ETS 'compressed' option.

The compressed format is using a slighty modified variant of the extern format
(term_to_binary). To not worsen key lookup's too much, the top tuple itself
and the key element are not compressed. Table objects with only immediate
non-key elements will therefor not gain anything (but actually consume one
extra word for "alloc_size").

15 files changed, 985 insertions, 421 deletions

diff --git a/erts/emulator/beam/dist.h b/erts/emulator/beam/dist.h
index 64caf34550..9ccc3e5ba9 100644
--- a/erts/emulator/beam/dist.h
+++ b/erts/emulator/beam/dist.h
@@ -38,6 +38,7 @@
 #define DFLAG_UNICODE_IO          0x1000
 #define DFLAG_DIST_HDR_ATOM_CACHE 0x2000
 #define DFLAG_SMALL_ATOM_TAGS     0x4000
+#define DFLAGS_INTERNAL_TAGS      0x8000
 
 /* All flags that should be enabled when term_to_binary/1 is used. */
 #define TERM_TO_BINARY_DFLAGS (DFLAG_EXTENDED_REFERENCES	\
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 89e3b3209c..75d8db880c 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -2002,6 +2002,8 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	BIF_RET(db_get_trace_control_word_0(BIF_P));
     } else if (ERTS_IS_ATOM_STR("ets_realloc_moves", BIF_ARG_1)) {
  	BIF_RET((erts_ets_realloc_always_moves) ? am_true : am_false);
+    } else if (ERTS_IS_ATOM_STR("ets_always_compress", BIF_ARG_1)) {
+	BIF_RET((erts_ets_always_compress) ? am_true : am_false);
     } else if (ERTS_IS_ATOM_STR("snifs", BIF_ARG_1)) {
 	Uint size = 0;
 	Uint *szp;
diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index 1c2c0fe4cb..8577354d27 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -179,6 +179,7 @@ extern DbTableMethod db_tree;
 
 int user_requested_db_max_tabs;
 int erts_ets_realloc_always_moves;
+int erts_ets_always_compress;
 static int db_max_tabs;
 static DbTable *meta_pid_to_tab; /* Pid mapped to owned tables */
 static DbTable *meta_pid_to_fixed_tab; /* Pid mapped to fixed tables */
@@ -931,7 +932,7 @@ BIF_RETTYPE ets_update_counter_3(BIF_ALIST_3)
 		position > arityval(handle.dbterm->tpl[0])) {
 		goto finalize;
 	    }
-	    oldcnt = handle.dbterm->tpl[position];
+	    oldcnt = db_do_read_element(&handle, position);
 	    if (is_big(oldcnt)) {
 		halloc_size += BIG_NEED_SIZE(big_arity(oldcnt));
 	    }
@@ -1276,7 +1277,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     UWord heir_data;
     Uint32 status;
     Sint keypos;
-    int is_named, is_fine_locked, frequent_read;
+    int is_named, is_fine_locked, frequent_read, is_compressed;
     int cret;
     DeclareTmpHeap(meta_tuple,3,BIF_P);
     DbTableMethod* meth;
@@ -1296,6 +1297,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     frequent_read = 0;
     heir = am_none;
     heir_data = (UWord) am_undefined;
+    is_compressed = erts_ets_always_compress;
 
     list = BIF_ARG_2;
     while(is_list(list)) {
@@ -1358,6 +1360,9 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
 	else if (val == am_named_table) {
 	    is_named = 1;
 	}
+	else if (val == am_compressed) {
+	    is_compressed = 1;
+	}
 	else if (val == am_set || val == am_protected)
 	    ;
 	else break;
@@ -1418,6 +1423,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     erts_smp_atomic_init(&tb->common.nitems, 0);
 
     tb->common.fixations = NULL;
+    tb->common.compress = is_compressed;
 
     cret = meth->db_create(BIF_P, tb);
     ASSERT(cret == DB_ERROR_NONE);
@@ -2572,7 +2578,7 @@ BIF_RETTYPE ets_match_object_3(BIF_ALIST_3)
 BIF_RETTYPE ets_info_1(BIF_ALIST_1)
 {
     static Eterm fields[] = {am_protection, am_keypos, am_type, am_named_table,
-	am_node, am_size, am_name, am_heir, am_owner, am_memory};
+	am_node, am_size, am_name, am_heir, am_owner, am_memory, am_compressed};
     Eterm results[sizeof(fields)/sizeof(Eterm)];
     DbTable* tb;
     Eterm res;
@@ -2837,6 +2843,7 @@ void init_db(void)
     erts_smp_atomic_init(&meta_pid_to_tab->common.nitems, 0);
     meta_pid_to_tab->common.slot   = -1;
     meta_pid_to_tab->common.meth   = &db_hash;
+    meta_pid_to_tab->common.compress = 0;
 
     erts_refc_init(&meta_pid_to_tab->common.ref, 1);
     erts_refc_init(&meta_pid_to_tab->common.fixref, 0);
@@ -2869,6 +2876,7 @@ void init_db(void)
     erts_smp_atomic_init(&meta_pid_to_fixed_tab->common.nitems, 0);
     meta_pid_to_fixed_tab->common.slot   = -1;
     meta_pid_to_fixed_tab->common.meth   = &db_hash;
+    meta_pid_to_fixed_tab->common.compress = 0;
 
     erts_refc_init(&meta_pid_to_fixed_tab->common.ref, 1);
     erts_refc_init(&meta_pid_to_fixed_tab->common.fixref, 0);
@@ -3077,7 +3085,7 @@ retry:
     db_unlock(tb,LCK_WRITE);
     heir_data = tb->common.heir_data;
     if (!is_immed(heir_data)) {
-	Eterm* tpv = DBTERM_BUF((DbTerm*)heir_data); /* tuple_val */
+	Eterm* tpv = ((DbTerm*)heir_data)->tpl; /* tuple_val */
 	ASSERT(arityval(*tpv) == 1);
 	heir_data = tpv[1];
     }
@@ -3251,7 +3259,8 @@ erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
 			  pp = &(*pp)->next) {
 			if ((*pp)->pid == pid) {
 			    DbFixation* fix = *pp;
-			    erts_refc_add(&tb->common.fixref,-fix->counter,0);
+			    long diff = -(long)fix->counter;
+			    erts_refc_add(&tb->common.fixref,diff,0);
 			    *pp = fix->next;
 			    erts_db_free(ERTS_ALC_T_DB_FIXATION,
 					 tb, fix, sizeof(DbFixation));
@@ -3469,8 +3478,8 @@ static void set_heir(Process* me, DbTable* tb, Eterm heir, UWord heir_data)
 
 	UseTmpHeap(2,me);
 	/* Make a dummy 1-tuple around data to use db_get_term() */
-	heir_data = (UWord) db_get_term(&tb->common, NULL, 0,
-					TUPLE1(tmp,heir_data));
+	heir_data = (UWord) db_store_term(&tb->common, NULL, 0,
+					  TUPLE1(tmp,heir_data));
 	UnUseTmpHeap(2,me);
 	ASSERT(!is_immed(heir_data));
     }
@@ -3481,7 +3490,7 @@ static void free_heir_data(DbTable* tb)
 {
     if (tb->common.heir != am_none && !is_immed(tb->common.heir_data)) {
 	DbTerm* p = (DbTerm*) tb->common.heir_data;
-	db_free_term_data(p);
+	db_cleanup_offheap_comp(p);
 	erts_db_free(ERTS_ALC_T_DB_TERM, tb, (void *)p,
 		     sizeof(DbTerm) + (p->size-1)*sizeof(Eterm));
     }
@@ -3618,10 +3627,13 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What)
 	ret = erts_this_dist_entry->sysname;
     } else if (What == am_named_table) {
 	ret = is_atom(tb->common.id) ? am_true : am_false;
+    } else if (What == am_compressed) {
+	ret = tb->common.compress ? am_true : am_false;
+    }
     /*
      * For debugging purposes
      */
-    } else if (What == am_data) { 
+    else if (What == am_data) {
 	print_table(ERTS_PRINT_STDOUT, NULL, 1, tb);
 	ret = am_true;
     } else if (What == am_atom_put("fixed",5)) { 
diff --git a/erts/emulator/beam/erl_db.h b/erts/emulator/beam/erl_db.h
index 7da28fad29..cb2da603f0 100644
--- a/erts/emulator/beam/erl_db.h
+++ b/erts/emulator/beam/erl_db.h
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 1996-2009. All Rights Reserved.
+ * Copyright Ericsson AB 1996-2010. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -61,6 +61,7 @@ void erts_db_foreach_offheap(DbTable *,
 
 extern int user_requested_db_max_tabs; /* set in erl_init */
 extern int erts_ets_realloc_always_moves;  /* set in erl_init */
+extern int erts_ets_always_compress;  /* set in erl_init */
 extern Export ets_select_delete_continue_exp;
 extern Export ets_select_count_continue_exp;
 extern Export ets_select_continue_exp;
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index fa707f4eed..14ee63100a 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -267,11 +267,11 @@ static ERTS_INLINE Sint next_slot_w(DbTableHash* tb, Uint ix,
  */
 #define BIN_FLAG_ALL_OBJECTS         BIN_FLAG_USR1
 
-/*
- * Size calculations
- */
-#define SIZ_OVERHEAD ((sizeof(HashDbTerm)/sizeof(Eterm)) - 1)
-#define SIZ_DBTERM(HDT) (SIZ_OVERHEAD + (HDT)->dbterm.size)
+
+static ERTS_INLINE void free_term(DbTableHash *tb, HashDbTerm* p)
+{
+    db_free_term((DbTable*)tb, p, offsetof(HashDbTerm, dbterm));
+}
 
 /*
  * Local types 
@@ -358,10 +358,8 @@ static HashDbTerm* search_list(DbTableHash* tb, Eterm key,
 			       HashValue hval, HashDbTerm *list);
 static void shrink(DbTableHash* tb, int nactive);
 static void grow(DbTableHash* tb, int nactive);
-static void free_term(DbTableHash *tb, HashDbTerm* p);
-static Eterm put_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2);
-static HashDbTerm* get_term(DbTableHash* tb, HashDbTerm* old, 
-			    Eterm obj, HashValue hval);
+static Eterm build_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2,
+			   DbTableHash*);
 static int analyze_pattern(DbTableHash *tb, Eterm pattern, 
 			   struct mp_info *mpi);
 
@@ -442,6 +440,7 @@ static ERTS_INLINE int has_live_key(DbTableHash* tb, HashDbTerm* b,
     if (b->hvalue != hval) return 0;
     else {
 	Eterm itemKey = GETKEY(tb, b->dbterm.tpl);
+	ASSERT(!is_header(itemKey));
 	return EQ(key,itemKey);
     }
 }
@@ -454,10 +453,38 @@ static ERTS_INLINE int has_key(DbTableHash* tb, HashDbTerm* b,
     if (b->hvalue != hval && b->hvalue != INVALID_HASH) return 0;
     else {
 	Eterm itemKey = GETKEY(tb, b->dbterm.tpl);
+	ASSERT(!is_header(itemKey));
 	return EQ(key,itemKey);
     }
 }
 
