CREATE DATA LOADER creates an automatic data loader that executes a COPY statement when new data files appear in a specified location. The loader records which files have already been successfully loaded and skips them.

CREATE DATA LOADER creates an automatic data loader that executes a COPY statement when new data files appear in a specified path. The loader records which files have already been successfully loaded and skips them. These events are recorded in the DATA_LOADER_EVENTS system table.

You can execute a data loader in the following ways:

Executing the loader automatically commits the transaction.

The DATA_LOADERS system table shows all defined loaders. The DATA_LOADER_EVENTS system table records paths that were attempted and their outcomes. To prevent unbounded growth, records in DATA_LOADER_EVENTS are purged after a specified retention interval. If previously-loaded files are still in the source path after this purge, the data loader sees them as new files and loads them again.


   [ RETRY LIMIT { NONE | DEFAULT | limit } ]
   [ RETENTION INTERVAL monitoring-retention ]
   [ TRIGGERED BY integration-json ]
   AS copy-statement


If a data loader with the same name in the same schema exists, replace it. The original data loader's monitoring table is dropped.

This option cannot be used with IF NOT EXISTS.


If an object with the same name exists, return without creating the object. If you do not use this directive and the object already exists, Vertica returns with an error message.

The IF NOT EXISTS clause is useful for SQL scripts where you might not know if the object already exists. The ON ERROR STOP directive can be helpful in scripts.

This option cannot be used with OR REPLACE.

Schema containing the data loader. The default schema is public.
Name of the data loader.
Maximum number of times to retry a failing file. Each time the data loader is executed, it attempts to load all files that have not yet been successfully loaded, up to this per-file limit. If set to DEFAULT, at load time the loader uses the value of the DataLoaderDefaultRetryLimit configuration parameter.

Default: DEFAULT

RETENTION INTERVAL monitoring-retention
How long to keep records in the events table. DATA_LOADER_EVENTS records events for all data loaders, but each data loader has its own retention interval.

Default: 14 days

TRIGGERED BY integration-json
Information about an external input for the data loader, a JSON object with the following keys:
  • provider: name of the provider; the only supported value is "AWS-SQS"
  • resourceUrl: endpoint for the integration

If a data loader has a trigger, the loader is initially disabled. When you are ready to use it, use ALTER DATA LOADER with the ENABLE option. When the loader is enabled, Vertica executes it automatically when the trigger produces notifications for new files. For details, see Triggers.

AS copy-statement
The COPY statement that the loader executes. The FROM clause typically uses a glob.


Non-superuser: CREATE privileges on the schema.


  • COPY NO COMMIT is not supported.
  • Data loaders are executed with COPY ABORT ON ERROR.
  • The COPY statement must specify file paths. You cannot use COPY FROM VERTICA.

Triggers (AWS SQS only)

If the data to be loaded is stored on AWS and you have configured an SQS queue, then instead of executing a data loader explicitly using EXECUTE DATA LOADER, you can define the loader to respond to S3 events. When files are added to the AWS bucket, a service running on AWS adds a message to the SQS queue. Vertica reads from this queue, executes the data loader, and, if the load was successful, removes the message from the queue. After the initial setup, this process is automatic.

To configure the data loader with a trigger, use the TRIGGERED BY option with a JSON object following this template:

  "provider" : "AWS-SQS",
  "resourceUrl" : ""

Use the following SQS parameters to authenticate to SQS:

  • SQSAuth, to set an ID and key for all queue access.
  • SQSQueueCredentials, to set per-queue access. Queue-specific values take precedence over SQSAuth.

A data loader with a trigger is initially disabled. Use ALTER DATA LOADER with the ENABLE option when you are ready to begin processing events. To pause execution, call ALTER DATA LOADER with the DISABLE option.

If a data loader has a trigger, you must disable it before dropping it.

File systems

The source path can be any shared file system or object store that all database nodes can access. To use an HDFS or Linux file system safely, you must prevent the loader from reading a partially-written file. One way to achieve this is to only execute the loader when files are not being written to the loader's path. Another way to achieve this is to write new files in a temporary location and move them to the loader's path only when they are complete.


   AS COPY s.local FROM 's3://b/data/*.dat';

=> SELECT name, schemaname, copystmt, retrylimit FROM data_loaders;
 name | schemaname |              copystmt                 | retrylimit 
 dl1  | s          | COPY s.local FROM 's3://b/data/*.dat' |         -1
(1 row)

See Automatic load for an extended example.

See also