Exports a table, columns from a table, or query results to files in the ORC format.

Exports a table, columns from a table, or query results to files in the ORC format.

You can use an OVER() clause to partition the data before export. You can partition data instead of or in addition to exporting the column data. Partitioning data can improve query performance by enabling partition pruning. See Partitioned data.

There are some limitations on the queries you can use in an export statement. See Query Restrictions.

You can export data stored in Vertica in ROS format and data from external tables.

File exporters are UDxs that cannot be run in fenced mode. If the ForceUDxFencedMode configuration parameter is set to true to support other UDxs, you can set it to false at the session level before performing the export.

This statement returns the number of rows written and logs information about exported files in a system table. See Monitoring exports.

During an export to HDFS or an NFS mount point, Vertica writes files to a temporary directory in the same location as the destination and renames the directory when the export is complete. Do not attempt to use the files in the temporary directory. During an export to S3, GCS, or Azure, Vertica writes files directly to the destination path, so you must wait for the export to finish before reading the files. For more information, see Exporting to object stores.


EXPORT [ /*+LABEL (label-string)*/ ] TO ORC 
   ( directory='path'[, param=value[,...] ] )
   [ OVER (over-clause ) ] AS SELECT query-expression


Assigns a label to a statement to identify it for profiling and debugging.
Specifies how to partition table data using PARTITION BY. Within partitions you can sort using ORDER BY. See SQL analytics. This clause may contain column references but not expressions.

If you partition data, Vertica creates a partition directory structure, transforming column names to lowercase. See Partitioned data for a description of the directory structure. If you use the fileName parameter, you cannot use partitioning.

If you omit this clause, Vertica optimizes for maximum parallelism.

Specifies the data to export. See Query Restrictions for important limitations.



The destination directory for the output files. The current user must have permission to write it. The destination can be on any of the following file systems:

See also: ifDirExists.


What to do if directory already exists, one of:

  • fail (default)

  • overwrite: replace the entire directory

  • append: export new files into the existing directory

If you specify overwrite for an export to an object store, the existing directory is deleted recursively at the beginning of the operation and is not restored if the operation fails. Be careful not to export to a directory containing data you want to keep. For an export to a Linux file system or HDFS, the directory is only overwritten if the export succeeds.

Do not do concurrent exports to the same directory. In particular, if you do so with a value of overwrite, all operations appear to succeed, but the results are incorrect.

When using append, be careful to use the same table schema. Otherwise, queries of external tables using this data path could fail.


If specified, all output is written to a single file of this name in the location specified by directory. While the query can be processed by multiple nodes, only a single node generates the output data. The fileSizeMB parameter is ignored, and the query cannot use partitioning in the OVER() clause.

Column compression type, one of:
  • Zlib

  • Uncompressed

Default: Zlib

The uncompressed size of exported stripes in MB, an integer value between 1 and 1024, inclusive.

Default: 250

Integer that specifies how frequently the exporter builds indexing statistics in the output, between 1 and 1000000 (1 million), inclusive. A value of 0 disables indexing. The exporter builds statistics after every rowIndexStride rows in each stripe, or once for stripes < rowIndexStride.

Default: 1000


The maximum file size of a single output file. This value is a hint, not a hard limit. A value of 0 specifies no limit. If filename is also specified, fileSizeMB is ignored.

This value affects the size of individual output files, not the total output size. For smaller values, Vertica divides the output into more files; all data is still exported.

Default: 10GB


For writes to HDFS only, permission to apply to all exported files. You can specify the value in Unix octal format (such as 665) or user-group-other format—for example, rwxr-xr-x. The value must be formatted as a string even if using the octal format.

Valid octal values range between 0 and 1777, inclusive. See HDFS Permissions in the Apache Hadoop documentation.

When writing files to any destination other than HDFS, this parameter has no effect.

Default: 660, regardless of the value of fs.permissions.umask-mode in hdfs-site.xml.


