Commit Graph

14 Commits

Author SHA1 Message Date
63f75bf2bc fix(FiveSql2): 5 more latent bugs — Resolve NULL, LEFT JOIN, UNION order, DATEADD, VIEW cleanup
Continues the static-analysis sweep from 7babfb7.

--- #3 Resolve NIL ambiguity (HIGH) ---

ResolveFromOuter returned NIL for both "column not found" and
"column value is NULL". Callers tested `xVal != NIL` to decide
success, which silently dropped legitimate NULL outer-row values
in correlated subqueries. Added a by-reference lFound flag so
callers distinguish the two cases.

--- #14 Multi-level LEFT JOIN null-fill (MEDIUM) ---

LEFT JOIN null-fill only fired at the last join level
(`nIdx >= Len(aJoins)`). For `a LEFT JOIN b ON ... JOIN c ON ...`
where b had no match, the null-fill for b was skipped and the
outer row was dropped entirely. Now recurses into subsequent joins
when the match fails, so the base case can still emit a row with
NULLs for b's columns.

--- #18 UNION/INTERSECT/EXCEPT applied after LIMIT (MEDIUM) ---

SQL standard requires set operations before ORDER BY / DISTINCT /
OFFSET / LIMIT. Reordered to:
  RIGHT JOIN pass → UNION/INTERSECT/EXCEPT → DISTINCT → ORDER BY
  → OFFSET → LIMIT.
Previously LIMIT clipped the first SELECT before UNION merged the
second's rows, producing more rows than intended.

--- #22 DATEADD month overflow (LOW) ---

`DATEADD('MONTH', 1, '2024-01-31')` produced `SToD("20240231")`
(Feb 31) → empty date. Now normalizes month overflow/underflow
into year rollover and clamps the day to the target month's last
day. Year addition also handles Feb 29 → Feb 28 on non-leap years.

--- #23 VIEW temp file leak (LOW) ---

TSqlIndex:CheckView creates `__view_<table>.dbf` temp files that
were never cleaned up. Added post-scan cleanup in RunSelect's
close section (after CTE cleanup) that erases matching temp files.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-16 20:34:42 +09:00
7babfb7281 fix(FiveSql2): 9 latent bugs from static analysis sweep
Systematic bug-hunt driven by an automated analysis of all FiveSql2
source files. Each fix is targeted — no speculative refactoring.

--- #1 CLASSDATA hSubCache leaked across queries (CRITICAL) ---

  CLASSDATA hSubCache INIT { => } SHARED

shared one hash across ALL TSqlExecutor instances. A non-correlated
subquery cached in query A was silently returned for an unrelated
query B if the subquery text happened to produce the same cache key.
Converted to instance DATA initialized in New().

--- #5+#21 IS NULL / COALESCE treated empty string as NULL (HIGH) ---

  RETURN xL == NIL .OR. ( ValType(xL) == "C" .AND. Empty(AllTrim(xL)) )

SQL standard: '' is a valid non-NULL value. Removed the empty-string
check from both IS NULL evaluation and COALESCE skip logic.

--- #4 Multiple ? parameters all returned first value (HIGH) ---

ND_PAR nodes had no index — EvalExpr always returned ::aParams[1].
Parser now stamps each ? with a sequential 1-based index in xNode[2].
EvalExpr uses it to return the correct ::aParams[n].

--- #10+#11 SqlEvalRowExpr missing / and || operators, single-arg
    function eval (MEDIUM) ---

Division and string concatenation fell through to RETURN NIL in the
row-expression evaluator used by recursive CTEs and aggregate
ComputeAgg. Also, multi-argument functions like SUBSTR(x,2,3) only
received the first argument. Both fixed.

--- #9 SUM/AVG/MIN/MAX of all NULLs returned 0 instead of NULL
    (MEDIUM) ---

SQL standard requires NULL. Changed the aggregate return path to
return NIL when nCount == 0 (SUM/AVG) or when xMin/xMax == NIL.

--- #8 MIN/MAX used SqlCoerceNum for comparison (MEDIUM) ---

Strings and dates were coerced to numbers (Val()) before comparing,
making MIN('banana') == MIN('apple') == 0. Switched to SqlCmpLt
which handles type-appropriate comparison.

--- #7 SqlExprHasAgg only checked top-level node (MEDIUM) ---

Expressions like `salary + COUNT(*)` were not detected as containing
an aggregate because the top node was ND_BIN, not ND_FN. Made the
function recursive — walks ND_BIN, ND_UNI, ND_FN args, ND_CASE
branches.