+static ERTS_INLINE HashDbTerm* new_dbterm(DbTableHash* tb, Eterm obj)
+{
+    HashDbTerm* p;
+    if (tb->common.compress) {
+	p = db_store_term_comp(&tb->common, NULL, offsetof(HashDbTerm,dbterm), obj);
+    }
+    else {
+	p = db_store_term(&tb->common, NULL, offsetof(HashDbTerm,dbterm), obj);
+    }
+    return p;
+}
+
+static ERTS_INLINE HashDbTerm* replace_dbterm(DbTableHash* tb, HashDbTerm* old,
+					      Eterm obj)
+{
+    HashDbTerm* ret;
+    ASSERT(old != NULL);
+    if (tb->common.compress) {
+	ret = db_store_term_comp(&tb->common, &(old->dbterm), offsetof(HashDbTerm,dbterm), obj);
+    }
+    else {
+	ret = db_store_term(&tb->common, &(old->dbterm), offsetof(HashDbTerm,dbterm), obj);
+    }
+    return ret;
+}
+
+
 
 /*
 ** External interface 
@@ -764,7 +791,7 @@ int db_put_hash(DbTable *tbl, Eterm obj, int key_clash_fail)
 	    ret = DB_ERROR_BADKEY;
 	    goto Ldone;
 	}
-	q = get_term(tb, b, obj, hval);
+	q = replace_dbterm(tb, b, obj);
 	q->next = bnext;
 	q->hvalue = hval; /* In case of INVALID_HASH */
 	*bp = q;
@@ -784,7 +811,7 @@ int db_put_hash(DbTable *tbl, Eterm obj, int key_clash_fail)
 	HashDbTerm** qp = bp;
 	q = b;
 	do {
-	    if (eq(make_tuple(q->dbterm.tpl), obj)) {
+	    if (db_eq(&tb->common,obj,&q->dbterm)) {
 		if (q->hvalue == INVALID_HASH) {
 		    erts_smp_atomic_inc(&tb->common.nitems);
 		    q->hvalue = hval;
@@ -803,7 +830,8 @@ int db_put_hash(DbTable *tbl, Eterm obj, int key_clash_fail)
     /*else DB_DUPLICATE_BAG */
 
 Lnew:
-    q = get_term(tb, NULL, obj, hval);
+    q = new_dbterm(tb, obj);
+    q->hvalue = hval;
     q->next = b;
     *bp = q;
     nitems = erts_smp_atomic_inctest(&tb->common.nitems);
@@ -844,7 +872,7 @@ int db_get_hash(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
 		while(b2 != NULL && has_key(tb,b2,key,hval))
 		    b2 = b2->next;
 	    }
-	    copy = put_term_list(p, b1, b2);
+	    copy = build_term_list(p, b1, b2, tb);
 	    CHECK_TABLES();
 	    *ret = copy;
 	    goto done;
@@ -967,13 +995,10 @@ static int db_get_element_hash(Process *p, DbTable *tbl,
 
     while(b1 != 0) {
 	if (has_live_key(tb,b1,key,hval)) {
-	    Eterm copy;
-
 	    if (ndex > arityval(b1->dbterm.tpl[0])) {
 		retval = DB_ERROR_BADITEM;
 		goto done;
 	    }
-
 	    if (tb->common.status & (DB_BAG | DB_DUPLICATE_BAG)) {
 		HashDbTerm* b;
 		HashDbTerm* b2 = b1->next;
@@ -987,15 +1012,12 @@ static int db_get_element_hash(Process *p, DbTable *tbl,
 		    }
 		    b2 = b2->next;
 		}
-
 		b = b1;
 		while(b != b2) {
 		    if (b->hvalue != INVALID_HASH) {
 			Eterm *hp;
-			Uint sz = size_object(b->dbterm.tpl[ndex])+2;
-			
-			hp = HAlloc(p, sz);
-			copy = copy_struct(b->dbterm.tpl[ndex], sz-2, &hp, &MSO(p));
+			Eterm copy = db_copy_element_from_ets(&tb->common, p,
+							      &b->dbterm, ndex, &hp, 2);
 			elem_list = CONS(hp, copy, elem_list);
 			hp += 2;
 		    }
@@ -1004,8 +1026,8 @@ static int db_get_element_hash(Process *p, DbTable *tbl,
 		*ret = elem_list;
 	    }
 	    else {
-		COPY_OBJECT(b1->dbterm.tpl[ndex], p, &copy);
-		*ret = copy;
+		Eterm* hp;
+		*ret = db_copy_element_from_ets(&tb->common, p, &b1->dbterm, ndex, &hp, 0);
 	    }
 	    retval = DB_ERROR_NONE;
 	    goto done;
@@ -1040,6 +1062,7 @@ int db_erase_bag_exact2(DbTable *tbl, Eterm key, Eterm value)
 
     ASSERT(!IS_FIXED(tb));
     ASSERT((tb->common.status & DB_BAG));
+    ASSERT(!tb->common.compress);
 
     while(b != 0) {
 	if (has_live_key(tb,b,key,hval)) {
@@ -1139,7 +1162,7 @@ static int db_erase_object_hash(DbTable *tbl, Eterm object, Eterm *ret)
     while(b != 0) {
 	if (has_live_key(tb,b,key,hval)) {
 	    ++nkeys;
-	    if (eq(object, make_tuple(b->dbterm.tpl))) {
+	    if (db_eq(&tb->common,object, &b->dbterm)) {
 		--nitems_diff;
 		if (nkeys==1 && IS_FIXED(tb)) { /* Pseudo remove */
 		    add_fixed_deletion(tb,ix);
@@ -1188,7 +1211,7 @@ static int db_slot_hash(Process *p, DbTable *tbl, Eterm slot_term, Eterm *ret)
     lck = RLOCK_HASH(tb, slot);
     nactive = NACTIVE(tb);
     if (slot < nactive) {
-	*ret = put_term_list(p, BUCKET(tb, slot), 0);
+	*ret = build_term_list(p, BUCKET(tb, slot), 0, tb);
 	retval = DB_ERROR_NONE;
     }
     else if (slot == nactive) {
@@ -1232,8 +1255,6 @@ static int db_select_continue_hash(Process *p,
     int num_left = 1000;
     HashDbTerm *current = 0;
     Eterm match_list;
-    Uint32 dummy;
-    unsigned sz;
     Eterm *hp;
     Eterm match_res;
     Sint got;
@@ -1285,26 +1306,14 @@ static int db_select_continue_hash(Process *p,
     }	  
     for(;;) {
 	if (current->hvalue != INVALID_HASH && 
-	    (match_res = 
-	     db_prog_match(p,mp,
-			   make_tuple(current->dbterm.tpl),
-			   NULL,0,&dummy),
+	    (match_res = db_prog_match_and_copy(&tb->common, p, mp, all_objects,
+						&current->dbterm, &hp, 2),
 	     is_value(match_res))) {
-	    if (all_objects) {
-		hp = HAlloc(p, current->dbterm.size + 2);
-		match_res = copy_shallow(DBTERM_BUF(&current->dbterm),
-					 current->dbterm.size,
-					 &hp,
-					 &MSO(p));
-	    } else {
-		sz = size_object(match_res);
-	    
-		hp = HAlloc(p, sz + 2);
-		match_res = copy_struct(match_res, sz, &hp, &MSO(p));
-	    }
-            match_list = CONS(hp, match_res, match_list);
+
+	    match_list = CONS(hp, match_res, match_list);
 	    ++got;
 	}
+
 	--num_left;
 	save_slot_ix = slot_ix;
 	if ((current = next(tb, (Uint*)&slot_ix, &lck, current)) == NULL) {
@@ -1395,9 +1404,7 @@ static int db_select_chunk_hash(Process *p, DbTable *tbl,
     HashDbTerm *current = 0;
     unsigned current_list_pos = 0;
     Eterm match_list;
-    Uint32 dummy;
     Eterm match_res;
-    unsigned sz;
     Eterm *hp;
     int num_left = 1000;
     Uint got = 0;
@@ -1464,22 +1471,9 @@ static int db_select_chunk_hash(Process *p, DbTable *tbl,
     for(;;) {
 	if (current != NULL) {
 	    if (current->hvalue != INVALID_HASH) {
-		match_res = db_prog_match(p,mpi.mp,
-					  make_tuple(current->dbterm.tpl),
-					  NULL,0,&dummy);
+		match_res = db_prog_match_and_copy(&tb->common, p, mpi.mp, 0,
+						   &current->dbterm, &hp, 2);
 		if (is_value(match_res)) {
-		    if (mpi.all_objects) {
-			hp = HAlloc(p, current->dbterm.size + 2);
-			match_res = copy_shallow(DBTERM_BUF(&current->dbterm),
-						 current->dbterm.size,
-						 &hp,
-						 &MSO(p));
-		    } else {
-			sz = size_object(match_res);
-			
-			hp = HAlloc(p, sz + 2);
-			match_res = copy_struct(match_res, sz, &hp, &MSO(p));
-		    }
 		    match_list = CONS(hp, match_res, match_list);
 		    ++got;
 		}
@@ -1594,7 +1588,6 @@ static int db_select_count_hash(Process *p,
     Uint slot_ix = 0;
     HashDbTerm* current = NULL;
     unsigned current_list_pos = 0;
-    Uint32 dummy;
     Eterm *hp;
     int num_left = 1000;
     Uint got = 0;
@@ -1644,8 +1637,8 @@ static int db_select_count_hash(Process *p,
     for(;;) {
 	if (current != NULL) {
 	    if (current->hvalue != INVALID_HASH) {
-		if (db_prog_match(p, mpi.mp, make_tuple(current->dbterm.tpl),
-				  NULL,0, &dummy) == am_true) {
+		if (db_prog_match_and_copy(&tb->common, p, mpi.mp, 0,
+					   &current->dbterm, NULL,0) == am_true) {
 		    ++got;
 		}
 		--num_left;
@@ -1713,7 +1706,6 @@ static int db_select_delete_hash(Process *p,
     Uint slot_ix = 0;
     HashDbTerm **current = NULL;
     unsigned current_list_pos = 0;
-    Uint32 dummy;
     Eterm *hp;
     int num_left = 1000;
     Uint got = 0;
@@ -1794,9 +1786,8 @@ static int db_select_delete_hash(Process *p,
 	} 
 	else {
 	    int did_erase = 0;
-	    if ((db_prog_match(p,mpi.mp,
-			       make_tuple((*current)->dbterm.tpl),
-			       NULL,0,&dummy)) == am_true) {
+	    if (db_prog_match_and_copy(&tb->common, p, mpi.mp, 0,
+				       &(*current)->dbterm, NULL, 0) == am_true) {
 		if (NFIXED(tb) > fixated_by_me) { /* fixated by others? */
 		    if (slot_ix != last_pseudo_delete) {
 			add_fixed_deletion(tb, slot_ix);
@@ -1859,7 +1850,6 @@ static int db_select_delete_continue_hash(Process *p,
     Uint slot_ix;
     Uint last_pseudo_delete = (Uint)-1;
     HashDbTerm **current = NULL;
-    Uint32 dummy;
     Eterm *hp;
     int num_left = 1000;
     Uint got;
@@ -1907,8 +1897,8 @@ static int db_select_delete_continue_hash(Process *p,
 	} 
 	else {
 	    int did_erase = 0;
-	    if ((db_prog_match(p,mp,make_tuple((*current)->dbterm.tpl),
-			       NULL,0,&dummy)) == am_true) {
+	    if (db_prog_match_and_copy(&tb->common, p, mp, 0,
+				       &(*current)->dbterm, NULL, 0) == am_true) {
 		if (NFIXED(tb) > fixated_by_me) { /* fixated by others? */
 		    if (slot_ix != last_pseudo_delete) {
 			add_fixed_deletion(tb, slot_ix);
@@ -1970,7 +1960,6 @@ static int db_select_count_continue_hash(Process *p,
     DbTableHash *tb = &tbl->hash;
     Uint slot_ix;
     HashDbTerm* current;
-    Uint32 dummy;
     Eterm *hp;
     int num_left = 1000;
     Uint got;
@@ -2008,8 +1997,8 @@ static int db_select_count_continue_hash(Process *p,
 		current = current->next;
 		continue;
 	    }
-	    if (db_prog_match(p, mp, make_tuple(current->dbterm.tpl),
-			      NULL,0,&dummy) == am_true) {
+	    if (db_prog_match_and_copy(&tb->common, p, mp, 0, &current->dbterm,
+				       NULL, 0) == am_true) {
 		++got;
 	    }
 	    --num_left;
@@ -2454,31 +2443,19 @@ static int free_seg(DbTableHash *tb, int free_records)
 }
 
