adjust index covereage adjustment

angelamayxie · angelamayxie · commit d1a637de3397 · 2025-08-04T10:03:22.000-07:00
diff --git a/sql/memo/coster.go b/sql/memo/coster.go
@@ -136,7 +136,7 @@ func (c *coster) costRel(ctx *sql.Context, n RelExpr, s sql.StatsProvider) (floa
 				expectedRightRows := selfJoinCard * matchRate
 
 				if expectedRightRows < lBest {
-					return lBest*(seqIOCostFactor) + (lBest+1+indexCoverageAdjustment(n.Lookup))*(cpuCostFactor+randIOCostFactor), nil
+					return lBest*(seqIOCostFactor) + (lBest+indexCoverageAdjustment(n.Lookup))*(cpuCostFactor+randIOCostFactor), nil
 				}
 
 				// Estimate for reading each left row and each expected right row

Original file line number	Diff line number	Diff line change
`@@ -136,7 +136,7 @@ func (c coster) costRel(ctx sql.Context, n RelExpr, s sql.StatsProvider) (floa`
`136`	`136`	`expectedRightRows := selfJoinCard * matchRate`
`137`	`137`
`138`	`138`	`if expectedRightRows < lBest {`
`139`		`- return lBest(seqIOCostFactor) + (lBest+1+indexCoverageAdjustment(n.Lookup))(cpuCostFactor+randIOCostFactor), nil`
	`139`	`+ return lBest(seqIOCostFactor) + (lBest+indexCoverageAdjustment(n.Lookup))(cpuCostFactor+randIOCostFactor), nil`
`140`	`140`	`}`
`141`	`141`
`142`	`142`	`// Estimate for reading each left row and each expected right row`