add a workaround for getFunctions in Thrift

src/main/java/com/databricks/jdbc/api/impl/DatabricksConnectionContext.java

@@ -969,6 +969,11 @@ public Integer getHttpConnectionRequestTimeout() {
     return null;
   }
 
+  @Override
+  public boolean enableShowCommandsForGetFunctions() {
+    return getParameter(DatabricksJdbcUrlParams.ENABLE_SHOW_COMMAND_FOR_GET_FUNCTIONS).equals("1");
+  }
+
   private static boolean nullOrEmptyString(String s) {
     return s == null || s.isEmpty();
   }

src/main/java/com/databricks/jdbc/api/impl/DatabricksDatabaseMetaData.java

@@ -9,6 +9,7 @@
 import com.databricks.jdbc.api.internal.IDatabricksSession;
 import com.databricks.jdbc.common.*;
 import com.databricks.jdbc.common.util.DriverUtil;
+import com.databricks.jdbc.common.util.WildcardUtil;
 import com.databricks.jdbc.dbclient.impl.common.MetadataResultSetBuilder;
 import com.databricks.jdbc.dbclient.impl.common.StatementId;
 import com.databricks.jdbc.exception.DatabricksSQLException;
@@ -1527,18 +1528,21 @@ public ResultSet getClientInfoProperties() throws SQLException {
   public ResultSet getFunctions(String catalog, String schemaPattern, String functionNamePattern)
       throws SQLException {
     LOGGER.debug(
-        String.format(
-            "public ResultSet getFunctions(String catalog = {}, String schemaPattern = {}, String functionNamePattern = {})",
-            catalog,
-            schemaPattern,
-            functionNamePattern));
+        "public ResultSet getFunctions(String catalog = {}, String schemaPattern = {}, String functionNamePattern = {})",
+        catalog,
+        schemaPattern,
+        functionNamePattern);
     throwExceptionIfConnectionIsClosed();
     try {
+      if (WildcardUtil.isNullOrEmpty(functionNamePattern)) {
+        functionNamePattern =
+            "%"; // This is because functionName is a required parameter in thrift flow.
+      }
       return session
           .getDatabricksMetadataClient()
           .listFunctions(session, catalog, schemaPattern, functionNamePattern);
     } catch (Exception e) {
-      LOGGER.error(e, "Unable to fetch functions, returning empty result set");
+      LOGGER.error(e, "Unable to fetch functions, returning empty result set {}", e);
       return metadataResultSetBuilder.getFunctionsResult(catalog, List.of());
     }
   }

src/main/java/com/databricks/jdbc/api/impl/arrow/InlineChunkProvider.java

@@ -45,11 +45,13 @@ public class InlineChunkProvider implements ChunkProvider {
     this.currentChunkIndex = -1;
     this.totalRows = 0;
     ByteArrayInputStream byteStream = initializeByteStream(resultsResp, session, parentStatement);
-    arrowResultChunk =
-        ArrowResultChunk.builder()
-            .withInputStream(byteStream, totalRows)
-            .withStatementId(parentStatement.getStatementId())
-            .build();
+    ArrowResultChunk.Builder builder =
+        ArrowResultChunk.builder().withInputStream(byteStream, totalRows);
+
+    if (parentStatement != null) {
+      builder.withStatementId(parentStatement.getStatementId());
+    }
+    arrowResultChunk = builder.build();
   }
 
   /**

src/main/java/com/databricks/jdbc/api/internal/IDatabricksConnectionContext.java

@@ -361,6 +361,8 @@ public interface IDatabricksConnectionContext {
   /** Returns the HTTP connection request timeout in seconds */
   Integer getHttpConnectionRequestTimeout();
 
+  boolean enableShowCommandsForGetFunctions();
+
   /** Returns whether batched INSERT optimization is enabled */
   boolean isBatchedInsertsEnabled();
 }

src/main/java/com/databricks/jdbc/common/DatabricksJdbcUrlParams.java

@@ -154,6 +154,8 @@ public enum DatabricksJdbcUrlParams {
       "HttpConnectionRequestTimeout", "HTTP connection request timeout in seconds"),
   CLOUD_FETCH_SPEED_THRESHOLD(
       "CloudFetchSpeedThreshold", "Minimum expected download speed in MB/s", "0.1"),
+  ENABLE_SHOW_COMMAND_FOR_GET_FUNCTIONS(
+      "EnableShowCommandForGetFunctions", "Use SQL command to fetch function list", "0"),
   ENABLE_BATCHED_INSERTS("EnableBatchedInserts", "Enable batched INSERT optimization", "0"),
   ENABLE_SQL_VALIDATION_FOR_IS_VALID(
       "EnableSQLValidationForIsValid",

src/main/java/com/databricks/jdbc/dbclient/impl/sqlexec/CommandBuilder.java

@@ -6,10 +6,10 @@
 
 import com.databricks.jdbc.api.internal.IDatabricksSession;
 import com.databricks.jdbc.common.util.WildcardUtil;
-import com.databricks.jdbc.exception.DatabricksSQLFeatureNotSupportedException;
+import com.databricks.jdbc.exception.DatabricksSQLException;
+import com.databricks.jdbc.exception.DatabricksValidationException;
 import com.databricks.jdbc.log.JdbcLogger;
 import com.databricks.jdbc.log.JdbcLoggerFactory;
-import java.sql.SQLException;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
@@ -74,7 +74,7 @@ private String fetchCatalogSQL() {
     return SHOW_CATALOGS_SQL;
   }
 
-  private String fetchSchemaSQL() throws SQLException {
+  private String fetchSchemaSQL() {
     LOGGER.debug(
         "Building command for fetching schema. Catalog %s, SchemaPattern %s and session context %s",
         catalogName, schemaPattern, sessionContext);
@@ -91,7 +91,7 @@ private String fetchSchemaSQL() throws SQLException {
     return showSchemasSQL;
   }
 
-  private String fetchTablesSQL() throws SQLException {
+  private String fetchTablesSQL() {
     LOGGER.debug(
         "Building command for fetching tables. Catalog %s, SchemaPattern %s, TablePattern %s and session context %s",
         catalogName, schemaPattern, tablePattern, sessionContext);
@@ -111,7 +111,7 @@ private String fetchTablesSQL() throws SQLException {
     return showTablesSQL;
   }
 
-  private String fetchColumnsSQL() throws SQLException {
+  private String fetchColumnsSQL() throws DatabricksSQLException {
     String contextString =
         String.format(
             "Building command for fetching columns. Catalog %s, SchemaPattern %s, TablePattern %s, ColumnPattern %s and session context : %s",
@@ -134,7 +134,7 @@ private String fetchColumnsSQL() throws SQLException {
     return showColumnsSQL;
   }
 
-  private String fetchFunctionsSQL() throws SQLException {
+  private String fetchFunctionsSQL() throws DatabricksSQLException {
     String contextString =
         String.format(
             "Building command for fetching functions. Catalog %s, SchemaPattern %s, FunctionPattern %s. With session context %s",
@@ -156,7 +156,7 @@ private String fetchTableTypesSQL() {
     return SHOW_TABLE_TYPES_SQL;
   }
 
-  private String fetchPrimaryKeysSQL() throws SQLException {
+  private String fetchPrimaryKeysSQL() throws DatabricksSQLException {
     String contextString =
         String.format(
             "Building command for fetching primary keys. Catalog %s, Schema %s, Table %s. With session context: %s",
@@ -170,7 +170,7 @@ private String fetchPrimaryKeysSQL() throws SQLException {
     return String.format(SHOW_PRIMARY_KEYS_SQL, catalogName, schemaName, tableName);
   }
 
