perf(bigquery-jdbc): optimize getExportedKeys performance using hybrid metadata lookup

java-bigquery-jdbc/src/main/java/com/google/cloud/bigquery/jdbc/BigQueryDatabaseMetaData.java

@@ -52,11 +52,17 @@
 import com.google.cloud.bigquery.exception.BigQueryJdbcException;
 import com.google.cloud.bigquery.jdbc.BigQueryJdbcTypeMappings.ColumnTypeInfo;
 import com.google.cloud.bigquery.jdbc.utils.BigQueryJdbcVersionUtility;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.sql.Connection;
 import java.sql.DatabaseMetaData;
+import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.RowIdLifetime;
 import java.sql.SQLException;
+import java.sql.Statement;
 import java.sql.Types;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -94,6 +100,8 @@ class BigQueryDatabaseMetaData implements DatabaseMetaData {
   private static final String PROCEDURE_TERM = "Procedure";
   private static final int DEFAULT_PAGE_SIZE = 500;
   private static final int DEFAULT_QUEUE_CAPACITY = 5000;
+  private static final String GET_EXPORTED_KEYS_SQL = "DatabaseMetaData_GetExportedKeys.sql";
+  private static String exportedKeysSqlContent;
   // Declared package-private for testing.
   static final String GOOGLE_SQL_QUOTED_IDENTIFIER = "`";
   // Does not include SQL:2003 Keywords as per JDBC spec.
@@ -2559,40 +2567,63 @@ public ResultSet getExportedKeys(String catalog, String schema, String table)
     final Schema resultSchema = defineForeignKeyResultSetSchema();
     final FieldList resultSchemaFields = resultSchema.getFields();
 
-    final List<FieldValueList> collectedResults = Collections.synchronizedList(new ArrayList<>());
-    List<DatasetId> targetDatasets = getTargetDatasets(catalog, null);
+    // Early return for PCNT catalog schemas (containing '.') as they do not support table
+    // constraints.
+    if (schema != null && schema.contains(".")) {
+      final BlockingQueue<BigQueryFieldValueListWrapper> queue = new LinkedBlockingQueue<>(1);
+      signalEndOfData(queue, resultSchemaFields);
+      return BigQueryJsonResultSet.of(resultSchema, 0, queue, null);
+    }
 
-    boolean ignoreAccessErrors = (catalog == null);
-    processTargetTablesConcurrently(
-        targetDatasets,
-        null,
-        collectedResults,
-        resultSchemaFields,
-        ignoreAccessErrors,
-        (bqTable, results, fields) -> {
-          TableConstraints constraints = bqTable.getTableConstraints();
-          if (constraints == null || constraints.getForeignKeys() == null) {
-            return;
-          }
-          for (ForeignKey fk : constraints.getForeignKeys()) {
-            TableId pkTableId = fk.getReferencedTable();
-            if (pkTableId == null
-                || !equalsOrNullMatchesAll(catalog, pkTableId.getProject())
-                || !equalsOrNullMatchesAll(schema, pkTableId.getDataset())
-                || !table.equals(pkTableId.getTable())) {
-              continue;
+    // Fallback Path: If catalog or schema is null, fall back to REST API metadata scan.
+    if (catalog == null || schema == null) {
+      final List<FieldValueList> collectedResults = Collections.synchronizedList(new ArrayList<>());
+      List<DatasetId> targetDatasets = getTargetDatasets(catalog, schema);
+
+      boolean ignoreAccessErrors = (catalog == null);
+      processTargetTablesConcurrently(
+          targetDatasets,
+          null,
+          collectedResults,
+          resultSchemaFields,
+          ignoreAccessErrors,
+          (bqTable, results, fields) -> {
+            TableConstraints constraints = bqTable.getTableConstraints();
+            if (constraints == null || constraints.getForeignKeys() == null) {
+              return;
             }
-            processForeignKey(fk, pkTableId, bqTable.getTableId(), results, fields);
-          }
-        });
+            for (ForeignKey fk : constraints.getForeignKeys()) {
+              TableId pkTableId = fk.getReferencedTable();
+              if (pkTableId == null
+                  || !equalsOrNullMatchesAll(catalog, pkTableId.getProject())
+                  || !equalsOrNullMatchesAll(schema, pkTableId.getDataset())
+                  || !table.equals(pkTableId.getTable())) {
+                continue;
+              }
+              processForeignKey(fk, pkTableId, bqTable.getTableId(), results, fields);
+            }
+          });
 
