S3

SQream DB has a native S3 connector for inserting data. The s3:// URI specifies an external file path on an S3 bucket.

File names may contain wildcard characters and the files can be a CSV or columnar format like Parquet and ORC.

S3 configuration

Any SQream DB host that has access to S3 endpoints can access S3 without any configuration.

To read files from an S3 bucket, it must have listable files.

S3 URI format

With S3, specify a location for a file (or files) when using COPY FROM or External Tables.

The general S3 syntax is: s3://bucket_name/path

Authentication

SQream DB supports AWS ID and AWS SECRET authentication. These should be specified when executing a statement.

Examples

Use an external table to stage data from S3 before loading from CSV, Parquet or ORC files.

Planning for data staging

For the following examples, we will want to interact with a CSV file. Here’s a peek at the table contents:

nba.csv
Name Team Number Position Age Height Weight College Salary
Avery Bradley Boston Celtics 0.0 PG 25.0 6-2 180.0 Texas 7730337.0
Jae Crowder Boston Celtics 99.0 SF 25.0 6-6 235.0 Marquette 6796117.0
John Holland Boston Celtics 30.0 SG 27.0 6-5 205.0 Boston University  
R.J. Hunter Boston Celtics 28.0 SG 22.0 6-5 185.0 Georgia State 1148640.0
Jonas Jerebko Boston Celtics 8.0 PF 29.0 6-10 231.0   5000000.0
Amir Johnson Boston Celtics 90.0 PF 29.0 6-9 240.0   12000000.0
Jordan Mickey Boston Celtics 55.0 PF 21.0 6-8 235.0 LSU 1170960.0
Kelly Olynyk Boston Celtics 41.0 C 25.0 7-0 238.0 Gonzaga 2165160.0
Terry Rozier Boston Celtics 12.0 PG 22.0 6-2 190.0 Louisville 1824360.0

The file is stored on S3, at s3://sqream-demo-data/nba_players.csv. This bucket is public and listable.

We will make note of the file structure, to create a matching CREATE_EXTERNAL_TABLE statement.

Creating the external table

Based on the source file structure, we we create an external table with the appropriate structure, and point it to the file.

CREATE EXTERNAL TABLE nba
(
   Name varchar(40),
   Team varchar(40),
   Number tinyint,
   Position varchar(2),
   Age tinyint,
   Height varchar(4),
   Weight real,
   College varchar(40),
   Salary float
 )
   USING FORMAT CSV -- Text file
   WITH  PATH  's3://sqream-demo-data/nba_players.csv'
   RECORD DELIMITER '\r\n'; -- DOS delimited file

The file format in this case is CSV, and it is stored as an S3 object (if the path is on HDFS, change the URI accordingly).

We also took note that the record delimiter was a DOS newline (\r\n).

Querying external tables

Let’s peek at the data from the external table:

t=> SELECT * FROM nba LIMIT 10;
name          | team           | number | position | age | height | weight | college           | salary
--------------+----------------+--------+----------+-----+--------+--------+-------------------+---------
Avery Bradley | Boston Celtics |      0 | PG       |  25 | 6-2    |    180 | Texas             |  7730337
Jae Crowder   | Boston Celtics |     99 | SF       |  25 | 6-6    |    235 | Marquette         |  6796117
John Holland  | Boston Celtics |     30 | SG       |  27 | 6-5    |    205 | Boston University |
R.J. Hunter   | Boston Celtics |     28 | SG       |  22 | 6-5    |    185 | Georgia State     |  1148640
Jonas Jerebko | Boston Celtics |      8 | PF       |  29 | 6-10   |    231 |                   |  5000000
Amir Johnson  | Boston Celtics |     90 | PF       |  29 | 6-9    |    240 |                   | 12000000
Jordan Mickey | Boston Celtics |     55 | PF       |  21 | 6-8    |    235 | LSU               |  1170960
Kelly Olynyk  | Boston Celtics |     41 | C        |  25 | 7-0    |    238 | Gonzaga           |  2165160
Terry Rozier  | Boston Celtics |     12 | PG       |  22 | 6-2    |    190 | Louisville        |  1824360
Marcus Smart  | Boston Celtics |     36 | PG       |  22 | 6-4    |    220 | Oklahoma State    |  3431040

Bulk loading a file from a public S3 bucket

The COPY FROM command can also be used to load data without staging it first.

Note

The bucket must be publicly available and objects can be listed

COPY nba FROM 's3://sqream-demo-data/nba.csv' WITH OFFSET 2 RECORD DELIMITER '\r\n';

Loading files from an authenticated S3 bucket

COPY nba FROM 's3://secret-bucket/*.csv' WITH OFFSET 2 RECORD DELIMITER '\r\n'
AWS_ID '12345678'
AWS_SECRET 'super_secretive_secret';