 
-static HashDbTerm* get_term(DbTableHash* tb, HashDbTerm* old, 
-			    Eterm obj, HashValue hval)
-{
-    HashDbTerm* p = db_get_term((DbTableCommon *) tb,
-				(old != NULL) ? &(old->dbterm) : NULL, 
-				((char *) &(old->dbterm)) - ((char *) old),
-				obj);
-    p->hvalue = hval;
-    /*p->next = NULL;*/ /*No Need */
-    return p;
-}
-
-
 /*
 ** Copy terms from ptr1 until ptr2
 ** works for ptr1 == ptr2 == 0  => []
 ** or ptr2 == 0
 */
-static Eterm put_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2)
+static Eterm build_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2,
+			   DbTableHash* tb)
 {
     int sz = 0;
     HashDbTerm* ptr;
     Eterm list = NIL;
     Eterm copy;
-    Eterm *hp;
+    Eterm *hp, *hend;
 
     ptr = ptr1;
     while(ptr != ptr2) {
@@ -2490,26 +2467,20 @@ static Eterm put_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2)
     }
 
     hp = HAlloc(p, sz);
+    hend = hp + sz;
 
     ptr = ptr1;
     while(ptr != ptr2) {
 	if (ptr->hvalue != INVALID_HASH) {
-	    copy = copy_shallow(DBTERM_BUF(&ptr->dbterm), ptr->dbterm.size, &hp, &MSO(p));
+	    copy = db_copy_object_from_ets(&tb->common, &ptr->dbterm, &hp, &MSO(p));
 	    list = CONS(hp, copy, list);
 	    hp  += 2;
 	}
 	ptr = ptr->next;
     }
-    return list;
-}
+    HRelease(p,hend,hp);
 
-static void free_term(DbTableHash *tb, HashDbTerm* p)
-{
-    db_free_term_data(&(p->dbterm));
-    erts_db_free(ERTS_ALC_T_DB_TERM,
-		 (DbTable *) tb,
-		 (void *) p,
-		 SIZ_DBTERM(p)*sizeof(Eterm));
+    return list;
 }
 
 /* Grow table with one new bucket.
@@ -2720,8 +2691,8 @@ static int db_lookup_dbterm_hash(DbTable *tbl, Eterm key, DbUpdateHandle* handle
 	    handle->tb = tbl;
 	    handle->bp = (void**) prevp;
 	    handle->dbterm = &b->dbterm;
-	    handle->new_size = b->dbterm.size;
 	    handle->mustResize = 0;
+	    handle->new_size = b->dbterm.size;
 	    handle->lck = lck;
 	    /* KEEP hval WLOCKED, db_finalize_dbterm_hash will WUNLOCK */
 	    return 1;
@@ -2742,37 +2713,14 @@ static void db_finalize_dbterm_hash(DbUpdateHandle* handle)
     erts_smp_rwmtx_t* lck = (erts_smp_rwmtx_t*) handle->lck;
 
     ERTS_SMP_LC_ASSERT(IS_HASH_WLOCKED(&tbl->hash,lck));  /* locked by db_lookup_dbterm_hash */
-    ASSERT(&oldp->dbterm == handle->dbterm);
 
-    if (handle->mustResize) {
-	ErlOffHeap tmp_offheap;
-	Eterm* top;
-	Eterm copy;
-	DbTerm* newDbTerm;
-	HashDbTerm* newp = erts_db_alloc(ERTS_ALC_T_DB_TERM, tbl,
-					 sizeof(HashDbTerm)+sizeof(Eterm)*(handle->new_size-1));    
-	sys_memcpy(newp, oldp, sizeof(HashDbTerm)-sizeof(DbTerm));  /* copy only hashtab header */
-	*(handle->bp) = newp;
-	newDbTerm = &newp->dbterm;
-    
-	newDbTerm->size = handle->new_size;
-	tmp_offheap.first = NULL;
-	tmp_offheap.overhead = 0;
-	
-	/* make a flat copy */
-	top = DBTERM_BUF(newDbTerm);
-	copy = copy_struct(make_tuple(handle->dbterm->tpl),
-			   handle->new_size,
-			   &top, &tmp_offheap);
-	newDbTerm->first_oh = tmp_offheap.first;
-	DBTERM_SET_TPL(newDbTerm,tuple_val(copy));
+    ASSERT((&oldp->dbterm == handle->dbterm) == !(tbl->common.compress && handle->mustResize));
 
+    if (handle->mustResize) {
+	db_finalize_resize(handle, offsetof(HashDbTerm,dbterm));
 	WUNLOCK_HASH(lck);
-		
-	db_free_term_data(handle->dbterm);
-	erts_db_free(ERTS_ALC_T_DB_TERM, tbl,
-		     (void *) (((char *) handle->dbterm) - (sizeof(HashDbTerm) - sizeof(DbTerm))),
-		     sizeof(HashDbTerm) + sizeof(Eterm)*(handle->dbterm->size-1));
+
+	free_term(&tbl->hash, oldp);
     }
     else {
 	WUNLOCK_HASH(lck);
@@ -2781,7 +2729,7 @@ static void db_finalize_dbterm_hash(DbUpdateHandle* handle)
     handle->dbterm = 0;
 #endif
     return;
-}   
+}
 
 static int db_delete_all_objects_hash(Process* p, DbTable* tbl)
 {
diff --git a/erts/emulator/beam/erl_db_tree.c b/erts/emulator/beam/erl_db_tree.c
index 5644e85f97..8108494fc5 100644
--- a/erts/emulator/beam/erl_db_tree.c
+++ b/erts/emulator/beam/erl_db_tree.c
@@ -122,12 +122,41 @@ static void release_stack(DbTableTree* tb, DbTreeStack* stack)
     }
 }
 
-static void reset_static_stack(DbTableTree* tb)
+static ERTS_INLINE void reset_static_stack(DbTableTree* tb)
 {
     tb->static_stack.pos = 0;
     tb->static_stack.slot = 0;
 }
 
+static ERTS_INLINE void free_term(DbTableTree *tb, TreeDbTerm* p)
+{
+    db_free_term((DbTable*)tb, p, offsetof(TreeDbTerm, dbterm));
+}
+
+static ERTS_INLINE TreeDbTerm* new_dbterm(DbTableTree *tb, Eterm obj)
+{
+    TreeDbTerm* p;
+    if (tb->common.compress) {
+	p = db_store_term_comp(&tb->common, NULL, offsetof(TreeDbTerm,dbterm), obj);
+    }
+    else {
+	p = db_store_term(&tb->common, NULL, offsetof(TreeDbTerm,dbterm), obj);
+    }
+    return p;
+}
+static ERTS_INLINE TreeDbTerm* replace_dbterm(DbTableTree *tb, TreeDbTerm* old,
+					      Eterm obj)
+{
+    TreeDbTerm* p;
+    ASSERT(old != NULL);
+    if (tb->common.compress) {
+	p = db_store_term_comp(&tb->common, &(old->dbterm), offsetof(TreeDbTerm,dbterm), obj);
+    }
+    else {
+	p = db_store_term(&tb->common, &(old->dbterm), offsetof(TreeDbTerm,dbterm), obj);
+    }
+    return p;
+}
 
 /*
 ** Some macros for "direction stacks"
@@ -178,12 +207,6 @@ static void do_dump_tree2(int to, void *to_arg, int show, TreeDbTerm *t,
 #endif
 
 /*
- * Size calculations
- */
-#define SIZ_OVERHEAD ((sizeof(TreeDbTerm)/sizeof(Eterm)) - 1)
-#define SIZ_DBTERM(TDT) (SIZ_OVERHEAD + (TDT)->dbterm.size)
-
-/*
 ** Datatypes
 */
 
@@ -263,9 +286,6 @@ static TreeDbTerm *linkout_tree(DbTableTree *tb, Eterm key);
 static TreeDbTerm *linkout_object_tree(DbTableTree *tb, 
 				       Eterm object);
 static int do_free_tree_cont(DbTableTree *tb, int num_left);
-static TreeDbTerm* get_term(DbTableTree *tb,
-			    TreeDbTerm* old, 
-			    Eterm obj);
 static void free_term(DbTableTree *tb, TreeDbTerm* p);
 static int balance_left(TreeDbTerm **this); 
 static int balance_right(TreeDbTerm **this); 
@@ -622,7 +642,7 @@ static int db_put_tree(DbTable *tbl, Eterm obj, int key_clash_fail)
 		erts_smp_atomic_dec(&tb->common.nitems);
 		return DB_ERROR_SYSRES;
 	    }
-	    *this = get_term(tb, NULL, obj);
+	    *this = new_dbterm(tb, obj);
 	    (*this)->balance = 0;
 	    (*this)->left = (*this)->right = NULL;
 	    break;
@@ -636,7 +656,7 @@ static int db_put_tree(DbTable *tbl, Eterm obj, int key_clash_fail)
 	    tstack[tpos++] = this;
 	    this = &((*this)->right);
 	} else if (!key_clash_fail) { /* Equal key and this is a set, replace. */
-	    *this = get_term(tb, *this, obj);
+	    *this = replace_dbterm(tb, *this, obj);
 	    break;
 	} else {
 	    return DB_ERROR_BADKEY; /* key already exists */
@@ -714,7 +734,7 @@ static int db_get_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
 {
     DbTableTree *tb = &tbl->tree;
     Eterm copy;
-    Eterm *hp;
+    Eterm *hp, *hend;
     TreeDbTerm *this;
 
     /*
@@ -728,11 +748,11 @@ static int db_get_tree(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
 	*ret = NIL;
     } else {
 	hp = HAlloc(p, this->dbterm.size + 2);
-	copy = copy_shallow(DBTERM_BUF(&this->dbterm), 
-			    this->dbterm.size, 
-			    &hp, 
-			    &MSO(p));
+	hend = hp + this->dbterm.size + 2;
+	copy = db_copy_object_from_ets(&tb->common, &this->dbterm, &hp, &MSO(p));
 	*ret = CONS(hp, copy, NIL);
+	hp += 2;
+	HRelease(p,hend,hp);
     }
     return DB_ERROR_NONE;
 }
@@ -766,18 +786,10 @@ static int db_get_element_tree(Process *p, DbTable *tbl,
     if (this == NULL) {
 	return DB_ERROR_BADKEY;
     } else {
-	Eterm element;
-	Uint sz;
 	if (ndex > arityval(this->dbterm.tpl[0])) {
 	    return DB_ERROR_BADPARAM;
 	}
-	element = this->dbterm.tpl[ndex];
-	sz = size_object(element);
-	hp = HAlloc(p, sz);
-	*ret = copy_struct(element, 
-			   sz, 
-			   &hp, 
-			   &MSO(p));
+	*ret = db_copy_element_from_ets(&tb->common, p, &this->dbterm, ndex, &hp, 0);
     }
     return DB_ERROR_NONE;
 }
@@ -815,7 +827,7 @@ static int db_slot_tree(Process *p, DbTable *tbl,
     DbTableTree *tb = &tbl->tree;
     Sint slot;
     TreeDbTerm *st;
-    Eterm *hp;
+    Eterm *hp, *hend;
     Eterm copy;
 
