diff --git a/build.gradle b/build.gradle
index 2e68982b1..fdfa2993f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -194,6 +194,10 @@ test {
     // set heap size for the test JVM(s)
     minHeapSize = "128m"
     maxHeapSize = "1G"
+
+    jacoco {
+        excludes = ['net/sf/jsqlparser/parser/CCJSqlParserTokenManager']
+    }
 }
 
 coveralls {
@@ -201,14 +205,6 @@ coveralls {
 }
 
 jacocoTestReport {
-    // Jacoco can't handle the TokenManager class
-    afterEvaluate {
-        classDirectories.setFrom(files(classDirectories.files.collect {
-            fileTree(dir: it, exclude: [
-                    "**CCJSqlParserTokenManager**"
-            ])
-        }))
-    }
     dependsOn test // tests are required to run before generating the report
     reports {
         xml.required = false
diff --git a/src/main/java/net/sf/jsqlparser/expression/operators/relational/LikeExpression.java b/src/main/java/net/sf/jsqlparser/expression/operators/relational/LikeExpression.java
index cf55678ce..08ac4888c 100644
--- a/src/main/java/net/sf/jsqlparser/expression/operators/relational/LikeExpression.java
+++ b/src/main/java/net/sf/jsqlparser/expression/operators/relational/LikeExpression.java
@@ -117,7 +117,7 @@ public LikeExpression withRightExpression(Expression arg0) {
     }
 
     public enum KeyWord {
-        LIKE, ILIKE, RLIKE, REGEXP, SIMILAR_TO;
+        LIKE, ILIKE, RLIKE, REGEXP_LIKE, REGEXP, SIMILAR_TO;
 
         public static KeyWord from(String keyword) {
             return Enum.valueOf(KeyWord.class, keyword.toUpperCase().replaceAll("\\s+", "_"));
diff --git a/src/main/java/net/sf/jsqlparser/parser/AbstractJSqlParser.java b/src/main/java/net/sf/jsqlparser/parser/AbstractJSqlParser.java
index 3c414d852..a39ac7e32 100644
--- a/src/main/java/net/sf/jsqlparser/parser/AbstractJSqlParser.java
+++ b/src/main/java/net/sf/jsqlparser/parser/AbstractJSqlParser.java
@@ -65,6 +65,14 @@ public P withBackslashEscapeCharacter(boolean allowBackslashEscapeCharacter) {
         return withFeature(Feature.allowBackslashEscapeCharacter, allowBackslashEscapeCharacter);
     }
 
+    public P withUnparenthesizedSubSelects() {
+        return withFeature(Feature.allowUnparenthesizedSubSelects, true);
+    }
+
+    public P withUnparenthesizedSubSelects(boolean allowUnparenthesizedSubSelects) {
+        return withFeature(Feature.allowUnparenthesizedSubSelects, allowUnparenthesizedSubSelects);
+    }
+
     public P withFeature(Feature f, boolean enabled) {
         getConfiguration().setValue(f, enabled);
         return me();
diff --git a/src/main/java/net/sf/jsqlparser/parser/feature/Feature.java b/src/main/java/net/sf/jsqlparser/parser/feature/Feature.java
index 244a3887e..75b5c78a5 100644
--- a/src/main/java/net/sf/jsqlparser/parser/feature/Feature.java
+++ b/src/main/java/net/sf/jsqlparser/parser/feature/Feature.java
@@ -787,6 +787,11 @@ public enum Feature {
      * allows Backslash '\' as Escape Character
      */
     allowBackslashEscapeCharacter(false),
+
+    /**
+     * allows sub selects without parentheses, e.g. `select * from dual where 1 = select 1`
+     */
+    allowUnparenthesizedSubSelects(false),
     ;
 
