MB-65809 Change how expression parsing is done when unmarshalling plan

miaobingjie · miaobingjie · commit b009b9cec7c6 · 2026-03-20T00:28:50.000Z
To properly handle subqueries in plan stability, we need a mechansim to identify the subquery expressions as they are unmarshalled from the plan. To assist in this capability, we modify the way we parse expressions as plan unmarshalling is done, such that instead of directly calling the parser, we add a level of indirection, by introducing a new parsing member function for each operator. This new function will call the parser to parse the expressions, and that's all it's doing currently, but we'll add functionality later on to look for subqueries after the expression is generated from the parser. During unmarshal of plan, any time we are dealing with an expression that can potentially contain one or more subqueries, we'll call this new function; in places where we know the expression cannot contain any subqueries, we still leave the original parsing call alone, i.e. still use the expression parser directly. Some examples of expressions that cannot contain subqueries include: - index cover and filter cover expressions - index spans - early filter that gets pushed down to various operators such as Filter, ExpressionScan, Unnest, IndexScan3, NLJoin, NLNest, HashJoin, HashNest, Unnest, etc. The generation of these early filters discard subquery filters - GROUP BY keys, Aggregate expressions (including window aggregates) - expressions in DDL statements, UPDATE STATISTICS statement, INFER statement - join bit filter expressions (bloom filters) for hash join/nest - KEY, VALUE, OPTIONS expressions for SendInsert, SendUpdate, SendUpsert, SendDelete - value expressions for ValueScan - expressions used for IndexFtsSearch (in FtsSearchInfo) - expressions used for vector search - ASC/DESC and NullPos specifications for ORDER BY Change-Id: I94c27f4973f9d1cbf39515f007e691f779b47fd3 Reviewed-on: https://review.couchbase.org/c/query/+/242025 Tested-by: Bingjie Miao <bingjie.miao@couchbase.com> Reviewed-by: Sitaram Vemulapalli <sitaram.vemulapalli@couchbase.com>
diff --git a/plan/base.go b/plan/base.go
@@ -43,6 +43,10 @@ func (this *readonly) SetPlanContext(planContext *planContext) {
 	this.planContext = planContext
 }
 
+func (this *readonly) parseExpression(s string) (expression.Expression, error) {
+	return parseWithContext(s, this.planContext)
+}
+
 type readwrite struct {
 	planContext *planContext
 }
@@ -66,6 +70,10 @@ func (this *readwrite) SetPlanContext(planContext *planContext) {
 	this.planContext = planContext
 }
 
+func (this *readwrite) parseExpression(s string) (expression.Expression, error) {
+	return parseWithContext(s, this.planContext)
+}
+
 // optimizer estimates
 type optEstimate struct {
 	cost        float64
diff --git a/plan/fetch.go b/plan/fetch.go
@@ -15,7 +15,6 @@ import (
 	"github.com/couchbase/query/datastore"
 	"github.com/couchbase/query/errors"
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 )
 
 type Fetch struct {
@@ -147,7 +146,7 @@ func (this *Fetch) UnmarshalJSON(body []byte) error {
 
 	if _unmarshalled.FromExpr != "" {
 		var expr expression.Expression
-		expr, err = parser.Parse(_unmarshalled.FromExpr)
+		expr, err = this.parseExpression(_unmarshalled.FromExpr)
 		if err == nil {
 			this.term = algebra.NewKeyspaceTermFromExpression(expr, _unmarshalled.As, nil, nil, 0)
 		}
@@ -266,7 +265,7 @@ func (this *DummyFetch) UnmarshalJSON(body []byte) error {
 	unmarshalOptEstimate(&this.optEstimate, _unmarshalled.OptEstimate)
 
 	if _unmarshalled.FromExpr != "" {
-		expr, err1 := parser.Parse(_unmarshalled.FromExpr)
+		expr, err1 := this.parseExpression(_unmarshalled.FromExpr)
 		if err1 != nil {
 			return err1
 		}
diff --git a/plan/filter.go b/plan/filter.go
@@ -12,7 +12,6 @@ import (
 	"encoding/json"
 
