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Overview

You can use this Snap to insert data parallelly across multi-threaded tasks. Compared to the Oracle Bulk Load Snap, this Snap executes a high-performance data load.

The Parallel Load Snap currently always auto-commits its database operations. The Auto commit setting in the Oracle Thin Account or Oracle Thin Dynamic Account configured for the Parallel Load snap does not affect the Snap’s behavior.

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Snap Type

The Oracle - Parallel Load Snap is a Write-type Snap that writes the specified data in the target table.

Prerequisites

Support for Ultra Pipelines  

Limitations

None.

Known Issues

The Schema name and Table name settings both accept schema from upstream snaps and offer suggestions for expressions; however, we recommend that you do not use those suggestions as they cause incorrect behavior.

Snap Views

Type

Format

Number of Views

Examples of Upstream and Downstream Snaps

Description

Input 

Document

  • Min: 1

  • Max: 2

  • Mapper

  • Copy

Requires the Schema name and Table name to process a certain number of input documents into a prepared insert query and execute all of the prepared input document values on that query as a batch.

Output

Document

  • Min: 0

  • Max: 1

  • Mapper

Snap outputs the number of documents successfully inserted into the target table in the output view document.

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 when 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.

Learn more about the behavior of Parallel Load Snap with open error views.

Snap Settings

Info
  • Asterisk ( * ): Indicates a mandatory field.

  • Add icon ( (blue star) ): Indicates that you can add fields in the field set.

  • Remove icon ( (blue star)): Indicates that you can remove fields from the field set.

  • Expression icon ((blue star)): Indicates the value is an expression (if enabled) or a static value (if disabled). Learn more about Using Expressions in SnapLogic.

  • Suggestion icon ((blue star)): Indicates a list that is dynamically populated based on the configuration.

  • Upload icon ((blue star)): Indicates that you can upload files. Learn more about managing Files.

Field Name

Field Type

Description

Label*

Default ValueOracle - Parallel Load
ExampleOracle - Parallel Load

String

Specify 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.

Schema name

Default Value: N/A
Example: Sys

String/Expression

Specify the database schema name.

You can pass the values as expressions using the pipeline parameters but cannot use values from the upstream Snap.

Table name*

Default Value: N/A
Example: people

String/Expression

Specify the table on which to execute the load operation.

You can pass the values as expressions using the pipeline parameters but cannot use values from the upstream Snap.

Create table if not present

Default Value: Deselected

Checkbox

Select this checkbox to automatically create the target table if it does not exist.

  • If a second input view is configured for the Snap and it contains a document with schema (metadata) from the source table, the Snap creates the new (target) table using the same schema (metadata). However, if the schema comes from a different database, the Snap might fail with the Unable to create table: "<table_name>" error due to data type incompatibility.

  • In the absence of a second input view, the Snap creates a table based on the data types of the columns generated from the first row of the input document (first input view).

The newly created table is not visible to subsequent database Snaps during runtime validation because of implementation details. If you want to immediately use the newly updated data, you must use a child pipeline invoked through the Pipeline Execute Snap.

Maximum thread count*


Default Value: 0
Example: 20

Integer/Expression

Specify the maximum number of threads allowed to perform data insertions simultaneously. If the value is 0, the snap automatically sets the number of threads equal to the number of available processors on the system.

Note

There is no upper limit for the Maximum thread count, therefore you should exercise caution when setting this value to avoid unexpected behavior or performance degrade.

Batch capacity*


Default Value: 1000
Example: 500

Integer/Expression

Specify the maximum number of records allowed in a single batch for an insertion task.

Note

There is no upper limit for Batch capacity, therefore you should exercise caution when setting this value to avoid unexpected behavior or performance degrade.

Snap memory usage: To gracefully handle failed record insertions, the Snap must retain some input document data in memory during the Snap execution. To calculate the memory usage follow this formula:
Max thread count * Batch capacity * 2 * typical record size
For example, with a Maximum thread count of 4, a Batch capacity of 10,000, and an average record size of 50 bytes, the input document data in Snap memory may peak at 4 million bytes.