     private final Object value;
diff --git a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
index a49e3c61f..dbd2a1d5c 100644
--- a/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
+++ b/src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt
@@ -396,6 +396,7 @@ TOKEN: /* SQL Keywords. prefixed with K_ to avoid name clashes */
 |   <K_REGEXP: "REGEXP">
 |   <K_RESPECT: "RESPECT">
 |   <K_RLIKE: "RLIKE">
+|   <K_REGEXP_LIKE: "REGEXP_LIKE">
 |   <K_REGISTER: "REGISTER">
 |   <K_REMOTE: "REMOTE">
 |   <K_RENAME:"RENAME">
@@ -1993,7 +1994,7 @@ String RelObjectNameWithoutValue() :
 {    Token tk = null; }
 {
     ( tk=<DATA_TYPE> | tk=<S_IDENTIFIER> | tk=<S_QUOTED_IDENTIFIER> |  tk=<K_DATE_LITERAL> | tk=<K_DATETIMELITERAL> | tk=<K_STRING_FUNCTION_NAME> | tk=<K_ISOLATION> | tk=<K_TIME_KEY_EXPR> | tk=<K_TEXT_LITERAL> 
-       | tk="ACTION" | tk="ACTIVE" | tk="ADD" | tk="ADVANCE" | tk="ADVISE" | tk="AGAINST" | tk="ALGORITHM" | tk="ALTER" | tk="ANALYZE" | tk="APPLY" | tk="APPROXIMATE" | tk="ARCHIVE" | tk="ARRAY" | tk="ASC" | tk="AT" | tk="AUTHORIZATION" | tk="AUTO" | tk="BASE64" | tk="BEGIN" | tk="BERNOULLI" | tk="BINARY" | tk="BIT" | tk="BLOCK" | tk="BROWSE" | tk="BUFFERS" | tk="BY" | tk="BYTE" | tk="BYTES" | tk="CACHE" | tk="CALL" | tk="CASCADE" | tk="CASE" | tk="CAST" | tk="CHANGE" | tk="CHANGES" | tk="CHAR" | tk="CHARACTER" | tk="CHECKPOINT" | tk="CLOSE" | tk="COLLATE" | tk="COLUMN" | tk="COLUMNS" | tk="COMMENT" | tk="COMMIT" | tk="CONCURRENTLY" | tk="CONFLICT" | tk="CONSTRAINTS" | tk="CONVERT" | tk="COSTS" | tk="CS" | tk="CYCLE" | tk="DATA" | tk="DATABASE" | tk="DATETIME" | tk="DBA_RECYCLEBIN" | tk="DDL" | tk="DECLARE" | tk="DEFERRABLE" | tk="DELAYED" | tk="DELETE" | tk="DESC" | tk="DESCRIBE" | tk="DISABLE" | tk="DISCONNECT" | tk="DIV" | tk="DML" | tk="DO" | tk="DOMAIN" | tk="DROP" | tk="DUMP" | tk="DUPLICATE" | tk="ELEMENTS" | tk="EMIT" | tk="ENABLE" | tk="END" | tk="ESCAPE" | tk="EXCLUDE" | tk="EXEC" | tk="EXECUTE" | tk="EXPLAIN" | tk="EXPLICIT" | tk="EXTENDED" | tk="EXTRACT" | tk="FALSE" | tk="FILTER" | tk="FIRST" | tk="FLUSH" | tk="FN" | tk="FOLLOWING" | tk="FORMAT" | tk="FULLTEXT" | tk="FUNCTION" | tk="GRANT" | tk="GROUP_CONCAT" | tk="GUARD" | tk="HASH" | tk="HIGH_PRIORITY" | tk="HISTORY" | tk="HOPPING" | tk="INCLUDE" | tk="INCLUDE_NULL_VALUES" | tk="INCREMENT" | tk="INDEX" | tk="INSERT" | tk="INTERLEAVE" | tk="INTERPRET" | tk="INVALIDATE" | tk="ISNULL" | tk="JSON" | tk="JSON_ARRAY" | tk="JSON_ARRAYAGG" | tk="JSON_OBJECT" | tk="JSON_OBJECTAGG" | tk="KEEP" | tk="KEY" | tk="KEYS" | tk="LAST" | tk="LEADING" | tk="LINK" | tk="LOCAL" | tk="LOCKED" | tk="LOG" | tk="LONGTEXT" | tk="LOOP" | tk="LOW_PRIORITY" | tk="MATCH" | tk="MATCHED" | tk="MATERIALIZED" | tk="MAX" | tk="MAXVALUE" | tk="MEDIUMTEXT" | tk="MEMBER" | tk="MERGE" | tk="MIN" | tk="MINVALUE" | tk="MODIFY" | tk="MOVEMENT" | tk="NEXT" | tk="NO" | tk="NOCACHE" | tk="NOKEEP" | tk="NOLOCK" | tk="NOMAXVALUE" | tk="NOMINVALUE" | tk="NOORDER" | tk="NOTHING" | tk="NOTNULL" | tk="NOVALIDATE" | tk="NOWAIT" | tk="NULLS" | tk="OF" | tk="OFF" | tk="OPEN" | tk="OVER" | tk="OVERLAPS" | tk="PARALLEL" | tk="PARENT" | tk="PARTITION" | tk="PATH" | tk="PERCENT" | tk="PLACING" | tk="PRECEDING" | tk="PRIMARY" | tk="PRIOR" | tk="PURGE" | tk="QUERY" | tk="QUICK" | tk="QUIESCE" | tk="RANGE" | tk="RAW" | tk="READ" | tk="RECURSIVE" | tk="RECYCLEBIN" | tk="REFERENCES" | tk="REFRESH" | tk="REGEXP" | tk="REGISTER" | tk="REMOTE" | tk="RENAME" | tk="REPEATABLE" | tk="REPLACE" | tk="RESET" | tk="RESPECT" | tk="RESTART" | tk="RESTRICT" | tk="RESTRICTED" | tk="RESUMABLE" | tk="RESUME" | tk="RETURN" | tk="RLIKE" | tk="ROLLBACK" | tk="ROLLUP" | tk="ROOT" | tk="ROW" | tk="ROWS" | tk="RR" | tk="RS" | tk="SAFE_CAST" | tk="SAVEPOINT" | tk="SCHEMA" | tk="SECURE" | tk="SEED" | tk="SEPARATOR" | tk="SEQUENCE" | tk="SESSION" | tk="SETS" | tk="SHARE" | tk="SHOW" | tk="SHUTDOWN" | tk="SIBLINGS" | tk="SIGNED" | tk="SIMILAR" | tk="SIZE" | tk="SKIP" | tk="STORED" | tk="STRING" | tk="STRUCT" | tk="SUSPEND" | tk="SWITCH" | tk="SYNONYM" | tk="SYSTEM" | tk="TABLE" | tk="TABLESPACE" | tk="TEMP" | tk="TEMPORARY" | tk="TEXT" | tk="THEN" | tk="TIMEOUT" | tk="TIMESTAMPTZ" | tk="TIMEZONE" | tk="TINYTEXT" | tk="TO" | tk="TRIGGER" | tk="TRUE" | tk="TRUNCATE" | tk="TRY_CAST" | tk="TUMBLING" | tk="TYPE" | tk="UNLOGGED" | tk="UNQIESCE" | tk="UNSIGNED" | tk="UPDATE" | tk="UPSERT" | tk="UR" | tk="USER" | tk="VALIDATE" | tk="VERBOSE" | tk="VIEW" | tk="VOLATILE" | tk="WAIT" | tk="WITHIN" | tk="WITHOUT" | tk="WITHOUT_ARRAY_WRAPPER" | tk="WORK" | tk="XML" | tk="XMLAGG" | tk="XMLDATA" | tk="XMLSCHEMA" | tk="XMLTEXT" | tk="XSINIL" | tk="YAML" | tk="YES" | tk="ZONE" )
+       | tk="ACTION" | tk="ACTIVE" | tk="ADD" | tk="ADVANCE" | tk="ADVISE" | tk="AGAINST" | tk="ALGORITHM" | tk="ALTER" | tk="ANALYZE" | tk="APPLY" | tk="APPROXIMATE" | tk="ARCHIVE" | tk="ARRAY" | tk="ASC" | tk="AT" | tk="AUTHORIZATION" | tk="AUTO" | tk="BASE64" | tk="BEGIN" | tk="BERNOULLI" | tk="BINARY" | tk="BIT" | tk="BLOCK" | tk="BROWSE" | tk="BUFFERS" | tk="BY" | tk="BYTE" | tk="BYTES" | tk="CACHE" | tk="CALL" | tk="CASCADE" | tk="CASE" | tk="CAST" | tk="CHANGE" | tk="CHANGES" | tk="CHAR" | tk="CHARACTER" | tk="CHECKPOINT" | tk="CLOSE" | tk="COLLATE" | tk="COLUMN" | tk="COLUMNS" | tk="COMMENT" | tk="COMMIT" | tk="CONCURRENTLY" | tk="CONFLICT" | tk="CONSTRAINTS" | tk="CONVERT" | tk="COSTS" | tk="CS" | tk="CYCLE" | tk="DATA" | tk="DATABASE" | tk="DATETIME" | tk="DBA_RECYCLEBIN" | tk="DDL" | tk="DECLARE" | tk="DEFERRABLE" | tk="DELAYED" | tk="DELETE" | tk="DESC" | tk="DESCRIBE" | tk="DISABLE" | tk="DISCONNECT" | tk="DIV" | tk="DML" | tk="DO" | tk="DOMAIN" | tk="DROP" | tk="DUMP" | tk="DUPLICATE" | tk="ELEMENTS" | tk="EMIT" | tk="ENABLE" | tk="END" | tk="ESCAPE" | tk="EXCLUDE" | tk="EXEC" | tk="EXECUTE" | tk="EXPLAIN" | tk="EXPLICIT" | tk="EXTENDED" | tk="EXTRACT" | tk="FALSE" | tk="FILTER" | tk="FIRST" | tk="FLUSH" | tk="FN" | tk="FOLLOWING" | tk="FORMAT" | tk="FULLTEXT" | tk="FUNCTION" | tk="GRANT" | tk="GROUP_CONCAT" | tk="GUARD" | tk="HASH" | tk="HIGH_PRIORITY" | tk="HISTORY" | tk="HOPPING" | tk="INCLUDE" | tk="INCLUDE_NULL_VALUES" | tk="INCREMENT" | tk="INDEX" | tk="INSERT" | tk="INTERLEAVE" | tk="INTERPRET" | tk="INVALIDATE" | tk="ISNULL" | tk="JSON" | tk="JSON_ARRAY" | tk="JSON_ARRAYAGG" | tk="JSON_OBJECT" | tk="JSON_OBJECTAGG" | tk="KEEP" | tk="KEY" | tk="KEYS" | tk="LAST" | tk="LEADING" | tk="LINK" | tk="LOCAL" | tk="LOCKED" | tk="LOG" | tk="LONGTEXT" | tk="LOOP" | tk="LOW_PRIORITY" | tk="MATCH" | tk="MATCHED" | tk="MATERIALIZED" | tk="MAX" | tk="MAXVALUE" | tk="MEDIUMTEXT" | tk="MEMBER" | tk="MERGE" | tk="MIN" | tk="MINVALUE" | tk="MODIFY" | tk="MOVEMENT" | tk="NEXT" | tk="NO" | tk="NOCACHE" | tk="NOKEEP" | tk="NOLOCK" | tk="NOMAXVALUE" | tk="NOMINVALUE" | tk="NOORDER" | tk="NOTHING" | tk="NOTNULL" | tk="NOVALIDATE" | tk="NOWAIT" | tk="NULLS" | tk="OF" | tk="OFF" | tk="OPEN" | tk="OVER" | tk="OVERLAPS" | tk="PARALLEL" | tk="PARENT" | tk="PARTITION" | tk="PATH" | tk="PERCENT" | tk="PLACING" | tk="PRECEDING" | tk="PRIMARY" | tk="PRIOR" | tk="PURGE" | tk="QUERY" | tk="QUICK" | tk="QUIESCE" | tk="RANGE" | tk="RAW" | tk="READ" | tk="RECURSIVE" | tk="RECYCLEBIN" | tk="REFERENCES" | tk="REFRESH" | tk="REGEXP" | tk="REGEXP_LIKE" | tk="REGISTER" | tk="REMOTE" | tk="RENAME" | tk="REPEATABLE" | tk="REPLACE" | tk="RESET" | tk="RESPECT" | tk="RESTART" | tk="RESTRICT" | tk="RESTRICTED" | tk="RESUMABLE" | tk="RESUME" | tk="RETURN" | tk="RLIKE" | tk="ROLLBACK" | tk="ROLLUP" | tk="ROOT" | tk="ROW" | tk="ROWS" | tk="RR" | tk="RS" | tk="SAFE_CAST" | tk="SAVEPOINT" | tk="SCHEMA" | tk="SECURE" | tk="SEED" | tk="SEPARATOR" | tk="SEQUENCE" | tk="SESSION" | tk="SETS" | tk="SHARE" | tk="SHOW" | tk="SHUTDOWN" | tk="SIBLINGS" | tk="SIGNED" | tk="SIMILAR" | tk="SIZE" | tk="SKIP" | tk="STORED" | tk="STRING" | tk="STRUCT" | tk="SUSPEND" | tk="SWITCH" | tk="SYNONYM" | tk="SYSTEM" | tk="TABLE" | tk="TABLESPACE" | tk="TEMP" | tk="TEMPORARY" | tk="TEXT" | tk="THEN" | tk="TIMEOUT" | tk="TIMESTAMPTZ" | tk="TIMEZONE" | tk="TINYTEXT" | tk="TO" | tk="TRIGGER" | tk="TRUE" | tk="TRUNCATE" | tk="TRY_CAST" | tk="TUMBLING" | tk="TYPE" | tk="UNLOGGED" | tk="UNQIESCE" | tk="UNSIGNED" | tk="UPDATE" | tk="UPSERT" | tk="UR" | tk="USER" | tk="VALIDATE" | tk="VERBOSE" | tk="VIEW" | tk="VOLATILE" | tk="WAIT" | tk="WITHIN" | tk="WITHOUT" | tk="WITHOUT_ARRAY_WRAPPER" | tk="WORK" | tk="XML" | tk="XMLAGG" | tk="XMLDATA" | tk="XMLSCHEMA" | tk="XMLTEXT" | tk="XSINIL" | tk="YAML" | tk="YES" | tk="ZONE" )
     { return tk.image; }
 }
 