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 )
 
 type Filter struct {
@@ -92,7 +91,7 @@ func (this *Filter) UnmarshalJSON(body []byte) error {
 	}
 
 	if _unmarshalled.Condition != "" {
-		this.cond, err = parser.Parse(_unmarshalled.Condition)
+		this.cond, err = this.parseExpression(_unmarshalled.Condition)
 		if err != nil {
 			return err
 		}
diff --git a/plan/join.go b/plan/join.go
@@ -15,7 +15,6 @@ import (
 	"github.com/couchbase/query/datastore"
 	"github.com/couchbase/query/errors"
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 )
 
 type Join struct {
@@ -151,7 +150,7 @@ func (this *Join) UnmarshalJSON(body []byte) error {
 
 	var keys_expr expression.Expression
 	if _unmarshalled.On != "" {
-		keys_expr, err = parser.Parse(_unmarshalled.On)
+		keys_expr, err = this.parseExpression(_unmarshalled.On)
 		if err != nil {
 			return err
 		}
@@ -169,7 +168,7 @@ func (this *Join) UnmarshalJSON(body []byte) error {
 	}
 
 	if _unmarshalled.OnFilter != "" {
-		this.onFilter, err = parser.Parse(_unmarshalled.OnFilter)
+		this.onFilter, err = this.parseExpression(_unmarshalled.OnFilter)
 		if err != nil {
 			return err
 		}
diff --git a/plan/join_hash.go b/plan/join_hash.go
@@ -164,7 +164,7 @@ func (this *HashJoin) UnmarshalJSON(body []byte) error {
 	}
 
 	if _unmarshalled.Onclause != "" {
-		this.onclause, err = parser.Parse(_unmarshalled.Onclause)
+		this.onclause, err = this.parseExpression(_unmarshalled.Onclause)
 		if err != nil {
 			return err
 		}
diff --git a/plan/join_index.go b/plan/join_index.go
@@ -203,7 +203,7 @@ func (this *IndexJoin) UnmarshalJSON(body []byte) error {
 
 	var keys_expr expression.Expression
 	if _unmarshalled.On != "" {
-		keys_expr, err = parser.Parse(_unmarshalled.On)
+		keys_expr, err = this.parseExpression(_unmarshalled.On)
 		if err != nil {
 			return err
 		}
diff --git a/plan/join_nl.go b/plan/join_nl.go
@@ -128,7 +128,7 @@ func (this *NLJoin) UnmarshalJSON(body []byte) error {
 	}
 
 	if _unmarshalled.Onclause != "" {
-		this.onclause, err = parser.Parse(_unmarshalled.Onclause)
+		this.onclause, err = this.parseExpression(_unmarshalled.Onclause)
 		if err != nil {
 			return err
 		}
diff --git a/plan/limit.go b/plan/limit.go
@@ -12,7 +12,6 @@ import (
 	"encoding/json"
 
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 )
 
 type Limit struct {
@@ -69,7 +68,7 @@ func (this *Limit) UnmarshalJSON(body []byte) error {
 		return err
 	}
 
-	this.expr, err = parser.Parse(_unmarshalled.Expr)
+	this.expr, err = this.parseExpression(_unmarshalled.Expr)
 	if err != nil {
 		return err
 	}
diff --git a/plan/merge.go b/plan/merge.go
@@ -15,7 +15,6 @@ import (
 	"github.com/couchbase/query/datastore"
 	"github.com/couchbase/query/errors"
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 )
 
 type Merge struct {
@@ -213,7 +212,7 @@ func (this *Merge) UnmarshalJSON(body []byte) error {
 	}
 
 	if _unmarshalled.Key != "" {
-		this.key, err = parser.Parse(_unmarshalled.Key)
+		this.key, err = this.parseExpression(_unmarshalled.Key)
 		if err != nil {
 			return err
 		}
@@ -223,7 +222,7 @@ func (this *Merge) UnmarshalJSON(body []byte) error {
 	this.fastDiscard = _unmarshalled.FastDiscard
 
