Staging Files

Databend recommends two file upload methods for stages: PRESIGN and PUT/GET commands. These methods enable direct data transfer between the client and your storage, eliminating intermediaries and resulting in cost savings by reducing traffic between Databend and your storage.

Alt text

The PRESIGN method generates a time-limited URL with a signature, which clients can use to securely initiate file uploads. This URL grants temporary access to the designated stage, allowing clients to directly transfer data without relying on Databend servers for the entire process, enhancing both security and efficiency.

If you're using BendSQL to manage files in a stage, you can use the PUT command for uploading files and the GET command for downloading files.

The GET command currently can only download all files in a stage, not individual ones.
These commands are exclusive to BendSQL and the GET command will not function when Databend uses the file system as the storage backend.

Examples

Uploading with Presigned URL

The following examples demonstrate how to upload a sample file (

books.parquet

) to the user stage, an internal stage, and an external stage with presigned URLs.

Upload to User Stage
Upload to Internal Stage
Upload to External Stage

PRESIGN UPLOAD @~/books.parquet;

Name   |Value                                                                                                                                                                                                                                                                                                                                                       |
-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
method |PUT                                                                                                                                                                                                                                                                                                                                                         |
headers|{"host":"s3.us-east-2.amazonaws.com"}                                                                                                                                                                                                                                                                                                                       |
url    |https://s3.us-east-2.amazonaws.com/databend-toronto/stage/user/root/books.parquet?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIASTQNLUZWP2UY2HSN%2F20230627%2Fus-east-2%2Fs3%2Faws4_request&X-Amz-Date=20230627T153448Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=84f1c280bff52f33c1914d64b2091d19650ad4882137013601fc44d26b607933|

curl -X PUT -T books.parquet "https://s3.us-east-2.amazonaws.com/databend-toronto/stage/user/root/books.parquet?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIASTQNLUZWP2UY2HSN%2F20230627%2Fus-east-2%2Fs3%2Faws4_request&X-Amz-Date=20230627T153448Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=84f1c280bff52f33c1914d64b2091d19650ad4882137013601fc44d26b607933"

Check the staged file:

LIST @~;

name         |size|md5                               |last_modified                |creator|
-------------+----+----------------------------------+-----------------------------+-------+
books.parquet| 998|"88432bf90aadb79073682988b39d461c"|2023-06-27 16:03:51.000 +0000|       |

CREATE STAGE my_internal_stage;

PRESIGN UPLOAD @my_internal_stage/books.parquet;

Name   |Value                                                                                                                                                                                                                                                                                                                                                                        |
-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
method |PUT                                                                                                                                                                                                                                                                                                                                                                          |
headers|{"host":"s3.us-east-2.amazonaws.com"}                                                                                                                                                                                                                                                                                                                                        |
url    |https://s3.us-east-2.amazonaws.com/databend-toronto/stage/internal/my_internal_stage/books.parquet?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIASTQNLUZWP2UY2HSN%2F20230628%2Fus-east-2%2Fs3%2Faws4_request&X-Amz-Date=20230628T022951Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=9cfcdf3b3554280211f88629d60358c6d6e6a5e49cd83146f1daea7dfe37f5c1|

curl -X PUT -T books.parquet "https://s3.us-east-2.amazonaws.com/databend-toronto/stage/internal/my_internal_stage/books.parquet?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIASTQNLUZWP2UY2HSN%2F20230628%2Fus-east-2%2Fs3%2Faws4_request&X-Amz-Date=20230628T022951Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=9cfcdf3b3554280211f88629d60358c6d6e6a5e49cd83146f1daea7dfe37f5c1"

Check the staged file:

LIST @my_internal_stage;

name                               |size  |md5                               |last_modified                |creator|
-----------------------------------+------+----------------------------------+-----------------------------+-------+
books.parquet                      |   998|"88432bf90aadb79073682988b39d461c"|2023-06-28 02:32:15.000 +0000|       |

CREATE STAGE my_external_stage url = 's3://databend' CONNECTION =(ENDPOINT_URL= 'http://127.0.0.1:9000' aws_key_id='ROOTUSER' aws_secret_key='CHANGEME123');

PRESIGN UPLOAD @my_external_stage/books.parquet;

