Merge #153362

craig[bot] · jbowens · craig[bot] · commit cecd5279349c · 2025-09-11T17:30:04.000Z
153362: storage: set default value separation minimum size to 256 bytes r=RaduBerinde a=jbowens

Lower the default minimum size that will trigger separation of value from 1 KiB to 256 bytes. Benchmarking kv0, kv50 and kv95 workloads showed consistent net benefit with values sized around ~256 bytes.

Epic: none
Release note: none

Co-authored-by: Jackson Owens &lt;jackson@cockroachlabs.com&gt;
diff --git a/pkg/storage/pebble.go b/pkg/storage/pebble.go
@@ -430,7 +430,7 @@ var (
 		"storage.value_separation.minimum_size",
 		"the minimum size of a value that will be separated into a blob file",
 		int64(metamorphic.ConstantWithTestRange("storage.value_separation.minimum_size",
-			1<<10 /* 1 KiB (default) */, 25 /* 25 bytes (minimum) */, 1<<20 /* 1 MiB (maximum) */)),
+			256 /* 256 bytes (default) */, 25 /* 25 bytes (minimum) */, 1<<20 /* 1 MiB (maximum) */)),
 		settings.IntWithMinimum(1),
 	)
 	valueSeparationMaxReferenceDepth = settings.RegisterIntSetting(

Original file line number	Diff line number	Diff line change
`@@ -430,7 +430,7 @@ var (`
`430`	`430`	`"storage.value_separation.minimum_size",`
`431`	`431`	`"the minimum size of a value that will be separated into a blob file",`
`432`	`432`	`int64(metamorphic.ConstantWithTestRange("storage.value_separation.minimum_size",`
`433`		`- 1<<10 /* 1 KiB (default) /, 25 / 25 bytes (minimum) /, 1<<20 / 1 MiB (maximum) */)),`
	`433`	`+ 256 /* 256 bytes (default) /, 25 / 25 bytes (minimum) /, 1<<20 / 1 MiB (maximum) */)),`
`434`	`434`	`settings.IntWithMinimum(1),`
`435`	`435`	`)`
`436`	`436`	`valueSeparationMaxReferenceDepth = settings.RegisterIntSetting(`