 	if _unmarshalled.Limit != "" {
-		this.limit, err = parser.Parse(_unmarshalled.Limit)
+		this.limit, err = this.parseExpression(_unmarshalled.Limit)
 		if err != nil {
 			return err
 		}
@@ -268,19 +267,19 @@ func (this *Merge) UnmarshalJSON(body []byte) error {
 	unmarshalOptEstimate(&this.optEstimate, _unmarshalled.OptEstimate)
 
 	if _unmarshalled.UpdateFilter != "" {
-		if this.updateFilter, err = parser.Parse(_unmarshalled.UpdateFilter); err != nil {
+		if this.updateFilter, err = this.parseExpression(_unmarshalled.UpdateFilter); err != nil {
 			return err
 		}
 	}
 
 	if _unmarshalled.DeleteFilter != "" {
-		if this.deleteFilter, err = parser.Parse(_unmarshalled.DeleteFilter); err != nil {
+		if this.deleteFilter, err = this.parseExpression(_unmarshalled.DeleteFilter); err != nil {
 			return err
 		}
 	}
 
 	if _unmarshalled.InsertFilter != "" {
-		if this.insertFilter, err = parser.Parse(_unmarshalled.InsertFilter); err != nil {
+		if this.insertFilter, err = this.parseExpression(_unmarshalled.InsertFilter); err != nil {
 			return err
 		}
 	}
diff --git a/plan/nest.go b/plan/nest.go
@@ -15,7 +15,6 @@ import (
 	"github.com/couchbase/query/datastore"
 	"github.com/couchbase/query/errors"
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 )
 
 type Nest struct {
@@ -151,7 +150,7 @@ func (this *Nest) UnmarshalJSON(body []byte) error {
 
 	var keys_expr expression.Expression
 	if _unmarshalled.On != "" {
-		keys_expr, err = parser.Parse(_unmarshalled.On)
+		keys_expr, err = this.parseExpression(_unmarshalled.On)
 		if err != nil {
 			return err
 		}
@@ -169,7 +168,7 @@ func (this *Nest) UnmarshalJSON(body []byte) error {
 	}
 
 	if _unmarshalled.OnFilter != "" {
-		this.onFilter, err = parser.Parse(_unmarshalled.OnFilter)
+		this.onFilter, err = this.parseExpression(_unmarshalled.OnFilter)
 		if err != nil {
 			return err
 		}
diff --git a/plan/nest_hash.go b/plan/nest_hash.go
@@ -162,7 +162,7 @@ func (this *HashNest) UnmarshalJSON(body []byte) error {
 	}
 
 	if _unmarshalled.Onclause != "" {
-		this.onclause, err = parser.Parse(_unmarshalled.Onclause)
+		this.onclause, err = this.parseExpression(_unmarshalled.Onclause)
 		if err != nil {
 			return err
 		}
diff --git a/plan/nest_index.go b/plan/nest_index.go
@@ -15,7 +15,6 @@ import (
 	"github.com/couchbase/query/datastore"
 	"github.com/couchbase/query/errors"
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 )
 
 type IndexNest struct {
@@ -157,7 +156,7 @@ func (this *IndexNest) UnmarshalJSON(body []byte) error {
 
 	var keys_expr expression.Expression
 	if _unmarshalled.On != "" {
-		keys_expr, err = parser.Parse(_unmarshalled.On)
+		keys_expr, err = this.parseExpression(_unmarshalled.On)
 		if err != nil {
 			return err
 		}
diff --git a/plan/nest_nl.go b/plan/nest_nl.go
@@ -126,7 +126,7 @@ func (this *NLNest) UnmarshalJSON(body []byte) error {
 	}
 
 	if _unmarshalled.Onclause != "" {
-		this.onclause, err = parser.Parse(_unmarshalled.Onclause)
+		this.onclause, err = this.parseExpression(_unmarshalled.Onclause)
 		if err != nil {
 			return err
 		}
diff --git a/plan/offset.go b/plan/offset.go
@@ -12,7 +12,6 @@ import (
 	"encoding/json"
 
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 )
 
 type Offset struct {
@@ -69,7 +68,7 @@ func (this *Offset) UnmarshalJSON(body []byte) error {
 		return err
 	}
 
