diff --git a/cache/cache.go b/cache/cache.go
index 596751b..691c7ce 100644
--- a/cache/cache.go
+++ b/cache/cache.go
@@ -1,8 +1,9 @@
 package cache
 
 import (
-	"sync"
+	"sync/atomic"
 
+	"github.com/aserto-dev/azm/mempool"
 	"github.com/aserto-dev/azm/model"
 	"github.com/aserto-dev/azm/model/diff"
 	stts "github.com/aserto-dev/azm/stats"
@@ -17,47 +18,39 @@ type (
 )
 
 type Cache struct {
-	model *model.Model
-	mtx   sync.RWMutex
+	model    atomic.Pointer[model.Model]
+	relsPool *mempool.RelationsPool
 }
 
 // New, create new model cache instance.
 func New(m *model.Model) *Cache {
-	return &Cache{
-		model: m,
-		mtx:   sync.RWMutex{},
+	cache := &Cache{
+		relsPool: mempool.NewRelationsPool(),
 	}
+
+	cache.model.Store(m)
+	return cache
 }
 
 // UpdateModel, swaps the cache model instance.
 func (c *Cache) UpdateModel(m *model.Model) error {
-	c.mtx.Lock()
-	defer c.mtx.Unlock()
-	c.model = m
+	c.model.Store(m)
 	return nil
 }
 
 func (c *Cache) CanUpdate(other *model.Model, stats *stts.Stats) error {
-	c.mtx.Lock()
-	defer c.mtx.Unlock()
-	return diff.CanUpdateModel(c.model, other, stats)
+	return diff.CanUpdateModel(c.model.Load(), other, stats)
 }
 
 // ObjectExists, checks if given object type name exists in the model cache.
 func (c *Cache) ObjectExists(on ObjectName) bool {
-	c.mtx.RLock()
-	defer c.mtx.RUnlock()
-
-	_, ok := c.model.Objects[on]
+	_, ok := c.model.Load().Objects[on]
 	return ok
 }
 
 // RelationExists, checks if given relation type, for the given object type, exists in the model cache.
 func (c *Cache) RelationExists(on ObjectName, rn RelationName) bool {
-	c.mtx.RLock()
-	defer c.mtx.RUnlock()
-
-	if obj, ok := c.model.Objects[on]; ok {
+	if obj, ok := c.model.Load().Objects[on]; ok {
 		_, ok := obj.Relations[rn]
 		return ok
 	}
@@ -66,10 +59,7 @@ func (c *Cache) RelationExists(on ObjectName, rn RelationName) bool {
 
 // PermissionExists, checks if given permission, for the given object type, exists in the model cache.
 func (c *Cache) PermissionExists(on ObjectName, pn RelationName) bool {
-	c.mtx.RLock()
-	defer c.mtx.RUnlock()
-
-	if obj, ok := c.model.Objects[on]; ok {
+	if obj, ok := c.model.Load().Objects[on]; ok {
 		_, ok := obj.Permissions[pn]
 		return ok
 	}
@@ -77,16 +67,11 @@ func (c *Cache) PermissionExists(on ObjectName, pn RelationName) bool {
 }
 
 func (c *Cache) Metadata() *model.Metadata {
-	c.mtx.RLock()
-	defer c.mtx.RUnlock()
-	return c.model.Metadata
+	return c.model.Load().Metadata
 }
 
-func (c *Cache) ValidateRelation(relation *dsc.Relation) error {
-	c.mtx.RLock()
-	defer c.mtx.RUnlock()
-
-	return c.model.ValidateRelation(
+func (c *Cache) ValidateRelation(relation *dsc.RelationIdentifier) error {
+	return c.model.Load().ValidateRelation(
 		ObjectName(relation.ObjectType),
 		model.ObjectID(relation.ObjectId),
 		RelationName(relation.Relation),
@@ -123,7 +108,7 @@ func (c *Cache) AssignableRelations(on, sn ObjectName, sr ...RelationName) ([]Re
 		}
 	}
 
-	matches := lo.PickBy(c.model.Objects[on].Relations, func(rn RelationName, r *model.Relation) bool {
+	matches := lo.PickBy(c.model.Load().Objects[on].Relations, func(rn RelationName, r *model.Relation) bool {
 		for _, ref := range r.Union {
 			if ref.Object != sn {
 				// type mismatch
diff --git a/cache/check.go b/cache/check.go
index cb800fe..f2d7e85 100644
--- a/cache/check.go
+++ b/cache/check.go
@@ -2,14 +2,19 @@ package cache
 
 import (
 	"github.com/aserto-dev/azm/graph"
+	"github.com/aserto-dev/azm/mempool"
 	dsr "github.com/aserto-dev/go-directory/aserto/directory/reader/v3"
 	"github.com/aserto-dev/go-directory/pkg/pb"
 	"github.com/aserto-dev/go-directory/pkg/prop"
 	"google.golang.org/protobuf/types/known/structpb"
 )
 
+// If true, use a shared memory pool for all requests.
+// Othersise, each call gets its own pool.
+const sharedPool = true
+
 func (c *Cache) Check(req *dsr.CheckRequest, relReader graph.RelationReader) (*dsr.CheckResponse, error) {
-	checker := graph.NewCheck(c.model, req, relReader)
+	checker := graph.NewCheck(c.model.Load(), req, relReader, c.relationsPool())
 
 	ctx := pb.NewStruct()
 
@@ -32,9 +37,9 @@ func (c *Cache) GetGraph(req *dsr.GetGraphRequest, relReader graph.RelationReade
 	)
 
 	if req.ObjectId == "" {
-		search, err = graph.NewObjectSearch(c.model, req, relReader)
+		search, err = graph.NewObjectSearch(c.model.Load(), req, relReader, c.relationsPool())
 	} else {
-		search, err = graph.NewSubjectSearch(c.model, req, relReader)
+		search, err = graph.NewSubjectSearch(c.model.Load(), req, relReader, c.relationsPool())
 	}
 
 	if err != nil {
@@ -43,3 +48,11 @@ func (c *Cache) GetGraph(req *dsr.GetGraphRequest, relReader graph.RelationReade
 
 	return search.Search()
 }
+
+func (c *Cache) relationsPool() *mempool.RelationsPool {
+	if sharedPool {
+		return c.relsPool
+	}
+
+	return mempool.NewRelationsPool()
+}
diff --git a/go.mod b/go.mod
index 2fef087..6a7980a 100644
--- a/go.mod
+++ b/go.mod
@@ -1,14 +1,16 @@
 module github.com/aserto-dev/azm
 