--- #13 SELECT * only expanded first table in JOINs (MEDIUM) ---

`SELECT * FROM orders o JOIN customers c ON ...` only included
fields from orders. Changed the expansion loop to iterate ALL
entries in ::aTables.

--- #2 s_aOuterStack not unwound on subquery error (HIGH) ---

SubqueryCached's PushOuter/PopOuter pair was not protected by
BEGIN SEQUENCE. A runtime error inside the subquery left a stale
entry on the module-level outer stack, corrupting all subsequent
queries' correlated column resolution. Wrapped in SEQUENCE/RECOVER.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-16 17:26:05 +09:00
6c8d5f8b3b fix(FiveSql2): correlated scalar subquery with JOIN — 3 interacting bugs
A scalar correlated subquery with a JOIN inside:

    SELECT e.name,
      (SELECT SUM(o.qty * p.price)
       FROM ord o INNER JOIN prod p ON o.prod_id = p.id
       WHERE o.emp_id = e.id) AS revenue
    FROM emp e WHERE e.dept = 'SALES'

returned wrong values (equal to SUM(qty) instead of SUM(qty*price))
or zero for all but the first outer row. Root cause was a triple
interaction between three independent bugs.

--- Bug 1: Subquery cache leaked across five_SQL invocations ---

hSubCorrCache, aSubCacheSlots, aSemiJoinSlots, nSubCacheSeq were
declared as DATA ... INIT { => } / {} / 0. In Five's compiled output,
hash/array INIT literals may share the same backing instance across
New() calls, so the cache from query A (SUM qty, no join) was still
there when query B ran, providing a hit on the same key — returning
A's cached (wrong) value instead of re-executing B's subquery.

Fix: explicit initialization in New().

--- Bug 2: aJoins alias mutation across subquery invocations ---

RunSelect's join-alias sync loop mutated aJoins[i][3] from the
user alias ("p") to the depth-suffixed temp alias ("FA_0003").
aJoins was a direct reference into hQuery["joins"], so the mutation
persisted across re-executions of the same hQuery. On the 2nd call,
the sync loop couldn't find a matching aTables entry because the
stale temp alias ("FA_0003") didn't match the new one ("FA_0005").
The join table's workarea was positioned wrong → empty join result.

Fix: deep-clone both ::aTables and aJoins at the start of RunSelect
so each invocation starts from the parsed originals.

--- Bug 3: SqlCollectCols stripped alias prefixes ---

When adding hidden columns for complex aggregate arguments (e.g.
SUM(o.qty * p.price)), SqlCollectCols returned bare names like
"qty" and "price" instead of qualified "o.qty" / "p.price". In a
JOIN context, unqualified "price" routed FetchRow to the first
table (ord) instead of prod — FieldPos returned 0, the column was
silently NIL, and the multiplication collapsed to qty*1 = qty.

Fix: new SqlCollectColExprs returns the original ND_COL AST nodes
with qualified names preserved. The hidden-column loop now inserts
these directly so FetchRow's dot-qualified path resolves to the
correct workarea via FindWA.

--- Verification ---

Deterministic 5-emp / 6-order / 3-product test:

    Expected revenues per emp:
      Emp 1: 2*10 + 3*20 = 80    → got 80.00 ✓
      Emp 2: 1*10 + 4*30 = 130   → got 130.00 ✓
      Emp 3: 5*20 = 100          → got 100.00 ✓
      Emp 4: no orders = 0       → got 0 ✓
      Emp 5: 7*10 = 70           → got 70.00 ✓

Also verified SUM(qty*2) and SUM(p.price) variants.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-16 11:33:35 +09:00
99f3ca5687 perf(FiveSql2): EXISTS semi-join lift — H3 correlated EXISTS ~2000x faster
Correlated EXISTS with high-cardinality keys was stuck at O(outer × inner)
because memoization couldn't amortize across unique correlation values.
H3 in the subquery stress bench:

    SELECT e.name FROM emp e
    WHERE EXISTS (SELECT 1 FROM ord WHERE ord.emp_id = e.id AND ord.qty > 15)

500 outer rows × 500 distinct e.id values × 5000-row ord scan = 10s,
with no path to improvement from caching the subquery result.

Fix: detect the semi-join shape on the subquery and rewrite it at
runtime into a non-correlated DISTINCT scan whose result is cached
as a hash set. Each outer row then becomes an O(1) hash probe.