Name   |Value                                                                                                                                                                                                                                                                                                      |
-------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
method |PUT                                                                                                                                                                                                                                                                                                        |
headers|{"host":"127.0.0.1:9000"}                                                                                                                                                                                                                                                                                  |
url    |http://127.0.0.1:9000/databend/books.parquet?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ROOTUSER%2F20230628%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20230628T040959Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=697d608750fdcfe4a0b739b409cd340272201351023baa823382bf8c3718a4bd|

curl -X PUT -T books.parquet "http://127.0.0.1:9000/databend/books.parquet?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=ROOTUSER%2F20230628%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20230628T040959Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=697d608750fdcfe4a0b739b409cd340272201351023baa823382bf8c3718a4bd"

Check the staged file:

LIST @my_external_stage;

name         |size|md5                               |last_modified                |creator|
-------------+----+----------------------------------+-----------------------------+-------+
books.parquet| 998|"88432bf90aadb79073682988b39d461c"|2023-06-28 04:13:15.178 +0000|       |

Uploading with PUT Command

The following examples demonstrate how to use BendSQL to upload a sample file (

books.parquet

) to the user stage, an internal stage, and an external stage with the PUT command.

Upload to User Stage
Upload to Internal Stage
Upload to External Stage

root@localhost:8000/default> PUT fs:///Users/eric/Documents/books.parquet @~

PUT fs:///Users/eric/Documents/books.parquet @~

┌───────────────────────────────────────────────┐
│                 file                │  status │
│                String               │  String │
├─────────────────────────────────────┼─────────┤
│ /Users/eric/Documents/books.parquet │ SUCCESS │
└───────────────────────────────────────────────┘

Check the staged file:

root@localhost:8000/default> LIST @~;

LIST @ ~

┌────────────────────────────────────────────────────────────────────────┐
│      name     │  size  │ ··· │     last_modified    │      creator     │
│     String    │ UInt64 │     │        String        │ Nullable(String) │
├───────────────┼────────┼─────┼──────────────────────┼──────────────────┤
│ books.parquet │    998 │ ... │ 2023-09-04 03:27:... │ NULL             │
└────────────────────────────────────────────────────────────────────────┘
1 row result in 0.287 sec. Processed 1 rows, 1 B (3.49 rows/s, 523 B/s)

root@localhost:8000/default> CREATE STAGE my_internal_stage;

CREATE STAGE my_internal_stage

0 row written in 0.049 sec. Processed 0 rows, 0 B (0 rows/s, 0 B/s)

root@localhost:8000/default> PUT fs:///Users/eric/Documents/books.parquet @my_internal_stage

PUT fs:///Users/eric/Documents/books.parquet @my_internal_stage

┌───────────────────────────────────────────────┐
│                 file                │  status │
│                String               │  String │
├─────────────────────────────────────┼─────────┤
│ /Users/eric/Documents/books.parquet │ SUCCESS │
└───────────────────────────────────────────────┘

Check the staged file:

root@localhost:8000/default> LIST @my_internal_stage;

LIST @my_internal_stage

┌────────────────────────────────────────────────────────────────────────┐
│      name     │  size  │ ··· │     last_modified    │      creator     │
│     String    │ UInt64 │     │        String        │ Nullable(String) │
├───────────────┼────────┼─────┼──────────────────────┼──────────────────┤
│ books.parquet │    998 │ ... │ 2023-09-04 03:32:... │ NULL             │
└────────────────────────────────────────────────────────────────────────┘
1 row result in 0.273 sec. Processed 1 rows, 1 B (3.67 rows/s, 550 B/s)

root@localhost:8000/default> CREATE STAGE my_external_stage url = 's3://databend' CONNECTION =(ENDPOINT_URL= 'http://127.0.0.1:9000' aws_key_id='ROOTUSER' aws_secret_key='CHANGEME123');

CREATE STAGE my_external_stage url = 's3://databend' CONNECTION =(
  ENDPOINT_URL = 'http://127.0.0.1:9000' aws_key_id = 'ROOTUSER' aws_secret_key = 'CHANGEME123'
)

0 row written in 0.024 sec. Processed 0 rows, 0 B (0 rows/s, 0 B/s)

root@localhost:8000/default> PUT fs:///Users/eric/Documents/books.parquet @my_external_stage

PUT fs:///Users/eric/Documents/books.parquet @my_external_stage

┌───────────────────────────────────────────────┐
│                 file                │  status │
│                String               │  String │
├─────────────────────────────────────┼─────────┤
│ /Users/eric/Documents/books.parquet │ SUCCESS │
└───────────────────────────────────────────────┘

Check the staged file:

root@localhost:8000/default> LIST @my_external_stage;

LIST @my_external_stage

┌──────────────────────────────────────────────────────────────────────┐
│         name         │ ··· │     last_modified    │      creator     │
│        String        │     │        String        │ Nullable(String) │
├──────────────────────┼─────┼──────────────────────┼──────────────────┤
│ books.parquet        │ ... │ 2023-09-04 03:37:... │ NULL             │
└──────────────────────────────────────────────────────────────────────┘
3 rows result in 0.272 sec. Processed 3 rows, 3 B (11.05 rows/s, 1.55 KiB/s)

Downloading with GET Command

The following examples demonstrate how to use BendSQL to download a sample file (

books.parquet

) from the user stage, an internal stage, and an external stage with the GET command.

