57d2908066
- Add isDelete flag to VersionedRecord to fix COMMIT treating empty values as DELETE. Previously version.xmax != TxnId(0) was never true for active transactions, so deletes inside transactions never removed rows. - Fix MIN/MAX aggregates skipping NULL: was checking for "\\N" instead of correct "\N" sentinel, so NULL values were never skipped. - Add duplicate alias deduplication in lowerSelect() and getSelectColumns(). Identical aliases now get _1, _2 suffixes (e.g. count(*), count(*)_1). - Add nil guard for expr.subqueryPlan in irekSubquery evalExpr handler. - Initialize txnManager in newExecutionContext to prevent segfault on BEGIN. - Add regression tests: DELETE in transaction, PK-only row survival, MIN/MAX NULL skipping.