feat: hint pragma (#169)

Author: KirillKurdyukov

hibernate-dialect/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.4.0 ##
+
+- Added hint for YQL pragma queries
+
 ## 1.3.0 ##
 
 - Added support UUID YDB type

hibernate-dialect/pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>tech.ydb.dialects</groupId>
     <artifactId>hibernate-ydb-dialect</artifactId>
-    <version>1.3.0</version>
+    <version>1.4.0</version>
 
     <packaging>jar</packaging>
 

hibernate-dialect/src/main/java/tech/ydb/hibernate/dialect/YdbDialect.java

@@ -64,6 +64,7 @@
 import tech.ydb.hibernate.dialect.exporter.EmptyExporter;
 import tech.ydb.hibernate.dialect.exporter.YdbIndexExporter;
 import tech.ydb.hibernate.dialect.hint.IndexQueryHintHandler;
+import tech.ydb.hibernate.dialect.hint.PragmaQueryHintHandler;
 import tech.ydb.hibernate.dialect.hint.QueryHintHandler;
 import tech.ydb.hibernate.dialect.hint.ScanQueryHintHandler;
 import tech.ydb.hibernate.dialect.translator.YdbSqlAstTranslatorFactory;
@@ -86,7 +87,8 @@ public class YdbDialect extends Dialect {
     private static final Exporter<Constraint> UNIQUE_KEY_EMPTY_EXPORTER = new EmptyExporter<>();
     private static final List<QueryHintHandler> QUERY_HINT_HANDLERS = List.of(
             IndexQueryHintHandler.INSTANCE,
-            ScanQueryHintHandler.INSTANCE
+            ScanQueryHintHandler.INSTANCE,
+            PragmaQueryHintHandler.INSTANCE
     );
     private static final ConcurrentHashMap<Integer, DecimalJdbcType> DECIMAL_JDBC_TYPE_CACHE = new ConcurrentHashMap<>();
 
@@ -203,7 +205,7 @@ public String addSqlHintOrComment(String sql, QueryOptions queryOptions, boolean
         if (queryOptions.getComment() != null) {
             boolean commentIsHint = false;
 
-            var hints = queryOptions.getComment().split(",");
+            var hints = queryOptions.getComment().split(";");
 
             for (var queryHintHandler : QUERY_HINT_HANDLERS) {
                 for (var hint : hints) {

hibernate-dialect/src/main/java/tech/ydb/hibernate/dialect/hint/IndexQueryHintHandler.java

@@ -26,10 +26,6 @@ public boolean commentIsHint(String comment) {
 
     @Override
     public String addQueryHints(String query, List<String> hints) {
-        if (hints.isEmpty()) {
-            return query;
-        }
-
         var useIndexes = new ArrayList<String>();
         hints.forEach(hint -> {
             if (hint.startsWith(HINT_USE_INDEX)) {

hibernate-dialect/src/main/java/tech/ydb/hibernate/dialect/hint/PragmaQueryHintHandler.java

@@ -0,0 +1,28 @@
+package tech.ydb.hibernate.dialect.hint;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * @author Kirill Kurdyukov
+ */
+public class PragmaQueryHintHandler implements QueryHintHandler {
+    public static final PragmaQueryHintHandler INSTANCE = new PragmaQueryHintHandler();
+
+    private static final String HINT_PRAGMA = "add_pragma:";
+
+    @Override
+    public String addQueryHints(String query, List<String> hints) {
+        var yqlHints = hints.stream()
+                .filter(hint -> hint.startsWith(HINT_PRAGMA))
+                .map(hint -> "PRAGMA " + hint.substring(HINT_PRAGMA.length()) + ";\n")
+                .collect(Collectors.joining());
+
+        return yqlHints + query;
+    }
+
+    @Override
+    public boolean commentIsHint(String comment) {
+        return comment.startsWith(HINT_PRAGMA);
+    }
+}

hibernate-dialect/src/main/java/tech/ydb/hibernate/dialect/hint/ScanQueryHintHandler.java

@@ -17,10 +17,6 @@ private ScanQueryHintHandler() {
 
     @Override
     public String addQueryHints(String query, List<String> hints) {
-        if (hints.isEmpty()) {
-            return query;
-        }
-
         AtomicBoolean useScan = new AtomicBoolean(false);
         hints.forEach(hint -> {
             if (hint.equals(HINT_USE_SCAN)) {

hibernate-dialect/src/test/java/tech/ydb/hibernate/student/StudentsRepositoryTest.java

@@ -201,6 +201,39 @@ void studentsByGroupName_Eager_OneToManyTest() {
         );
     }
 
+    @Test
+    void studentByGroupNameUsingPragmaHintTest() {
+        inTransaction(
+                session -> {
+                    /*
+                        PRAGMA ydb.HashJoinMode='grace'; PRAGMA Warning("disable", "1101"); select
+                            g1_0.GroupId,
+                            g1_0.GroupName,
+                            s1_0.GroupId,
+                            s1_0.StudentId,
+                            s1_0.StudentName
+                        from
+                            Groups g1_0
+                        join
+                            Students s1_0
+                                on g1_0.GroupId=s1_0.GroupId
+                        where
+                            g1_0.GroupName='M3439'
+                     */
+                    List<Student> students = session
+                            .createQuery("FROM Group g JOIN FETCH g.students WHERE g.name = 'M3439'", Group.class)
+                            .addQueryHint("add_pragma:ydb.HashJoinMode='grace'")
+                            .addQueryHint("add_pragma:Warning(\"disable\", \"1101\")")
+                            .getSingleResult().getStudents();
+
+                    assertEquals(2, students.size());
+
+                    assertEquals("Петров П.П.", students.get(0).getName());
+                    assertEquals("Сидоров С.С.", students.get(1).getName());
+                }
+        );
+    }
+
     @Test
     void groupsByLecturerIdAndCourseId_Eager_ManyToManyTest() {
         inTransaction(
@@ -313,8 +346,9 @@ private static void checkCourses(List<Course> courses) {
     }
 
     @Test
-    void useIndexAndUseScanHintsTogetherTest() {
+    void useAllHintsTogetherTest() {
         /*
+        PRAGMA Warning("disable", "1101");
         scan select
             g1_0.GroupId,
             g1_0.GroupName
@@ -329,6 +363,7 @@ void useIndexAndUseScanHintsTogetherTest() {
                             .createQuery("FROM Group g WHERE g.name = 'M3439'", Group.class)
                             .addQueryHint("use_index:group_name_index") // Hibernate
                             .addQueryHint("use_scan")
+                            .addQueryHint("add_pragma:Warning(\"disable\", \"1101\")")
                             .getSingleResult();
 
                     assertEquals("M3439", group.getName());
@@ -337,6 +372,7 @@ void useIndexAndUseScanHintsTogetherTest() {
 
 
         /*
+        PRAGMA Warning("disable", "1101");
         scan select
             g1_0.GroupId,
             g1_0.GroupName
@@ -349,7 +385,8 @@ void useIndexAndUseScanHintsTogetherTest() {
                 session -> {
                     Group group = session
                             .createQuery("FROM Group g WHERE g.name = 'M3439'", Group.class)
-                            .setHint(HibernateHints.HINT_COMMENT, "use_index:group_name_index, use_scan") // JPA
+                            .setHint(HibernateHints.HINT_COMMENT,
+                                    "use_index:group_name_index;use_scan;add_pragma:Warning(\"disable\", \"1101\")")
                             .getSingleResult();
 
                     assertEquals("M3439", group.getName());