[Fix](Nereids) rand() and uuid() should not fold constant (#22492)

rand() and uuid() should not fold constant and we change the default value of fold constant for non-deterministic function to false.

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/executable/ExecutableFunctions.java

@@ -31,15 +31,12 @@ import org.apache.doris.nereids.trees.expressions.literal.TinyIntLiteral;
 import org.apache.doris.nereids.trees.expressions.literal.VarcharLiteral;
 
 import java.math.BigInteger;
-import java.util.Random;
-import java.util.UUID;
 
 /**
  * functions that can be executed in FE.
  */
 public class ExecutableFunctions {
     public static final ExecutableFunctions INSTANCE = new ExecutableFunctions();
-    private static final Random RANDOM = new Random();
 
     /**
      * other scalar function
@@ -112,19 +109,4 @@ public class ExecutableFunctions {
     public static Expression pi() {
         return new DoubleLiteral(Math.PI);
     }
-
-    @ExecFunction(name = "uuid", argTypes = {}, returnType = "VARCHAR")
-    public static Expression uuid() {
-        return new VarcharLiteral(UUID.randomUUID().toString());
-    }
-
-    @ExecFunction(name = "rand", argTypes = {}, returnType = "DOUBLE")
-    public static Expression rand() {
-        return new DoubleLiteral(RANDOM.nextDouble());
-    }
-
-    @ExecFunction(name = "random", argTypes = {}, returnType = "DOUBLE")
-    public static Expression random() {
-        return new DoubleLiteral(RANDOM.nextDouble());
-    }
 }

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/scalar/Random.java

@@ -20,6 +20,7 @@ package org.apache.doris.nereids.trees.expressions.functions.scalar;
 import org.apache.doris.catalog.FunctionSignature;
 import org.apache.doris.nereids.trees.expressions.Expression;
 import org.apache.doris.nereids.trees.expressions.functions.ExplicitlyCastableSignature;
+import org.apache.doris.nereids.trees.expressions.functions.Nondeterministic;
 import org.apache.doris.nereids.trees.expressions.visitor.ExpressionVisitor;
 import org.apache.doris.nereids.types.BigIntType;
 import org.apache.doris.nereids.types.DoubleType;
@@ -33,7 +34,7 @@ import java.util.List;
  * ScalarFunction 'random'. This class is generated by GenerateFunction.
  */
 public class Random extends ScalarFunction
-        implements ExplicitlyCastableSignature {
+        implements ExplicitlyCastableSignature, Nondeterministic {
 
     public static final List<FunctionSignature> SIGNATURES = ImmutableList.of(
             FunctionSignature.ret(DoubleType.INSTANCE).args(),

fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java

@@ -1000,7 +1000,7 @@ public class SessionVariable implements Serializable, Writable {
     public boolean enableMinidump = false;
 
     @VariableMgr.VarAttr(name = ENABLE_FOLD_NONDETERMINISTIC_FN)
-    public boolean enableFoldNondeterministicFn = true;
+    public boolean enableFoldNondeterministicFn = false;
 
     @VariableMgr.VarAttr(name = MINIDUMP_PATH)
     public String minidumpPath = "";

fe/fe-core/src/test/java/org/apache/doris/planner/QueryPlanTest.java

@@ -856,7 +856,7 @@ public class QueryPlanTest extends TestWithFeService {
                 + "from test.test1 "
                 + "where time_col = case when date_format(now(),'%H%i')  < 123 then date_format(date_sub("
                 + "now(),2),'%Y%m%d') else date_format(date_sub(now(),1),'%Y%m%d') end";
-        Assert.assertFalse(StringUtils.containsIgnoreCase(getSQLPlanOrErrorMsg("explain " + caseWhenSql),
+        Assert.assertTrue(StringUtils.containsIgnoreCase(getSQLPlanOrErrorMsg("explain " + caseWhenSql),
                 "CASE WHEN"));
 
         // test 1: case when then