-  private String fetchForeignKeysSQL() throws SQLException {
+  private String fetchForeignKeysSQL() throws DatabricksSQLException {
     String contextString =
         String.format(
             "Building command for fetching foreign keys. Catalog %s, Schema %s, Table %s. With session context: %s",
@@ -184,7 +184,7 @@ private String fetchForeignKeysSQL() throws SQLException {
     return String.format(SHOW_FOREIGN_KEYS_SQL, catalogName, schemaName, tableName);
   }
 
-  public String getSQLString(CommandName command) throws SQLException {
+  public String getSQLString(CommandName command) throws DatabricksSQLException {
     switch (command) {
       case LIST_CATALOGS:
         return fetchCatalogSQL();
@@ -203,7 +203,7 @@ public String getSQLString(CommandName command) throws SQLException {
       case LIST_FOREIGN_KEYS:
         return fetchForeignKeysSQL();
     }
-    throw new DatabricksSQLFeatureNotSupportedException(
+    throw new DatabricksValidationException(
         String.format("Invalid command issued %s. Context: %s", command, sessionContext));
   }
 }

src/main/java/com/databricks/jdbc/dbclient/impl/thrift/DatabricksThriftServiceClient.java

@@ -1,9 +1,11 @@
 package com.databricks.jdbc.dbclient.impl.thrift;
 
+import static com.databricks.jdbc.common.EnvironmentVariables.DEFAULT_STATEMENT_TIMEOUT_SECONDS;
 import static com.databricks.jdbc.common.EnvironmentVariables.JDBC_THRIFT_VERSION;
 import static com.databricks.jdbc.common.util.DatabricksThriftUtil.*;
 import static com.databricks.jdbc.common.util.DatabricksTypeUtil.DECIMAL;
 import static com.databricks.jdbc.common.util.DatabricksTypeUtil.getDecimalTypeString;
+import static com.databricks.jdbc.dbclient.impl.sqlexec.CommandName.LIST_FUNCTIONS;
 import static com.databricks.jdbc.dbclient.impl.sqlexec.ResultConstants.TYPE_INFO_RESULT;
 
 import com.databricks.jdbc.api.impl.*;
@@ -19,6 +21,7 @@
 import com.databricks.jdbc.dbclient.IDatabricksMetadataClient;
 import com.databricks.jdbc.dbclient.impl.common.MetadataResultSetBuilder;
 import com.databricks.jdbc.dbclient.impl.common.StatementId;
+import com.databricks.jdbc.dbclient.impl.sqlexec.CommandBuilder;
 import com.databricks.jdbc.exception.DatabricksHttpException;
 import com.databricks.jdbc.exception.DatabricksParsingException;
 import com.databricks.jdbc.exception.DatabricksSQLException;
@@ -144,7 +147,7 @@ public DatabricksResultSet executeStatement(
     LOGGER.debug(
         String.format(
             "public DatabricksResultSet executeStatement(String sql = {%s}, Compute cluster = {%s}, Map<Integer, ImmutableSqlParameter> parameters = {%s}, StatementType statementType = {%s}, IDatabricksSession session)",
-            sql, computeResource.toString(), parameters.toString(), statementType));
+            sql, computeResource, parameters.toString(), statementType));
 
     DatabricksThreadContextHolder.setStatementType(statementType);
 
@@ -200,11 +203,14 @@ private TExecuteStatementReq getRequest(
         parameters.values().stream()
             .map(this::mapToSparkParameterListItem)
             .collect(Collectors.toList());
-
+    int timeout = DEFAULT_STATEMENT_TIMEOUT_SECONDS;
+    if (parentStatement != null && parentStatement.getStatement() != null) {
+      timeout = parentStatement.getStatement().getQueryTimeout();
+    }
     TExecuteStatementReq request =
         new TExecuteStatementReq()
             .setStatement(sql)
-            .setQueryTimeout(parentStatement.getStatement().getQueryTimeout())
+            .setQueryTimeout(timeout)
             .setSessionHandle(Objects.requireNonNull(session.getSessionInfo()).sessionHandle())
             .setCanReadArrowResult(this.connectionContext.shouldEnableArrow())
             .setUseArrowNativeTypes(arrowNativeTypes);
@@ -228,7 +234,7 @@ private TExecuteStatementReq getRequest(
       request.setUseArrowNativeTypes(arrowNativeTypes);
     }
 
