feat: view index on select from (#140)

Author: KirillKurdyukov

.github/workflows/ci-hibernate-dialect.yaml

@@ -20,7 +20,7 @@ jobs:
 
     strategy:
       matrix:
-        java: [ '17' ]
+        java: [ '17', '21' ]
 
     steps:
       - uses: actions/checkout@v4

hibernate-dialect/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.9.5 ##
+
+- Added query hint for view index for "select * from ... where" queries
+
 ## 0.9.4 ##
 
 - Fixed the generated bool value

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

@@ -1,6 +1,7 @@
 package tech.ydb.hibernate.dialect;
 
 import java.time.LocalDateTime;
+import java.util.List;
 import org.hibernate.boot.model.FunctionContributions;
 import org.hibernate.boot.model.TypeContributions;
 import org.hibernate.dialect.Dialect;
@@ -51,6 +52,7 @@
 import org.hibernate.type.StandardBasicTypes;
 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.translator.YdbSqlAstTranslatorFactory;
 import tech.ydb.hibernate.dialect.types.LocalDateTimeJavaType;
 import tech.ydb.hibernate.dialect.types.LocalDateTimeJdbcType;
@@ -118,6 +120,11 @@ public void initializeFunctionRegistry(FunctionContributions functionContributio
         );
     }
 
+    @Override
+    public String getQueryHintString(String query, List<String> hintList) {
+        return IndexQueryHintHandler.INSTANCE.addQueryHints(query, hintList);
+    }
+
     @Override
     public LimitHandler getLimitHandler() {
         return LimitOffsetLimitHandler.INSTANCE;

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

@@ -0,0 +1,42 @@
+package tech.ydb.hibernate.dialect.hint;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * @author Kirill Kurdyukov
+ */
+public class IndexQueryHintHandler {
+    private static final Pattern SELECT_FROM_WHERE_QUERY_PATTERN = Pattern
+            .compile("^\\s*(select.+?from\\s+\\w+)(.+where.+)$", Pattern.CASE_INSENSITIVE);
+
+    public static final String HINT_USE_INDEX = "use_index:";
+    public static final IndexQueryHintHandler INSTANCE = new IndexQueryHintHandler();
+
+    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)) {
+                useIndexes.add(hint.substring(HINT_USE_INDEX.length()));
+            }
+        });
+
+        if (!useIndexes.isEmpty()) {
+            Matcher matcher = SELECT_FROM_WHERE_QUERY_PATTERN.matcher(query);
+            if (matcher.matches() && matcher.groupCount() > 1) {
+                String startToken = matcher.group(1);
+                String endToken = matcher.group(2);
+
+                return startToken + " view " + String.join(", ", useIndexes) + endToken;
+            }
+        }
+
+        return query;
+    }
+}

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

@@ -143,7 +143,6 @@ void studentsAndCourses_Lazy_ManyToManyTest() {
         );
     }
 
-
     @Test
     void studentsByGroupName_Lazy_OneToManyTest() {
         inTransaction(
@@ -160,6 +159,20 @@ void studentsByGroupName_Lazy_OneToManyTest() {
         );
     }
 
+    @Test
+    void groupByGroupName_ViewIndex() {
+        inTransaction(
+                session -> {
+                    Group group = session
+                            .createQuery("FROM Group g WHERE g.name = 'M3439'", Group.class)
+                            .addQueryHint("use_index:group_name_index")
+                            .getSingleResult();
+
+                    assertEquals("M3439", group.getName());
+                }
+        );
+    }
+
     @Test
     void studentsByGroupName_Eager_OneToManyTest() {
         inTransaction(

hibernate-dialect/src/test/java/tech/ydb/hibernate/student/entity/Group.java

@@ -7,11 +7,10 @@
 import jakarta.persistence.NamedQuery;
 import jakarta.persistence.OneToMany;
 import jakarta.persistence.Table;
+import java.util.List;
 import lombok.Getter;
 import lombok.Setter;
 
-import java.util.List;
-
 /**
  * @author Kirill Kurdyukov
  */