Message Format

The Message Format tab will only be shown if the task is defined with a streaming target endpoint that supports this feature.

When a task is defined with such an endpoint, you can specify a custom message format that will override the default Replicate message format. This may be useful if the consumer application needs to process the message in a particular format.

The custom message format can be defined at task level and/or at table level. When it is defined at both task and table level, the message format defined for the table will take precedence over the message format defined for the task.

For information on defining a custom message format at table level, see Message format.

General rules and usage guidelines

When defining a custom message, it is import to consider the rules and usage guidelines listed below.

Section names:

The following naming rules apply:

• Section names must start with the characters a-z, A-Z, or _ (an underscore) and can then be followed by any of the following characters: a-z, A-Z, 0-9, _
• With the exception of the Record name and Key name sections (that do not end with a slash), removing the slash from section names will flatten the hierarchy of the associated section (see Slashes below).
• All section names except Record name and Key name can be deleted (see Deletion: below)

• The Data name and Include record Before-data section names cannot both be deleted

• The Data name and Include record Before-data section names cannot be the same

Slashes:

Some of the section names in the UI end with a slash (e.g. beforeData/). The purpose of the slash is to maintain a hierarchy of the different sections within the message. If the slash is removed, the following will occur:

• The hierarchical structure of that section will be flattened, resulting in the section name being removed from the message
• The section name will be prefixed to the actual metadata, either directly or using a separator character (e.g. an underscore) that you appended to the name

Example of a data message when headers/ is specified with a slash:

		"message":{
		        "data":{
			      "COL1": "159",
			      "COL2": "159"
                       },
                       "beforeData": null,
		        "headers": {
			"operation": "INSERT",
			"changeSequence": "2018100811484900000000233",

Example of a data message when headers_ is specified with an underscore instead of a slash:

		"message":{
		        "data":{
			      "COL1": "159",
			      "COL2": "159"
                       },
                       "beforeData": null,                     
                       "headers_operation": "INSERT",
			"headers_changeSequence": "2018100811484900000000233",

Deletion:

Deleting a section name from the message will flatten the hierarchical structure of that section. This will result in all of that section's data appearing immediately below the content of the preceding section.

Example of a data message with the headers section name:

	        "message":{
		        "data":{
			      "COL1": "159",
			      "COL2": "159"
                       },
		        "headers": {
			"operation": "INSERT",
			"changeSequence": "2018100811484900000000233",

Example of a data message without the headers section name:

	        "message":{
		        "data":{
			      "COL1": "159",
			      "COL2": "159"
                       },
                       "beforeData": null,                   
                       "operation": "INSERT",
			"changeSequence": "2018100811484900000000233",

Variables

You can add variables to names by clicking the button at the end of the row. The following variables are available:

• SERVER_NAME - The host name of the Replicate Server
• TARGET_TABLE_NAME - The name of the table
• TARGET_TABLE_OWNER - The table owner
• TASK_NAME - The name of the Replicate task

Defining a custom message format

To define a custom message format, click the Custom Message Format button and configure the options as described in the table below.

To revert to the default message format, click the Default Message Format button.