@@ -2382,7 +2383,7 @@ List<LateralView> LateralViews():
 }
 {
     lateralView = LateralView() { lateralViews.add(lateralView); }
-    ( lateralView = LateralView() { lateralViews.add(lateralView); } )*
+    ( LOOKAHEAD(2) lateralView = LateralView() { lateralViews.add(lateralView); } )*
 
     {
         return lateralViews;
@@ -2487,11 +2488,11 @@ PlainSelect PlainSelect() #PlainSelect:
 
     [ LOOKAHEAD(2) intoTables = IntoClause() { plainSelect.setIntoTables(intoTables); } ]
     [ LOOKAHEAD(2) <K_FROM> fromItem=FromItem()
-        [ lateralViews=LateralViews() ]
+        [ LOOKAHEAD(2) lateralViews=LateralViews() ]
         [ LOOKAHEAD(2) joins=JoinsList() ]
     ]
     [ LOOKAHEAD(3) <K_FROM> <K_ONLY> { plainSelect.setUsingOnly(true); } fromItem=FromItem()
-            [ lateralViews=LateralViews() ]
+            [ LOOKAHEAD(2) lateralViews=LateralViews() ]
             [ LOOKAHEAD(2) joins=JoinsList() ]
     ]
 
@@ -4004,6 +4005,7 @@ Expression LikeExpression(Expression leftExpression) #LikeExpression:
         token = <K_LIKE>
         | token = <K_ILIKE>
         | token = <K_RLIKE>
+        | token = <K_REGEXP_LIKE>
         | token = <K_REGEXP>
         | token = <K_SIMILAR_TO>
     ) { result.setLikeKeyWord( LikeExpression.KeyWord.from(token.image)); }
@@ -4613,7 +4615,9 @@ Expression PrimaryExpression() #PrimaryExpression:
 
         | "{ts" token=<S_CHAR_LITERAL> "}" { retval = new TimestampValue(token.image); }
 
-        | LOOKAHEAD( ParenthesedSelect() , {!interrupted} ) retval=ParenthesedSelect()
+        | LOOKAHEAD( Select() , { getAsBoolean(Feature.allowUnparenthesizedSubSelects) && !interrupted } ) retval=Select()
+
+        | LOOKAHEAD( ParenthesedSelect() , { !getAsBoolean(Feature.allowUnparenthesizedSubSelects) && !interrupted } ) retval=ParenthesedSelect()
 
         |
         (
@@ -5655,7 +5659,7 @@ Function InternalFunction(boolean escaped):
             |
             LOOKAHEAD(3) expressionList=ExpressionList() [ orderByList = OrderByElements() { retval.setOrderByElements(orderByList); } ]
             |
-            expr = Select() { expressionList = new ExpressionList(expr); }
+            LOOKAHEAD({ !getAsBoolean(Feature.allowUnparenthesizedSubSelects) }) expr = Select() { expressionList = new ExpressionList(expr); }
         )
     ]
 
diff --git a/src/site/sphinx/keywords.rst b/src/site/sphinx/keywords.rst
index 78c17aa0b..551a9b320 100644
--- a/src/site/sphinx/keywords.rst
+++ b/src/site/sphinx/keywords.rst
@@ -39,7 +39,7 @@ The following Keywords are **restricted** in JSQLParser-|JSQLPARSER_VERSION| and
 +----------------------+-------------+-----------+
 | DEFAULT              | Yes         |           |
 +----------------------+-------------+-----------+
-| DISTINCT             | Yes         | Yes       |
+| DISTINCT             | Yes         | Yes       | 
 +----------------------+-------------+-----------+
 | DOUBLE               | Yes         |           | 
 +----------------------+-------------+-----------+
diff --git a/src/test/java/net/sf/jsqlparser/expression/FunctionTest.java b/src/test/java/net/sf/jsqlparser/expression/FunctionTest.java
index e2e36dc7d..72f703c38 100644
--- a/src/test/java/net/sf/jsqlparser/expression/FunctionTest.java
+++ b/src/test/java/net/sf/jsqlparser/expression/FunctionTest.java
@@ -76,6 +76,13 @@ void testSubSelectArrayWithoutKeywordParameter() throws JSQLParserException {
         TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true);
     }
 
+    @Test
+    void testSubSelectParameterWithoutParentheses() throws JSQLParserException {
+        String sqlStr = "SELECT COALESCE(SELECT mycolumn FROM mytable, 0)";
+        TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true,
+                parser -> parser.withUnparenthesizedSubSelects(true));
+    }
+
     @Test
     void testSimpleFunctionIssue2059() throws JSQLParserException {
         String sqlStr = "select count(*) from zzz";
diff --git a/src/test/java/net/sf/jsqlparser/statement/select/NestedBracketsPerformanceTest.java b/src/test/java/net/sf/jsqlparser/statement/select/NestedBracketsPerformanceTest.java
index 51b041470..240e10bf9 100644
--- a/src/test/java/net/sf/jsqlparser/statement/select/NestedBracketsPerformanceTest.java
+++ b/src/test/java/net/sf/jsqlparser/statement/select/NestedBracketsPerformanceTest.java
@@ -18,8 +18,10 @@
 import java.util.logging.Logger;
 
 import static net.sf.jsqlparser.test.TestUtils.assertSqlCanBeParsedAndDeparsed;
+import org.junit.jupiter.api.Assertions;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.fail;
+import org.junit.jupiter.api.function.Executable;
 
