CharlesKWON
935883bb88
TSqlExecutor:FetchRow was the per-row workhorse for aggregation, HAVING, and window queries. Even with the pre-built aFetchCache binding columns to (nWA, nFPos), the PRG FOR loop paid one method dispatch per column per row (dbSelectArea, FieldGet, AllTrim, AAdd) — profile pinned it at ~30% of B4 CPU. SqlFetchRowFast collapses the cache-path loop into a single Go call: - bound entry: SelectByNum + area.GetValue directly - unbound (aggregate/expression): self:EvalExpr via Send - character values: TrimSpace inline The PRG FetchRow keeps its original cache-miss fallback path unchanged for rare queries where aFetchCache isn't built. Bench deltas (median of 3 steady runs, 1000 iters): B4_GROUP_HAVING 418 → 327 us -22% (1.28x) B9_ROW_NUMBER 191 → 120 us -37% (1.59x) B10_RANK_PART 228 → 135 us -41% (1.69x) B11_SUM_OVER 249 → 156 us -37% (1.60x) B14_COUNT 235 → 219 us -7% B15_CTE_WIN_JOIN 1577 → 1452 us -8% Single-table SELECT (B1-B3, B5-B7, B8) stays flat — those already hit the column-binding fast path and don't need aggregate dispatch. FiveSql2 43/43, Harbour compat 56/56. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
FiveSql2 — SQL Engine for Harbour DBF/NTX/CDX
Pratt parser + SQL:1992-2023 full standard support Supports both NTX (Clipper) and CDX (FoxPro/ADS) indexes
Architecture
five_SQL("SELECT ...")
│
├── TSqlLexer Tokenizer
├── TSqlParser2 Pratt parser (data-driven operators)
├── TSqlExecutor Query executor (Volcano model)
│ ├── TSqlAlias Central alias manager (no collisions)
│ ├── TSqlIndex NTX/CDX index optimization (auto-detect)
│ ├── TSqlAgg GROUP BY / aggregation
│ ├── TSqlSort ORDER BY / DISTINCT
│ ├── TSqlDDL CREATE/DROP/ALTER TABLE/INDEX
│ └── TSqlTxn BEGIN/COMMIT/ROLLBACK
├── TSqlExpr AST nodes + expression evaluation
└── TSqlFunc 60+ scalar functions
Build & Test
export PATH="/path/to/harbour-core/bin/linux/gcc:$PATH"
export HB_INSTALL_PREFIX="/path/to/harbour-core"
make # Build all tests
make test # Run all 157 tests
make bench # Parser benchmark
make clean # Clean
SQL Standard Coverage
| Standard | Features | Tests |
|---|---|---|
| SQL:1992 | SELECT, JOIN, GROUP BY, HAVING, Subquery, CASE, CAST | 43 |
| SQL:1999 | CTE, Recursive CTE, Window Functions, MERGE | 10 |
| SQL:2003 | SIMILAR TO, GROUPING SETS, LATERAL, Window frames | 64 |
| SQL:2008 | FETCH/OFFSET, FOR UPDATE, Extended MERGE | (incl.) |
| SQL:2016 | JSON functions, LISTAGG | (incl.) |
| SQL:2023 | ANY_VALUE, GREATEST/LEAST, BOOL_AND/OR | (incl.) |
| Challenge | LeetCode-level complex queries | 15 |
| Extreme | Production analytics stress tests | 15 |
Adding New Operators
Edit TSqlParser2.prg, method InitInfixTables():
::hInfixTT[ TK_MYOP ] := { "<=>", 40, 41, ND_BIN }
One line. No structural changes needed.
Copyright
Copyright (c) 2025-2026 Charles KWON (Charles KWON OhJun) Email: charleskwonohjun@gmail.com All rights reserved.