-    Comparator<FieldValueList> comparator = defineFkTableSortComparator(resultSchemaFields);
-    sortResults(collectedResults, comparator, "getExportedKeys", LOG);
+      Comparator<FieldValueList> comparator = defineFkTableSortComparator(resultSchemaFields);
+      sortResults(collectedResults, comparator, "getExportedKeys", LOG);
 
-    final BlockingQueue<BigQueryFieldValueListWrapper> queue =
-        new LinkedBlockingQueue<>(DEFAULT_QUEUE_CAPACITY);
-    Future<?> fetcherFuture = populateQueueAsync(collectedResults, queue, resultSchemaFields);
-    return BigQueryJsonResultSet.of(resultSchema, -1, queue, null, fetcherFuture);
+      final BlockingQueue<BigQueryFieldValueListWrapper> queue =
+          new LinkedBlockingQueue<>(DEFAULT_QUEUE_CAPACITY);
+      Future<?> fetcherFuture = populateQueueAsync(collectedResults, queue, resultSchemaFields);
+      return BigQueryJsonResultSet.of(resultSchema, -1, queue, null, fetcherFuture);
+    }
+
+    String sql = getExportedKeysSqlContent();
+    String formattedSql = replaceSqlParameters(sql, catalog, schema);
+    PreparedStatement stmt = this.connection.prepareStatement(formattedSql);
+    try {
+      stmt.closeOnCompletion();
+      stmt.setString(1, table);
+      return stmt.executeQuery();
+    } catch (SQLException e) {
+      closeStatementIgnoreException(stmt);
+      throw new BigQueryJdbcException("Error executing getExportedKeys", e);
+    }
   }
 
   @Override
@@ -5353,4 +5384,43 @@ private Comparator<FieldValueList> defineFkTableSortComparator(FieldList resultS
             (FieldValueList fvl) -> getLongValueOrNull(fvl, KEY_SEQ_IDX),
             Comparator.nullsFirst(Long::compareTo));
   }
+
+  private static synchronized String getExportedKeysSqlContent() {
+    if (exportedKeysSqlContent == null) {
+      exportedKeysSqlContent = readSqlFromFile(GET_EXPORTED_KEYS_SQL);
+    }
+    return exportedKeysSqlContent;
+  }
+
+  static String readSqlFromFile(String filename) {
+    try (InputStream in = BigQueryDatabaseMetaData.class.getResourceAsStream(filename)) {
+      if (in == null) {
+        throw new IllegalArgumentException("SQL file not found: " + filename);
+      }
+      ByteArrayOutputStream result = new ByteArrayOutputStream();
+      byte[] buffer = new byte[1024];
+      int length;
+      while ((length = in.read(buffer)) != -1) {
+        result.write(buffer, 0, length);
+      }
+      return result.toString(StandardCharsets.UTF_8.name());
+    } catch (IOException e) {
+      throw new RuntimeException("Failed to read SQL file: " + filename, e);
+    }
+  }
+
+  String replaceSqlParameters(String sql, String... params) throws SQLException {
+    return String.format(sql, (Object[]) params);
+  }
+
+  private void closeStatementIgnoreException(Statement stmt) {
+    if (stmt == null) {
+      return;
+    }
+    try {
+      stmt.close();
+    } catch (SQLException e) {
+      // ignore
+    }
+  }
 }

java-bigquery-jdbc/src/main/resources/com/google/cloud/bigquery/jdbc/DatabaseMetaData_GetExportedKeys.sql

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+SELECT referenced_table_catalog AS PKTABLE_CAT,
+       referenced_table_schema  AS PKTABLE_SCHEM,
+       referenced_table_name    AS PKTABLE_NAME,
+       referenced_column_name   AS PKCOLUMN_NAME,
+       table_catalog            AS FKTABLE_CAT,
+       table_schema             AS FKTABLE_SCHEM,
+       table_name               AS FKTABLE_NAME,
+       column_name              AS FKCOLUMN_NAME,
+       ordinal_position         AS KEY_SEQ,
+       NULL                     AS UPDATE_RULE,
+       NULL                     AS DELETE_RULE,
+       constraint_name          AS FK_NAME,
+       NULL                     AS PK_NAME,
+       NULL                     AS DEFERRABILITY
+FROM `%1$s.%2$s.INFORMATION_SCHEMA.KEY_COLUMN_USAGE`
+WHERE referenced_table_name = ?
+ORDER BY FKTABLE_CAT, FKTABLE_SCHEM, FKTABLE_NAME, KEY_SEQ

java-bigquery-jdbc/src/test/java/com/google/cloud/bigquery/jdbc/it/ITDatabaseMetadataTest.java