 /**
  *
@@ -35,14 +37,15 @@ public class NestedBracketsPerformanceTest {
     public void testIssue766() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed(
                 "SELECT concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat(concat('1','2'),'3'),'4'),'5'),'6'),'7'),'8'),'9'),'10'),'11'),'12'),'13'),'14'),'15'),'16'),'17'),'18'),'19'),'20'),'21'),col1 FROM tbl t1",
-                true);
+                true, parser -> parser.withTimeOut(60000));
     }
 
     @Test
     @Timeout(2000)
     public void testIssue766_2() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed(
-                "SELECT concat(concat(concat('1', '2'), '3'), '4'), col1 FROM tbl t1");
+                "SELECT concat(concat(concat('1', '2'), '3'), '4'), col1 FROM tbl t1", true,
+                parser -> parser.withTimeOut(60000));
     }
 
     @Test
@@ -50,7 +53,7 @@ public void testIssue766_2() throws JSQLParserException {
     public void testIssue235() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed(
                 "SELECT CASE WHEN ( CASE WHEN ( CASE WHEN ( CASE WHEN ( 1 ) THEN 0 END ) THEN 0 END ) THEN 0 END ) THEN 0 END FROM a",
-                true);
+                true, parser -> parser.withTimeOut(60000));
     }
 
     @Test
@@ -71,7 +74,7 @@ public void testNestedCaseWhenWithoutBracketsIssue1162() throws JSQLParserExcept
                 + "WHEN WDGFLD.PORTTYPE = 1 THEN 'INPUT PORT'\n" + "ELSE CASE\n"
                 + "WHEN WDGFLD.PORTTYPE = 1 THEN 'INPUT PORT'\n"
                 + "ELSE CASE WHEN WDGFLD.PORTTYPE = 1 THEN 'INPUT PORT' ELSE '0' END END END END END END END END END END END END END END COLUMNALIAS\n"
-                + "FROM TABLE1", true);
+                + "FROM TABLE1", true, parser -> parser.withTimeOut(60000));
     }
 
     @Test
@@ -92,26 +95,31 @@ public void testNestedCaseWhenWithBracketsIssue1162() throws JSQLParserException
                 + "WHEN WDGFLD.PORTTYPE = 1 THEN 'INPUT PORT'\n" + "ELSE (CASE\n"
                 + "WHEN WDGFLD.PORTTYPE = 1 THEN 'INPUT PORT'\n"
                 + "ELSE (CASE WHEN WDGFLD.PORTTYPE = 1 THEN 'INPUT PORT' ELSE '0' END) END) END) END) END) END) END) END) END) END) END) END) END) END COLUMNALIAS\n"
-                + "FROM TABLE1", true);
+                + "FROM TABLE1", true, parser -> parser.withTimeOut(60000));
     }
 
     @Test
-    @Timeout(2000)
-    @Disabled
+    @Timeout(10000)
     public void testIssue496() throws JSQLParserException {
-        assertSqlCanBeParsedAndDeparsed(
-                "select isNull(charLen(TEST_ID,0)+ isNull(charLen(TEST_DVC,0)+ isNull(charLen(TEST_NO,0)+ isNull(charLen(ATEST_ID,0)+ isNull(charLen(TESTNO,0)+ isNull(charLen(TEST_CTNT,0)+ isNull(charLen(TEST_MESG_CTNT,0)+ isNull(charLen(TEST_DTM,0)+ isNull(charLen(TEST_DTT,0)+ isNull(charLen(TEST_ADTT,0)+ isNull(charLen(TEST_TCD,0)+ isNull(charLen(TEST_PD,0)+ isNull(charLen(TEST_VAL,0)+ isNull(charLen(TEST_YN,0)+ isNull(charLen(TEST_DTACM,0)+ isNull(charLen(TEST_MST,0) from test_info_m",
-                true);
+        Assertions.assertThrowsExactly(JSQLParserException.class, new Executable() {
+            @Override
+            public void execute() throws Throwable {
+                assertSqlCanBeParsedAndDeparsed(
+                        "select isNull(charLen(TEST_ID,0)+ isNull(charLen(TEST_DVC,0)+ isNull(charLen(TEST_NO,0)+ isNull(charLen(ATEST_ID,0)+ isNull(charLen(TESTNO,0)+ isNull(charLen(TEST_CTNT,0)+ isNull(charLen(TEST_MESG_CTNT,0)+ isNull(charLen(TEST_DTM,0)+ isNull(charLen(TEST_DTT,0)+ isNull(charLen(TEST_ADTT,0)+ isNull(charLen(TEST_TCD,0)+ isNull(charLen(TEST_PD,0)+ isNull(charLen(TEST_VAL,0)+ isNull(charLen(TEST_YN,0)+ isNull(charLen(TEST_DTACM,0)+ isNull(charLen(TEST_MST,0) from test_info_m",
+                        true, parser -> parser.withTimeOut(6000));
+            }
+        });
+
     }
 
