Search notes:

Oracle: External Tables

Types of external tables

There are four types of external tables. Depending on the type, Oracle uses a different driver to access the data in the external table:

Driver
Oracle loader	The default driver. External data is read only and resides in a text file (for example a CSV file).
Oracle datapump	The external data is stored in binary dump files. Exporting data to the external location is possible, but the DML statements `update` and `delete` cannot be used to modify the external data.
Oracle HDFS	Data is stored in a Hadoop distributed file system (HDFS)
Oracle HIVE	Data is stored in Apache HIVE.

TODO

The preprocess directive.

Inline external tables (select * from external (col_1 integer, …) type oracle_loader … ;).

See also

Reading CSV files or Excel sheets with external tables.

Loading dates with external tables.

Compare external tables with using SQL*Loader for importing data into a database.

dba_external_locations, dba_external_tables

The EXTERNAL TABLE ACCESS FULL plan operator.

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 8 attempt to write a readonly database in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php:78 Stack trace: #0 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(78): PDOStatement->execute(Array) #1 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(30): insert_webrequest_('/notes/developm...', 1758194038, '216.73.216.150', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/development/databases/Oracle/objects/tables/external/index(68): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78