-	this.expr, err = parser.Parse(_unmarshalled.Expr)
+	this.expr, err = this.parseExpression(_unmarshalled.Expr)
 	if err != nil {
 		return err
 	}
diff --git a/plan/order.go b/plan/order.go
@@ -144,7 +144,7 @@ func (this *Order) UnmarshalJSON(body []byte) error {
 
 	this.terms = make(algebra.SortTerms, len(_unmarshalled.Terms))
 	for i, term := range _unmarshalled.Terms {
-		expr, err := parser.Parse(term.Expr)
+		expr, err := this.parseExpression(term.Expr)
 		if err != nil {
 			return err
 		}
@@ -205,14 +205,14 @@ func (this *Order) UnmarshalJSON(body []byte) error {
 	}
 	this.flags = _unmarshalled.Flags
 	if offsetExprStr := _unmarshalled.OffsetExpr; offsetExprStr != "" {
-		offsetExpr, err := parser.Parse(offsetExprStr)
+		offsetExpr, err := this.parseExpression(offsetExprStr)
 		if err != nil {
 			return err
 		}
 		this.offset = NewOffset(offsetExpr, PLAN_COST_NOT_AVAIL, PLAN_CARD_NOT_AVAIL, PLAN_SIZE_NOT_AVAIL, PLAN_COST_NOT_AVAIL)
 	}
 	if limitExprStr := _unmarshalled.LimitExpr; limitExprStr != "" {
-		limitExpr, err := parser.Parse(limitExprStr)
+		limitExpr, err := this.parseExpression(limitExprStr)
 		if err != nil {
 			return err
 		}
diff --git a/plan/parser.go b/plan/parser.go
@@ -0,0 +1,18 @@
+//  Copyright 2026-Present Couchbase, Inc.
+//
+//  Use of this software is governed by the Business Source License included
+//  in the file licenses/BSL-Couchbase.txt.  As of the Change Date specified
+//  in that file, in accordance with the Business Source License, use of this
+//  software will be governed by the Apache License, Version 2.0, included in
+//  the file licenses/APL2.txt.
+
+package plan
+
+import (
+	"github.com/couchbase/query/expression"
+	"github.com/couchbase/query/expression/parser"
+)
+
+func parseWithContext(s string, plContext *planContext) (expression.Expression, error) {
+	return parser.Parse(s)
+}
diff --git a/plan/project.go b/plan/project.go
@@ -13,7 +13,6 @@ import (
 
 	"github.com/couchbase/query/algebra"
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 	"github.com/couchbase/query/sort"
 	"github.com/couchbase/query/value"
 )
@@ -182,7 +181,7 @@ func (this *InitialProject) UnmarshalJSON(body []byte) error {
 	for i, term_data := range _unmarshalled.Terms {
 		var expr expression.Expression
 		if term_data.Expr != "" {
-			expr, err = parser.Parse(term_data.Expr)
+			expr, err = this.parseExpression(term_data.Expr)
 			if err != nil {
 				return err
 			}
@@ -322,7 +321,7 @@ func (this *IndexCountProject) UnmarshalJSON(body []byte) error {
 	for i, term_data := range _unmarshalled.Terms {
 		var expr expression.Expression
 		if term_data.Expr != "" {
-			expr, err = parser.Parse(term_data.Expr)
+			expr, err = this.parseExpression(term_data.Expr)
 			if err != nil {
 				return err
 			}
diff --git a/plan/scan_distinct.go b/plan/scan_distinct.go
@@ -14,7 +14,6 @@ import (
 	"github.com/couchbase/query/datastore"
 	"github.com/couchbase/query/errors"
 	"github.com/couchbase/query/expression"
-	"github.com/couchbase/query/expression/parser"
 	"github.com/couchbase/query/value"
 )
 
