From 80ac0d7c82cc325932c1934ad9f7e55e8ed3e479 Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Fri, 23 Dec 2022 20:24:20 +0000
Subject: [PATCH] promql: add benchmark for match against blank string

Blank strings are not handled efficiently by tsdb.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
---
 promql/bench_test.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/promql/bench_test.go b/promql/bench_test.go
index 6fb20d1aba..8abfcfdd20 100644
--- a/promql/bench_test.go
+++ b/promql/bench_test.go
@@ -174,6 +174,15 @@ func rangeQueryCases() []benchCase {
 		{
 			expr: "a_X + on(l) group_right a_one",
 		},
+		// Label compared to blank string.
+		{
+			expr:  "count({__name__!=\"\"})",
+			steps: 1,
+		},
+		{
+			expr:  "count({__name__!=\"\",l=\"\"})",
+			steps: 1,
+		},
 	}
 
 	// X in an expr will be replaced by different metric sizes.