-go 1.22.9
+go 1.22.10
 
-toolchain go1.23.3
+toolchain go1.23.4
+
+// replace github.com/aserto-dev/go-directory => ../go-directory
 
 require (
 	github.com/antlr4-go/antlr/v4 v4.13.1
 	github.com/aserto-dev/errors v0.0.11
-	github.com/aserto-dev/go-directory v0.33.1
-	github.com/deckarep/golang-set/v2 v2.6.0
+	github.com/aserto-dev/go-directory v0.33.2
+	github.com/deckarep/golang-set/v2 v2.7.0
 	github.com/hashicorp/go-multierror v1.1.1
 	github.com/mitchellh/hashstructure/v2 v2.0.2
 	github.com/nsf/jsondiff v0.0.0-20230430225905-43f6cf3098c1
@@ -16,23 +18,24 @@ require (
 	github.com/rs/zerolog v1.33.0
 	github.com/samber/lo v1.47.0
 	github.com/stretchr/testify v1.10.0
-	google.golang.org/grpc v1.68.0
+	google.golang.org/grpc v1.68.1
 	google.golang.org/protobuf v1.35.2
 	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
-	buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.35.2-20240920164238-5a7b106cbb87.1 // indirect
+	buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.35.2-20241127180247-a33202765966.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.24.0 // indirect
 	github.com/hashicorp/errwrap v1.1.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f // indirect
-	golang.org/x/net v0.31.0 // indirect
-	golang.org/x/sys v0.27.0 // indirect
-	golang.org/x/text v0.20.0 // indirect
-	google.golang.org/genproto/googleapis/api v0.0.0-20241118233622-e639e219e697 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20241118233622-e639e219e697 // indirect
+	golang.org/x/exp v0.0.0-20241210194714-1829a127f884 // indirect
+	golang.org/x/net v0.32.0 // indirect
+	golang.org/x/sys v0.28.0 // indirect
+	golang.org/x/text v0.21.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20241209162323-e6fa225c2576 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20241209162323-e6fa225c2576 // indirect
 )
diff --git a/go.sum b/go.sum
index cafda7f..27253bb 100644
--- a/go.sum
+++ b/go.sum
@@ -1,18 +1,16 @@
-buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.35.2-20240920164238-5a7b106cbb87.1 h1:7QIeAuTdLp173vC/9JojRMDFcpmqtoYrxPmvdHAOynw=
-buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.35.2-20240920164238-5a7b106cbb87.1/go.mod h1:mnHCFccv4HwuIAOHNGdiIc5ZYbBCvbTWZcodLN5wITI=
+buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.35.2-20241127180247-a33202765966.1 h1:jLd96rDDNJ+zIJxvV/L855VEtrjR0G4aePVDlCpf6kw=
+buf.build/gen/go/bufbuild/protovalidate/protocolbuffers/go v1.35.2-20241127180247-a33202765966.1/go.mod h1:mnHCFccv4HwuIAOHNGdiIc5ZYbBCvbTWZcodLN5wITI=
 github.com/antlr4-go/antlr/v4 v4.13.1 h1:SqQKkuVZ+zWkMMNkjy5FZe5mr5WURWnlpmOuzYWrPrQ=
 github.com/antlr4-go/antlr/v4 v4.13.1/go.mod h1:GKmUxMtwp6ZgGwZSva4eWPC5mS6vUAmOABFgjdkM7Nw=
 github.com/aserto-dev/errors v0.0.11 h1:CXo+Uwmh09doG2HvL1SC8Fnne8f9VPrGyEQPtogAfyY=
 github.com/aserto-dev/errors v0.0.11/go.mod h1:T1YQOtcxpgBriPTn5HXJkD/QukYz5YojYOIzGMo0ybM=
-github.com/aserto-dev/go-directory v0.33.1-0.20241125175915-5cffa131b985 h1:Pjpoa4n8Kx1KBaQ8GyW9Y9bVnbzTwWkx7gDhL5huhmI=
-github.com/aserto-dev/go-directory v0.33.1-0.20241125175915-5cffa131b985/go.mod h1:eEvIFY+t6WclhJPHbu+Y17ghF4qRYc36UkJL5UNPVPY=
-github.com/aserto-dev/go-directory v0.33.1 h1:jLyzMRu5Omw5KJ2cmqnGZZbrF091HFHnt9awhqZhSq8=
-github.com/aserto-dev/go-directory v0.33.1/go.mod h1:0Ng9lPTahslSN/ONoWCceG6Q1ukpSfxYEu589eCReRM=
+github.com/aserto-dev/go-directory v0.33.2 h1:QJwzSmfxJ7EG0RzWsgu7In5cAeGtZURZklSsHhMOFh8=
+github.com/aserto-dev/go-directory v0.33.2/go.mod h1:gK239V0htJtp0/BwvbTrYv/XIphoK/AugP8sw3m8B0s=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/deckarep/golang-set/v2 v2.6.0 h1:XfcQbWM1LlMB8BsJ8N9vW5ehnnPVIw0je80NsVHagjM=
-github.com/deckarep/golang-set/v2 v2.6.0/go.mod h1:VAky9rY/yGXJOLEDv3OMci+7wtDpOF4IN+y82NBOac4=
+github.com/deckarep/golang-set/v2 v2.7.0 h1:gIloKvD7yH2oip4VLhsv3JyLLFnC0Y2mlusgcvJYW5k=
+github.com/deckarep/golang-set/v2 v2.7.0/go.mod h1:VAky9rY/yGXJOLEDv3OMci+7wtDpOF4IN+y82NBOac4=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
@@ -41,6 +39,8 @@ github.com/nsf/jsondiff v0.0.0-20230430225905-43f6cf3098c1 h1:dOYG7LS/WK00RWZc8X
 github.com/nsf/jsondiff v0.0.0-20230430225905-43f6cf3098c1/go.mod h1:mpRZBD8SJ55OIICQ3iWH0Yz3cjzA61JdqMLoWXeB2+8=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 h1:GFCKgmp0tecUJ0sJuv4pzYCqS9+RGSn52M3FUwPs+uo=
+github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10/go.mod h1:t/avpk3KcrXxUnYOhZhMXJlSEyie6gQbtLq5NM3loB8=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
@@ -52,23 +52,23 @@ github.com/samber/lo v1.47.0 h1:z7RynLwP5nbyRscyvcD043DWYoOcYRv3mV8lBeqOCLc=
 github.com/samber/lo v1.47.0/go.mod h1:RmDH9Ct32Qy3gduHQuKJ3gW1fMHAnE/fAzQuf6He5cU=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f h1:XdNn9LlyWAhLVp6P/i8QYBW+hlyhrhei9uErw2B5GJo=
-golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f/go.mod h1:D5SMRVC3C2/4+F/DB1wZsLRnSNimn2Sp/NPsCrsv8ak=
-golang.org/x/net v0.31.0 h1:68CPQngjLL0r2AlUKiSxtQFKvzRVbnzLwMUn5SzcLHo=
-golang.org/x/net v0.31.0/go.mod h1:P4fl1q7dY2hnZFxEk4pPSkDHF+QqjitcnDjUQyMM+pM=
+golang.org/x/exp v0.0.0-20241210194714-1829a127f884 h1:Y/Mj/94zIQQGHVSv1tTtQBDaQaJe62U9bkDZKKyhPCU=
+golang.org/x/exp v0.0.0-20241210194714-1829a127f884/go.mod h1:qj5a5QZpwLU2NLQudwIN5koi3beDhSAlJwa67PuM98c=
+golang.org/x/net v0.32.0 h1:ZqPmj8Kzc+Y6e0+skZsuACbx+wzMgo5MQsJh9Qd6aYI=
+golang.org/x/net v0.32.0/go.mod h1:CwU0IoeOlnQQWJ6ioyFrfRuomB8GKF6KbYXZVyeXNfs=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
-golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.20.0 h1:gK/Kv2otX8gz+wn7Rmb3vT96ZwuoxnQlY+HlJVj7Qug=
-golang.org/x/text v0.20.0/go.mod h1:D4IsuqiFMhST5bX19pQ9ikHC2GsaKyk/oF+pn3ducp4=
-google.golang.org/genproto/googleapis/api v0.0.0-20241118233622-e639e219e697 h1:pgr/4QbFyktUv9CtQ/Fq4gzEE6/Xs7iCXbktaGzLHbQ=
-google.golang.org/genproto/googleapis/api v0.0.0-20241118233622-e639e219e697/go.mod h1:+D9ySVjN8nY8YCVjc5O7PZDIdZporIDY3KaGfJunh88=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20241118233622-e639e219e697 h1:LWZqQOEjDyONlF1H6afSWpAL/znlREo2tHfLoe+8LMA=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20241118233622-e639e219e697/go.mod h1:5uTbfoYQed2U9p3KIj2/Zzm02PYhndfdmML0qC3q3FU=
-google.golang.org/grpc v1.68.0 h1:aHQeeJbo8zAkAa3pRzrVjZlbz6uSfeOXlJNQM0RAbz0=
-google.golang.org/grpc v1.68.0/go.mod h1:fmSPC5AsjSBCK54MyHRx48kpOti1/jRfOlwEWywNjWA=
+golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
+golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
+google.golang.org/genproto/googleapis/api v0.0.0-20241209162323-e6fa225c2576 h1:CkkIfIt50+lT6NHAVoRYEyAvQGFM7xEwXUUywFvEb3Q=
+google.golang.org/genproto/googleapis/api v0.0.0-20241209162323-e6fa225c2576/go.mod h1:1R3kvZ1dtP3+4p4d3G8uJ8rFk/fWlScl38vanWACI08=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20241209162323-e6fa225c2576 h1:8ZmaLZE4XWrtU3MyClkYqqtl6Oegr3235h7jxsDyqCY=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20241209162323-e6fa225c2576/go.mod h1:5uTbfoYQed2U9p3KIj2/Zzm02PYhndfdmML0qC3q3FU=
+google.golang.org/grpc v1.68.1 h1:oI5oTa11+ng8r8XMMN7jAOmWfPZWbYpCFaMUTACxkM0=
+google.golang.org/grpc v1.68.1/go.mod h1:+q1XYFJjShcqn0QZHvCyeR4CXPA+llXIeUIfIe00waw=
 google.golang.org/protobuf v1.35.2 h1:8Ar7bF+apOIoThw1EdZl0p1oWvMqTHmpA2fRTyZO8io=
 google.golang.org/protobuf v1.35.2/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
diff --git a/graph/check.go b/graph/check.go
index 7ca3f85..c943d69 100644
--- a/graph/check.go
+++ b/graph/check.go
@@ -1,6 +1,7 @@
 package graph
 
