Amazon S3¶

SQream uses 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 in CSV or columnar format, such as Parquet and ORC.

The Amazon S3 describes the following topics:

S3 Configuration
S3 URI Format
Authentication
Examples

S3 Configuration ¶

Any database host with access to S3 endpoints can access S3 without any configuration. To read files from an S3 bucket, the database must have listable files.

S3 URI Format ¶

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

The following is an example of the general S3 syntax:

s3://bucket_name/path

Authentication ¶

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

Examples ¶

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

The Examples section includes the following examples:

Planning for Data Staging
Creating a Foreign Table
Querying Foreign Tables
Bulk Loading a File from a Public S3 Bucket
Loading Files from an Authenticated S3 Bucket

Planning for Data Staging ¶

The examples in this section are based on a CSV file, as shown in the following table:

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 Amazon S3, and this bucket is public and listable. To create a matching CREATE FOREIGN TABLE statement you can make note of the file structure.

Creating a Foreign Table ¶

Based on the source file’s structure, you can create a foreign table with the appropriate structure, and point it to your file as shown in the following example:

CREATE FOREIGN 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
 )
 WRAPPER csv_fdw
 OPTIONS
   (
      LOCATION = 's3://sqream-demo-data/nba_players.csv',
      RECORD_DELIMITER = '\r\n' -- DOS delimited file
   )
 ;

In the example above the file format is CSV, and it is stored as an S3 object. If the path is on HDFS, you must change the URI accordingly. Note that the record delimiter is a DOS newline (\r\n).

For more information, see the following:

Creating a foreign table - see create a foreign table.
Using SQream in an HDFS environment - see Using SQream in an HDFS Environment.

Querying Foreign Tables ¶

The following shows the data in the foreign 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.

The following is an example of bulk loading a file from a public S3 bucket:

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

For more information on the COPY FROM command, see COPY FROM.

Loading Files from an Authenticated S3 Bucket ¶

The following is an example of loading fles 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';