     /*
@@ -847,11 +859,11 @@ static int db_slot_tree(Process *p, DbTable *tbl,
 	return DB_ERROR_UNSPEC;
     }
     hp = HAlloc(p, st->dbterm.size + 2);
-    copy = copy_shallow(DBTERM_BUF(&st->dbterm), 
-			st->dbterm.size, 
-			&hp, 
-			&MSO(p));
+    hend = hp + st->dbterm.size + 2;
+    copy = db_copy_object_from_ets(&tb->common, &st->dbterm, &hp, &MSO(p));
     *ret = CONS(hp, copy, NIL);
+    hp += 2;
+    HRelease(p,hend,hp);
     return DB_ERROR_NONE;
 }
 
@@ -1738,7 +1750,7 @@ static int db_select_delete_tree(Process *p, DbTable *tbl,
 ** Other interface routines (not directly coupled to one bif)
 */
 
-/* Display hash table contents (for dump) */
+/* Display tree contents (for dump) */
 static void db_print_tree(int to, void *to_arg, 
 			  int show,
 			  DbTable *tbl)
@@ -1926,7 +1938,7 @@ static TreeDbTerm *linkout_object_tree(DbTableTree *tb,
 	    tstack[tpos++] = this;
 	    this = &((*this)->right);
 	} else { /* Equal key, found the only possible matching object*/
-	    if (!eq(object,make_tuple((*this)->dbterm.tpl))) {
+	    if (!db_eq(&tb->common,object,&(*this)->dbterm)) {
 		return NULL;
 	    }
 	    q = (*this);
@@ -2079,15 +2091,6 @@ static void do_dump_tree(int to, void *to_arg, TreeDbTerm *t)
     }
 }
 
-static void free_term(DbTableTree *tb, TreeDbTerm* p)
-{
-    db_free_term_data(&(p->dbterm));
-    erts_db_free(ERTS_ALC_T_DB_TERM,
-		 (DbTable *) tb,
-		 (void *) p,
-		 SIZ_DBTERM(p)*sizeof(Uint));
-}
-
 static int do_free_tree_cont(DbTableTree *tb, int num_left)
 {
     TreeDbTerm *root;
@@ -2118,17 +2121,6 @@ static int do_free_tree_cont(DbTableTree *tb, int num_left)
     return 1;
 }
 
-static TreeDbTerm* get_term(DbTableTree *tb,
-			    TreeDbTerm* old, 
-			    Eterm obj) 
-{
-    TreeDbTerm* p = db_get_term((DbTableCommon *) tb,
-				(old != NULL) ? &(old->dbterm) : NULL, 
-				((char *) &(old->dbterm)) - ((char *) old),
-				obj);
-    return p;
-}
-
 /*
  * Deletion helpers
  */
@@ -2570,46 +2562,21 @@ static int db_lookup_dbterm_tree(DbTable *tbl, Eterm key, DbUpdateHandle* handle
 
     handle->tb = tbl;
     handle->dbterm = &(*pp)->dbterm;
+    handle->mustResize = 0;
     handle->bp = (void**) pp;
     handle->new_size = (*pp)->dbterm.size;
-    handle->mustResize = 0;
     return 1;
 }
 
 static void db_finalize_dbterm_tree(DbUpdateHandle* handle)
 {
     if (handle->mustResize) {
-	ErlOffHeap tmp_offheap;
-	Eterm* top;
-	Eterm copy;
-	DbTerm* newDbTerm;
-	DbTableTree *tb = &handle->tb->tree;
 	TreeDbTerm* oldp = (TreeDbTerm*) *handle->bp;
-	TreeDbTerm* newp = erts_db_alloc(ERTS_ALC_T_DB_TERM,
-					 handle->tb,
-					 sizeof(TreeDbTerm)+sizeof(Eterm)*(handle->new_size-1));
-	memcpy(newp, oldp, sizeof(TreeDbTerm)-sizeof(DbTerm));  /* copy only tree header */
-	*(handle->bp) = newp;
-	reset_static_stack(tb);
-	newDbTerm = &newp->dbterm;
-    
-	newDbTerm->size = handle->new_size;
-	tmp_offheap.first = NULL;
-	tmp_offheap.overhead = 0;
-	
-	/* make a flat copy */
-	top = DBTERM_BUF(newDbTerm);
-	copy = copy_struct(make_tuple(handle->dbterm->tpl),
-			   handle->new_size,
-			   &top, &tmp_offheap);
-	newDbTerm->first_oh = tmp_offheap.first;
-	DBTERM_SET_TPL(newDbTerm,tuple_val(copy));
-    
-	db_free_term_data(handle->dbterm);
-	erts_db_free(ERTS_ALC_T_DB_TERM,
-		     handle->tb,
-		     (void *) (((char *) handle->dbterm) - (sizeof(TreeDbTerm) - sizeof(DbTerm))),
-		     sizeof(TreeDbTerm) + sizeof(Eterm)*(handle->dbterm->size-1));
+
+	db_finalize_resize(handle, offsetof(TreeDbTerm,dbterm));
+	reset_static_stack(&handle->tb->tree);
+
+	free_term(&handle->tb->tree, oldp);
     }
 #ifdef DEBUG
     handle->dbterm = 0;
@@ -3009,7 +2976,7 @@ static int doit_select(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 {
     struct select_context *sc = (struct select_context *) ptr;
     Eterm ret;
-    Uint32 dummy;
+    Eterm* hp;
 
     sc->lastobj = this->dbterm.tpl;
     
@@ -3024,24 +2991,9 @@ static int doit_select(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 					   this->dbterm.tpl)) > 0))) {
 	return 0;
     }
-    ret = db_prog_match(sc->p, sc->mp,
-			make_tuple(this->dbterm.tpl), 
-			NULL,0, &dummy);
+    ret = db_prog_match_and_copy(&tb->common,sc->p,sc->mp,sc->all_objects,
+				 &this->dbterm, &hp, 2);
     if (is_value(ret)) {
-	Uint sz;
-	Eterm *hp;
-	if (sc->all_objects) {
-	    hp = HAlloc(sc->p, this->dbterm.size + 2);
-	    ret = copy_shallow(DBTERM_BUF(&this->dbterm),
-				     this->dbterm.size,
-				     &hp,
-			             &MSO(sc->p));
-	} else {
-	    sz = size_object(ret);
-	    hp = HAlloc(sc->p, sz + 2);
-	    ret = copy_struct(ret, sz, 
-			      &hp, &MSO(sc->p));
-	}
 	sc->accum = CONS(hp, ret, sc->accum);
     }
     if (MBUF(sc->p)) {
@@ -3062,7 +3014,6 @@ static int doit_select_count(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 {
     struct select_count_context *sc = (struct select_count_context *) ptr;
     Eterm ret;
-    Uint32 dummy;
 
     sc->lastobj = this->dbterm.tpl;
     
@@ -3073,9 +3024,8 @@ static int doit_select_count(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 					  this->dbterm.tpl)) > 0)) {
 	return 0;
     }
-    ret = db_prog_match(sc->p, sc->mp,
-			make_tuple(this->dbterm.tpl), 
-			NULL,0, &dummy);
+    ret = db_prog_match_and_copy(&tb->common, sc->p, sc->mp, 0,
+				 &this->dbterm, NULL, 0);
     if (ret == am_true) {
 	++(sc->got);
     }
@@ -3090,7 +3040,7 @@ static int doit_select_chunk(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 {
     struct select_context *sc = (struct select_context *) ptr;
     Eterm ret;
-    Uint32 dummy;
+    Eterm* hp;
 
     sc->lastobj = this->dbterm.tpl;
     
@@ -3106,25 +3056,10 @@ static int doit_select_chunk(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 	return 0;
     }
 
-    ret = db_prog_match(sc->p, sc->mp,
-			make_tuple(this->dbterm.tpl), 
-			NULL,0, &dummy);
+    ret = db_prog_match_and_copy(&tb->common, sc->p, sc->mp, sc->all_objects,
+				 &this->dbterm, &hp, 2);
     if (is_value(ret)) {
-	Uint sz;
-	Eterm *hp;
-
 	++(sc->got);
-	if (sc->all_objects) {
-	    hp = HAlloc(sc->p, this->dbterm.size + 2);
-	    ret = copy_shallow(DBTERM_BUF(&this->dbterm),
-				     this->dbterm.size,
-				     &hp,
-			             &MSO(sc->p));
-	} else {
-	    sz = size_object(ret);
-	    hp = HAlloc(sc->p, sz + 2);
-	    ret = copy_struct(ret, sz, &hp, &MSO(sc->p));
-	}
 	sc->accum = CONS(hp, ret, sc->accum);
     }
     if (MBUF(sc->p)) {
@@ -3146,7 +3081,6 @@ static int doit_select_delete(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 {
     struct select_delete_context *sc = (struct select_delete_context *) ptr;
     Eterm ret;
-    Uint32 dummy;
     Eterm key;
 
     if (sc->erase_lastterm)
@@ -3159,9 +3093,8 @@ static int doit_select_delete(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 			 GETKEY_WITH_POS(sc->keypos, 
 					 this->dbterm.tpl)) > 0)
 	return 0;
-    ret = db_prog_match(sc->p, sc->mp,
-			make_tuple(this->dbterm.tpl), 
-			NULL,0, &dummy);
+    ret = db_prog_match_and_copy(&tb->common, sc->p, sc->mp, 0,
+				 &this->dbterm, NULL, 0);
     if (ret == am_true) {
 	key = GETKEY(sc->tb, this->dbterm.tpl);
 	linkout_tree(sc->tb, key);
diff --git a/erts/emulator/beam/erl_db_util.c b/erts/emulator/beam/erl_db_util.c
index 2f34561234..e773361619 100644
--- a/erts/emulator/beam/erl_db_util.c
+++ b/erts/emulator/beam/erl_db_util.c
@@ -25,7 +25,6 @@
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
 #endif
-
 #include "sys.h"
 #include "erl_vm.h"
 #include "global.h"
@@ -890,6 +889,8 @@ static Eterm match_spec_test(Process *p, Eterm against, Eterm spec, int trace);
 
 static Eterm seq_trace_fake(Process *p, Eterm arg1);
 