 import (
+	"github.com/aserto-dev/azm/mempool"
 	"github.com/aserto-dev/azm/model"
 	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
 	dsr "github.com/aserto-dev/go-directory/aserto/directory/reader/v3"
@@ -15,9 +16,10 @@ type Checker struct {
 	getRels RelationReader
 
 	memo *checkMemo
+	pool *mempool.RelationsPool
 }
 
-func NewCheck(m *model.Model, req *dsr.CheckRequest, reader RelationReader) *Checker {
+func NewCheck(m *model.Model, req *dsr.CheckRequest, reader RelationReader, pool *mempool.RelationsPool) *Checker {
 	return &Checker{
 		m: m,
 		params: &relation{
@@ -29,6 +31,7 @@ func NewCheck(m *model.Model, req *dsr.CheckRequest, reader RelationReader) *Che
 		},
 		getRels: reader,
 		memo:    newCheckMemo(req.Trace),
+		pool:    pool,
 	}
 }
 
@@ -88,8 +91,14 @@ func (c *Checker) checkRelation(params *relation) (checkStatus, error) {
 	r := c.m.Objects[params.ot].Relations[params.rel]
 	steps := c.m.StepRelation(r, params.st)
 
+	// Reuse the same slice in all steps.
+	relsPtr := c.pool.GetSlice()
+	defer c.pool.PutSlice(relsPtr)
+
 	for _, step := range steps {
-		req := &dsc.Relation{
+		*relsPtr = (*relsPtr)[:0]
+
+		req := &dsc.RelationIdentifier{
 			ObjectType:  params.ot.String(),
 			ObjectId:    params.oid.String(),
 			Relation:    params.rel.String(),
@@ -97,33 +106,34 @@ func (c *Checker) checkRelation(params *relation) (checkStatus, error) {
 		}
 
 		switch {
+		case step.IsDirect():
+			req.SubjectId = params.sid.String()
 		case step.IsWildcard():
 			req.SubjectId = "*"
 		case step.IsSubject():
 			req.SubjectRelation = step.Relation.String()
 		}
 