--- What we lift ---

  SELECT ... FROM inner_table
  WHERE inner.col = outer.col [AND other_non_correlated_preds]

Shape constraints (all must hold):
  - single table, no JOIN
  - no GROUP BY, no HAVING, no UNION
  - WHERE is an AND tree containing an equi-term where one side is
    a column with an alias prefix from the subquery's own FROM
    and the other is a column from an outer alias
  - the remaining AND terms (non-correlated residue) have no
    outer references of their own — rules out patterns like
    `WHERE e2.dept = e.dept AND e2.salary > e.salary` where the
    second term can't live without the outer context

--- How the lift works ---

1. Walk the WHERE as a flat AND-term list
2. Find and remove the first correlated equi-term, remember the
   inner column name and outer column reference
3. Verify residue is non-correlated via a recursive AST walker
   (SemiJoinHasOuterRef) — bail to fallback if not
4. Clone hQuery with:
     columns  = {DISTINCT inner.col}
     where    = residue (or NIL)
     distinct = .T.
     limit / top / order_by / group_by / having cleared
5. Run the cloned subquery once via a nested TSqlExecutor — no
   PushOuter because it's now non-correlated
6. Build a hash set keyed on SqlValToStr(each distinct inner value)
7. Per EXISTS probe: Resolve the outer column reference, look up
   in the hash set

Cached in ::aSemiJoinSlots indexed by xSubNode identity so the
analysis + lifted scan runs exactly once per subquery expression.
Subqueries that don't match the shape store the sentinel "NO" so
subsequent probes skip re-analysis and fall through to the existing
SubqueryCached + LIMIT 1 path.

NOT EXISTS works through the same path — lNegate flag just flips
the final hash-lookup result.

--- Bench (emp=500, prod=100, ord=5k) ---

  Pattern                         Before      After      Speedup
  ────────────────────────────────────────────────────────────
  H3  EXISTS correlated           10.0s       4.5ms      ~2200x
  H8  NOT EXISTS self-join         900ms      890ms      same (can't lift:
                                                          remainder
                                                          `e2.salary > e.salary`
                                                          is correlated)
  H11 Scalar + EXISTS + derived    3.2s       1.0s       3.2x

H8 correctly falls through to the non-lifted path because the
remainder outer-reference check (SemiJoinHasOuterRef) rejects the
`e2.salary > e.salary` term. The 5-row answer is still correct.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS
  - H3 returns 125 rows (matches pre-change correct result)
  - H8 returns 5 rows (matches pre-change correct result)

Known pre-existing bug, unrelated: H7 (scalar correlated subquery
with inner INNER JOIN) returns zero for rows 2..N — workarea state
leaks between consecutive subquery invocations. Not touched here,
filed for follow-up.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-15 23:06:35 +09:00
ce7593c50f perf(FiveSql2): EXISTS → LIMIT 1 early exit, subquery identity via AScan
Extreme subquery stress bench (12 patterns spanning scalar-in-SELECT,
nested correlation, EXISTS, NOT IN, derived tables, self-joins, and
mixed combinations) exposed three weaknesses in the post-ROLLUP state:

1. EXISTS / NOT EXISTS evaluated the full subquery result per outer
   row, even though it only needs to know whether any row matches.
2. EXISTS was routed through a separate code path that bypassed the
   correlated-memoization cache from 2d90236.
3. The previous SubqueryCached identified each subquery node by
   mutating slot 6 on the ast array via ASize — which interacted
   badly with downstream code paths expecting the original shape
   (derived-table queries panicked on ArrayPop after the ASize).

Fixes:

* EXISTS / NOT EXISTS now route through SubqueryCached the same way
  ND_SUB in WHERE does, so correlated EXISTS predicates memoize on
  outer free-variable values when the cardinality is low.

* The EXISTS handler plants `hQuery["limit"] := 1` on the subquery
  before the first execution. EXISTS doesn't care about the rest
  of the result rows, so dropping the scan cap saves full-scan
  cost in the common case.

* A new early-termination branch in RunSelect's scan loop exits
  the `WHILE !Eof()` as soon as aRows reaches nLimit, guarded by
  the same "no ORDER BY / GROUP BY / agg / DISTINCT" precondition
  (those need the full input). This is what makes the LIMIT 1
  injection actually pay off — before, LIMIT was only applied via
  ASize after the full materialized scan.

* SubqueryCached no longer mutates the parse tree. Instead of
  ASize-ing the node and stashing cache metadata in slot 6, it
  keeps a per-executor aSubCacheSlots list of
  {xSubNode, {id, aFreeVars}} pairs and identifies nodes by
  Harbour's reference-equality `==` on arrays. O(n) lookup in n =
  number of distinct subqueries in the query, which is ≤ 4 or so
  for all realistic queries, so the linear scan is free. Fixes the
  derived-table ArrayPop panic.

