MB-35392 Make sure ANY clause is properly covered by array index

Change-Id: Ib26ae94c2b1a5bc687ec0154b9fc91a12c1ffca3
Reviewed-on: http://review.couchbase.org/112882
Reviewed-by: Sitaram Vemulapalli <sitaram.vemulapalli@couchbase.com>
Tested-by: Bingjie Miao <bingjie.miao@couchbase.com>

expression/base.go

@@ -53,6 +53,7 @@ const (
 type CoveredOptions struct {
 	skip    bool
 	trickle bool
+	chkvar  bool
 }
 
 func (this *ExpressionBase) String() string {

expression/expression.go

@@ -349,6 +349,11 @@ Function rather than method to make sure we don't pick up
 ExpressionBase.CoveredBy() in error
 */
 func IsCovered(expr Expression, keyspace string, exprs Expressions) bool {
-	isCovered := expr.CoveredBy(keyspace, exprs, CoveredOptions{skip: false, trickle: false})
+	isCovered := expr.CoveredBy(keyspace, exprs, CoveredOptions{skip: false, trickle: false, chkvar: false})
+	return isCovered == CoveredSkip || isCovered == CoveredEquiv || isCovered == CoveredTrue
+}
+
+func IsVarCovered(expr Expression, keyspace string, exprs Expressions) bool {
+	isCovered := expr.CoveredBy(keyspace, exprs, CoveredOptions{skip: false, trickle: false, chkvar: true})
 	return isCovered == CoveredSkip || isCovered == CoveredEquiv || isCovered == CoveredTrue
 }

expression/identifier.go

@@ -106,18 +106,26 @@ func (this *Identifier) CoveredBy(keyspace string, exprs Expressions, options Co
 	// MB-25317, if this is not the right keyspace, ignore the expression altogether
 	// MB-25370 this only applies for keyspace terms, not variables!
 	if (this.IsKeyspaceAlias() && this.identifier != keyspace) ||
-		this.IsProjectionAlias() || this.IsBindingVariable() {
+		this.IsProjectionAlias() || (!options.chkvar && this.IsBindingVariable()) {
 		return CoveredSkip
 	}
 
 	for _, expr := range exprs {
 		if this.EquivalentTo(expr) {
 			switch eType := expr.(type) {
 			case *Identifier:
-				if !this.IsKeyspaceAlias() {
-					return CoveredTrue
-				} else if eType.identifier != keyspace {
-					return CoveredSkip
+				if options.chkvar && this.IsBindingVariable() {
+					if eType.identifier == keyspace {
+						return CoveredTrue
+					} else {
+						return CoveredSkip
+					}
+				} else {
+					if !this.IsKeyspaceAlias() {
+						return CoveredTrue
+					} else if eType.identifier != keyspace {
+						return CoveredSkip
+					}
 				}
 			default:
 				return CoveredTrue

planner/sarg_any.go

@@ -107,7 +107,7 @@ func anySargFor(pred, key, cond expression.Expression, isJoin, doSelec bool,
 		}
 	}
 
-	if err != nil || !expression.IsCovered(pred, alias, exprs) {
+	if err != nil || !expression.IsVarCovered(pred, alias, exprs) {
 		sp.SetExact(false)
 	}
 

test/gsi/test_cases/cover/case_cover2.json

@@ -0,0 +1,35 @@
+[
+    {
+        "testcase": "ANY clause NOT covered",
+        "ignore": "index_id",
+        "explain": {
+            "disabled": false,
+            "results": [
+                {
+                    "present": true
+                }
+            ],
+            "statement": "SELECT true AS present FROM $explan AS p WHERE ANY v WITHIN p.plan.`~children` SATISFIES v.`#operator` LIKE 'IndexScan%' AND v.covers IS MISSING END"
+        },
+        "statements":"SELECT RAW meta().id FROM shellTest WHERE type=\"doc\" AND owner=\"xyz\" AND ANY v IN Names SATISFIES (v.fname='John' AND v.lname ='Doe') END",
+        "results": [
+    ]
+    },
+    {
+        "testcase": "ANY clause covered",
+        "ignore": "index_id",
+        "explain": {
+            "disabled": false,
+            "results": [
+                {
+                    "present": true
+                }
+            ],
+            "statement": "SELECT true AS present FROM $explan AS p WHERE ANY v WITHIN p.plan.`~children` SATISFIES v.`#operator` LIKE 'IndexScan%' AND ARRAY_LENGTH(v.covers) > 0 END"
+        },
+        "statements":"SELECT RAW meta().id FROM shellTest WHERE type=\"doc\" AND owner=\"xyz\" AND ANY v IN Names SATISFIES (v.fname='John') END",
+        "results": [
+    ]
+    }
+]
+

test/gsi/test_cases/cover/cover_test.go

@@ -31,9 +31,12 @@ func TestCover(t *testing.T) {
 	runStmt(qc, "CREATE INDEX ixCover5 on shellTest (email,VMs,join_day) WHERE (10 < join_day)")
 	runStmt(qc, "CREATE INDEX ixCover6 on shellTest(main.status)")
 	runStmt(qc, "CREATE INDEX ixCover7 on shellTest(main.owner)")
+	runStmt(qc, "CREATE INDEX ixCover8 on shellTest(ALL ARRAY v.fname FOR v IN Names END) WHERE type=\"doc\" AND owner=\"xyz\"")
 
 	runMatch("case_cover.json", false, false, qc, t)
 
+	runMatch("case_cover2.json", false, true, qc, t)
+
 	runStmt(qc, "DROP PRIMARY INDEX on shellTest")
 	runStmt(qc, "DROP INDEX shellTest.ixCover")
 	runStmt(qc, "DROP INDEX shellTest.ixCover2")
@@ -42,4 +45,5 @@ func TestCover(t *testing.T) {
 	runStmt(qc, "DROP INDEX shellTest.ixCover5")
 	runStmt(qc, "DROP INDEX shellTest.ixCover6")
 	runStmt(qc, "DROP INDEX shellTest.ixCover7")
+	runStmt(qc, "DROP INDEX shellTest.ixCover8")
 }