-		rels, err := c.getRels(req)
-		if err != nil {
+		if err := c.getRels(req, c.pool, relsPtr); err != nil {
 			return checkStatusFalse, err
 		}
 
 		switch {
 		case step.IsDirect():
-			for _, rel := range rels {
+			for _, rel := range *relsPtr {
 				if rel.SubjectId == params.sid.String() {
 					return checkStatusTrue, nil
 				}
 			}
 
 		case step.IsWildcard():
-			if len(rels) > 0 {
+			if len(*relsPtr) > 0 {
 				// We have a wildcard match.
 				return checkStatusTrue, nil
 			}
 
 		case step.IsSubject():
-			for _, rel := range rels {
+			for _, rel := range *relsPtr {
 				if status, err := c.check(&relation{
 					ot:  step.Object,
 					oid: ObjectID(rel.SubjectId),
@@ -190,17 +200,21 @@ func (c *Checker) checkPermission(params *relation) (checkStatus, error) {
 
 func (c *Checker) expandTerm(pt *model.PermissionTerm, params *relation) (relations, error) {
 	if pt.IsArrow() {
-		// Resolve the base of the arrow.
-		rels, err := c.getRels(&dsc.Relation{
+		query := &dsc.RelationIdentifier{
 			ObjectType: params.ot.String(),
 			ObjectId:   params.oid.String(),
 			Relation:   pt.Base.String(),
-		})
+		}
+
+		relsPtr := c.pool.GetSlice()
+
+		// Resolve the base of the arrow.
+		err := c.getRels(query, c.pool, relsPtr)
 		if err != nil {
 			return relations{}, err
 		}
 
-		expanded := lo.Map(rels, func(rel *dsc.Relation, _ int) *relation {
+		expanded := lo.Map(*relsPtr, func(rel *dsc.RelationIdentifier, _ int) *relation {
 			return &relation{
 				ot:  model.ObjectName(rel.SubjectType),
 				oid: ObjectID(rel.SubjectId),
@@ -210,6 +224,8 @@ func (c *Checker) expandTerm(pt *model.PermissionTerm, params *relation) (relati
 			}
 		})
 
+		c.pool.PutSlice(relsPtr)
+
 		return expanded, nil
 	}
 
diff --git a/graph/check_test.go b/graph/check_test.go
index abe0f4d..115fa03 100644
--- a/graph/check_test.go
+++ b/graph/check_test.go
@@ -5,73 +5,77 @@ import (
 	"testing"
 
 	azmgraph "github.com/aserto-dev/azm/graph"
+	"github.com/aserto-dev/azm/mempool"
 	v3 "github.com/aserto-dev/azm/v3"
+	"github.com/rs/zerolog"
 	"github.com/stretchr/testify/assert"
 )
 
-func TestCheck(t *testing.T) {
-	tests := []struct {
-		check    string
-		expected bool
-	}{
-		// Relations
-		{"doc:doc1#owner@user:user1", false},
-		{"doc:doc1#viewer@user:user1", true},
-		{"doc:doc2#viewer@user:user1", true},
-		{"doc:doc2#viewer@user:userX", true},
-		{"doc:doc1#viewer@user:user2", true},
-		{"doc:doc1#viewer@user:user3", true},
-		{"doc:doc1#viewer@group:d1_viewers", false},
-
-		{"group:yin#member@user:yin_user", true},
-		{"group:yin#member@user:yang_user", true},
-		{"group:yang#member@user:yin_user", true},
-		{"group:yang#member@user:yang_user", true},
-
-		{"group:alpha#member@user:user1", false},
-
-		// Permissions
-		{"doc:doc1#can_change_owner@user:d1_owner", true},
-		{"doc:doc1#can_change_owner@user:user1", false},
-		{"doc:doc1#can_change_owner@user:userX", false},
-
-		{"doc:doc1#can_read@user:d1_owner", true},
-		{"doc:doc1#can_read@user:f1_owner", true},
-		{"doc:doc1#can_read@user:user1", true},
-		{"doc:doc1#can_read@user:f1_viewer", true},
-		{"doc:doc1#can_read@user:userX", false},
-
-		{"doc:doc1#can_write@user:d1_owner", true},
-		{"doc:doc1#can_write@user:f1_owner", true},
-		{"doc:doc1#can_write@user:user2", false},
-
-		{"folder:folder1#owner@user:f1_owner", true},
-		{"folder:folder1#can_create_file@user:f1_owner", true},
-		{"folder:folder1#can_share@user:f1_owner", true},
-
-		// intersection
-		{"doc:doc1#can_share@user:d1_owner", false},
-		{"doc:doc1#can_share@user:f1_owner", true},
-
-		// negation
-		{"folder:folder1#can_read@user:f1_owner", true},
-		{"doc:doc1#viewer@user:f1_owner", false},
-		{"doc:doc1#can_invite@user:f1_owner", true},
-
-		// cycles
-		{"cycle:loop#can_delete@user:loop_owner", true},
-		{"cycle:loop#can_delete@user:user1", false},
-	}
+var tests = []struct {
+	check    string
+	expected bool
+}{
+	// Relations
+	{"doc:doc1#owner@user:user1", false},
+	{"doc:doc1#viewer@user:user1", true},
+	{"doc:doc2#viewer@user:user1", true},
+	{"doc:doc2#viewer@user:userX", true},
+	{"doc:doc1#viewer@user:user2", true},
+	{"doc:doc1#viewer@user:user3", true},
+	{"doc:doc1#viewer@group:d1_viewers", false},
+
+	{"group:yin#member@user:yin_user", true},
+	{"group:yin#member@user:yang_user", true},
+	{"group:yang#member@user:yin_user", true},
+	{"group:yang#member@user:yang_user", true},
+
+	{"group:alpha#member@user:user1", false},
+
+	// Permissions
+	{"doc:doc1#can_change_owner@user:d1_owner", true},
+	{"doc:doc1#can_change_owner@user:user1", false},
+	{"doc:doc1#can_change_owner@user:userX", false},
+
+	{"doc:doc1#can_read@user:d1_owner", true},
+	{"doc:doc1#can_read@user:f1_owner", true},
+	{"doc:doc1#can_read@user:user1", true},
+	{"doc:doc1#can_read@user:f1_viewer", true},
+	{"doc:doc1#can_read@user:userX", false},
+
+	{"doc:doc1#can_write@user:d1_owner", true},
+	{"doc:doc1#can_write@user:f1_owner", true},
+	{"doc:doc1#can_write@user:user2", false},
+
+	{"folder:folder1#owner@user:f1_owner", true},
+	{"folder:folder1#can_create_file@user:f1_owner", true},
+	{"folder:folder1#can_share@user:f1_owner", true},
+
+	// intersection
+	{"doc:doc1#can_share@user:d1_owner", false},
+	{"doc:doc1#can_share@user:f1_owner", true},
+
+	// negation
+	{"folder:folder1#can_read@user:f1_owner", true},
+	{"doc:doc1#viewer@user:f1_owner", false},
+	{"doc:doc1#can_invite@user:f1_owner", true},
+
+	// cycles
+	{"cycle:loop#can_delete@user:loop_owner", true},
+	{"cycle:loop#can_delete@user:user1", false},
+}
 
