Add CONSTRAINT ASSUME support in CREATE TABLE parsing

Previously only CONSTRAINT ... CHECK was supported. Now also supports
CONSTRAINT ... ASSUME which is used for query optimization hints.

Author: claude

parser/parser.go

@@ -2044,7 +2044,7 @@ func (p *Parser) parseCreateTable(create *ast.CreateQuery) {
 					create.Projections = append(create.Projections, proj)
 				}
 			} else if p.currentIs(token.CONSTRAINT) {
-				// Parse CONSTRAINT name CHECK (expression)
+				// Parse CONSTRAINT name CHECK/ASSUME (expression)
 				p.nextToken() // skip CONSTRAINT
 				constraintName := p.parseIdentifierName() // constraint name
 				if p.currentIs(token.CHECK) {
@@ -2055,6 +2055,14 @@ func (p *Parser) parseCreateTable(create *ast.CreateQuery) {
 						Expression: p.parseExpression(LOWEST),
 					}
 					create.Constraints = append(create.Constraints, constraint)
+				} else if p.currentIs(token.IDENT) && strings.ToUpper(p.current.Value) == "ASSUME" {
+					p.nextToken() // skip ASSUME
+					constraint := &ast.Constraint{
+						Position:   p.current.Pos,
+						Name:       constraintName,
+						Expression: p.parseExpression(LOWEST),
+					}
+					create.Constraints = append(create.Constraints, constraint)
 				} else {
 					// Skip other constraint types we don't know about
 					for !p.currentIs(token.COMMA) && !p.currentIs(token.RPAREN) && !p.currentIs(token.EOF) {

parser/testdata/01622_constraints_simple_optimization/metadata.json

@@ -1,11 +1 @@
-{
-  "explain_todo": {
-    "stmt12": true,
-    "stmt18": true,
-    "stmt21": true,
-    "stmt24": true,
-    "stmt27": true,
-    "stmt30": true,
-    "stmt33": true
-  }
-}
+{}

parser/testdata/01622_constraints_where_optimization/metadata.json

@@ -1,6 +1 @@
-{
-  "explain_todo": {
-    "stmt18": true,
-    "stmt5": true
-  }
-}
+{}

parser/testdata/01623_constraints_column_swap/metadata.json

@@ -1,7 +1 @@
-{
-  "explain_todo": {
-    "stmt28": true,
-    "stmt40": true,
-    "stmt8": true
-  }
-}
+{}

parser/testdata/01625_constraints_index_append/metadata.json

@@ -1,5 +1 @@
-{
-  "explain_todo": {
-    "stmt5": true
-  }
-}
+{}

parser/testdata/03362_optimize_using_constraints_type_mismatch/metadata.json

@@ -1,5 +1 @@
-{
-  "explain_todo": {
-    "stmt2": true
-  }
-}
+{}