A chart is a graphical representation of your search results that shows the relationship between two or more fields2. You can display a chart in stack mode by changing the Stack Mode option in the Format menu2. Stack mode allows you to stack multiple series on top of each other in a chart to show the cumulative values of each series2. Therefore, option C is correct, while options A, B and D are incorrect because they are not ways to display a chart in stack mode.

A field alias is a way to assign an alternative name to an existing field without changing the original field name or value2. You can use field aliases to make your field names more consistent or descriptive across different sources or sourcetypes2. When you run a search without any transforming commands in Smart Mode, Splunk automatically identifies and displays interesting fields in your results2. Interesting fields are fields that appear in at least 20 percent of events or have high variability among values2. If you have created a field alias based on an original field, both the original field name and the alias name will appear in the Interesting Fields list if they meet these criteria2. However, only one of them will appear in each event depending on which one you have specified in your search string2. Therefore, option B is correct, while options A, C and D are incorrect.

The correct answer is B. A field added by an automatic lookup.

A calculated field is a field that is added to events at search time by using an eval expression. A calculated field can use the values of two or more fields that are already present in the events to perform calculations. A calculated field can use any field as a source, as long as the field is extracted before the calculated field is defined1.

An automatic lookup is a way to enrich events with additional fields from an external source, such as a CSV file or a database. An automatic lookup can add fields to events based on the values of existing fields, such as host, source, sourcetype, or any other extracted field2. An automatic lookup is performed before the calculated fields are defined, so the fields added by the lookup can be used as sources for the calculated fields3.

Therefore, a calculated field can use a field added by an automatic lookup as a source.

In Splunk, a field alias is used to create an alternative name for an existing field, making it easier to refer to data in a consistent manner across different searches and reports. Field aliases can be applied to both calculated fields and extracted fields. Calculated fields are those that are created using eval expressions, while extracted fields are typically those parsed from the raw data at index time or search time. This flexibility allows users to streamline their searches by using more intuitive field names without altering the underlying data. Field aliases cannot be applied to data in a lookup table, specific individual fields within a dataset, or directly to a host, source, or sourcetype.

Field aliases can only be applied after fields have been extracted .

Extract: “Field extraction occurs before field aliasing in the search-time data processing order. Field aliases depend on extracted field names to function.”

Thus, fields must first be extracted before any alias can be assigned.

A calculated field in Splunk is designed to automatically add fields at search time using an eval expression. This feature allows users to define new fields based on existing data without needing to manually include an eval command in every search. Calculated fields simplify repeated search tasks by embedding the eval logic directly into the field configuration.

When you define a calculated field, you can specify the name of the field that the eval expression will create or modify. If the name of the calculated field matches the name of an existing extracted field, the calculated field will override the extracted field and replace its value with the result of the eval expression. This means that the original value of the extracted field will not be available for searching or analysis. To avoid this, you should use a unique name for your calculated field or use a different name for your extracted field2

1: Splunk Core Certified Power User Track, page 9. 2: Splunk Documentation, Configure calculated fields with props.conf.