+func TestCheck(t *testing.T) {
 	m, err := v3.LoadFile("./check_test.yaml")
 	assert.NoError(t, err)
 	assert.NotNil(t, m)
 
+	pool := mempool.NewRelationsPool()
+
 	for _, test := range tests {
 		t.Run(test.check, func(tt *testing.T) {
 			assert := assert.New(tt)
 
-			checker := azmgraph.NewCheck(m, checkReq(test.check), rels.GetRelations)
+			checker := azmgraph.NewCheck(m, checkReq(test.check, true), rels.GetRelations, pool)
 
 			res, err := checker.Check()
 			assert.NoError(err)
@@ -79,6 +83,30 @@ func TestCheck(t *testing.T) {
 			assert.Equal(test.expected, res)
 		})
 	}
+}
+
+func BenchmarkCheck(b *testing.B) {
+	zerolog.SetGlobalLevel(zerolog.InfoLevel)
+
+	m, err := v3.LoadFile("./check_test.yaml")
+	if err != nil {
+		b.Fatalf("failed to load model: %s", err)
+	}
+
+	pool := mempool.NewRelationsPool()
+
+	b.ResetTimer()
+	for _, test := range tests {
+		assert := assert.New(b)
+
+		b.StopTimer()
+		checker := azmgraph.NewCheck(m, checkReq(test.check, false), rels.GetRelations, pool)
+		b.StartTimer()
+
+		res, err := checker.Check()
+		assert.NoError(err)
+		assert.Equal(test.expected, res)
+	}
 
 }
 
diff --git a/graph/objects.go b/graph/objects.go
index 8da33e1..d90f004 100644
--- a/graph/objects.go
+++ b/graph/objects.go
@@ -3,6 +3,7 @@ package graph
 import (
 	"strings"
 
+	"github.com/aserto-dev/azm/mempool"
 	"github.com/aserto-dev/azm/model"
 	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
 	dsr "github.com/aserto-dev/go-directory/aserto/directory/reader/v3"
@@ -16,7 +17,7 @@ type ObjectSearch struct {
 	wildcardSearch *SubjectSearch
 }
 
-func NewObjectSearch(m *model.Model, req *dsr.GetGraphRequest, reader RelationReader) (*ObjectSearch, error) {
+func NewObjectSearch(m *model.Model, req *dsr.GetGraphRequest, reader RelationReader, pool *mempool.RelationsPool) (*ObjectSearch, error) {
 	params := searchParams(req)
 	if err := validate(m, params); err != nil {
 		return nil, err
@@ -40,6 +41,7 @@ func NewObjectSearch(m *model.Model, req *dsr.GetGraphRequest, reader RelationRe
 			getRels: invertedRelationReader(im, reader),
 			memo:    newSearchMemo(req.Trace),
 			explain: req.Explain,
+			pool:    pool,
 		}},
 		wildcardSearch: &SubjectSearch{graphSearch{
 			m:       im,
@@ -47,6 +49,7 @@ func NewObjectSearch(m *model.Model, req *dsr.GetGraphRequest, reader RelationRe
 			getRels: invertedRelationReader(im, reader),
 			memo:    newSearchMemo(req.Trace),
 			explain: req.Explain,
+			pool:    pool,
 		}},
 	}, nil
 }
@@ -125,22 +128,24 @@ func wildcardParams(params *relation) *relation {
 }
 
 func invertedRelationReader(m *model.Model, reader RelationReader) RelationReader {
-	return func(r *dsc.Relation) ([]*dsc.Relation, error) {
+	return func(r *dsc.RelationIdentifier, relPool MessagePool[*dsc.RelationIdentifier], out *Relations) error {
 		ir := uninvertRelation(m, relationFromProto(r))
-		res, err := reader(ir.asProto())
-		if err != nil {
-			return nil, err
+		if err := reader(ir.asProto(), relPool, out); err != nil {
+			return err
 		}
 
-		return lo.Map(res, func(r *dsc.Relation, _ int) *dsc.Relation {
-			return &dsc.Relation{
+		res := *out
+		for i, r := range res {
+			res[i] = &dsc.RelationIdentifier{
 				ObjectType:  r.SubjectType,
 				ObjectId:    r.SubjectId,
 				Relation:    r.Relation,
 				SubjectType: r.ObjectType,
 				SubjectId:   r.ObjectId,
 			}
-		}), nil
+		}
+
+		return nil
 	}
 }
 
diff --git a/graph/objects_test.go b/graph/objects_test.go
index 3d9bf0e..989e10d 100644
--- a/graph/objects_test.go
+++ b/graph/objects_test.go
@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/aserto-dev/azm/graph"
+	"github.com/aserto-dev/azm/mempool"
 	"github.com/aserto-dev/azm/model"
 	v3 "github.com/aserto-dev/azm/v3"
 	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
@@ -35,11 +36,13 @@ func TestSearchObjects(t *testing.T) {
 		im.Validate(model.SkipNameValidation, model.AllowPermissionInArrowBase),
 	)
 
+	pool := mempool.NewRelationsPool()
+
 	for _, test := range searchObjectsTests {
 		t.Run(test.search, func(tt *testing.T) {
 			assert := assert.New(tt)
 
-			objSearch, err := graph.NewObjectSearch(m, graphReq(test.search), rels.GetRelations)
+			objSearch, err := graph.NewObjectSearch(m, graphReq(test.search), rels.GetRelations, pool)
 			assert.NoError(err)
 
 			res, err := objSearch.Search()
diff --git a/graph/relation.go b/graph/relation.go
index bf05d67..e3def96 100644
--- a/graph/relation.go
+++ b/graph/relation.go
@@ -19,8 +19,8 @@ type relation struct {
 
 type relations []*relation
 
-// converts a dsc.Relation to a relation.
-func relationFromProto(rel *dsc.Relation) *relation {
+// converts a dsc.RelationIdentifier to a relation.
+func relationFromProto(rel *dsc.RelationIdentifier) *relation {
 	return &relation{
 		ot:   model.ObjectName(rel.ObjectType),
 		oid:  ObjectID(rel.ObjectId),
@@ -31,8 +31,8 @@ func relationFromProto(rel *dsc.Relation) *relation {
 	}
 }
 
-func (r *relation) asProto() *dsc.Relation {
-	return &dsc.Relation{
+func (r *relation) asProto() *dsc.RelationIdentifier {
+	return &dsc.RelationIdentifier{
 		ObjectType:      string(r.ot),
 		ObjectId:        string(r.oid),
 		Relation:        string(r.rel),
diff --git a/graph/search.go b/graph/search.go
index 49cb3a8..319e8e6 100644
--- a/graph/search.go
+++ b/graph/search.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/aserto-dev/azm/mempool"
 	"github.com/aserto-dev/azm/model"
 	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
 	dsr "github.com/aserto-dev/go-directory/aserto/directory/reader/v3"
@@ -12,21 +13,31 @@ import (
 	"google.golang.org/protobuf/types/known/structpb"
 )
 