For writes to HDFS only, permission to apply to all exported directories. Values follow the same rules as those for fileMode. Further, you must give the Vertica HDFS user full permission, at least rwx------ or 700.

When writing files to any destination other than HDFS, this parameter has no effect.

Default: 755, regardless of the value of fs.permissions.umask-mode in hdfs-site.xml.



  • Source table: SELECT

  • Source table schema: USAGE

  • Destination directory: Write

Query restrictions

You must provide an alias column label for selected column targets that are expressions.

If you partition the output, you cannot specify schema and table names in the SELECT statement. Specify only the column name.

The query can contain only a single outer SELECT statement. For example, you cannot use UNION:

=> EXPORT TO ORC(directory = '/mnt/shared_nfs/accounts/rm')
   SELECT 1 as account_id, '{}' as json, 0 hash
   SELECT 2 as account_id, '{}' as json, 1 hash;
ERROR 8975:  Only a single outer SELECT statement is supported
HINT:  Please use a subquery for multiple outer SELECT statements

Instead, rewrite the query to use a subquery:

=> EXPORT TO ORC(directory = '/mnt/shared_nfs/accounts/rm')
     SELECT 1 as account_id, '{}' as json, 0 hash
     SELECT 2 as account_id, '{}' as json, 1 hash
   ) a;
 Rows Exported
(1 row)

To use composite statements such as UNION, INTERSECT, and EXCEPT, rewrite them as subqueries.

Data types

EXPORT TO ORC converts Vertica data types to Hive data types as shown in the following table.

Vertica Data Type Hive Data Type
VARCHAR, LONG VARCHAR VARCHAR (max 64KB) or STRING (can be read as either)
DATE DATE if supported by your version of Hive, otherwise INT96 (can be read as TIMESTAMP)
TIMESTAMP, TIMESTAMPTZ TIMESTAMP. Vertica does not convert TIMESTAMP values to UTC. To avoid problems arising from time zones, use TIMESTAMPTZ instead of TIMESTAMP.
ARRAY, SET Not supported
ROW Not supported

Decimal precision must be <= 38.

The exported Hive types might not be identical to the Vertica types. For example, a Vertica INT is exported as a Hive BIGINT. When defining Hive external tables to read exported data, you might have to adjust column definitions.

This operation exports raw Flex columns as binary data.


The export operation always creates (or appends to) an output directory, even if all output is written to a single file or the query produces zero rows.

Output file names follow the pattern: prefix-nodename-threadId[-sequenceNumber].orc. prefix is typically an 8-character hash, but can be longer if the export appended to an existing directory. A sequence number is added if an export needs to be broken into pieces to satisfy fileSizeMB.

Column names in partition directories are lowercase.

Files exported to a local file system by any Vertica user are owned by the Vertica superuser. Files exported to HDFS or object stores are owned by the Vertica user who exported the data.

Making concurrent exports to the same output destination is an error and can produce incorrect results.

Exports to the local file system can be to an NFS mount (shared) or to the Linux file system on each node (non-shared). For details, see Exporting to the Linux file system. Exports to non-shared local file systems have the following restrictions:

  • The output directory must not exist on any node.

  • You must have a USER storage location or superuser privileges.

  • You cannot override the permissions mode of 700 for directories and 600 for files.

Exports to object-store file systems are not atomic. Be careful to wait for the export to finish before using the data. For details, see Exporting to object stores.


The following example demonstrates partitioning and exporting data. EXPORT TO ORC first partitions the data on region and then, within each partition, sorts by store.

=> EXPORT TO ORC(directory='gs://DataLake/user2/data')
  OVER(PARTITION BY store.region ORDER BY store.ID)
  AS SELECT sale.price, sale.date, store.ID
  FROM public.sales sale
  JOIN public.vendor store ON sale.distribID = store.ID;

For more examples, see EXPORT TO PARQUET, which (aside from a few parameters) behaves the same as EXPORT TO ORC.