Bench impact (emp=500, prod=100, ord=5k — subquery hell):

  Pattern                           Before    After   Δ
  ───────────────────────────────────────────────────────
  H3  Correlated EXISTS             13.3s    10.0s   1.3x
  H7  Scalar-in-SELECT + JOIN        362ms    2ms   181x
  H8  NOT EXISTS self-join            1.8s  900ms   2.0x
  H11 Scalar + EXISTS + derived     13.7s    3.2s   4.3x
  (H1, H2, H5, H6, H9, H10, H12 unchanged at 3–72ms)

H7's 181x is the scalar-in-SELECT-list memoization payoff — each
dept's revenue subquery used to run 100 times (once per SALES emp),
now runs once per distinct dept.

H3's 1.3x is the best we can do without semi-join lift: 500 outer
rows × 500 unique correlation keys = 500 cache misses, and the 375
rows whose correlation finds no match must scan the full ord table
to confirm emptiness. Fixing that needs the optimizer to rewrite
`WHERE EXISTS (SELECT 1 FROM ord WHERE ord.emp_id = e.id AND ...)`
into `WHERE e.id IN (SELECT DISTINCT emp_id FROM ord WHERE ...)`,
which is a real query-rewrite feature left for a follow-up.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-15 16:31:36 +09:00
2d9023622c feat(FiveSql2): ROLLUP/CUBE/GROUPING SETS + correlated subquery memoization
Two SQL:2013 features that were stubs or bugs. Both ship together
because they share testing infrastructure (the SQL:2013 analytics
bench).

--- 1. ROLLUP / CUBE / GROUPING SETS (TSqlAgg) ---

The parser has recognized these for a while, storing them as
`ND_FN "ROLLUP"` / "CUBE" / "GROUPING SETS" nodes inside the
GROUP BY list. GroupBy never actually expanded them — it treated
the ND_FN as an opaque group term, which meant every row hashed
into the empty bucket and the query returned a single row.

New TSqlAgg:ExpandGroupingSets walks the aGroupBy array and
expands each ROLLUP / CUBE / GSETS modifier into a list of flat
grouping sets by cross-product with the surrounding plain terms:

    GROUP BY ROLLUP(a, b, c)          → {(a,b,c), (a,b), (a), ()}
    GROUP BY CUBE(a, b)               → {(a,b), (a), (b), ()}
    GROUP BY GROUPING SETS((a,b),())  → as-is
    GROUP BY x, ROLLUP(a, b)          → {(x,a,b), (x,a), (x)}

When the expansion produces more than one set, GroupBy recurses
once per set (passing the plain flat set) and NILs out SELECT
columns that aren't in the current set — the standard subtotal
placeholder. Fast path (no ROLLUP/CUBE/GSETS node) short-circuits
to the original single-pass logic.

Correctness check: `SELECT region, SUM(amount) FROM sales GROUP BY
ROLLUP(region)` on a 5-region dataset now returns 6 rows (5
per-region subtotals + 1 grand total row with region=NIL). Was 1.

--- 2. Correlated subquery memoization (TSqlExecutor) ---

Committed 9e0f82c fixed a silent caching bug that made correlated
subqueries return the first outer-row's result for every subsequent
row, at the cost of dropping caching entirely — every outer row
re-executed the subquery. For Q8 in the SQL:2013 bench (1000 emps,
correlated on 3 distinct depts) that was 4.9 seconds.

The right answer is to memoize per outer-key, not globally. This
commit adds:

  - TSqlExecutor:CollectFreeVars(hQ): walks a subquery's WHERE,
    columns, and HAVING for ND_COL references whose alias prefix
    isn't one of the subquery's own FROM tables. Those are the
    outer columns the subquery actually depends on.

  - TSqlExecutor:SubqueryCached(xSubNode): runs the free-var
    analysis once per distinct AST node (memoized onto a 6th slot
    on the node), builds a cache key from the current values of
    those free vars via ::Resolve(), looks up in ::hSubCorrCache,
    executes on miss. Non-correlated subqueries end up with an
    empty free-var list → single cache entry → same behavior as
    the old CacheSubquery fast path.

  - ND_SUB and ND_SUB-in-IN handlers route through SubqueryCached
    instead of the split cache/push-outer logic.

Plus a correctness fix that SubqueryCached surfaced: when a
subquery runs at nDepth > 1, TSqlExecutor rewrites each FROM
table's alias to a depth-suffixed temp (so concurrent opens of
the same file don't collide). Previously the original user-written
alias was only preserved in aTables[i][3] for single-char aliases.
Multi-char aliases like `emp e2` lost their original after the
rename, so FindWA("E2") failed, Resolve("e2.dept") returned NIL,
and `WHERE e2.dept = e1.dept` evaluated NIL=NIL → every row was
filtered out → subquery AVG returned 0 → outer `salary > 0` was
trivially true for everyone. Now we always stash the original
alias in [3] before the rename.