+static void db_free_tmp_uncompressed(DbTerm* obj);
+
 
 /*
 ** Interface routines.
@@ -1604,6 +1605,7 @@ static Eterm dpm_array_to_list(Process *psp, Eterm *arr, int arity)
     }
     return ret;
 }
+
 /*
 ** Execution of the match program, this is Pam.
 ** May return THE_NON_VALUE, which is a bailout.
@@ -2391,33 +2393,46 @@ void db_do_update_element(DbUpdateHandle* handle,
 
     if (is_both_immed(newval,oldval)) {
 	handle->dbterm->tpl[position] = newval;
+#ifdef DEBUG_CLONE
+	if (handle->dbterm->debug_clone) {
+	    handle->dbterm->debug_clone[position] = newval;
+	}
+#endif
 	return;
     }
-    else if (!handle->mustResize && is_boxed(newval)) {
-	newp = boxed_val(newval);
-	switch (*newp & _TAG_HEADER_MASK) {
-	case _TAG_HEADER_POS_BIG:
-	case _TAG_HEADER_NEG_BIG:
-	case _TAG_HEADER_FLOAT:
-	case _TAG_HEADER_HEAP_BIN:	    
-	    newval_sz = header_arity(*newp) + 1;	    
-	    if (is_boxed(oldval)) {
-		oldp = boxed_val(oldval);
-		switch (*oldp & _TAG_HEADER_MASK) {
-		case _TAG_HEADER_POS_BIG:
-		case _TAG_HEADER_NEG_BIG:
-		case _TAG_HEADER_FLOAT:
-		case _TAG_HEADER_HEAP_BIN:
-		    oldval_sz = header_arity(*oldp) + 1;
-		    if (oldval_sz == newval_sz) {
-			/* "self contained" terms of same size, do memcpy */
-			sys_memcpy(oldp, newp, newval_sz*sizeof(Eterm));			
-			return;
+    if (!handle->mustResize) {
+	if (handle->tb->common.compress) {
+	    handle->dbterm = db_alloc_tmp_uncompressed(&handle->tb->common,
+						       handle->dbterm);
+	    handle->mustResize = 1;
+	    oldval = handle->dbterm->tpl[position];
+	}
+	else if (is_boxed(newval)) {
+	    newp = boxed_val(newval);
+	    switch (*newp & _TAG_HEADER_MASK) {
+	    case _TAG_HEADER_POS_BIG:
+	    case _TAG_HEADER_NEG_BIG:
+	    case _TAG_HEADER_FLOAT:
+	    case _TAG_HEADER_HEAP_BIN:
+		newval_sz = header_arity(*newp) + 1;
+		if (is_boxed(oldval)) {
+		    oldp = boxed_val(oldval);
+		    switch (*oldp & _TAG_HEADER_MASK) {
+		    case _TAG_HEADER_POS_BIG:
+		    case _TAG_HEADER_NEG_BIG:
+		    case _TAG_HEADER_FLOAT:
+		    case _TAG_HEADER_HEAP_BIN:
+			oldval_sz = header_arity(*oldp) + 1;
+			if (oldval_sz == newval_sz) {
+			    /* "self contained" terms of same size, do memcpy */
+				sys_memcpy(oldp, newp, newval_sz*sizeof(Eterm));
+			    return;
+			}
+			goto both_size_set;
 		    }
-		    goto both_size_set;
 		}
+		goto new_size_set;
 	    }
-	    goto new_size_set;
 	}
     }
     /* Not possible for simple memcpy or dbterm is already non-contiguous, */
@@ -2436,84 +2451,372 @@ both_size_set:
     handle->mustResize = 1;
 }
 
+static ERTS_INLINE byte* db_realloc_term(DbTableCommon* tb, void* old,
+					 Uint old_sz, Uint new_sz, Uint offset)
+{
+    byte* ret;
+    if (erts_ets_realloc_always_moves) {
+	ret = erts_db_alloc(ERTS_ALC_T_DB_TERM, (DbTable*)tb, new_sz);
+	sys_memcpy(ret, old, offset);
+	erts_db_free(ERTS_ALC_T_DB_TERM, (DbTable*)tb, old, old_sz);
+    } else {
+	ret = erts_db_realloc(ERTS_ALC_T_DB_TERM, (DbTable*)tb,
+			      old, old_sz, new_sz);
+    }
+    return ret;
+}
+
+/* Allocated size of a compressed dbterm
+*/
+static ERTS_INLINE Uint db_alloced_size_comp(DbTerm* obj)
+{
+    return obj->tpl[arityval(*obj->tpl) + 1];
+}
+
+void db_free_term(DbTable *tb, void* basep, Uint offset)
+{
+    DbTerm* db = (DbTerm*) ((byte*)basep + offset);
+    Uint size;
+    if (tb->common.compress) {
+	db_cleanup_offheap_comp(db);
+	size = db_alloced_size_comp(db);
+    }
+    else {
+	ErlOffHeap tmp_oh;
+	tmp_oh.first = db->first_oh;
+	erts_cleanup_offheap(&tmp_oh);
+	size = offset + offsetof(DbTerm,tpl) + db->size*sizeof(Eterm);
+    }
+    erts_db_free(ERTS_ALC_T_DB_TERM, tb, basep, size);
+}
+
+static ERTS_INLINE Uint align_up(Uint value, Uint pow2)
+{
+    ASSERT((pow2 & (pow2-1)) == 0);
+    return (value + (pow2-1)) & ~(pow2-1);
+}
+
+/* Compressed size of an uncompressed term
+*/
+static Uint db_size_dbterm_comp(DbTableCommon* tb, Eterm obj)
+{
+    Eterm* tpl = tuple_val(obj);
+    int i;
+    Uint size = sizeof(DbTerm)
+	+ arityval(*tpl) * sizeof(Eterm)
+        + sizeof(Uint); /* "alloc_size" */
+
+    for (i = arityval(*tpl); i>0; i--) {
+	if (i != tb->keypos && is_not_immed(tpl[i])) {
+	    size += erts_encode_ext_size_ets(tpl[i]);
+	}
+    }
+    size += size_object(tpl[tb->keypos]) * sizeof(Eterm);
+    return align_up(size, sizeof(Uint));
+}
+
+/* Conversion between top tuple element and pointer to compressed data
+*/
+static ERTS_INLINE Eterm ext2elem(Eterm* tpl, byte* ext)
+{
+    return (((Uint)(ext - (byte*)tpl)) << _TAG_PRIMARY_SIZE) | TAG_PRIMARY_HEADER;
+}
+static ERTS_INLINE byte* elem2ext(Eterm* tpl, Uint ix)
+{
+    ASSERT(is_header(tpl[ix]));
+    return (byte*)tpl + (tpl[ix] >> _TAG_PRIMARY_SIZE);
+}
+
+static void* copy_to_comp(DbTableCommon* tb, Eterm obj, DbTerm* dest,
+			  Uint alloc_size)
+{
+    ErlOffHeap tmp_offheap;
+    Eterm* src = tuple_val(obj);
+    Eterm* tpl = dest->tpl;
+    Eterm key = src[tb->keypos];
+    int arity = arityval(src[0]);
+    union {
+	Eterm* ep;
+	byte* cp;
+	UWord ui;
+    }top;
+    int i;
+
+    top.ep = tpl+ 1 + arity + 1;
+    tpl[0] = src[0];
+    tpl[arity + 1] = alloc_size;
+
+    tmp_offheap.first = NULL;
+    tpl[tb->keypos] = copy_struct(key, size_object(key), &top.ep, &tmp_offheap);
+    dest->first_oh = tmp_offheap.first;
+    for (i=1; i<=arity; i++) {
+	if (i != tb->keypos) {
+	    if (is_immed(src[i])) {
+		tpl[i] = src[i];
+	    }
+	    else {
+		tpl[i] = ext2elem(tpl, top.cp);
+		top.cp = erts_encode_ext_ets(src[i], top.cp, &dest->first_oh);
+	    }
+	}
+    }
+
+#ifdef DEBUG_CLONE
+    {
+	Eterm* dbg_top = erts_alloc(ERTS_ALC_T_DB_TERM, dest->size * sizeof(Eterm));
+	dest->debug_clone = dbg_top;
+	tmp_offheap.first = dest->first_oh;
+	copy_struct(obj, dest->size, &dbg_top, &tmp_offheap);
+	dest->first_oh = tmp_offheap.first;
+	ASSERT(dbg_top == dest->debug_clone + dest->size);
+    }
+#endif
+    return top.cp;
+}
 
 /*
 ** Copy the object into a possibly new DbTerm, 
 ** offset is the offset of the DbTerm from the start
-** of the sysAllocaed structure, The possibly realloced and copied
+** of the allocated structure, The possibly realloced and copied
 ** structure is returned. Make sure (((char *) old) - offset) is a 
 ** pointer to a ERTS_ALC_T_DB_TERM allocated data area.
 */
-void* db_get_term(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj)
+void* db_store_term(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj)
 {
+    byte* basep;
+    DbTerm* newp;
+    Eterm* top;
     int size = size_object(obj);
-    void *structp = ((char*) old) - offset;
-    DbTerm* p;
-    Eterm copy;
-    Eterm *top;
     ErlOffHeap tmp_offheap;
 
     if (old != 0) {
+	basep = ((byte*) old) - offset;
 	tmp_offheap.first  = old->first_oh;
-	tmp_offheap.overhead = 0;
 	erts_cleanup_offheap(&tmp_offheap);
 	old->first_oh = tmp_offheap.first;
 	if (size == old->size) {
-	    p = old;
-	} else {
+	    newp = old;
+	}
+	else {
 	    Uint new_sz = offset + sizeof(DbTerm) + sizeof(Eterm)*(size-1);
 	    Uint old_sz = offset + sizeof(DbTerm) + sizeof(Eterm)*(old->size-1);
 
-	    if (erts_ets_realloc_always_moves) {
-		void *nstructp = erts_db_alloc(ERTS_ALC_T_DB_TERM,
-					       (DbTable *) tb,
-					       new_sz);
-		memcpy(nstructp,structp,offset);
-		erts_db_free(ERTS_ALC_T_DB_TERM,
-			     (DbTable *) tb,
-			     structp,
-			     old_sz);
-		structp = nstructp;
-	    } else {
-		structp = erts_db_realloc(ERTS_ALC_T_DB_TERM,
-					  (DbTable *) tb,
-					  structp,
-					  old_sz,
-					  new_sz);
-	    }
-	    p = (DbTerm*) ((void *)(((char *) structp) + offset));
+	    basep = db_realloc_term(tb, basep, old_sz, new_sz, offset);
+	    newp = (DbTerm*) (basep + offset);
 	}
     }
     else {
-	structp = erts_db_alloc(ERTS_ALC_T_DB_TERM,
-				(DbTable *) tb,
-				(offset
-				 + sizeof(DbTerm)
-				 + sizeof(Eterm)*(size-1)));
-	p = (DbTerm*) ((void *)(((char *) structp) + offset));
-    }
-    p->size = size;
+	basep = erts_db_alloc(ERTS_ALC_T_DB_TERM, (DbTable *)tb,
+			      (offset + sizeof(DbTerm) + sizeof(Eterm)*(size-1)));
+	newp = (DbTerm*) (basep + offset);
+    }
+    newp->size = size;
+    top = newp->tpl;
     tmp_offheap.first  = NULL;
-    tmp_offheap.overhead = 0;
+    copy_struct(obj, size, &top, &tmp_offheap);
+    newp->first_oh = tmp_offheap.first;
+#ifdef DEBUG_CLONE
+    newp->debug_clone = NULL;
+#endif
+    return basep;
+}
+
+
+void* db_store_term_comp(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj)
+{
+    Uint new_sz = offset + db_size_dbterm_comp(tb, obj);
+    byte* basep;
+    DbTerm* newp;
+    byte* top;
+
+    ASSERT(tb->compress);
+    if (old != 0) {
+	Uint old_sz = db_alloced_size_comp(old);
+	db_cleanup_offheap_comp(old);
+
+	basep = ((byte*) old) - offset;
+	if (new_sz == old_sz) {
+	    newp = old;
+	}
+	else {
+	    basep = db_realloc_term(tb, basep, old_sz, new_sz, offset);
+	    newp = (DbTerm*) (basep + offset);
+	}
+    }
+    else {
+	basep = erts_db_alloc(ERTS_ALC_T_DB_TERM, (DbTable*)tb, new_sz);
+	newp = (DbTerm*) (basep + offset);
+    }
+
+    newp->size = size_object(obj);
+    top = copy_to_comp(tb, obj, newp, new_sz);
+    ASSERT(top <= basep + new_sz);
+
+    // SVERK: realloc?
+
+    return basep;
+}
+
+
+void db_finalize_resize(DbUpdateHandle* handle, Uint offset)
+{
+    DbTable* tbl = handle->tb;
+    DbTerm* newDbTerm;
+    Uint alloc_sz = offset +
+	(tbl->common.compress ?
+	 db_size_dbterm_comp(&tbl->common, make_tuple(handle->dbterm->tpl)) :
+	 sizeof(DbTerm)+sizeof(Eterm)*(handle->new_size-1));
+    byte* newp = erts_db_alloc(ERTS_ALC_T_DB_TERM, tbl, alloc_sz);
+    byte* oldp = *(handle->bp);
+
+    sys_memcpy(newp, oldp, offset);  /* copy only hash/tree header */
+    *(handle->bp) = newp;
+    newDbTerm = (DbTerm*) (newp + offset);
+    newDbTerm->size = handle->new_size;
+
+    /* make a flat copy */
+
+    if (tbl->common.compress) {
+	copy_to_comp(&tbl->common, make_tuple(handle->dbterm->tpl),
+		     newDbTerm, alloc_sz);
+	db_free_tmp_uncompressed(handle->dbterm);
+    }
+    else {
+	Eterm* top;
+	ErlOffHeap tmp_offheap;
+	tmp_offheap.first = NULL;
+	top = newDbTerm->tpl;
+	copy_struct(make_tuple(handle->dbterm->tpl), handle->new_size,
+		    &top, &tmp_offheap);
+	newDbTerm->first_oh = tmp_offheap.first;
+#ifdef DEBUG_CLONE
+	newDbTerm->debug_clone = NULL;
+#endif
+	ASSERT((byte*)top <= (newp + alloc_sz));
+    }
+}
 