     @Test
-    // @Todo Investigate performance deterioration since JSQLParser 5.0pre development
+    @Timeout(2000)
     public void testIssue856() throws JSQLParserException {
         String sql = "SELECT "
                 + buildRecursiveBracketExpression(
                         "if(month(today()) = 3, sum(\"Table5\".\"Month 002\"), $1)", "0", 3)
                 + " FROM mytbl";
-        assertSqlCanBeParsedAndDeparsed(sql);
+        assertSqlCanBeParsedAndDeparsed(sql, true, parser -> parser.withTimeOut(60000));
     }
 
     @Test
@@ -127,6 +135,7 @@ public void testRecursiveBracketExpressionIssue1019() {
     // maxDepth = 10 collides with the Parser Timeout = 6 seconds
     // @todo: implement methods to set the Parser Timeout explicitly and on demand
     @Test
+    @Timeout(20000)
     public void testRecursiveBracketExpressionIssue1019_2() throws JSQLParserException {
         // Temporally set the maxDepth to be 6, was 8 before this
         doIncreaseOfParseTimeTesting("IF(1=1, $1, 2)", "1", 6);
@@ -135,18 +144,22 @@ public void testRecursiveBracketExpressionIssue1019_2() throws JSQLParserExcepti
     @Test
     @Timeout(2000)
     public void testIssue1013() throws JSQLParserException {
-        assertSqlCanBeParsedAndDeparsed("SELECT ((((((((((((((((tblA)))))))))))))))) FROM mytable");
+        assertSqlCanBeParsedAndDeparsed("SELECT ((((((((((((((((tblA)))))))))))))))) FROM mytable",
+                true, parser -> parser.withTimeOut(60000));
     }
 
     @Test
     @Timeout(2000)
     public void testIssue1013_2() throws JSQLParserException {
-        assertSqlCanBeParsedAndDeparsed("SELECT * FROM ((((((((((((((((tblA))))))))))))))))");
+        assertSqlCanBeParsedAndDeparsed("SELECT * FROM ((((((((((((((((tblA))))))))))))))))", true,
+                parser -> parser.withTimeOut(60000));
     }
 
     @Test
+    @Timeout(2000)
     public void testIssue1013_3() throws JSQLParserException {
-        assertSqlCanBeParsedAndDeparsed("SELECT * FROM (((tblA)))");
+        assertSqlCanBeParsedAndDeparsed("SELECT * FROM (((tblA)))", true,
+                parser -> parser.withTimeOut(60000));
     }
 
     @Test
@@ -158,7 +171,7 @@ public void testIssue1013_4() throws JSQLParserException {
         }
         String sql = "SELECT * FROM " + s;
         LOG.info("testing " + sql);
-        assertSqlCanBeParsedAndDeparsed(sql);
+        assertSqlCanBeParsedAndDeparsed(sql, true, parser -> parser.withTimeOut(60000));
     }
 
     /**
@@ -166,7 +179,8 @@ public void testIssue1013_4() throws JSQLParserException {
      *
      * @throws JSQLParserException
      */
-    // @Test(timeout = 6000)
+    @Test
+    @Timeout(2000)
     public void testIncreaseOfParseTime() throws JSQLParserException {
         // Temporally set the maxDepth to be 6, was 50 before this
         doIncreaseOfParseTimeTesting("concat($1,'B')", "'A'", 6);
@@ -180,7 +194,7 @@ private void doIncreaseOfParseTimeTesting(String template, String finalExpressio
             String sql = "SELECT " + buildRecursiveBracketExpression(template, finalExpression, i)
                     + " FROM mytbl";
             long startTime = System.currentTimeMillis();
-            assertSqlCanBeParsedAndDeparsed(sql, true);
+            assertSqlCanBeParsedAndDeparsed(sql, true, parser -> parser.withTimeOut(60000));
             long durationTime = System.currentTimeMillis() - startTime;
 
             if (i > 0) {
@@ -199,6 +213,7 @@ private void doIncreaseOfParseTimeTesting(String template, String finalExpressio
     }
 