--- Bench (SQL:2013 analytics, 10 queries, emp=1k, sales=20k) ---

  Query                        Before        After     Δ
  ────────────────────────────────────────────────────────
  Q6 RECURSIVE hierarchy       (prev fix)    30ms
  Q7 ROLLUP subtotals          86ms, 1 row   106ms, 6 rows  (correct)
  Q8 Correlated subquery       4933ms        20ms           ~245x
  (all other queries unchanged at 4–230ms)

Q8 30-row sanity regression test (emp.dept in {A,B,C}, deterministic
salaries so hand-computed averages are 155/810/1765):

    SELECT name, dept, salary FROM emp e1
    WHERE salary > (SELECT AVG(salary) FROM emp e2 WHERE e2.dept = e1.dept)

  Before: 30 rows (wrong — returns all)
  After:  15 rows (correct — 5 above each dept's average)

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-15 10:13:31 +09:00
9e0f82c5a8 perf+fix(FiveSql2): recursive-CTE hash join + correct correlated subqueries
Two fixes uncovered by a SQL:2013 analytics benchmark covering the
query patterns people actually run on DBF data (OLAP, BI, hierarchy
traversal).

--- Fix 1: correlated subquery was silently wrong ---

EvalExpr's ND_SUB handler only pushed the outer context when
`s_aOuterStack` was already non-empty — otherwise it routed the
subquery through CacheSubquery, which stores the first result under
a key derived from the subquery's syntax tokens. For a correlated
subquery in a top-level WHERE:

    SELECT name, dept, salary FROM emp e1
    WHERE salary > (SELECT AVG(salary) FROM emp e2 WHERE e2.dept = e1.dept)

the first outer row saw an empty stack, cached the result, and
every subsequent outer row got the same cached value regardless of
e1.dept. The query returned all 1000 employees instead of the 505
who actually beat their department's average.

Fix: always PushOuter + Run, no cache. Correctness over caching.
Trade-off: non-correlated scalar subqueries now re-execute per
outer row. A proper per-outer-key memoization is deferred — it
requires walking the subquery AST to collect free variables.

--- Fix 2: WITH RECURSIVE hierarchy join was O(m*n) ---

RecCteJoin (the in-memory join used when a recursive CTE's step
references both a real table and the CTE frontier) ran a flat
nested loop: for each DBF row × each prev-iteration row, build a
combined row buffer and run SqlEvalRowExpr on the ON condition.

For a 4-level 1000-employee hierarchy that's ~1M ON evaluations,
~4.6 seconds.

Fix: detect the shape `dbfAlias.col = cteAlias.col` at join-setup
time, build a PRG hash on the CTE frontier keyed by its join column
(aPrevRows is always small — at most the last iteration's emitted
rows), then scan the DBF side once and probe the hash. Complex ON
predicates fall through to the original nested loop.

--- Bench (SQL:2013 analytics, emp=1k, sales=20k, evt=30k) ---

  Query                              Before     After    Speedup
  ──────────────────────────────────────────────────────────────
  RECURSIVE hierarchy 4-level        4603ms     30ms     ~150x
  Correlated subquery (all emp)      10ms     4933ms ✓ (correct)

Other SQL:2013 queries (ROW_NUMBER top-N, running total, moving
average, DENSE_RANK, LAG, NTILE, gaps-and-islands) are all in the
expected 10–230ms range for these dataset sizes, unchanged by
this commit.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS

Known follow-ups (not in this commit):
  - Q7 ROLLUP(col) parses but isn't expanded in GroupBy — returns
    a single grand-total row instead of per-value + total. Grouping
    sets implementation is a separate feature.
  - Correlated subquery memoization by outer free-variable key
    would bring Q8 from 4.9s back to ~50ms for small cardinality
    correlations — requires AST free-var analysis.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-14 23:25:58 +09:00
64b7cf6676 perf(FiveSql2): compound-AND equi-join picks up hash path — CTE+JOIN 22x
FiveSql2's HashJoin only recognized bare equi-terms (xOnCond[1]=ND_BIN,
xOnCond[2]="="), so a compound ON predicate like

    ON e.dept_id = t.dept_id AND e.salary = t.max_sal

fell through to the nested-loop ELSE branch:

    dbSelectArea(nInnerWA)
    dbGoTop()
    WHILE !Eof()
        IF SqlIsTrue(EvalExpr(xOnCond))
            JoinRecurse(...)
        ENDIF
        dbSkip()
    ENDDO

That's O(outer × inner) per outer row, re-evaluating the full AND tree
every probe. Query Q7 in the complex benchmark (CTE top_emp joined back
to emp on compound key) ran at 4.6 seconds for 100 inner × 10k outer.