-    top = DBTERM_BUF(p);
-    copy = copy_struct(obj, size, &top, &tmp_offheap);
-    p->first_oh = tmp_offheap.first;
-    DBTERM_SET_TPL(p,tuple_val(copy));
+Eterm db_copy_from_comp(DbTableCommon* tb, DbTerm* bp, Eterm** hpp,
+			     ErlOffHeap* off_heap)
+{
+    Eterm* hp = *hpp;
+    int i, arity = arityval(bp->tpl[0]);
+
+    hp[0] = bp->tpl[0];
+    *hpp += arity + 1;
+
+    hp[tb->keypos] = copy_struct(bp->tpl[tb->keypos],
+				 size_object(bp->tpl[tb->keypos]),
+				 hpp, off_heap);
+    for (i=arity; i>0; i--) {
+	if (i != tb->keypos) {
+	    if (is_immed(bp->tpl[i])) {
+		hp[i] = bp->tpl[i];
+	    }
+	    else {
+		hp[i] = erts_decode_ext_ets(hpp, off_heap,
+					    elem2ext(bp->tpl, i));
+	    }
+	}
+    }
+    ASSERT((*hpp - hp) <= bp->size);
+#ifdef DEBUG_CLONE
+    ASSERT(eq(make_tuple(hp),make_tuple(bp->debug_clone)));
+#endif
+    return make_tuple(hp);
+}
 
-    return structp;
+Eterm db_copy_element_from_ets(DbTableCommon* tb, Process* p,
+			       DbTerm* obj, Uint pos,
+			       Eterm** hpp, Uint extra)
+{
+    if (is_immed(obj->tpl[pos])) {
+	*hpp = HAlloc(p, extra);
+	return obj->tpl[pos];
+    }
+    if (tb->compress && pos != tb->keypos) {
+	byte* ext = elem2ext(obj->tpl, pos);
+	Sint sz = erts_decode_ext_size_ets(ext, db_alloced_size_comp(obj)) + extra;
+	Eterm* hp = HAlloc(p, sz);
+	Eterm* endp = hp + sz;
+	Eterm copy = erts_decode_ext_ets(&hp, &MSO(p), ext);
+	*hpp = hp;
+	hp += extra;
+	HRelease(p, endp, hp);
+#ifdef DEBUG_CLONE
+	ASSERT(eq(copy,obj->debug_clone[pos]));
+#endif
+	return copy;
+    }
+    else {
+	Uint sz = size_object(obj->tpl[pos]);
+	*hpp = HAlloc(p, sz + extra);
+	return copy_struct(obj->tpl[pos], sz, hpp, &MSO(p));
+    }
 }
 
 
-void db_free_term_data(DbTerm* p)
+/* Our own "cleanup_offheap"
+ * as refc-binaries may be unaligned in compressed terms
+*/
+void db_cleanup_offheap_comp(DbTerm* obj)
+{
+    union erl_off_heap_ptr u;
+    ProcBin tmp;
+
+    for (u.hdr = obj->first_oh; u.hdr; u.hdr = u.hdr->next) {
+	if ((UWord)u.voidp % sizeof(UWord) != 0) { /* unaligned ptr */
+	    sys_memcpy(&tmp, u.voidp, sizeof(tmp));
+	    /* Warning, must pass (void*)-variable to memcpy. Otherwise it will
+	       cause Bus error on Sparc due to false compile time assumptions
+	       about word aligned memory (type cast is not enough) */
+	    u.pb = &tmp;
+	}
+	switch (thing_subtag(u.hdr->thing_word)) {
+	case REFC_BINARY_SUBTAG:
+	    if (erts_refc_dectest(&u.pb->val->refc, 0) == 0) {
+		erts_bin_free(u.pb->val);
+	    }
+	    break;
+	case FUN_SUBTAG:
+	    ASSERT(u.pb != &tmp);
+	    if (erts_refc_dectest(&u.fun->fe->refc, 0) == 0) {
+		erts_erase_fun_entry(u.fun->fe);
+	    }
+	    break;
+	default:
+	    ASSERT(is_external_header(u.hdr->thing_word));
+	    ASSERT(u.pb != &tmp);
+	    erts_deref_node_entry(u.ext->node);
+	    break;
+	}
+    }
+#ifdef DEBUG_CLONE
+    if (obj->debug_clone != NULL) {
+	erts_free(ERTS_ALC_T_DB_TERM, obj->debug_clone);
+	obj->debug_clone = NULL;
+    }
+#endif
+}
+
+int db_eq_comp(DbTableCommon* tb, Eterm a, DbTerm* b)
 {
     ErlOffHeap tmp_offheap;
-    tmp_offheap.first = p->first_oh;
-    tmp_offheap.overhead = 0;
+    Eterm* allocp;
+    Eterm* hp;
+    Eterm tmp_b;
+    int is_eq;
+
+    ASSERT(tb->compress);
+    hp = allocp = erts_alloc(ERTS_ALC_T_TMP, b->size*sizeof(Eterm));
+    tmp_offheap.first = NULL;
+    tmp_b = db_copy_from_comp(tb, b, &hp, &tmp_offheap);
+    is_eq = eq(a,tmp_b);
     erts_cleanup_offheap(&tmp_offheap);
+    erts_free(ERTS_ALC_T_TMP, allocp);
+    return is_eq;
 }
 
-
 /*
 ** Check if object represents a "match" variable 
 ** i.e and atom $N where N is an integer 
@@ -4404,7 +4707,65 @@ static Eterm seq_trace_fake(Process *p, Eterm arg1)
     }
     return result;
 }
-    
+
+DbTerm* db_alloc_tmp_uncompressed(DbTableCommon* tb, DbTerm* org)
+{
+    ErlOffHeap tmp_offheap;
+    DbTerm* res = erts_alloc(ERTS_ALC_T_TMP,
+			     sizeof(DbTerm) + org->size*sizeof(Eterm));
+    Eterm* hp = res->tpl;
+    tmp_offheap.first = NULL;
+    db_copy_from_comp(tb, org, &hp, &tmp_offheap);
+    res->first_oh = tmp_offheap.first;
+    res->size = org->size;
+#ifdef DEBUG_CLONE
+    res->debug_clone = NULL;
+#endif
+    return res;
+}
+
+void db_free_tmp_uncompressed(DbTerm* obj)
+{
+    ErlOffHeap off_heap;
+    off_heap.first = obj->first_oh;
+    erts_cleanup_offheap(&off_heap);
+#ifdef DEBUG_CLONE
+    ASSERT(obj->debug_clone == NULL);
+#endif
+    erts_free(ERTS_ALC_T_TMP, obj);
+}
+
+Eterm db_prog_match_and_copy(DbTableCommon* tb, Process* c_p, Binary* bprog,
+			     int all, DbTerm* obj, Eterm** hpp, Uint extra)
+{
+    Uint32 dummy;
+    Eterm res;
+
+    if (tb->compress) {
+	obj = db_alloc_tmp_uncompressed(tb, obj);
+    }
+
+    res = db_prog_match(c_p, bprog, make_tuple(obj->tpl), NULL, 0, &dummy);
+
+    if (is_value(res) && hpp!=NULL) {
+	if (all) {
+	    *hpp = HAlloc(c_p, obj->size + extra);
+	    res = copy_shallow(obj->tpl, obj->size, hpp, &MSO(c_p));
+	}
+	else {
+	    Uint sz = size_object(res);
+	    *hpp = HAlloc(c_p, sz + extra);
+	    res = copy_struct(res, sz, hpp, &MSO(c_p));
+	}
+    }
+
+    if (tb->compress) {
+	db_free_tmp_uncompressed(obj);
+    }
+    return res;
+}
+
+
 #ifdef DMC_DEBUG
 /*
 ** Disassemble match program
diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h
index 0f333e8b34..10ba755e80 100644
--- a/erts/emulator/beam/erl_db_util.h
+++ b/erts/emulator/beam/erl_db_util.h
@@ -52,22 +52,27 @@
 				     is broken.*/
 #define DB_ERROR_UNSPEC   -10    /* Unspecified error */
 
+/*#define DEBUG_CLONE*/
 
 /*
  * A datatype for a database entry stored out of a process heap
  */
 typedef struct db_term {
     struct erl_off_heap_header* first_oh; /* Off heap data for term. */
-    Uint size;		   /* Size of term in "words" */
-    Eterm tpl[1];          /* Untagged "constant pointer" to top tuple */
-                           /* (assumed to be first in buffer) */
+    Uint size;		   /* Heap size of term in "words" */
+#ifdef DEBUG_CLONE
+    Eterm* debug_clone;    /* An uncompressed copy */
+#endif
+    Eterm tpl[1];          /* Term data. Top tuple always first */
+
+    /* Compression: is_immed and key element are uncompressed.
+       Compressed elements are stored in external format after each other
+       last in dbterm. The top tuple elements contains byte offsets, to
+       the start of the data, tagged as headers.
+       The allocated size of the dbterm in bytes is stored at tpl[arity+1].
+     */
 } DbTerm;
 
-/* "Assign" a value to DbTerm.tpl */
-#define DBTERM_SET_TPL(dbtermPtr,tplPtr) ASSERT((tplPtr)==(dbtermPtr->tpl))
-/* Get start of term buffer */
-#define DBTERM_BUF(dbtermPtr) ((dbtermPtr)->tpl)
-
 union db_table;
 typedef union db_table DbTable;
 
@@ -186,6 +191,12 @@ typedef struct db_table_method
 
 } DbTableMethod;
 
+typedef struct db_fixation {
+    Eterm pid;
+    Uint counter;
+    struct db_fixation *next;
+} DbFixation;
+
 /*
  * This structure contains data for all different types of database
  * tables. Note that these fields must match the same fields
@@ -194,13 +205,6 @@ typedef struct db_table_method
  * operations may be the same on different types of tables.
  */
 
