Vertica - Execute

The Vertica - Execute Snap enables you to execute SQL statements in a Vertica database. Tables can be created and dropped with this Snap. SELECT queries can also be executed. This Snap works only with single queries.

Note: You can drop your database with it, so be cautious.
If a SELECT query is executed, the query's results are merged into the incoming document and any existing keys will have their values overwritten. Additionally, the original document is written if there are no results from the query.

Note: The Vertica Execute Snap is for simple DML (SELECT, INSERT, UPDATE, DELETE) type statements.

Prerequisites

None.

Behavior Change

If the input view is not defined and the Pass through field is selected, the Snap sends an empty input document to the output view when the input view is not defined.

Supported Accounts

Snap views

Type Description Examples of upstream and downstream Snaps
Input

This Snap has at most one document input view. If the input view is defined, then the WHERE clause can substitute incoming values for a given expression.
Output

This Snap has at most one document output view.
Error

This Snap has at most one document error view and produces zero or more documents in the view.

Warning: Database Write Snaps output all records of a batch (as configured in your account settings) to the error view if the write fails during batch processing.

Snap settings

Legend:
  • Expression icon (): Allows using pipeline parameters to set field values dynamically (if enabled). SnapLogic Expressions are not supported. If disabled, you can provide a static value.
  • SnapGPT (): Generates SnapLogic Expressions based on natural language using SnapGPT. Learn more.
  • Suggestion icon (): Populates a list of values dynamically based on your Snap configuration. You can select only one attribute at a time using the icon. Type into the field if it supports a comma-separated list of values.
  • Upload : Uploads files. Learn more.
Learn more about the icons in the Snap settings dialog.
Field/Field set Description
Label

String

Required. Specify a unique name for the Snap. Modify this to be more appropriate, especially if more than one of the same Snaps is in the pipeline.

Default value: Vertica Execute

Example: Vertica Execute
SQL statement

String/Expression

 Required. Specify the SQL statement to execute on the server. There are two possible scenarios that you encounter when working with SQL statements in SnapLogic. You must understand the following scenarios to successfully execute your SQL statements:

Scenario 1: Executing SQL statements without expressions

If the expression toggle of the SQL statement field is not selected:

  • The SQL statement must not be within quotes.
  • The $<variable_name> parts of the SQL statement are expressions. In the below example, $id and $book.

Additionally, the JSON path is allowed only in the WHERE clause. If the SQL statement starts with SELECT (case-insensitive), the Snap regards it as a select-type query and executes once per input document. If not, it regards it as write-type query and executes in batch mode.

Scenario 2: Executing SQL queries with expressions

If the expression toggle of the SQL statement field is selected:

  • The SQL statement must be within quotes.
  • The + $<variable_name> + parts of the SQL statement are expressions, and must not be within quotes. In the below example, $tablename.
  • The $<variable_name> parts of the SQL statement are bind parameter, and must be within quotes. In the below example, $id and $book.
Note: Table name and column names must not be provided as bind parameters. Only values can be provided as bind parameters.
Note: We recommend you to add a single query in the SQL Statement field.

Known issue: When the SQL statement property is an expression, the pipeline parameters are shown in the suggest, but not the input schema.

Important notes:

  • The non-expression form uses bind parameters, so it is much faster than executing N arbitrary SQL expressions.
  • Using expressions that join strings together to create SQL queries or conditions has a potential SQL injection risk and hence unsafe. Ensure that you understand all implications and risks involved before using concatenation of strings with '=' Expression enabled.
Warning:

Single quotes in values must be escaped

Any relational database (RDBMS) treats single quotes (') as special symbols. So, single quotes in the data or values passed through a DML query may cause the Snap to fail when the query is executed. Ensure that you pass two consecutive single quotes in place of one within these values to escape the single quote through these queries.

For example:

  • If string has no single quotes: pass 'Schaum Series'
  • If string contains single quotes: pass 'O''Reilly''s Publication' for the value O'Reilly's Publication

Default value: N/A
Query type

Dropdown list

 Select the type of query for your SQL statement (Read or Write). When Auto is selected, the Snap tries to determine the query type automatically. If the execution result of the query is not as expected, you can change the query type to Read or Write.

Default value: Auto

Example: Read
Pass through

Checkbox

 Select this checkbox to pass the output view under the key 'original'. This property applies only to the Execute Snaps with SELECT statement.

Default value: Selected
Ignore empty result

Checkbox

 If selected, no document will be written to the output view when a SELECT operation does not produce any result. If this property is not selected and the Pass through property is selected, the input document will be passed through to the output view.

Default value: Not selected
Number of retries

Integer/Expression

 Specify the maximum number of retry attempts the Snap must make in case of network failure. When you set the Number of retries to more than 0, the Snap generates duplicate records when the connection is not established. To prevent duplicate records, we recommend that you follow one of the following:
  • Set the Number of retries to 0 (default value) to prevent duplicate records from being passed downstream while executing a pipeline.
  • Use a Primary key to prevent records from being inserted into the database.
  • Use an Upsert instead of an Insert statement.

Default value: 0

Example: 2
Retry interval (seconds)

Integer/Expression

 Specify the maximum resting time in seconds between subsequent retries.

Default value: 1

Example: 2
Auto commit

Dropdown list

 Select one of the options for this property to override the state of the Auto commit property on the account. The Auto commit at the Snap level has three values: True, False, and Use account setting. The expected functionality for these modes are:
  • True - The Snap will execute with auto-commit enabled regardless of the value set for Auto commit in the Account used by the Snap.
  • False - The Snap will execute with auto-commit disabled regardless of the value set for Auto commit in the Account used by the Snap.
  • Use account setting - The Snap will execute with Auto commit property value inherited by the Account used by the Snap.
Note: 'Auto commit' may be enabled for certain use cases if PostgreSQL jdbc driver is used in either Redshift, PostgreSQL or generic JDBC Snap. But the JDBC driver may cause out of memory issues when Select statements are executed. In those cases, "Auto commit" in Snap property should be set to 'False' and the Fetch size in the "Account setting" can be increased for optimal performance.
Note: DDL statements may auto-commit even if the transaction auto-commit mode is off. We recommend that you isolate DDL statements in a separate pipeline and turn on the Auto commit property.

Default value: Use account setting
Snap Execution

Dropdown list

Choose one of the three modes in which the Snap executes. The available options are:

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.

Default value: Execute only

Example: Validate & Execute