Maximum error count*


Default Value50 
Example:10

Integer/Expression

Specify the maximum number of record insertion errors allowed before execution stops on the next error. For example, if you specify a value of 10, the pipeline execution continues until the number of failed records exceeds 10.

A value of -1 means no limit. At least one more error document than the specified maximum value is expected, but task concurrency may result in additional error documents. This applies only when the error behavior is set to Route Error Data to Error View.

Truncate table before load


Default Value: Deselected

Checkbox/Expression

Select this checkbox to truncate the target table before loading data.

Snap Execution

Default Value
Example: Validate & Execute

Dropdown list

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.

Troubleshooting

Error

Reason

Resolution

Pre-load truncation of the target table failed

The target table may not exist or a database access error may have occurred when trying to execute the TRUNCATE statement.

Verify your database credentials and ensure the target table exists, then try again.

Unable to determine target table column names

The connection used to retrieve table metadata displayed an exception while closing.

Verify the target table column names and try again.

Behavior of Parallel Load Execution with Open Error Views

The following table describes the expected behavior for the general outcomes of Parallel Load execution when the Snap has an open error view (that is, when you select Route Error Data to Error View for When error occurs).

Committed database insertions

Error view

Output preview

Snap outcome

Final Snap state

All insertions committed.

N/A

One document containing
<insert_count> field with an integer value indicating the number of inserted records successfully.

All input records are successfully inserted to the target database.

Success

One error document for each record that failed to insert.

One document containing
<insert_count> field with an integer value indicating the number of inserted records successfully.

Some input records individually fail to insert into the target database, but do not exceed maximum error count.

Success

Insertions made successfully
prior to the Maximum
error count being
exceeded may be
committed.

Multiple error documents, one for each record that failed to insert.
The total number of error documents should be
equal to at least the Maximum
error count plus one, but might be more due to concurrency of attempted insertions.

One document containing
<insert_count> field with an integer value indicating the number of inserted records successfully
prior to exceeding maximum
error count.

Enough input records individually fail to insert to exceed the Maximum error count and cause the Snap to end execution early.

Success

Insertions made
successfully prior to the
Snap-failing error may be
committed.

One error document for
each record that individually
failed insertion (if any).

One document containing
<insert_count> field with an integer value indicating the number of inserted records successfully prior to the (Snap-failing) error.

An error occurs beyond the scope of any individual record.

Failure

Individual record insertion failures occur when the database encounters an error during the insertion of a record. These failures are recoverable and specific to one input document. For example, an error might occur if the value of a document field is incompatible with the data type of the target column.

Examples

Parallel Loading for Document Insertion

The following example pipeline demonstrates the use of Parallel Load to insert 1000 documents. It showcases Parallel Load's efficiency and capability in managing large-scale data insertion tasks.

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On validation, the pipeline inserts a maximum of 400 records simultaneously, across 4 threads handling 100 records each. The image below displays only 50 records because the Preview document count is set to 50.

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Download this pipeline

Handle Database Insertion Failures with Open Error View

This example demonstrates a Mapper Snap configuration designed to intentionally cause a small number of records to fail during database insertion. For every failed insertion, an error document is generated. Specifically, out of 1000 records, 7 are expected to fail, resulting in 7 error documents, while the remaining 993 records are successfully inserted. The count of successful insertions is also recorded in the output document. This pipeline demonstrates how to manage and log insertion errors efficiently.

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Inserted records

Insertion failed records

ex-pl-output-inserted-records.png

ex-pl-error-output.png

Download this pipeline

Downloads

Info
  1. Download and import the pipeline into the SnapLogic application.

  2. Configure Snap accounts, as applicable.

  3. Provide pipeline parameters, as applicable.

Attachments
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