     @Test
+    @Timeout(2000)
     public void testRecursiveBracketExpression() {
         assertEquals("concat('A','B')",
                 buildRecursiveBracketExpression("concat($1,'B')", "'A'", 0));
@@ -227,10 +242,11 @@ public void testIssue1103() throws JSQLParserException {
                         + "ROUND(ROUND(ROUND(ROUND(ROUND(ROUND(ROUND(ROUND(0\n"
                         + ",0),0),0),0),0),0),0),0)\n" + ",0),0),0),0),0),0),0),0)\n"
                         + ",0),0),0),0),0),0),0),0)\n" + ",0),0),0),0),0),0),0),0)",
-                true);
+                true, parser -> parser.withTimeOut(60000));
     }
 
     @Test
+    @Timeout(2000)
     public void testDeepFunctionParameters() throws JSQLParserException {
         String sqlStr = "SELECT  a.*\n"
                 + "        , To_Char( a.eingangsdat, 'MM.YY' ) AS eingmonat\n"
@@ -354,7 +370,7 @@ public void testDeepFunctionParameters() throws JSQLParserException {
                 + "                FROM beschfehler\n"
                 + "                WHERE beschfehler_id = a.beschwkat_id ), 0 ) > 0\n";
 
-        assertSqlCanBeParsedAndDeparsed(sqlStr, true);
+        assertSqlCanBeParsedAndDeparsed(sqlStr, true, parser -> parser.withTimeOut(60000));
     }
 
     @Test
diff --git a/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java b/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java
index 6ef1fc163..1f0c3b931 100644
--- a/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java
+++ b/src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java
@@ -2896,6 +2896,12 @@ public void testRlike() throws JSQLParserException {
                 "SELECT * FROM mytable WHERE first_name RLIKE '^Ste(v|ph)en$'");
     }
 
+    @Test
+    public void testRegexpLike() throws JSQLParserException {
+        assertSqlCanBeParsedAndDeparsed(
+                "SELECT * FROM mytable WHERE first_name REGEXP_LIKE '^Ste(v|ph)en$'");
+    }
+
     @Test
     public void testBooleanFunction1() throws JSQLParserException {
         String stmt = "SELECT * FROM mytable WHERE test_func(col1)";
@@ -5953,6 +5959,26 @@ void testGroupByWithHaving() throws JSQLParserException {
         Assertions.assertInstanceOf(Select.class, stmt);
     }
 
+    @ParameterizedTest
+    @ValueSource(strings = {
+            "SELECT SELECT 1",
+            "SELECT 1 WHERE 1 = SELECT 1",
+            "SELECT 1 WHERE 1 IN SELECT 1"
+    })
+    public void testUnparenthesizedSubSelect(String sqlStr) throws JSQLParserException {
+        TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true,
+                parser -> parser.withUnparenthesizedSubSelects(true));
+
+        Assertions.assertThrowsExactly(JSQLParserException.class, new Executable() {
+            @Override
+            public void execute() throws Throwable {
+                TestUtils.assertSqlCanBeParsedAndDeparsed(sqlStr, true,
+                        parser -> parser.withUnparenthesizedSubSelects(false));
+            }
+
+        });
+    }
+
     @Test
     void testInsertWithinCte() throws JSQLParserException {
         String sqlStr = "WITH inserted AS ( " +
@@ -6079,5 +6105,4 @@ void testSelectAndInsertWithin2Ctes() throws JSQLParserException {
                 insert.toString());
         assertEquals(" inserted", withItems.get(1).getAlias().toString());
     }
-
 }
diff --git a/src/test/java/net/sf/jsqlparser/util/validation/validator/ExpressionValidatorTest.java b/src/test/java/net/sf/jsqlparser/util/validation/validator/ExpressionValidatorTest.java
index 56453ae29..edba27f66 100644
--- a/src/test/java/net/sf/jsqlparser/util/validation/validator/ExpressionValidatorTest.java
+++ b/src/test/java/net/sf/jsqlparser/util/validation/validator/ExpressionValidatorTest.java
@@ -189,6 +189,12 @@ public void testRlike() throws JSQLParserException {
                 EXPRESSIONS);
     }
 
+    @Test
+    public void testRegexpLike() throws JSQLParserException {
+        validateNoErrors("SELECT * FROM mytable WHERE first_name REGEXP_LIKE '^Ste(v|ph)en$'", 1,
+                EXPRESSIONS);
+    }
+
     @Test
     public void testSimilarTo() throws JSQLParserException {
         validateNoErrors(