Fix has two pieces:

1. **Probe-term extraction in JoinRecurse**: when xOnCond is an AND,
   walk the left-associative chain looking for the first equi-term
   (`a.x = b.x`). Use that as the hash-probe key, drive the normal
   hash-join code path through it.

2. **Post-filter in HashJoin**: after a hash match, if the *original*
   xOnCond was compound, re-evaluate the full predicate with
   EvalExpr to drop matches that satisfied the hash key but not the
   rest of the AND (e.g. same dept but different salary). Bare equi-
   joins still skip the re-eval — the hash match is conclusive.

Bench (10k × 100 × compound ON predicate):

  Query                          Before     After    Speedup
  ─────────────────────────────────────────────────────────
  Q7 CTE + JOIN compound ON      4573ms     209ms    21.9x

Still works for the existing bare equi case (43-test unchanged) and
the 3-way JOIN case (no regression). Falls back to the generic nested
loop only when no probe-term can be extracted at all.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS
  - Q7 result: 100 rows (correct)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-14 20:31:27 +09:00
c6799a599e fix(FiveSql2): GROUP BY with aliased SELECT collapses all rows into one
Surfaced by complex-query benchmarking. Query like:

    SELECT d.name AS dept, COUNT(*) AS n, SUM(o.amount) AS total
    FROM dept d INNER JOIN emp e ON ... INNER JOIN ord o ON ...
    GROUP BY d.name

returned exactly 1 row instead of 100. Removing the AS aliases made
it work correctly. Semantic bug, not a performance issue.

Root cause: TSqlAgg:GroupBy resolved each GROUP BY column by calling
FindColIdx against aFN — the output alias list. For GROUP BY d.name
with d.name AS dept, the group expression's column name was looked
up in {"dept","n","total"} and missed. FindColIdx returned 0, every
row got an empty group key, and the hash collapsed everything into
one bucket.

Fix: new FindGroupIdx walks aCols (SELECT list expressions) instead,
matching the GROUP BY column against each SELECT item's source
expression ND_COL name. Handles qualified refs (d.name -> NAME) and
falls back to FindColIdx for cases where GROUP BY uses a column not
in the SELECT list.

Also hoisted the resolution out of the per-row loop — GROUP BY
columns resolve once into aGroupIdx[] so each row just indexes.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - Complex bench Q4: 1 row -> 100 rows (correct)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-14 20:25:02 +09:00
bfc6ded8cb perf(FiveSql2): SqlHashBuild + FetchRow column binding — 3-way JOIN 3x
Complex-query benchmarking turned up two hot paths that the earlier
SqlScan/SqlEach work didn't touch: multi-table JOIN and nested-scan
row fetching. This commit hits both.

--- Part 1: SqlHashBuild — Go-native hash-join build ---

FiveSql2's HashJoin previously built the inner-side hash in PRG:

    WHILE !Eof()
      xVal := FieldGet(nFPos)
      cKey := SqlValToStr(xVal)
      IF !hb_HHasKey(hHash, cKey) ; hHash[cKey] := {} ; ENDIF
      AAdd(hHash[cKey], RecNo())
      dbSkip()
    ENDDO

That loop runs at ~40μs per row from class dispatch + hb_HHasKey
lookups + AAdd growth + SqlValToStr formatting. On a 50k-row inner
table that's ~2 seconds wasted on what should be a sub-50ms
housekeeping op.

New hbrtl.SqlHashBuild does the same thing in one Go-native pass:

  - Direct *dbf.DBFArea loop (no interface dispatch, same devirt as
    SqlScan)
  - Go `map[string][]int64` accumulates RecNos by key — one
    allocation per distinct key
  - Inline ASCII-only digit formatter for numeric keys (strconv.Itoa
    is allocation-heavy for small ints)
  - CHAR keys are right-trimmed to match SqlCmpEq semantics so the
    hash probe matches what EvalExpr would compute
  - Final Five hash is built once from Keys/Values/Order slices
    directly, skipping the per-key hb_HSet path

HashJoin now calls `SqlHashBuild(nFPos)` instead of running the
PRG loop.

--- Part 2: TSqlExecutor:BuildFetchCache ---

The JOIN fallback loop calls FetchRow per row. FetchRow was already
column-ref-aware but did the string parse (`At + SubStr + Upper`)
and `::FindWA` linear scan every single invocation. For a 50k-row
join emitting 50k result rows, that's ~200k redundant resolutions.

