This JDBC External Data Source library is implemented with "External Data Source" mechanism to query the JDBC table from Impala server.

Following two source files consists Impala specific logic: JdbcDataSource.java util/QueryConditionUtil.java

Other source files, which add supports to access external database tables through JDBC drivers, are replicated from Hive JDBC Storage Handler with some modifications: (https://github.com/apache/hive/tree/master/jdbc-handler/src/main/java/org/apache/hive/storage/jdbc) conf/DatabaseType.java remove dbType for HIVE, DERBY, and METASTORE. conf/JdbcStorageConfig.java don't use org.apache.hadoop.hive.conf.Constants conf/JdbcStorageConfigManager.java add functions: convertMapToConfiguration(), getQueryToExecute(), getOrigQueryToExecute() remove functions: copyConfigurationToJob(), countNonNull(), getPasswordFromProperties(), copySecretsToJob(), convertPropertiesToConfiguration(), resolveMetadata(), getMetastoreDatabaseType(), getMetastoreConnectionURL(), getMetastoreDriver(), getMetastoreJdbcUser(), getMetastoreJdbcPasswd(). modify functions: checkRequiredPropertiesAreDefined() dao/DB2DatabaseAccessor.java remove function constructQuery() dao/DatabaseAccessor.java remoce following APIs: getColumnNames(), getColumnTypes(), getRecordWriter(), getBounds(), needColumnQuote(). remove following parameters for API getRecordIterator(): 'partitionColumn', 'lowerBound', and 'upperBound'. dao/DatabaseAccessorFactory.java remove dbType for HIVE, DERBY, and METASTORE. dao/GenericJdbcDatabaseAccessor.java add member variable: dataSourceCache remove member variable typeInfoTranslator remove functions: getColumnMetadata(), getColumnMetadata(), getColumnNames() getColumnTypes(), getColNamesFromRS(), getColTypesFromRS(), getMetaDataQuery(), getRecordWriter(), constructQuery(), addBoundaryToQuery(), removeDbcpPrefix(), getFromProperties(), getBounds(), quote(), needColumnQuote(), getQualifiedTableName(), selectAllFromTable(), finalize(). remove following parameters for API getRecordIterator(): 'partitionColumn', 'lowerBound', and 'upperBound'. Modify functions: close(). dao/JdbcRecordIterator.java remove member variable accessor, remove parameter 'accessor' from ctor, remove functions: remove() modify functions: next(), close() dao/JethroDatabaseAccessor.java remove getMetaDataQuery() dao/MsSqlDatabaseAccessor.java dao/MySqlDatabaseAccessor.java remove function needColumnQuote() dao/OracleDatabaseAccessor.java remove function constructQuery() dao/PostgresDatabaseAccessor.java exception/JdbcDatabaseAccessException.java renamed from exception/HiveJdbcDatabaseAccessException.java