-type ObjectID = model.ObjectID
+type (
+	ObjectID  = model.ObjectID
+	Relations = []*dsc.RelationIdentifier
 
-// RelationReader retrieves relations that match the given filter.
-type RelationReader func(*dsc.Relation) ([]*dsc.Relation, error)
+	searchPath relations
+
+	object struct {
+		Type model.ObjectName
+		ID   ObjectID
+	}
 
-type searchPath relations
+	// The results of a search is a map where the key is a matching relations
+	// and the value is a list of paths that connect the search object and subject.
+	searchResults map[object][]searchPath
+)
 
-type object struct {
-	Type model.ObjectName
-	ID   ObjectID
+type MessagePool[T any] interface {
+	Get() T
+	Put(T)
 }
 
-// The results of a search is a map where the key is a matching relations
-// and the value is a list of paths that connect the search object and subject.
-type searchResults map[object][]searchPath
+type RelationPool = MessagePool[*dsc.RelationIdentifier]
+
+// RelationReader retrieves relations that match the given filter.
+type RelationReader func(*dsc.RelationIdentifier, RelationPool, *Relations) error
 
 // Objects returns the objects from the search results.
 func (r searchResults) Objects() []*dsc.ObjectIdentifier {
@@ -92,6 +103,7 @@ type graphSearch struct {
 
 	memo    *searchMemo
 	explain bool
+	pool    *mempool.RelationsPool
 }
 
 func validate(m *model.Model, params *relation) error {
@@ -120,7 +132,6 @@ func searchParams(req *dsr.GetGraphRequest) *relation {
 		sid:  ObjectID(req.SubjectId),
 		srel: model.RelationName(req.SubjectRelation),
 	}
-
 }
 
 type searchCall struct {
@@ -157,7 +168,6 @@ func (m *searchMemo) MarkVisited(params *relation) searchStatus {
 func (m *searchMemo) MarkComplete(params *relation, results searchResults) {
 	m.visited[*params] = results
 	m.trace(params, searchStatusComplete)
-
 }
 
 func (m *searchMemo) Status(params *relation) searchStatus {
diff --git a/graph/subjects.go b/graph/subjects.go
index 71d02cc..cd2c0dd 100644
--- a/graph/subjects.go
+++ b/graph/subjects.go
@@ -1,6 +1,7 @@
 package graph
 
 import (
+	"github.com/aserto-dev/azm/mempool"
 	"github.com/aserto-dev/azm/model"
 	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
 	dsr "github.com/aserto-dev/go-directory/aserto/directory/reader/v3"
@@ -12,7 +13,12 @@ type SubjectSearch struct {
 	graphSearch
 }
 
-func NewSubjectSearch(m *model.Model, req *dsr.GetGraphRequest, reader RelationReader) (*SubjectSearch, error) {
+func NewSubjectSearch(
+	m *model.Model,
+	req *dsr.GetGraphRequest,
+	reader RelationReader,
+	pool *mempool.RelationsPool,
+) (*SubjectSearch, error) {
 	params := searchParams(req)
 	if err := validate(m, params); err != nil {
 		return nil, err
@@ -24,6 +30,7 @@ func NewSubjectSearch(m *model.Model, req *dsr.GetGraphRequest, reader RelationR
 		getRels: reader,
 		memo:    newSearchMemo(req.Trace),
 		explain: req.Explain,
+		pool:    pool,
 	}}, nil
 }
 
@@ -108,7 +115,7 @@ func (s *SubjectSearch) findNeighbor(step *model.RelationRef, params *relation)
 		sid = "*"
 	}
 
-	req := &dsc.Relation{
+	req := &dsc.RelationIdentifier{
 		ObjectType:  params.ot.String(),
 		ObjectId:    params.oid.String(),
 		Relation:    params.rel.String(),
@@ -118,12 +125,12 @@ func (s *SubjectSearch) findNeighbor(step *model.RelationRef, params *relation)
 
 	results := searchResults{}
 
-	rels, err := s.getRels(req)
-	if err != nil {
+	relsPtr := s.pool.GetSlice()
+	if err := s.getRels(req, s.pool, relsPtr); err != nil {
 		return results, err
 	}
 
-	for _, rel := range rels {
+	for _, rel := range *relsPtr {
 		if rel.SubjectId != "*" && params.oid != ObjectID(rel.ObjectId) {
 			continue
 		}
@@ -146,25 +153,29 @@ func (s *SubjectSearch) findNeighbor(step *model.RelationRef, params *relation)
 		results[*subj] = path
 	}
 
+	s.pool.PutSlice(relsPtr)
+
 	return results, nil
 }
 
 func (s *SubjectSearch) searchSubjectRelation(step *model.RelationRef, params *relation) (searchResults, error) {
 	results := searchResults{}
 
-	req := &dsc.Relation{
+	req := &dsc.RelationIdentifier{
 		ObjectType:      params.ot.String(),
 		ObjectId:        params.oid.String(),
 		Relation:        params.rel.String(),
 		SubjectType:     step.Object.String(),
 		SubjectRelation: step.Relation.String(),
 	}
-	rels, err := s.getRels(req)
-	if err != nil {
+
+	relsPtr := s.pool.GetSlice()
+	if err := s.getRels(req, s.pool, relsPtr); err != nil {
 		return results, err
 	}
+	defer s.pool.PutSlice(relsPtr)
 
-	for _, rel := range rels {
+	for _, rel := range *relsPtr {
 		current := relationFromProto(rel)
 
 		if params.srel == model.RelationName(rel.SubjectRelation) && params.st == model.ObjectName(rel.SubjectType) {
@@ -281,17 +292,20 @@ func (s *SubjectSearch) expandTerm(o *model.Object, pt *model.PermissionTerm, pa
 }
 
 func (s *SubjectSearch) expandRelationArrow(pt *model.PermissionTerm, params *relation) ([]*relation, error) {
-	// Resolve the base of the arrow.
-	rels, err := s.getRels(&dsc.Relation{
+	relsPtr := s.pool.GetSlice()
+
+	req := &dsc.RelationIdentifier{
 		ObjectType: params.ot.String(),
 		ObjectId:   params.oid.String(),
 		Relation:   pt.Base.String(),
-	})
-	if err != nil {
+	}
+
+	// Resolve the base of the arrow.
+	if err := s.getRels(req, s.pool, relsPtr); err != nil {
 		return []*relation{}, err
 	}
 