Download from User Stage
Download from Internal Stage
Download from External Stage

root@localhost:8000/default> LIST @~;

LIST @ ~

┌────────────────────────────────────────────────────────────────────────┐
│      name     │  size  │ ··· │     last_modified    │      creator     │
│     String    │ UInt64 │     │        String        │ Nullable(String) │
├───────────────┼────────┼─────┼──────────────────────┼──────────────────┤
│ books.parquet │    998 │ ... │ 2023-09-04 03:27:... │ NULL             │
└────────────────────────────────────────────────────────────────────────┘
1 row result in 0.287 sec. Processed 1 rows, 1 B (3.49 rows/s, 523 B/s)

root@localhost:8000/default> GET @~/ fs:///Users/eric/Downloads/fromStage/;

GET @~/ fs:///Users/eric/Downloads/fromStage/

┌─────────────────────────────────────────────────────────┐
│                      file                     │  status │
│                     String                    │  String │
├───────────────────────────────────────────────┼─────────┤
│ /Users/eric/Downloads/fromStage/books.parquet │ SUCCESS │
└─────────────────────────────────────────────────────────┘

root@localhost:8000/default> LIST @my_internal_stage;

LIST @my_internal_stage

┌────────────────────────────────────────────────────────────────────────┐
│      name     │  size  │ ··· │     last_modified    │      creator     │
│     String    │ UInt64 │     │        String        │ Nullable(String) │
├───────────────┼────────┼─────┼──────────────────────┼──────────────────┤
│ books.parquet │    998 │ ... │ 2023-09-04 03:32:... │ NULL             │
└────────────────────────────────────────────────────────────────────────┘
1 row result in 0.273 sec. Processed 1 rows, 1 B (3.67 rows/s, 550 B/s)

root@localhost:8000/default> GET @my_internal_stage/ fs:///Users/eric/Downloads/fromStage/;


GET @my_internal_stage/ fs:///Users/eric/Downloads/fromStage/

┌─────────────────────────────────────────────────────────┐
│                      file                     │  status │
│                     String                    │  String │
├───────────────────────────────────────────────┼─────────┤
│ /Users/eric/Downloads/fromStage/books.parquet │ SUCCESS │
└─────────────────────────────────────────────────────────┘

root@localhost:8000/default> LIST @my_external_stage;

LIST @my_external_stage

┌──────────────────────────────────────────────────────────────────────┐
│         name         │ ··· │     last_modified    │      creator     │
│        String        │     │        String        │ Nullable(String) │
├──────────────────────┼─────┼──────────────────────┼──────────────────┤
│ books.parquet        │ ... │ 2023-09-04 03:37:... │ NULL             │
└──────────────────────────────────────────────────────────────────────┘
3 rows result in 0.272 sec. Processed 3 rows, 3 B (11.05 rows/s, 1.55 KiB/s)

root@localhost:8000/default> GET @my_external_stage/ fs:///Users/eric/Downloads/fromStage/;


GET @my_external_stage/ fs:///Users/eric/Downloads/fromStage/

┌─────────────────────────────────────────────────────────┐
│                      file                     │  status │
│                     String                    │  String │
├───────────────────────────────────────────────┼─────────┤
│ /Users/eric/Downloads/fromStage/books.parquet │ SUCCESS │
└─────────────────────────────────────────────────────────┘

Staging Files

Examples

Uploading with Presigned URL

Uploading with PUT Command

Downloading with GET Command

Join our growing community

GitHub

Slack

Twitter

YouTube

Explore Databend Cloud for FREE

Examples​

Uploading with Presigned URL​

Uploading with PUT Command​

Downloading with GET Command​

Join our growing community

GitHub

Slack

Twitter

YouTube

Explore Databend Cloud for FREE

Examples

Uploading with Presigned URL

Uploading with PUT Command

Downloading with GET Command