In this article

Overview

You can use this Snap to execute a SELECT query on CSV, JSON, and Parquet S3 objects, which may be compressed in GZIP or BZIP2 format.

AWS S3 does not define any folder object and the '/' characters are part of the S3 object key names.
This Snap captures metadata and lineage information from the input document.

Snap Type

The S3 Select Snap is a Read-type Snap that reads a subset of your S3 data based on a SELECT query.

Prerequisites

A valid S3 account with the required permissions.

Support for Ultra Pipelines

Works in Ultra Pipelines.

Limitations

The conditional fields Field Delimiter, Record Delimiter, Quote Character, Quote Escape Character, and File Header Info associated with the CSV Data Format are not displayed for non-CSV data formats. They are also not displayed if the Data Format field is expression-enabled. If you plan to make the Data Format expression-enabled to process the CSV-related properties, follow these steps:

Set CSV as the Data Format.
Configure the conditional fields.
Enable the expression.

You must follow these steps because the values of these properties are used during the execution only if the value of the Data Format is set to CSV, even when the associated conditional fields are not displayed.

Known Issues

None.

Snap Views

Type

Format

Number of Views

Examples of Upstream and Downstream Snaps

Description

Input

Document

Min: 0
Max: 1

Mapper
JSON Parser

An upstream Snap is optional. Any document with key-value pairs to evaluate expression properties.

Output

Binary

Min: 0
Max: 1

CSV Parser
JSON Parser
Mapper (binary input view)
File Writer

An example of the output binary data is as following:

Output preview of table containing preview in text format

Error

Error handling is a generic way to handle errors without losing data or failing the Snap execution. You can handle the errors that the Snap might encounter while running the Pipeline by choosing one of the following options from the When errors occur list under the Views tab:

Stop Pipeline Execution: Stops the current pipeline execution if the Snap encounters an error.
Discard Error Data and Continue: Ignores the error, discards that record, and continues with the remaining records.
Route Error Data to Error View: Routes the error data to an error view without stopping the Snap execution.

Learn more about Error handling in Pipelines.

Snap Settings

Asterisk ( * ): Indicates a mandatory field.
Suggestion icon ( ): Indicates a list that is dynamically populated based on the configuration.
Expression icon ( ): Indicates the value is an expression (if enabled) or a static value (if disabled). Learn more about Using Expressions in SnapLogic.
Add icon ( ): Indicates that you can add fields in the fieldset.
Remove icon ( ): Indicates that you can remove fields from the fieldset.
Upload icon ( ): Indicates that you can upload files.