New BuildFetchCache walks the SELECT list once before the scan and
pre-binds each plain-column expression to `{nWA, nFPos}`. FetchRow's
new fast path checks ::aFetchCache and jumps straight to
`dbSelectArea + FieldGet` when bound. Complex exprs (functions,
CASE, subqueries) still fall through to EvalExpr.

::aFetchCache is set right before the join WHILE loop and cleared
after — no cross-query bleed.

--- Bench (50k ord × 10k emp × 100 dept, 3-run steady state) ---

  Query                        Before      After     Speedup
  ────────────────────────────────────────────────────────────
  2-way INNER JOIN, 10k rows   91ms        68ms      1.34x
  2-way JOIN + GROUP BY        110ms       94ms      1.17x
  3-way INNER JOIN COUNT       2610ms      610ms     4.28x
  3-way JOIN + GROUP BY        2860ms      830ms     3.45x

The 3-way speedup is almost entirely SqlHashBuild. The 2-way case
benefits from the fetch cache because its per-row cost is dominated
by FetchRow (no second hash build to amortize).

--- Limits still standing ---

CTE + JOIN queries (Q7 in bench_complex: ~4.5s) aren't affected by
either optimization — CTE materialization goes through a different
path that writes/reads a temp DBF. Follow-up target.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-14 18:47:20 +09:00
e75167c2e9 feat(FiveSql2): five_SQL block-callback integration — SQL beats raw PRG
Wires the new SqlEach RTL into FiveSql2's front-end so users write
the SQL they know and opt into streaming with a familiar Harbour
code block — no manual RTL plumbing.

API:

    /* Existing array form — unchanged, 43-test still green */
    aR := five_SQL( "SELECT name FROM t" )

    /* New block form — zero intermediate rows, 2x raw PRG */
    five_SQL( "SELECT id, name FROM t WHERE salary > 50000", NIL,
              {|nID, cName| Process(nID, cName)} )

Parameter order (cSQL, aParams, bBlock) keeps backward compatibility
with every existing call site. Passing NIL for aParams when only a
block is needed is standard Harbour idiom.

Routing:
  * TFiveSQL:Execute now takes an optional bBlock parameter and
    stores it on TSqlExecutor as ::bRowBlock.
  * TSqlExecutor:RunSelect's existing Go fast path (same guards as
    before: single table, no JOIN/GROUP/aggregate, plain column
    projections, WHERE compilable via SqlExprToPrg) branches on
    ::bRowBlock:
      - block present → SqlEach streams rows through the block
      - block absent  → SqlScan materializes into aRows (current path)
  * Post-processing (GROUP BY / ORDER BY / window / DISTINCT / LIMIT)
    runs on empty aRows when block mode fires — all are no-ops on
    empty input, so the sequence stays harmless.
  * RunSelect returns NIL (not {fields, rows}) when ::bRowBlock was
    used — signals "streaming semantics, all work done in the block".

Complex queries (JOIN, GROUP BY, subquery, window, ORDER BY not
matchable by an index, LIMIT/OFFSET, etc.) still fall back to the
array path even when a block is supplied — those genuinely require
materialization. Block mode is a fast-path opt-in, not a semantic
change.

End-to-end bench (50k rows, steady state — includes the user-side
loop/block for every row):

  Path                                   Time     Speedup vs raw
  ──────────────────────────────────────────────────────────────
  Raw PRG DO WHILE !Eof() + WHERE sum    7.6ms    1.00x
  five_SQL array + FOR                   7.7ms    ~same
  five_SQL + block (new)                 3.7ms    2.05x ← beats raw
  ──────────────────────────────────────────────────────────────
  Raw PRG no WHERE                       6.1ms    1.00x
  five_SQL + block, no WHERE             2.9ms    2.10x ← beats raw

SQL now pays for itself on end-to-end timing — not just competitive
with hand-rolled RDD loops, but faster than them. The layered cost
of FieldGet's Frame+RTL-dispatch that hand-written loops incur per
call is gone; the block-callback path captures *dbf.DBFArea directly
via FastFieldGetter and uses PcOpFieldGet to bypass dispatch in the
compiled WHERE predicate.

Validation:
  - FiveSql2 43/43 (array API unchanged)
  - Harbour compat 51/51
  - go test ./... ALL PASS

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-14 17:00:46 +09:00
ad69221136 revert(FiveSql2): restore TSqlIndex:FindExclusive scan
Previous short-circuit (return 0 unconditionally) was a workaround
for two bugs that are both fixed now:

  1. gengo PushLocal(0) panic on unresolved identifiers
     → fixed by 08ad6f4 (PushMemvar fallback).
  2. dbInfo(DBI_FULLPATH / DBI_SHARED) returning NIL
     → fixed by d74014a (real implementations).

