What types of fields are identified in your data at the INDEX time?

At index time in Splunk, the primary focus is on identifying and processing fields that are automatically assigned by Splunk based on the data being indexed. Default fields are predefined by Splunk and include essential metadata such as host, source, and sourcetype, which are critical for indexing and searching the data effectively. These fields are automatically extracted and populated when data is ingested.

Default fields play a crucial role in ensuring that the data is organized and searchable from the moment it enters Splunk. They help in categorizing the data and making it easier to locate during queries and searches, which enhances efficiency in data retrieval.

While other types of fields mentioned might be relevant at search time or in the context of manual field extraction, it is the default fields that are specifically identified at index time, providing a foundational structure for indexing within Splunk.