Which of the following is the most efficient search?

Question

Options

• Aindex=www status=200 uri=/cart/checkout | append [search index = sales] | stats count,
• B(index=www status=200 uri=/cart/checkout) OR (index=sales) | stats count, sum(revenue) as
• Cindex=www | append [search index = sales] | stats count, sum(revenue) as total_revenue by
• D(index=www) OR (index=sales) | search (index=www status=200 uri=/cart/checkout) OR

• A
  16% (7)
• B
  70% (30)
• C
  5% (2)
• D
  9% (4)

Explanation

Option B is the most efficient because it pushes all filtering to the index search level using an inline OR, allowing Splunk to retrieve only the relevant events from each index in a single pass without any subsearches or post-retrieval filtering.

• A is inefficient because append [search ...] spawns a subsearch, which runs separately, loads results into memory, and then merges them - a costly two-phase operation.
• C is doubly inefficient: it retrieves all events from index=www with no early filtering, then compounds the problem with an expensive append subsearch.
• D retrieves all events from both indexes first, then applies | search as a post-pipeline filter - a "filter late" anti-pattern that makes Splunk do unnecessary work before narrowing results.

Memory tip: Think "filter early, filter inline." Conditions placed directly in the initial search string are evaluated at the index tier (cheapest), while | search filters late at the search tier (expensive), and append [search ...] adds a full subsearch on top of that (most expensive). In Splunk, the earlier and more inline your filters, the better.

No community discussion yet for this question.