@@ -57,6 +57,8 @@ public class ITDatabaseMetadataTest extends ITBase {
   private static final String CONSTRAINTS_TABLE_NAME = "JDBC_CONSTRAINTS_TEST_TABLE";
   private static final String CONSTRAINTS_TABLE_NAME2 = "JDBC_CONSTRAINTS_TEST_TABLE2";
   private static final String CONSTRAINTS_TABLE_NAME3 = "JDBC_CONSTRAINTS_TEST_TABLE3";
+  private static final String PCNT_SCHEMA = "bq-drivers-test-warehouse.jdbc_pcnt_test_namespace";
+  private static final String PCNT_TABLE_NAME = "PCNT_TEST_TABLE";
   private static final Pattern VERSION_PATTERN =
       Pattern.compile("^(\\d+)\\.(\\d+)(?:\\.\\d+)+\\s*.*");
   private static final String DEFAULT_CATALOG = ServiceOptions.getDefaultProjectId();
@@ -387,6 +389,62 @@ public void testGetExportedKeys_noKeys() throws SQLException {
     }
   }
 
+  @Test
+  public void testGetPrimaryKeys_pcntTable() throws SQLException {
+    try (Connection connection = DriverManager.getConnection(ITBase.connectionUrl);
+        ResultSet primaryKeys =
+            connection.getMetaData().getPrimaryKeys(PROJECT_ID, PCNT_SCHEMA, PCNT_TABLE_NAME)) {
+      Assertions.assertNotNull(primaryKeys);
+      ResultSetMetaData pkMetaData = primaryKeys.getMetaData();
+      Assertions.assertEquals(6, pkMetaData.getColumnCount());
+      Assertions.assertFalse(primaryKeys.next());
+    }
+  }
+
+  @Test
+  public void testGetImportedKeys_pcntTable() throws SQLException {
+    try (Connection connection = DriverManager.getConnection(ITBase.connectionUrl);
+        ResultSet importedKeys =
+            connection.getMetaData().getImportedKeys(PROJECT_ID, PCNT_SCHEMA, PCNT_TABLE_NAME)) {
+      Assertions.assertNotNull(importedKeys);
+      ResultSetMetaData ikMetaData = importedKeys.getMetaData();
+      Assertions.assertEquals(14, ikMetaData.getColumnCount());
+      Assertions.assertFalse(importedKeys.next());
+    }
+  }
+
+  @Test
+  public void testGetExportedKeys_pcntTable() throws SQLException {
+    try (Connection connection = DriverManager.getConnection(ITBase.connectionUrl);
+        ResultSet exportedKeys =
+            connection.getMetaData().getExportedKeys(PROJECT_ID, PCNT_SCHEMA, PCNT_TABLE_NAME)) {
+      Assertions.assertNotNull(exportedKeys);
+      ResultSetMetaData ekMetaData = exportedKeys.getMetaData();
+      Assertions.assertEquals(14, ekMetaData.getColumnCount());
+      Assertions.assertFalse(exportedKeys.next());
+    }
+  }
+
+  @Test
+  public void testGetCrossReference_pcntTable() throws SQLException {
+    try (Connection connection = DriverManager.getConnection(ITBase.connectionUrl);
+        ResultSet crossReference =
+            connection
+                .getMetaData()
+                .getCrossReference(
+                    PROJECT_ID,
+                    PCNT_SCHEMA,
+                    PCNT_TABLE_NAME,
+                    PROJECT_ID,
+                    PCNT_SCHEMA,
+                    PCNT_TABLE_NAME)) {
+      Assertions.assertNotNull(crossReference);
+      ResultSetMetaData crMetaData = crossReference.getMetaData();
+      Assertions.assertEquals(14, crMetaData.getColumnCount());
+      Assertions.assertFalse(crossReference.next());
+    }
+  }
+
   @Test
   public void testMetadataResultSetsDoNotInterfere() throws SQLException {
     try (Connection connection = DriverManager.getConnection(ITBase.connectionUrl)) {