chore(3vl): pushdown/3VL consistency test + doc follow-ups#76
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The interpreter's `eval_binop` yields `Value::Null` for a null-operand comparison; the pushdown `cmp_values` yields `false`. They produce identical rows because the value-predicate pushdown only lifts positive `attr op literal` AND-conjuncts, where a null operand means "drop" under both — and pushing a conjunct out of an OR / under a NOT is already forbidden (wrong for non-null rows too). `tests/pushdown_null_test.rs` pins this across the node-scan, LTJ `NodeAttrCmp`, and btree range-fold paths, so a future optimizer change that pushes a non-conjunct is caught. Also documents the invariant and the exact "unify into a shared cmp_3vl" trigger on `cmp_values`. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds iso-gql-gaps.md §3.4 (the CLAUDE.md "Null semantics" note pointed here but the entry was missing): froGQL empties on type errors (FPPC model) where ISO wants a hard `22G12`/`22G03` data exception — essential-error hard-abort, material `NOT NULL` types, closed-graph property validation. Also notes that `IN`-as-membership is a froGQL extension (SQL-3VL-consistent; not in ISO/FPPC), in the doc and the eval_binop comment. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Follow-ups after the 3VL merge (#73).
Pushdown/3VL consistency (the substantive bit)
The interpreter (
eval_binop) returnsValue::Nullfor a null-operand comparison; the pushdown (cmp_values) returnsfalse. These stay row-equivalent not by luck: the value-predicate pushdown only lifts positiveattr op literalAND-conjuncts, where a null operand means drop under both — and pushing a conjunct out of anOR/ under aNOTis already forbidden (wrong for non-null rows too). The keep-despite-null shapes (… OR true,NOT (…)) stay residual on the 3VL interpreter.tests/pushdown_null_test.rspins this across the node-scan, LTJNodeAttrCmp, and btree range-fold paths. It fails if the optimizer ever pushes a non-conjunct, or if the two comparison cores drift on keep/drop.cmp_valuesnow documents the invariant and the exact trigger to unify into a sharedcmp_3vlcore: if a pushed comparison's value is ever consumed as something other than keep/drop (e.g. a future computed-column pushdown feeding a projection/CASE).Docs
docs/internals/iso-gql-gaps.md §3.4— records the ISO data-exceptions workstream the CLAUDE.md "Null semantics" note already pointed at (essential-error hard-abort22G12, materialNOT NULL22G12/22G03, closed-graph property validation).IN-as-membership as a froGQL extension (SQL-3VL-consistent; not in ISO GQL nor FPPC) in the doc and theeval_binopcomment.No behavior change.
cargo fmt/clippy -Dclean; full sweep green.🤖 Generated with Claude Code