Why COBOL main menu search is instantaneous I asked Claude and it explains as follows: Why COBOL search is instantaneous Why not just use Python + pandas, SQLite FTS, or ripgrep? The answer is in what the COBOL + IBM STL approach eliminates entirely. No parsing, no allocation, no dispatch Every record in every .DAT file is fixed-width. COBOL declares the exact byte layout in the DATA DIVISION at compile time: 05 SEC10K-TICKER PIC X(10). ← starts at byte 1 05… https://felixquinihildebet.wordpress.com/2026/04/12/why-cobol-main-menu-search-is-instantaneous/