Field Name	Field Type	Field Dependency	Description
Label* Default Value: S3 Select Example: Select Invoices from Q4 2018	String	None	The name for the Snap. You can modify this to be more specific, especially if you have more than one of the same Snap in your Pipeline.
Bucket* Default Value: None Example: mybucket mybucket@eu-west-1 Example of S3 Bucket in S3 region: mybucket@s3.eu-west-1.amazonaws.com Example of S3 VPC endpoint: my-bucket@bucket.vpce-028b7814794578709-vu0vvauy.s3.us-west-2.vpce.amazonaws.com testBucket@bucket.vpce-028b7814794578709-vu0vvauy.s3.us-west-2.vpce.amazonaws.com	String/Expression/Suggestion	None	Specify the S3 bucket name where S3 objects are located. Do not add S3:/// before bucket name, because the Snap can fail. Bucket names are unique globally and can be accessed without its region name in most cases. If you cannot access a bucket name without its region name, you can specify the region information in the following syntax `<S3_bucket_name>@<region_name>` You can also access the S3 bucket in an S3 Virtual Private Cloud (VPC) endpoint by specifying the bucket name in the following syntax: `<S3_bucket_name>@<VPC_S3_endpoint>` Note: If you enter an incorrect region name, but the bucket name is valid, the AWS S3 service may successfully access the bucket without any error.
Object Key* Default Value: None Examples: test.csv abc/test.json abc/xyz/test.xml	String/Expression/Suggestion	None	Specify the S3 object key name, which may include one or more forward-slash ('/') characters. The forward-slash character is part of the S3 object key name and there is no folder object defined in AWS S3. The maximum length of the suggested list is 1,000.
Select Query* Default Value: None Example: select from S3Object*	String/Expression	None	Enter a SELECT query to be executed on the S3 object. For a detailed description on using the SELECT command, refer to the Amazon documentation: https://docs.aws.amazon.com/AmazonS3/latest/userguide/s3-glacier-select-sql-reference-select.html
Input Data Format
Compression Type* Default Value: None Example: GZIP	String/Expression/Dropdown list	None	Select one of the following compression types: NONE, GZIP, or BZIP2. The Amazon S3 Select service does not support Compression Type BZIP2 or GZIP for the Parquet input data type.
Data format* Default Value: CSV Examples: JSON	String/Expression/Dropdown list	None	Select one of the data formats for the input data: CSV, JSON or Parquet.
Field Delimiter Default Value: `,` (Comma) Examples: `\|` (Pipe) `\t` (tab)	String/Expression	Appears when you select CSV* for Data Format.*	Enter the field delimiter character used in the input data.
Record Delimiter Default Value: LF (new line) Examples: CRLF	String/Expression/Suggestion	Appears when you select CSV* for Data Format.*	Enter the record delimiter used in the input data.
Quote Character Default Value: `"` (double quote) Example: `'` (single quote)	String/Expression	Appears when you select CSV* for Data Format.*	Enter the quote character used in the input data.
Quote Escape Character Default Value: `\` Example: `"`	String/Expression	Appears when you select CSV* for Data Format.*	Enter the escape character used to escape quote characters inside the values, where values are wrapped around quote characters in the input data. Note that some CSV file uses double quote character to escape double quotes inside values. For example, `"He said ""Yes"""`, which means: `He said "Yes"` when it is parsed.
File Header Info Default Value: USE Examples: NONE IGNORE	Dropdown list	Appears when you select CSV* for Data Format.*	Specify whether to use the header information in the SELECT query.
Show Advanced Properties Default Value: Deselected	Checkbox	None	Select this checkbox to display the advanced properties. Deselect this checkbox to hide the properties.
Maximum Retries* Default Value: 3 Example: 2	Integer/Expression	Appears when you select Show Advanced Properties* checkbox.*	Specify the maximum number of retry attempts to perform in case of a temporary network loss.
Snap Execution Default Value: Example: Validate & Execute	Dropdown list	None	Select one of the following three modes in which the Snap executes: Validate & Execute: Performs limited execution of the Snap, and generates a data preview during Pipeline validation. Subsequently, performs full execution of the Snap (unlimited records) during Pipeline runtime. Execute only: Performs full execution of the Snap during Pipeline execution without generating preview data. Disabled: Disables the Snap and all Snaps that are downstream from it.

Examples

Selecting a Subset of Data from an Amazon S3 Object (CSV file)

This example Pipeline demonstrates how to use the Amazon S3 Select Snap to select a subset of data from a CSV file.

Pipeline shows multiple outputs for S3 Select

Prerequisites: A valid AWS S3 Account

In this example we take a CSV file and use S3 Select to output different subsets of the data.

Overview of steps:

Upload a single CSV file to the S3 object using the CSV Generator Snap.
Format the file using the CSV Formatter Snap.
Upload the file using the S3 Upload Snap.
Copy the output of the S3 Upload Snap to 4 different flows using the S3 Copy Snap.
Select a subset of the data using the S3 Select Snap.

Configure the CSV Generator Snap to generate a new CSV document for the downstream Snap in the Pipeline.
Configure the CSV Formatter Snap to format the data as specified in the Snap's settings.
Configure the S3 Upload Snap to upload the S3 object (select/demo.csv) object to the S3 object bucket.
Use the Copy Snap to send the same information to multiple endpoints. Configure the Copy Snap to copy the S3 object document stream to the Snap's output views. In this example we configured four different output views.
Configure the S3 Select Snap to select a subset of the data from the S3 object. On validation, the Snap retrieves the data based on the SELECT statement.
Under Settings, expand the Input Data Format section to select options for File Header Info. This is where you specify whether to use the header information in the SELECT statement.
Add a CSV Parser Snap after each S3 Select Snap to read the CSV binary data from its input view, parse it, and then write it to its output view.
In this example we configured different output views that use different settings for File Header Info:
1. Output 1: USE means the header data is used in the SELECT statement. In this example we are referencing a column name in the header (variety = 'Setosa').
  SELECT * FROM s3Object s WHERE s.variety = 'Setosa'
2. Output 2: IGNORE means the header data is ignored in the SELECT statement. Here, we are using a column index instead of the column name to refer to the same column in the header (s._5 = 'Setosa').
  SELECT * FROM s3Object s WHERE s._5 = 'Setosa'
3. Output 3: NONE means there is no header data in the SELECT statement.
  SELECT * FROM s3Object s

Download this Pipeline.

Selecting a Subset of Data from an Amazon S3 Object (JSON file)

This example Pipeline demonstrates how to use the Amazon S3 Select Snap to select a subset of data from a JSON file.

Pipeline showing the Snaps in this example