Accessing File-Based External Tables

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Accessing File-Based External Tables

To create an external table definition, you specify the format of your input files and the location of your external data sources. For information about input file formats, see Formatting Data Files.

Use one of the following protocols to access external table data sources. You cannot mix protocols in CREATE EXTERNAL TABLE statements.

  • gpfdist: points to a directory on the file host and serves external data files to all Greenplum Database segments in parallel.
  • gpfdists: the secure version of gpfdist.
  • file:// accesses external data files on a segment host that the Greenplum superuser (gpadmin ) can access.
  • gphdfs: accesses files on a Hadoop Distributed File System (HDFS).

gpfdist and gpfdists require a one-time setup during table creation.