@@ -178,14 +177,14 @@ func (this *DistinctScan) UnmarshalJSON(body []byte) error {
 	this.scan = scan_op.(SecondaryScan)
 
 	if _unmarshalled.Limit != "" {
-		this.limit, err = parser.Parse(_unmarshalled.Limit)
+		this.limit, err = this.parseExpression(_unmarshalled.Limit)
 		if err != nil {
 			return err
 		}
 	}
 
 	if _unmarshalled.Offset != "" {
-		this.offset, err = parser.Parse(_unmarshalled.Offset)
+		this.offset, err = this.parseExpression(_unmarshalled.Offset)
 		if err != nil {
 			return err
 		}
diff --git a/plan/scan_expression.go b/plan/scan_expression.go
@@ -135,7 +135,7 @@ func (this *ExpressionScan) UnmarshalJSON(body []byte) error {
 	}
 
 	if _unmarshalled.FromExpr != "" {
-		this.fromExpr, err = parser.Parse(_unmarshalled.FromExpr)
+		this.fromExpr, err = this.parseExpression(_unmarshalled.FromExpr)
 	}
 	this.alias = _unmarshalled.Alias
 	// we use uncorrelated in marshall such that in mixed node cluster
diff --git a/plan/scan_index.go b/plan/scan_index.go
@@ -265,7 +265,7 @@ func (this *IndexScan) UnmarshalJSON(body []byte) error {
 	this.distinct = _unmarshalled.Distinct
 
 	if _unmarshalled.Limit != "" {
-		this.limit, err = parser.Parse(_unmarshalled.Limit)
+		this.limit, err = this.parseExpression(_unmarshalled.Limit)
 		if err != nil {
 			return err
 		}
diff --git a/plan/scan_index2.go b/plan/scan_index2.go
@@ -288,14 +288,14 @@ func (this *IndexScan2) UnmarshalJSON(body []byte) error {
 	this.hasDeltaKeyspace = _unmarshalled.HasDeltaKeyspace
 
 	if _unmarshalled.Offset != "" {
-		this.offset, err = parser.Parse(_unmarshalled.Offset)
+		this.offset, err = this.parseExpression(_unmarshalled.Offset)
 		if err != nil {
 			return err
 		}
 	}
 
 	if _unmarshalled.Limit != "" {
-		this.limit, err = parser.Parse(_unmarshalled.Limit)
+		this.limit, err = this.parseExpression(_unmarshalled.Limit)
 		if err != nil {
 			return err
 		}
diff --git a/plan/scan_index3.go b/plan/scan_index3.go
diff --git a/plan/scan_intersect.go b/plan/scan_intersect.go
diff --git a/plan/scan_intersect_ord.go b/plan/scan_intersect_ord.go
diff --git a/plan/scan_key.go b/plan/scan_key.go
diff --git a/plan/scan_primary.go b/plan/scan_primary.go
diff --git a/plan/scan_primary3.go b/plan/scan_primary3.go
diff --git a/plan/scan_union.go b/plan/scan_union.go
diff --git a/plan/unnest.go b/plan/unnest.go
diff --git a/plan/update.go b/plan/update.go
diff --git a/plan/with.go b/plan/with.go

