v26.10.0-pre

chusql-core/engine/src/ChuSQL/Core/Engine/Algebra/Cost.hs

@@ -34,6 +34,8 @@ estimateRows h lo hi = max 0 (min total (round (sum (zipWith overlap [0 ..] (his
     width = if histHigh h > histLow h then (histHigh h - histLow h) / fromIntegral (length (histBuckets h)) else 0
     lower = maybe (-1 / 0) id (boundOf lo)
     upper = maybe (1 / 0) id (boundOf hi)
+    -- | 第 i 个桶与区间重叠的行数
+    overlap :: Int -> Int -> Double
     overlap i count
         | width <= 0 = if lower <= histLow h && histLow h <= upper then fromIntegral count else 0
         | otherwise = fromIntegral count * hit / width

chusql-core/engine/src/ChuSQL/Core/Engine/Semantic.hs

@@ -6,7 +6,6 @@ import ChuSQL.Core.Engine.Syntax.AST
 import ChuSQL.Core.Engine.Syntax.Parser (parseExpression)
 import Data.Char (isAlphaNum, isAscii, toLower)
 import Data.List (intercalate, isInfixOf, isPrefixOf, nub)
-import Data.Maybe (fromMaybe)
 
 -- 语义检查：表和列在不在、类型对不对，全部在执行前查。
 
@@ -766,7 +765,7 @@ resolveFrom db _ (FromSubquery mAlias stmt) = do
     inner <- resolveSubqueryStatement db [] stmt
     named <- nameDerivedColumns inner
     Right (FromSubquery mAlias named)
-resolveFrom db outer fromC@(FromJoin kind left right cond) = do
+resolveFrom db outer (FromJoin kind left right cond) = do
     l <- resolveFrom db outer left
     r <- resolveFrom db outer right
     env <- checkFrom db outer (FromJoin kind l r cond)

chusql-core/engine/src/ChuSQL/Core/Engine/Syntax/Parser.hs

@@ -693,17 +693,17 @@ checkCteArity name cols out
 
 -- | 把语句里对 CTE 的引用换成派生表
 expandStatement :: [(String, Statement)] -> Statement -> Either String Statement
-expandStatement env q = case q of
+expandStatement env stmt = case stmt of
     q@Select { selectFrom = fromC, selectWhere = mWhere } -> do
         fromC' <- expandClause env fromC
         w <- traverse (expandExpr env) mWhere
         Right q { selectFrom = fromC', selectWhere = w }
     q@SelectExpr { selectFrom = fromC, selectItems = items, selectWhere = mWhere } -> do
         fromC' <- expandClause env fromC
-        items' <- traverse (\(label, e) -> fmap ((,) label) (expandExpr env e)) items
+        items' <- traverse (\(name, e) -> fmap ((,) name) (expandExpr env e)) items
         w <- traverse (expandExpr env) mWhere
         Right q { selectFrom = fromC', selectItems = items', selectWhere = w }
-    _ -> Right q
+    _ -> Right stmt
 
 -- | 来源树里的 CTE 引用换成派生表
 expandClause :: [(String, Statement)] -> FromClause -> Either String FromClause