-	expanded := lo.Map(rels, func(rel *dsc.Relation, _ int) *relation {
+	expanded := lo.Map(*relsPtr, func(rel *dsc.RelationIdentifier, _ int) *relation {
 		return &relation{
 			ot:   model.ObjectName(rel.SubjectType),
 			oid:  ObjectID(rel.SubjectId),
@@ -302,6 +316,8 @@ func (s *SubjectSearch) expandRelationArrow(pt *model.PermissionTerm, params *re
 		}
 	})
 
+	s.pool.PutSlice(relsPtr)
+
 	return expanded, nil
 }
 
diff --git a/graph/subjects_test.go b/graph/subjects_test.go
index 8e38164..91dedd4 100644
--- a/graph/subjects_test.go
+++ b/graph/subjects_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	azmgraph "github.com/aserto-dev/azm/graph"
+	"github.com/aserto-dev/azm/mempool"
 	"github.com/aserto-dev/azm/model"
 	v3 "github.com/aserto-dev/azm/v3"
 	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
@@ -18,11 +19,13 @@ func TestSearchSubjects(t *testing.T) {
 	assert.NoError(t, err)
 	assert.NotNil(t, m)
 
+	pool := mempool.NewRelationsPool()
+
 	for _, test := range searchSubjectsTests {
 		t.Run(test.search, func(tt *testing.T) {
 			assert := assert.New(tt)
 
-			subjSearch, err := azmgraph.NewSubjectSearch(m, graphReq(test.search), rels.GetRelations)
+			subjSearch, err := azmgraph.NewSubjectSearch(m, graphReq(test.search), rels.GetRelations, pool)
 			assert.NoError(err)
 
 			res, err := subjSearch.Search()
diff --git a/graph/utils_test.go b/graph/utils_test.go
index 0b68bd7..49e59f9 100644
--- a/graph/utils_test.go
+++ b/graph/utils_test.go
@@ -4,6 +4,7 @@ import (
 	"regexp"
 	"testing"
 
+	"github.com/aserto-dev/azm/graph"
 	"github.com/aserto-dev/azm/model"
 	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
 	dsr "github.com/aserto-dev/go-directory/aserto/directory/reader/v3"
@@ -11,8 +12,8 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func checkReq(expr string) *dsr.CheckRequest {
-	return parseRelation(expr).checkReq()
+func checkReq(expr string, trace bool) *dsr.CheckRequest {
+	return parseRelation(expr).checkReq(trace)
 }
 
 func graphReq(expr string) *dsr.GetGraphRequest {
@@ -49,25 +50,25 @@ func parseRelation(r string) *relation {
 	return rel
 }
 
-func (r *relation) proto() *dsc.Relation {
-	return &dsc.Relation{
-		ObjectType:      r.ObjectType.String(),
-		ObjectId:        r.ObjectID.String(),
-		Relation:        r.Relation.String(),
-		SubjectType:     r.SubjectType.String(),
-		SubjectId:       r.SubjectID.String(),
-		SubjectRelation: r.SubjectRelation.String(),
-	}
+func (r *relation) proto(pool graph.MessagePool[*dsc.RelationIdentifier]) *dsc.RelationIdentifier {
+	rel := pool.Get()
+	rel.ObjectType = r.ObjectType.String()
+	rel.ObjectId = r.ObjectID.String()
+	rel.Relation = r.Relation.String()
+	rel.SubjectType = r.SubjectType.String()
+	rel.SubjectId = r.SubjectID.String()
+	rel.SubjectRelation = r.SubjectRelation.String()
+	return rel
 }
 
-func (r *relation) checkReq() *dsr.CheckRequest {
+func (r *relation) checkReq(trace bool) *dsr.CheckRequest {
 	return &dsr.CheckRequest{
 		ObjectType:  r.ObjectType.String(),
 		ObjectId:    r.ObjectID.String(),
 		Relation:    r.Relation.String(),
 		SubjectType: r.SubjectType.String(),
 		SubjectId:   r.SubjectID.String(),
-		Trace:       true,
+		Trace:       trace,
 	}
 }
 
@@ -96,7 +97,7 @@ func NewRelationsReader(rels ...string) RelationsReader {
 	})
 }
 
-func (r RelationsReader) GetRelations(req *dsc.Relation) ([]*dsc.Relation, error) {
+func (r RelationsReader) GetRelations(req *dsc.RelationIdentifier, pool graph.MessagePool[*dsc.RelationIdentifier], out *graph.Relations) error {
 	ot := model.ObjectName(req.ObjectType)
 	oid := model.ObjectID(req.ObjectId)
 	rn := model.RelationName(req.Relation)
@@ -113,9 +114,11 @@ func (r RelationsReader) GetRelations(req *dsc.Relation) ([]*dsc.Relation, error
 			(sr == "" || rel.SubjectRelation == sr)
 	})
 
-	return lo.Map(matches, func(r *relation, _ int) *dsc.Relation {
-		return r.proto()
-	}), nil
+	for _, rel := range matches {
+		*out = append(*out, rel.proto(pool))
+	}
+
+	return nil
 }
 