Original file line number	Diff line number	Diff line change
`@@ -43,6 +43,10 @@ func (this readonly) SetPlanContext(planContext planContext) {`
`43`	`43`	`this.planContext = planContext`
`44`	`44`	`}`
`45`	`45`
	`46`	`+func (this *readonly) parseExpression(s string) (expression.Expression, error) {`
	`47`	`+ return parseWithContext(s, this.planContext)`
	`48`	`+}`
	`49`	`+`
`46`	`50`	`type readwrite struct {`
`47`	`51`	`planContext *planContext`
`48`	`52`	`}`
`@@ -66,6 +70,10 @@ func (this readwrite) SetPlanContext(planContext planContext) {`
`66`	`70`	`this.planContext = planContext`
`67`	`71`	`}`
`68`	`72`
	`73`	`+func (this *readwrite) parseExpression(s string) (expression.Expression, error) {`
	`74`	`+ return parseWithContext(s, this.planContext)`
	`75`	`+}`
	`76`	`+`
`69`	`77`	`// optimizer estimates`
`70`	`78`	`type optEstimate struct {`
`71`	`79`	`cost float64`
Original file line number	Diff line number	Diff line change
`@@ -12,7 +12,6 @@ import (`
`12`	`12`	`"encoding/json"`
`13`	`13`
`14`	`14`	`"github.com/couchbase/query/expression"`
`15`		`- "github.com/couchbase/query/expression/parser"`
`16`	`15`	`)`
`17`	`16`
`18`	`17`	`type Filter struct {`
`@@ -92,7 +91,7 @@ func (this *Filter) UnmarshalJSON(body []byte) error {`
`92`	`91`	`}`
`93`	`92`
`94`	`93`	`if _unmarshalled.Condition != "" {`
`95`		`- this.cond, err = parser.Parse(_unmarshalled.Condition)`
	`94`	`+ this.cond, err = this.parseExpression(_unmarshalled.Condition)`
`96`	`95`	`if err != nil {`
`97`	`96`	`return err`
`98`	`97`	`}`
Original file line number	Diff line number	Diff line change
`@@ -15,7 +15,6 @@ import (`
`15`	`15`	`"github.com/couchbase/query/datastore"`
`16`	`16`	`"github.com/couchbase/query/errors"`
`17`	`17`	`"github.com/couchbase/query/expression"`
`18`		`- "github.com/couchbase/query/expression/parser"`
`19`	`18`	`)`
`20`	`19`
`21`	`20`	`type Join struct {`
`@@ -151,7 +150,7 @@ func (this *Join) UnmarshalJSON(body []byte) error {`
`151`	`150`
`152`	`151`	`var keys_expr expression.Expression`
`153`	`152`	`if _unmarshalled.On != "" {`
`154`		`- keys_expr, err = parser.Parse(_unmarshalled.On)`
	`153`	`+ keys_expr, err = this.parseExpression(_unmarshalled.On)`
`155`	`154`	`if err != nil {`
`156`	`155`	`return err`
`157`	`156`	`}`
`@@ -169,7 +168,7 @@ func (this *Join) UnmarshalJSON(body []byte) error {`
`169`	`168`	`}`
`170`	`169`
`171`	`170`	`if _unmarshalled.OnFilter != "" {`
`172`		`- this.onFilter, err = parser.Parse(_unmarshalled.OnFilter)`
	`171`	`+ this.onFilter, err = this.parseExpression(_unmarshalled.OnFilter)`
`173`	`172`	`if err != nil {`
`174`	`173`	`return err`
`175`	`174`	`}`
Original file line number	Diff line number	Diff line change
`@@ -164,7 +164,7 @@ func (this *HashJoin) UnmarshalJSON(body []byte) error {`
`164`	`164`	`}`
`165`	`165`
`166`	`166`	`if _unmarshalled.Onclause != "" {`
`167`		`- this.onclause, err = parser.Parse(_unmarshalled.Onclause)`
	`167`	`+ this.onclause, err = this.parseExpression(_unmarshalled.Onclause)`
`168`	`168`	`if err != nil {`
`169`	`169`	`return err`
`170`	`170`	`}`
Original file line number	Diff line number	Diff line change
`@@ -203,7 +203,7 @@ func (this *IndexJoin) UnmarshalJSON(body []byte) error {`
`203`	`203`
`204`	`204`	`var keys_expr expression.Expression`
`205`	`205`	`if _unmarshalled.On != "" {`
`206`		`- keys_expr, err = parser.Parse(_unmarshalled.On)`
	`206`	`+ keys_expr, err = this.parseExpression(_unmarshalled.On)`
`207`	`207`	`if err != nil {`
`208`	`208`	`return err`
`209`	`209`	`}`
Original file line number	Diff line number	Diff line change
`@@ -128,7 +128,7 @@ func (this *NLJoin) UnmarshalJSON(body []byte) error {`
`128`	`128`	`}`
`129`	`129`
`130`	`130`	`if _unmarshalled.Onclause != "" {`
`131`		`- this.onclause, err = parser.Parse(_unmarshalled.Onclause)`
	`131`	`+ this.onclause, err = this.parseExpression(_unmarshalled.Onclause)`
`132`	`132`	`if err != nil {`
`133`	`133`	`return err`
`134`	`134`	`}`