[WIP] perf(core): Add a new mutation pipeline for per predicate runners

TESTING.md

@@ -87,7 +87,7 @@ programmatic control over local Dgraph clusters. Most newer integration2 and upg
 
 ## Module Structure
 
-The main module is `github.com/hypermodeinc/dgraph`
+The main module is `github.com/dgraph-io/dgraph`
 
 The codebase is organized into several key packages:
 

dgraph/cmd/alpha/run.go

@@ -274,6 +274,16 @@ they form a Raft group and provide synchronous replication.
 			"with structured fields including trace ID for correlation with distributed traces. "+
 			"Disabled by default (0). Note: enabling this logs query text which may contain "+
 			"sensitive data; do not enable in deployments with strict data privacy requirements.").
+		Flag("mutations-pipeline-threshold",
+			"Per-mutation edge-count threshold for routing through the per-predicate "+
+				"mutation pipeline, which parallelizes work across distinct predicates "+
+				"in a single mutation. 0 disables the pipeline entirely (all mutations "+
+				"take the legacy path). 1 always uses the pipeline. A value N>1 uses "+
+				"the pipeline only when len(edges) >= N, leaving small interactive "+
+				"mutations on the legacy path — the pipeline pays per-predicate "+
+				"goroutine spin-up cost, so tiny mutations are slightly slower on it; "+
+				"bulk multi-predicate mutations are faster (crossover ~100 edges in "+
+				"benchmarks here).").
 		String())
 }
 
@@ -796,6 +806,7 @@ func run() {
 	x.Config.NormalizeCompatibilityMode = featureFlagsConf.GetString("normalize-compatibility-mode")
 	enableDetailedMetrics := featureFlagsConf.GetBool("enable-detailed-metrics")
 	x.WorkerConfig.SlowQueryLogThreshold = featureFlagsConf.GetDuration("log-slow-query-threshold")
+	x.WorkerConfig.MutationsPipelineThreshold = int(featureFlagsConf.GetInt64("mutations-pipeline-threshold"))
 
 	x.PrintVersion()
 	glog.Infof("x.Config: %+v", x.Config)

graphql/admin/admin.go

@@ -655,6 +655,10 @@ func newAdminResolver(
 			return
 		}
 
+		if len(pl.Postings) == 2 && string(pl.Postings[0].Value) == "_STAR_ALL" {
+			pl.Postings = pl.Postings[1:]
+		}
+
 		// There should be only one posting.
 		if len(pl.Postings) != 1 {
 			glog.Errorf("Only one posting is expected in the graphql schema posting list but got %d",