sistats

Description

The sistats command is one of several commands that you can use to create summary indexes. Summary indexing is one of the methods that you can use to speed up searches that take a long time to run.

The sistats command is the summary indexing version of the stats command, which calculates aggregate statistics over the dataset.

The sistats command populates a summary index. You must then create a report to generate the summary statistics. See the Usage section.

Syntax

Required syntax is in bold.

sistats

[allnum=<bool>]

[delim=<string>]

( <stats-agg-term>... | <sparkline-agg-term>... )

[<by-clause>]

For descriptions of each of the arguments in this syntax, refer to the stats command.

Usage

The summary indexes exist separately from your main indexes.

After you create the summary index, create a report by running a search against the summary index. You use the exact same search string that you used to populate the summary index, substituting the stats command for the sistats command, to create your reports.

For more information, see About report acceleration and summary indexing and Use summary indexing for increased reporting efficiency in the Knowledge Manager Manual.

Supported functions

You can use a wide range of functions with the sistats command. For general information about using functions, see Statistical and charting functions.

• For a list of statistical functions by category, see Function list by category
• For an alphabetical list of statistical functions, see Alphabetical list of functions

Statistical functions that are not applied to specific fields

With the exception of the count function, when you pair the sistats command with functions that are not applied to specific fields or eval expressions that resolve into fields, the search head processes it as if it were applied to a wildcard for all fields. In other words, when you have | sistats avg in a search, it returns results for | sistats avg(*).

This "implicit wildcard" syntax is officially deprecated, however. Make the wildcard explicit. Write | sistats <function>(*) when you want a function to apply to all possible fields.

Memory and sistats search performance

A pair of limits.conf settings strike a balance between the performance of sistats searches and the amount of memory they use during the search process, in RAM and on disk. If your sistats searches are consistently slow to complete you can adjust these settings to improve their performance, but at the cost of increased search-time memory usage, which can lead to search failures.

If you have Splunk Cloud you will need to file a Support ticket to change these settings.

For more information, see Memory and stats search performance in the Search Manual.

Examples

Example 1:

Create a summary index with the statistics about the average, for each hour, of any unique field that ends with the string "lay". For example, delay, xdelay, relay, etc.

... | sistats avg(*lay) BY date_hour

To create a report, run a search against the summary index using this search

index=summary | stats avg(*lay) BY date_hour

See also

Commands

collect

overlap

sichart

sirare

sitop

sitimechart

Related information

For a detailed explanation and examples of summary indexing, see Use summary indexing for increased reporting efficiency in the Knowledge Manager Manual.