-    int maxRows = parentStatement.getMaxRows();
+    int maxRows = (parentStatement == null) ? 0 : parentStatement.getMaxRows();
     if (maxRows > 0) { // set request param only if user has set maxRows.
       // Similar
       // behavior
@@ -436,13 +442,34 @@ public DatabricksResultSet listFunctions(
       String catalog,
       String schemaNamePattern,
       String functionNamePattern)
-      throws DatabricksSQLException {
+      throws SQLException {
     String context =
         String.format(
             "Fetching functions using Thrift client. Session {%s}, catalog {%s}, schemaNamePattern {%s}, functionNamePattern {%s}.",
             session.toString(), catalog, schemaNamePattern, functionNamePattern);
     DatabricksThreadContextHolder.setSessionId(session.getSessionId());
     LOGGER.debug(context);
+    if (connectionContext.enableShowCommandsForGetFunctions()) {
+      String showFunctionsSqlCommand =
+          new CommandBuilder(catalog, session)
+              .setSchemaPattern(schemaNamePattern)
+              .setFunctionPattern(functionNamePattern)
+              .getSQLString(LIST_FUNCTIONS);
+      LOGGER.debug(
+          "Fetching functions using SQL Command {{}}. Session {{}}",
+          showFunctionsSqlCommand,
+          session.toString());
+      try (DatabricksResultSet rs =
+          executeStatement(
+              showFunctionsSqlCommand,
+              session.getComputeResource(),
+              Collections.emptyMap(),
+              StatementType.METADATA,
+              session,
+              null)) {
+        return metadataResultSetBuilder.getFunctionsResult(rs, catalog);
+      }
+    }
     TGetFunctionsReq request =
         new TGetFunctionsReq()
             .setSessionHandle(Objects.requireNonNull(session.getSessionInfo()).sessionHandle())

src/test/java/com/databricks/jdbc/dbclient/impl/sqlexec/CommandBuilderTest.java

@@ -6,7 +6,7 @@
 
 import com.databricks.jdbc.api.internal.IDatabricksSession;
 import com.databricks.jdbc.common.util.WildcardUtil;
-import com.databricks.jdbc.exception.DatabricksSQLFeatureNotSupportedException;
+import com.databricks.jdbc.exception.DatabricksValidationException;
 import java.sql.SQLException;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
@@ -200,7 +200,6 @@ void shouldThrowExceptionForUnsupportedCommand() {
 
     CommandName mockCommand = mock(CommandName.class);
 
-    assertThrows(
-        DatabricksSQLFeatureNotSupportedException.class, () -> builder.getSQLString(mockCommand));
+    assertThrows(DatabricksValidationException.class, () -> builder.getSQLString(mockCommand));
   }
 }

src/test/java/com/databricks/jdbc/dbclient/impl/sqlexec/DatabricksMetadataSdkClientTest.java

@@ -742,7 +742,7 @@ void testListCrossReferences_notAvailable() throws Exception {
 
   @ParameterizedTest
   @MethodSource("listFunctionsTestParams")
-  void testTestFunctions(
+  void testGetFunctions(
       String sql, String catalog, String schema, String functionPattern, String description)
       throws SQLException {
     when(session.getComputeResource()).thenReturn(WAREHOUSE_COMPUTE);
@@ -768,7 +768,6 @@ void testTestFunctions(
     when(mockedResultSet.getMetaData()).thenReturn(mockedMetaData);
     DatabricksResultSet actualResult =
         metadataClient.listFunctions(session, catalog, schema, functionPattern);
-
     assertEquals(
         actualResult.getStatementStatus().getState(), StatementState.SUCCEEDED, description);
     assertEquals(actualResult.getStatementId(), GET_FUNCTIONS_STATEMENT_ID, description);