-typedef struct db_fixation {
-    Eterm pid;
-    Uint counter;
-    struct db_fixation *next;
-} DbFixation;
-
-
 typedef struct db_table_common {
     erts_refc_t ref;
     erts_refc_t fixref;       /* fixation counter */
@@ -226,6 +230,7 @@ typedef struct db_table_common {
     Uint32 status;            /* bit masks defined  below */
     int slot;                 /* slot index in meta_main_tab */
     int keypos;               /* defaults to 1 */
+    int compress;
 } DbTableCommon;
 
 /* These are status bit patterns */
@@ -252,6 +257,54 @@ typedef struct db_table_common {
 #define IS_FIXED(T) (NFIXED(T) != 0) 
 
 Eterm erts_ets_copy_object(Eterm, Process*);
+Eterm db_copy_from_comp(DbTableCommon* tb, DbTerm* bp, Eterm** hpp,
+			ErlOffHeap* off_heap);
+int db_eq_comp(DbTableCommon* tb, Eterm a, DbTerm* b);
+DbTerm* db_alloc_tmp_uncompressed(DbTableCommon* tb, DbTerm* org);
+
+ERTS_GLB_INLINE Eterm db_copy_object_from_ets(DbTableCommon* tb, DbTerm* bp,
+					      Eterm** hpp, ErlOffHeap* off_heap);
+ERTS_GLB_INLINE int db_eq(DbTableCommon* tb, Eterm a, DbTerm* b);
+ERTS_GLB_INLINE Eterm db_do_read_element(DbUpdateHandle* handle, Sint position);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE Eterm db_copy_object_from_ets(DbTableCommon* tb, DbTerm* bp,
+					      Eterm** hpp, ErlOffHeap* off_heap)
+{
+    if (tb->compress) {
+	return db_copy_from_comp(tb, bp, hpp, off_heap);
+    }
+    else {
+	return copy_shallow(bp->tpl, bp->size, hpp, off_heap);
+    }
+}
+
+ERTS_GLB_INLINE int db_eq(DbTableCommon* tb, Eterm a, DbTerm* b)
+{
+    if (!tb->compress) {
+	return eq(a, make_tuple(b->tpl));
+    }
+    else {
+	return db_eq_comp(tb, a, b);
+    }
+}
+
+/* Must be called to read elements after db_lookup_dbterm.
+** Will decompress if needed. */
+ERTS_GLB_INLINE Eterm db_do_read_element(DbUpdateHandle* handle, Sint position)
+{
+    Eterm elem = handle->dbterm->tpl[position];
+    if (!is_header(elem)) {
+	return elem;
+    }
+    ASSERT(((DbTableCommon*)handle->tb)->compress);
+    ASSERT(!handle->mustResize);
+    handle->dbterm = db_alloc_tmp_uncompressed((DbTableCommon*)handle->tb, handle->dbterm);
+    handle->mustResize = 1;
+    return handle->dbterm->tpl[position];
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
 
 /* optimised version of copy_object (normal case? atomic object) */
 #define COPY_OBJECT(obj, p, objp) \
@@ -277,14 +330,19 @@ Eterm db_set_trace_control_word_1(Process *p, Eterm val);
 
 void db_initialize_util(void);
 Eterm db_getkey(int keypos, Eterm obj);
-void db_free_term_data(DbTerm* p);
-void* db_get_term(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj);
+void db_cleanup_offheap_comp(DbTerm* p);
+void db_free_term(DbTable *tb, void* basep, Uint offset);
+void* db_store_term(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj);
+void* db_store_term_comp(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj);
+Eterm db_copy_element_from_ets(DbTableCommon* tb, Process* p, DbTerm* obj,
+			       Uint pos, Eterm** hpp, Uint extra);
 int db_has_variable(Eterm obj);
 int db_is_variable(Eterm obj);
+Eterm db_do_read_element(DbUpdateHandle* handle, Sint position);
 void db_do_update_element(DbUpdateHandle* handle,
 			  Sint position,
 			  Eterm newval);
-void db_finalize_update_element(DbUpdateHandle* handle);
+void db_finalize_resize(DbUpdateHandle* handle, Uint offset);
 Eterm db_add_counter(Eterm** hpp, Eterm counter, Eterm incr);
 Eterm db_match_set_lint(Process *p, Eterm matchexpr, Uint flags);
 Binary *db_match_set_compile(Process *p, Eterm matchexpr, 
@@ -366,6 +424,8 @@ Binary *db_match_compile(Eterm *matchexpr, Eterm *guards,
 			 Eterm *body, int num_matches, 
 			 Uint flags, 
 			 DMCErrInfo *err_info);
+Eterm db_prog_match_and_copy(DbTableCommon* tb, Process* c_p, Binary* bprog,
+			     int all, DbTerm* obj, Eterm** hpp, Uint extra);
 /* Returns newly allocated MatchProg binary with refc == 0*/
 Eterm db_prog_match(Process *p, Binary *prog, Eterm term, Eterm *termp, int arity,
 		    Uint32 *return_flags /* Zeroed on enter */);
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index a2fd5921a2..a9f4f041ac 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -807,6 +807,7 @@ early_init(int *argc, char **argv) /*
     erl_sys_args(argc, argv);
 
     erts_ets_realloc_always_moves = 0;
+    erts_ets_always_compress = 0;
     erts_dist_buf_busy_limit = ERTS_DE_BUSY_LIMIT;
 
     return ncpu;
@@ -1028,15 +1029,20 @@ erl_start(int argc, char **argv)
 	    break;
 
 	case 'e':
-	    /* set maximum number of ets tables */
-	    arg = get_arg(argv[i]+2, argv[i+1], &i);
-	    if (( user_requested_db_max_tabs = atoi(arg) ) < 0) {
-		erts_fprintf(stderr, "bad maximum number of ets tables %s\n", arg);
-		erts_usage();
+	    if (sys_strcmp("c", argv[i]+2) == 0) {
+		erts_ets_always_compress = 1;
+	    }
+	    else {
+		/* set maximum number of ets tables */
+		arg = get_arg(argv[i]+2, argv[i+1], &i);
+		if (( user_requested_db_max_tabs = atoi(arg) ) < 0) {
+		    erts_fprintf(stderr, "bad maximum number of ets tables %s\n", arg);
+		    erts_usage();
+		}
+		VERBOSE(DEBUG_SYSTEM,
+			("using maximum number of ets tables %d\n",
+			 user_requested_db_max_tabs));
 	    }
-	    VERBOSE(DEBUG_SYSTEM,
-                    ("using maximum number of ets tables %d\n",
-                     user_requested_db_max_tabs));
 	    break;
 
 	case 'i':
diff --git a/erts/emulator/beam/erl_vm.h b/erts/emulator/beam/erl_vm.h
index cd63401581..48fa99934e 100644
--- a/erts/emulator/beam/erl_vm.h
+++ b/erts/emulator/beam/erl_vm.h
@@ -199,6 +199,7 @@ extern int BIN_VH_MIN_SIZE;	/* minimum virtual (bin) heap */
 extern int erts_atom_table_size;/* Atom table size */
 
 #define ORIG_CREATION 0
+#define INTERNAL_CREATION 255
 
 /* macros for extracting bytes from uint16's */
 
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index d7c8aa84e9..328aa2be6a 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -49,10 +49,8 @@
 #define in_area(ptr,start,nbytes) ((Uint)((char*)(ptr) - (char*)(start)) < (nbytes))
 
 #define MAX_STRING_LEN 0xffff
-#define dec_set_creation(nodename,creat)				\
-  (((nodename) == erts_this_node->sysname && (creat) == ORIG_CREATION)	\
-   ? erts_this_node->creation						\
-   : (creat))
+
+#define is_valid_creation(Cre) ((unsigned)(Cre) < MAX_CREATION || (Cre) == INTERNAL_CREATION)
 
 #undef ERTS_DEBUG_USE_DIST_SEP
 #ifdef DEBUG
@@ -83,14 +81,14 @@
  *
  */
 
-static byte* enc_term(ErtsAtomCacheMap *, Eterm, byte*, Uint32);
+static byte* enc_term(ErtsAtomCacheMap *, Eterm, byte*, Uint32, struct erl_off_heap_header** off_heap);
 static Uint is_external_string(Eterm obj, int* p_is_string);
 static byte* enc_atom(ErtsAtomCacheMap *, Eterm, byte*, Uint32);
 static byte* enc_pid(ErtsAtomCacheMap *, Eterm, byte*, Uint32);
 static byte* dec_term(ErtsDistExternal *, Eterm**, byte*, ErlOffHeap*, Eterm*);
 static byte* dec_atom(ErtsDistExternal *, byte*, Eterm*);
 static byte* dec_pid(ErtsDistExternal *, Eterm**, byte*, ErlOffHeap*, Eterm*);
-static Sint decoded_size(byte *ep, byte* endp, int only_heap_bins);
+static Sint decoded_size(byte *ep, byte* endp, int only_heap_bins, int internal_tags);
 
 
 static Uint encode_size_struct2(ErtsAtomCacheMap *, Eterm, unsigned);
@@ -461,6 +459,12 @@ Uint erts_encode_ext_size(Eterm term)
 	+ 1 /* VERSION_MAGIC */;
 }
 
+Uint erts_encode_ext_size_ets(Eterm term)
+{
+    return encode_size_struct2(NULL, term, TERM_TO_BINARY_DFLAGS|DFLAGS_INTERNAL_TAGS);
+}
+
+
 void erts_encode_dist_ext(Eterm term, byte **ext, Uint32 flags, ErtsAtomCacheMap *acmp)
 {
     byte *ep = *ext;
@@ -468,7 +472,7 @@ void erts_encode_dist_ext(Eterm term, byte **ext, Uint32 flags, ErtsAtomCacheMap
     if (!(flags & DFLAG_DIST_HDR_ATOM_CACHE))
 #endif
 	*ep++ = VERSION_MAGIC;
-    ep = enc_term(acmp, term, ep, flags);
+    ep = enc_term(acmp, term, ep, flags, NULL);
     if (!ep)
 	erl_exit(ERTS_ABORT_EXIT,
 		 "%s:%d:erts_encode_dist_ext(): Internal data structure error\n",
@@ -480,7 +484,7 @@ void erts_encode_ext(Eterm term, byte **ext)
 {
     byte *ep = *ext;
     *ep++ = VERSION_MAGIC;
-    ep = enc_term(NULL, term, ep, TERM_TO_BINARY_DFLAGS);
+    ep = enc_term(NULL, term, ep, TERM_TO_BINARY_DFLAGS, NULL);
     if (!ep)
 	erl_exit(ERTS_ABORT_EXIT,
 		 "%s:%d:erts_encode_ext(): Internal data structure error\n",
@@ -488,6 +492,12 @@ void erts_encode_ext(Eterm term, byte **ext)
     *ext = ep;
 }
 
+byte* erts_encode_ext_ets(Eterm term, byte *ep, struct erl_off_heap_header** off_heap)
+{
+    return enc_term(NULL, term, ep, TERM_TO_BINARY_DFLAGS|DFLAGS_INTERNAL_TAGS,
+		    off_heap);
+}
+
 ErtsDistExternal *
 erts_make_dist_ext_copy(ErtsDistExternal *edep, Uint xsize)
 {
@@ -813,7 +823,7 @@ erts_decode_dist_ext_size(ErtsDistExternal *edep, int no_refc_bins)
 	    goto fail;
 	ep = edep->extp+1;
     }
-    res = decoded_size(ep, edep->ext_endp, no_refc_bins);
+    res = decoded_size(ep, edep->ext_endp, no_refc_bins, 0);
     if (res >= 0)
 	return res;
  fail:
@@ -825,9 +835,17 @@ Sint erts_decode_ext_size(byte *ext, Uint size, int no_refc_bins)
 {
     if (size == 0 || *ext != VERSION_MAGIC)
 	return -1;
-    return decoded_size(ext+1, ext+size, no_refc_bins);
+    return decoded_size(ext+1, ext+size, no_refc_bins, 0);
 }
 
