality or schema across sheets, improved error isolation, and clearer audit trails. It supports incremental updates when individual sheets change, without reprocessing the entire workbook. Limitations arise from inconsistent column naming, unit mismatches, and conflicting per-sheet assumptions that must be reconciled during merging.

Common use cases include financial reports with separate sheets for revenue and expenses, inventory lists divided by location, and scientific data collected in multiple sheets. See also ETL, data wrangling, spreadsheets, and workbook processing.