 type parseTest struct {
diff --git a/mempool/mempool.go b/mempool/mempool.go
new file mode 100644
index 0000000..578f115
--- /dev/null
+++ b/mempool/mempool.go
@@ -0,0 +1,81 @@
+package mempool
+
+import (
+	"sync"
+)
+
+const defaultSliceCapacity = 2048
+
+type Pool[T any] struct {
+	sync.Pool
+}
+
+func (p *Pool[T]) Get() T {
+	return p.Pool.Get().(T)
+}
+
+func (p *Pool[T]) Put(x T) {
+	p.Pool.Put(x)
+}
+
+func NewPool[T any](newF func() T) *Pool[T] {
+	return &Pool[T]{
+		Pool: sync.Pool{
+			New: func() interface{} {
+				return newF()
+			},
+		},
+	}
+}
+
+func NewSlicePool[T any](capacity int) *Pool[*[]T] {
+	return NewPool(func() *[]T {
+		s := make([]T, 0, capacity)
+		return &s
+	})
+}
+
+type Allocator[T any] interface {
+	New() T
+	Reset(T)
+}
+
+type CollectionPool[T any] struct {
+	slicePool *Pool[*[]T]
+	msgPool   *Pool[T]
+	alloc     Allocator[T]
+}
+
+func NewCollectionPool[T any](alloc Allocator[T]) *CollectionPool[T] {
+	return &CollectionPool[T]{
+		slicePool: NewSlicePool[T](defaultSliceCapacity),
+		alloc:     alloc,
+		msgPool: NewPool(func() T {
+			return alloc.New()
+		}),
+	}
+}
+
+func (p CollectionPool[T]) GetSlice() *[]T {
+	return p.slicePool.Get()
+}
+
+func (p *CollectionPool[T]) PutSlice(s *[]T) {
+	for _, item := range *s {
+		p.alloc.Reset(item)
+		p.msgPool.Put(item)
+	}
+
+	*s = (*s)[:0]
+	p.slicePool.Put(s)
+}
+
+// nolint: gocritic // commentedOutCode
+func (p *CollectionPool[T]) Get() T {
+	return p.msgPool.New().(T)
+	// return p.msgPool.Get()
+}
+
+func (p *CollectionPool[T]) Put(t T) {
+	p.msgPool.Put(t)
+}
diff --git a/mempool/relation.go b/mempool/relation.go
new file mode 100644
index 0000000..1a24fd4
--- /dev/null
+++ b/mempool/relation.go
@@ -0,0 +1,34 @@
+package mempool
+
+import (
+	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+type RelationsPool = CollectionPool[*dsc.RelationIdentifier]
+
+func NewRelationsPool() *RelationsPool {
+	return NewCollectionPool[*dsc.RelationIdentifier](NewRelationAllocator())
+}
+
+type RelationAllocator struct {
+	tsPool *Pool[*timestamppb.Timestamp]
+}
+
+func NewRelationAllocator() *RelationAllocator {
+	return &RelationAllocator{
+		tsPool: NewPool[*timestamppb.Timestamp](
+			func() *timestamppb.Timestamp {
+				return new(timestamppb.Timestamp)
+			}),
+	}
+}
+
+func (ra *RelationAllocator) New() *dsc.RelationIdentifier {
+	rel := dsc.RelationIdentifierFromVTPool()
+	return rel
+}
+
+func (ra *RelationAllocator) Reset(rel *dsc.RelationIdentifier) {
+	rel.ReturnToVTPool()
+}
diff --git a/model/inverse.go b/model/inverse.go
index cf773dc..b1334db 100644
--- a/model/inverse.go
+++ b/model/inverse.go
@@ -2,6 +2,7 @@ package model
 
 import (
 	"fmt"
+	"os"
 
 	set "github.com/deckarep/golang-set/v2"
 	"github.com/samber/lo"
@@ -14,7 +15,11 @@ const (
 )
 
 func (m *Model) Invert() *Model {
-	return newInverter(m).invert()
+	if m.inverted == nil {
+		fmt.Fprintln(os.Stderr, "load inverted model")
+		m.inverted = newInverter(m).invert()
+	}
+	return m.inverted
 }
 
 type inverter struct {
diff --git a/model/model.go b/model/model.go
index 5d5ab32..3a61bfd 100644
--- a/model/model.go
+++ b/model/model.go
@@ -19,6 +19,7 @@ type Model struct {
 	Version  int                    `json:"version"`
 	Objects  map[ObjectName]*Object `json:"types"`
 	Metadata *Metadata              `json:"metadata"`
+	inverted *Model                 `json:"-"`
 }
 
 type Metadata struct {
@@ -33,6 +34,7 @@ func New(r io.Reader) (*Model, error) {
 	if err := dec.Decode(&m); err != nil {
 		return nil, err
 	}
+	m.inverted = newInverter(&m).invert()
 	return &m, nil
 }
 
@@ -64,8 +66,10 @@ func (r *relation) String() string {
 	return fmt.Sprintf("%s:%s#%s@%s:%s%s", r.on, r.oid, r.rn, r.sn, r.sid, srn)
 }
 
-type objSet set.Set[ObjectName]
-type relSet set.Set[RelationRef]
+type (
+	objSet set.Set[ObjectName]
+	relSet set.Set[RelationRef]
+)
 
 func (m *Model) Reader() (io.Reader, error) {
 	b := bytes.Buffer{}
diff --git a/safe/relation.go b/safe/relation.go
index dbd218a..54214c1 100644
--- a/safe/relation.go
+++ b/safe/relation.go
@@ -13,11 +13,11 @@ import (
 
 // SafeRelation identifier.
 type SafeRelation struct {
-	*dsc3.Relation
+	*dsc3.RelationIdentifier
 	HasSubjectRelation bool
 }
 
-func Relation(i *dsc3.Relation) *SafeRelation { return &SafeRelation{i, true} }
+func Relation(i *dsc3.RelationIdentifier) *SafeRelation { return &SafeRelation{i, true} }
 
 type SafeRelationIdentifier struct {
 	*model.RelationRef
@@ -35,7 +35,7 @@ type SafeRelations struct {
 func GetRelation(i *dsr3.GetRelationRequest) *SafeRelations {
 	return &SafeRelations{
 		&SafeRelation{
-			Relation: &dsc3.Relation{
+			RelationIdentifier: &dsc3.RelationIdentifier{
 				ObjectType:      i.ObjectType,
 				ObjectId:        i.ObjectId,
 				Relation:        i.Relation,
@@ -51,7 +51,7 @@ func GetRelation(i *dsr3.GetRelationRequest) *SafeRelations {
 func GetRelations(i *dsr3.GetRelationsRequest) *SafeRelations {
 	return &SafeRelations{
 		&SafeRelation{
-			Relation: &dsc3.Relation{
+			RelationIdentifier: &dsc3.RelationIdentifier{
 				ObjectType:      i.ObjectType,
 				ObjectId:        i.ObjectId,
 				Relation:        i.Relation,
@@ -79,7 +79,7 @@ func (i *SafeRelation) Subject() *dsc3.ObjectIdentifier {
 }
 
 func (i *SafeRelation) Validate(mc *cache.Cache) error {
-	if i == nil || i.Relation == nil {
+	if i == nil || i.RelationIdentifier == nil {
 		return derr.ErrInvalidRelation.Msg("relation not set (nil)")
 	}
 
@@ -109,11 +109,11 @@ func (i *SafeRelation) Validate(mc *cache.Cache) error {
 		}
 	}
 
-	return mc.ValidateRelation(i.Relation)
+	return mc.ValidateRelation(i.RelationIdentifier)
 }
 
 func (i *SafeRelations) Validate(mc *cache.Cache) error {
-	if i == nil || i.SafeRelation.Relation == nil {
+	if i == nil || i.SafeRelation.RelationIdentifier == nil {
 		return derr.ErrInvalidRelation.Msg("relation not set (nil)")
 	}
 
@@ -152,7 +152,7 @@ func (i *SafeRelation) Hash() string {
 	h := fnv.New64a()
 	h.Reset()
 
-	if i != nil && i.Relation != nil {
+	if i != nil && i.RelationIdentifier != nil {
 		if _, err := h.Write([]byte(i.GetObjectId())); err != nil {
 			return DefaultHash
 		}