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Using metadata files to create topic tables in a relational database

You can load a metadata file to

and create a topic table in a relational database that is based on the structure of the file.

When you use a metadata file to create a topic table, you can define table attributes in the file before you load it to

Cloud Integration Hub

. For example, define column data type and precision, or define a column as a filter accelerator that is not encrypted.

You can use JSON, XML, XLS, and XLSX metadata files to create topic tables.

The metadata file must contain the following fields, and must not contain any other fields:

columnName: Mandatory.
Name of the table column.
The name must begin with an alphabetic character or underscore and can contain only alphanumeric characters or underscores.
filterAccelerator: Optional.
Indicates that the column will be used in subscription queries and requires performance-related handling by
Cloud Integration Hub
. Use this indicator with topics that you plan to use for unbound subscriptions.
By default, false.

When you use filter accelerators, consider the following guidelines:

Filter accelerators slow down the writing of publication data to the
Cloud Integration Hub
publication repository.
Filter accelerators have no impact on subscriptions that do not use filters.
You can enable encryption for a new topic data on a hosted
Cloud Integration Hub
publication repository. To use a column as a filter accelerator, you must define the value of the column's
encryption
field to
false
.
datatype: Optional. Data type of the field. By default, string.; The file can contain fields of the following data types:; String
Decimal
Double
Int32
Int64
Date_time
Text
precision: Optional. Applies to data types that support precision. The default precision value depends on the data type of the field:
String: 255
Decimal: 15
Text: 10000
scale: Optional. Applies to data types that support data scaling. The default scale value depends on the data type of the field:
Decimal: 0. If the decimal field isn't encrypted and the published value is less than the topic decimal scale value,
Cloud Integration Hub
adds zeros to the decimal value. For example, if you define a scale of 4 for a decimal of 15.4,
Cloud Integration Hub
publishes and consumes the data with a decimal of 15.4000.
Date_time: 0. For example, if you define a scale of 2 for a date_time of
2022-02-04 00:40:23.946
,
Cloud Integration Hub
rounds the date_time to
2022-02-04 00:40:23.950
. Applies to a hosted publication repository.
All other data types: empty
encryption: Optional. Applies to a hosted publication repository.
required: Optional. Applies to a relational topic table. If this option is set to true, ensure that the data is published to the required fields. If the published data doesn't meet the required mandatory fields criteria, the event fails.

If a file doesn't contain all the mandatory fields, loading the file to

Cloud Integration Hub

fails.

If a file contains identical rows,

Cloud Integration Hub

adds only the first row to the topic table.

Example table in a JSON file: [ {"columnName":"id", "filterAccelerator": "false", "dataType": "int32", "encryption":false, "required":true}, {"columnName":"name", "filterAccelerator": "false", "dataType": "string", "precision" : 100, "encryption":false, "required":true}, {"columnName":"age", "filterAccelerator": "true", "dataType": "decimal", "precision" : 3, "encryption":"true", "required":true}, {"columnName":"city", "filterAccelerator": "True", "dataType": "string", "precision" : 50, "encryption":"FALSE", "required":true}, {"columnName":"salary", "filterAccelerator": false, "dataType": "decimal", "precision" : 15, "scale":2, "encryption":true, "required":true} ]
Example table in an XML file: <table> <column> <columnName>id</columnName> <dataType>int32</dataType> <encryption>false</encryption> <required>false</required> <filterAccelerator>true</filterAccelerator> </column> <column> <columnName>name</columnName> <dataType>String</dataType> <encryption>true</encryption> <required>true</required> <precision>100</precision> <filterAccelerator>false</filterAccelerator> </column> </table>
Example table in an XLS or XLSX file: columnName
filterAccelerator
dataType
precision
scale
encryption
required

id
TRUE
Int32

FALSE
true

name
FALSE
String
255

FALSE
true