Restoring the original scan: walk workareas 1..250, check if any
holds an exclusive lock on the target DBF. With dbInfo now functional
and the DBI_* constants defined in include/dbinfo.ch (commit 3a00aa5),
this gives FiveSql2 real pre-flight conflict detection for concurrent
table access rather than silently proceeding into a lock failure.

Validation:
  - FiveSql2 43/43
  - standalone PRG with dbUseArea + five_SQL works (was the original
    repro that triggered the workaround)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-14 12:07:40 +09:00
8aaed994f4 perf(FiveSql2): hybrid fast path — 11x speedup on string WHERE scans
Implements hybrid execution model: keep AST tree-walk for SQL:2013+
features (Window, Recursive CTE, JOIN, aggregates) while compiling
simple SELECT hot paths to Go + pcode. See docs/FiveSql2-Hybrid-Plan.md
for the full architecture rationale (why not SQLite-style VDBE).

Hot path (single table, no joins/groups/aggregates):
  - TryBuildFieldPositions: resolves SELECT column list to FieldPos
    array once per query (bails to PRG loop on any complex expr).
  - TryCompileWhere + SqlExprToPrg: walks WHERE AST, emits equivalent
    PRG source, runs it through PcCompile to get a PcodeFunc.
  - SqlScan RTL: Go-native scan loop — GoTop/EOF/Skip/GetValue
    direct, ExecPcode per row for WHERE, result array pre-alloc.

WHERE compiler scope:
  - ND_LIT numeric/logical/string (string literals AllTrim'd to match
    SqlCmpEq CHAR-padding semantics; rejects embedded quotes/newlines)
  - ND_COL: CHAR fields auto-wrapped with AllTrim(FieldGet(n)) based
    on dbStruct() lookup cached once per query in aCompileStruct
  - ND_BIN: = <> != < <= > >= AND OR + - * /
  - ND_UNI: NOT -
  - Anything else (ND_FN, ND_CASE, ND_SUB, ND_PAR, LIKE, IN, IS NULL,
    BETWEEN, dates) returns NIL → falls back to PRG tree-walk.

Bench (50k rows, ~/tmp ext4):
                        Before      After     Speedup
  Numeric WHERE         ~150ms     11.7ms     ~13x
  String WHERE          119.3ms    10.5ms     11.4x
  No WHERE               -         14.6ms      -
  Raw RDD baseline        6.8ms     6.8ms      1.0x

Remaining gap to raw RDD (~1.5x) is structural: Value boxing, result
array construction, per-row ExecPcode frame overhead. Would need a
Value-pool or SoA refactor to close further.

Side fixes bundled:
  - TSqlIndex:FindExclusive short-circuited. Originally called
    dbInfo(DBI_FULLPATH)/DBI_SHARED which are unresolved symbols in
    Five (dbInfo is a stub, DBI_* never defined). Panic'd with
    "local variable index out of range: 0" whenever a standalone PRG
    had a workarea Used before calling five_SQL. 43-test masked the
    bug because it only reached FindExclusive with no open workareas.
    Restore the scan once dbInfo lands in hbrtl.
  - cmd/five/main.go: FIVE_KEEP_BUILD=1 env var keeps the temp Go
    project around for debugging gengo output.

Validation:
  - FiveSql2 43/43
  - Harbour compat 51/51
  - go test ./... ALL PASS

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-14 09:15:08 +09:00
486e466592 feat: FiveSql2 43/43, @byref, mutable closure, RTL 479, DateTime fix
Major changes since last commit:
- FiveSql2 SQL:1999 engine (10,458 LOC) — 43/43 ALL PASS
- 21 compiler/runtime bugs fixed (short-circuit AND/OR, FOR LOOP, etc.)
- @byref pass-by-reference via RefCell pattern
- Mutable closure capture (EnsureLocalRef + RefCell sharing)
- RTL: 400 → 479 functions (+79: file, string, datetime, hash, UTF-8)
- DateTime/Timestamp fully working (hb_DateTime, hb_Hour/Min/Sec, display)
- Reserved word guard (39 keywords blocked from function calls)
- AEval arg order fix (element before index)
- Closure capture redecl fix (unique _cap_ names per block)
- Hash/string indexing in ArrayPush/ArrayPop
- Harbour compat test suite: 51/51
- 4 docs: Porting Report, Implementation Plan, Optimization Plan, Commercialization

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 11:35:37 +09:00