+Sint erts_decode_ext_size_ets(byte *ext, Uint size)
+{
+    Sint sz = decoded_size(ext, ext+size, 0, 1);
+    ASSERT(sz >= 0);
+    return sz;
+}
+
+
 /*
 ** hpp is set to either a &p->htop or
 ** a pointer to a memory pointer (form message buffers)
@@ -887,7 +905,13 @@ Eterm erts_decode_ext(Eterm **hpp, ErlOffHeap *off_heap, byte **ext)
     return obj;
 }
 
-
+Eterm erts_decode_ext_ets(Eterm **hpp, ErlOffHeap *off_heap, byte *ext)
+{
+    Eterm obj;
+    ext = dec_term(NULL, hpp, ext, off_heap, &obj);
+    ASSERT(ext);
+    return obj;
+}
 
 /**********************************************************************/
 
@@ -964,6 +988,7 @@ term_to_binary_1(Process* p, Eterm Term)
     return erts_term_to_binary(p, Term, 0, TERM_TO_BINARY_DFLAGS);
 }
 
+
 Eterm
 term_to_binary_2(Process* p, Eterm Term, Eterm Flags)
 {
@@ -1075,7 +1100,7 @@ binary2term_prepare(ErtsBinary2TermState *state, byte *data, Sint data_size)
 	    goto error;
 	size = (Sint) dest_len;
     }
-    res = decoded_size(state->extp, state->extp + size, 0);
+    res = decoded_size(state->extp, state->extp + size, 0, 0);
     if (res < 0)
 	goto error;
     return res;
@@ -1183,7 +1208,8 @@ BIF_RETTYPE binary_to_term_2(BIF_ALIST_2)
         opt = CAR(list_val(opts));
         if (opt == am_safe) {
 	    fakedep.flags |= ERTS_DIST_EXT_BTT_SAFE;
-        } else {
+        }
+	else {
             goto error;
         }
         opts = CDR(list_val(opts));
@@ -1255,7 +1281,7 @@ erts_term_to_binary(Process* p, Eterm Term, int level, Uint flags)
 	    bytes = erts_alloc(ERTS_ALC_T_TMP, size);
 	}
 
-	if ((endp = enc_term(NULL, Term, bytes, flags))
+	if ((endp = enc_term(NULL, Term, bytes, flags, NULL))
 	    == NULL) {
 	    erl_exit(1, "%s, line %d: bad term: %x\n",
 		     __FILE__, __LINE__, Term);
@@ -1300,7 +1326,7 @@ erts_term_to_binary(Process* p, Eterm Term, int level, Uint flags)
 	bin = new_binary(p, (byte *)NULL, size);
 	bytes = binary_bytes(bin);
 	bytes[0] = VERSION_MAGIC;
-	if ((endp = enc_term(NULL, Term, bytes+1, flags))	
+	if ((endp = enc_term(NULL, Term, bytes+1, flags, NULL))
 	    == NULL) {
 	    erl_exit(1, "%s, line %d: bad term: %x\n",
 		     __FILE__, __LINE__, Term);
@@ -1330,6 +1356,21 @@ enc_atom(ErtsAtomCacheMap *acmp, Eterm atom, byte *ep, Uint32 dflags)
 
     ASSERT(is_atom(atom));
 
+    if (dflags & DFLAGS_INTERNAL_TAGS) {
+	Uint aval = atom_val(atom);
+	ASSERT(aval < (1<<24));
+	if (aval >= (1 << 16)) {
+	    *ep++ = ATOM_INTERNAL_REF3;
+	    put_int24(aval, ep);
+	    ep += 3;
+	}
+	else {
+	    *ep++ = ATOM_INTERNAL_REF2;
+	    put_int16(aval, ep);
+	    ep += 2;
+	}
+	return ep;
+    }
     /*
      * term_to_binary/1,2 and the initial distribution message
      * don't use the cache.
@@ -1379,7 +1420,8 @@ enc_pid(ErtsAtomCacheMap *acmp, Eterm pid, byte* ep, Uint32 dflags)
     ep += 4;
     put_int32(os, ep);
     ep += 4;
-    *ep++ = pid_creation(pid);
+    *ep++ = (is_internal_pid(pid) && (dflags & DFLAGS_INTERNAL_TAGS)) ?
+	INTERNAL_CREATION : pid_creation(pid);
     return ep;
 }
 
@@ -1418,6 +1460,23 @@ dec_atom(ErtsDistExternal *edep, byte* ep, Eterm* objp)
         }
 	ep += len;
 	break;
+    case ATOM_INTERNAL_REF2:
+	n = get_int16(ep);
+	ep += 2;
+	if (n >= atom_table_size()) {
+	    goto error;
+	}
+	*objp = make_atom(n);
+	break;
+    case ATOM_INTERNAL_REF3:
+	n = get_int24(ep);
+	ep += 3;
+	if (n >= atom_table_size()) {
+	    goto error;
+	}
+	*objp = make_atom(n);
+	break;
+
     default:
     error:
 	*objp = NIL;	/* Don't leave a hole in the heap */
@@ -1426,6 +1485,19 @@ dec_atom(ErtsDistExternal *edep, byte* ep, Eterm* objp)
     return ep;
 }
 
+static ERTS_INLINE ErlNode* dec_get_node(Eterm sysname, Uint creation)
+{
+    switch (creation) {
+    case INTERNAL_CREATION:
+	return erts_this_node;
+    case ORIG_CREATION:
+	if (sysname == erts_this_node->sysname) {
+	    creation = erts_this_node->creation;
+	}
+    }
+    return erts_find_or_insert_node(sysname,creation);
+}
+
 static byte*
 dec_pid(ErtsDistExternal *edep, Eterm** hpp, byte* ep, ErlOffHeap* off_heap, Eterm* objp)
 {
@@ -1449,18 +1521,20 @@ dec_pid(ErtsDistExternal *edep, Eterm** hpp, byte* ep, ErlOffHeap* off_heap, Ete
     ep += 4;
     if (ser > ERTS_MAX_PID_SERIAL)
 	return NULL;
-    if ((cre = get_int8(ep)) >= MAX_CREATION)
-	return NULL;
+    cre = get_int8(ep);
     ep += 1;
 
+    if (!is_valid_creation(cre)) {
+	return NULL;
+    }
+    data = make_pid_data(ser, num);
+
     /*
      * We are careful to create the node entry only after all
      * validity tests are done.
      */
-    cre = dec_set_creation(sysname,cre);
-    node = erts_find_or_insert_node(sysname,cre);
+    node = dec_get_node(sysname, cre);
 
-    data = make_pid_data(ser, num);
     if(node == erts_this_node) {
 	*objp = make_internal_pid(data);
     } else {
@@ -1485,7 +1559,8 @@ dec_pid(ErtsDistExternal *edep, Eterm** hpp, byte* ep, ErlOffHeap* off_heap, Ete
 #define ENC_LAST_ARRAY_ELEMENT ((Eterm) 3)
 
 static byte*
-enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
+enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags,
+	 struct erl_off_heap_header** off_heap)
 {
     DECLARE_WSTACK(s);
     Uint n;
@@ -1637,12 +1712,14 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
 	    Uint32 *ref_num;
 
 	    ASSERT(dflags & DFLAG_EXTENDED_REFERENCES);
+
 	    *ep++ = NEW_REFERENCE_EXT;
 	    i = ref_no_of_numbers(obj);
 	    put_int16(i, ep);
 	    ep += 2;
 	    ep = enc_atom(acmp,ref_node_name(obj),ep,dflags);
-	    *ep++ = ref_creation(obj);
+	    *ep++ = ((dflags & DFLAGS_INTERNAL_TAGS) && is_internal_ref(obj)) ?
+		INTERNAL_CREATION : ref_creation(obj);
 	    ref_num = ref_numbers(obj);
 	    for (j = 0; j < i; j++) {
 		put_int32(ref_num[j], ep);
@@ -1658,7 +1735,8 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
 	    j = port_number(obj);
 	    put_int32(j, ep);
 	    ep += 4;
-	    *ep++ = port_creation(obj);
+	    *ep++ = ((dflags & DFLAGS_INTERNAL_TAGS) && is_internal_port(obj)) ?
+		INTERNAL_CREATION : port_creation(obj);
 	    break;
 
 	case LIST_DEF:
@@ -1738,6 +1816,41 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
 		byte* bytes;
 
 		ERTS_GET_BINARY_BYTES(obj, bytes, bitoffs, bitsize);
+		if (dflags & DFLAGS_INTERNAL_TAGS) {
+		    ProcBin* pb = (ProcBin*) binary_val(obj);
+		    Uint bytesize = pb->size;
+		    if (pb->thing_word == HEADER_SUB_BIN) {
+			ErlSubBin* sub = (ErlSubBin*)pb;
+			pb = (ProcBin*) binary_val(sub->orig);
+			ASSERT(bytesize == sub->size);
+			bytesize += (bitoffs + bitsize + 7) / 8;
+		    }
+		    if (pb->thing_word == HEADER_PROC_BIN
+			&& heap_bin_size(bytesize) > PROC_BIN_SIZE) {
+			ProcBin tmp;
+			if (bitoffs || bitsize) {
+			    *ep++ = BIT_BINARY_INTERNAL_REF;
+			    *ep++ = bitoffs;
+			    *ep++ = bitsize;
+			}
+			else {
+			    *ep++ = BINARY_INTERNAL_REF;
+			}
+			if (pb->flags) {
+			    erts_emasculate_writable_binary(pb);
+			}
+			erts_refc_inc(&pb->val->refc, 2);
+
+			sys_memcpy(&tmp, pb, sizeof(ProcBin));
+			tmp.next = *off_heap;
+			tmp.bytes = bytes;
+			tmp.size = bytesize;
+			sys_memcpy(ep, &tmp, sizeof(ProcBin));
+			*off_heap = (struct erl_off_heap_header*) ep;
+			ep += sizeof(ProcBin);
+			break;
+		    }
+		}
 		if (bitsize == 0) {
 		    /* Plain old byte-sized binary. */
 		    *ep++ = BINARY_EXT;
@@ -1773,8 +1886,8 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
 		    *ep++ = SMALL_INTEGER_EXT;
 		    *ep++ = bitsize;
 		}
-		break;
 	    }
+	    break;
 	case EXPORT_DEF:
 	    {
 		Export* exp = *((Export **) (export_val(obj) + 1));
@@ -1782,7 +1895,7 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
 		    *ep++ = EXPORT_EXT;
 		    ep = enc_atom(acmp, exp->code[0], ep, dflags);
 		    ep = enc_atom(acmp, exp->code[1], ep, dflags);
-		    ep = enc_term(acmp, make_small(exp->code[2]), ep, dflags);
+		    ep = enc_term(acmp, make_small(exp->code[2]), ep, dflags, off_heap);
 		} else {
 		    /* Tag, arity */
 		    *ep++ = SMALL_TUPLE_EXT;
@@ -1818,8 +1931,8 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
 		    put_int32(funp->num_free, ep);
 		    ep += 4;
 		    ep = enc_atom(acmp, funp->fe->module, ep, dflags);
-		    ep = enc_term(acmp, make_small(funp->fe->old_index), ep, dflags);
-		    ep = enc_term(acmp, make_small(funp->fe->old_uniq), ep, dflags);
+		    ep = enc_term(acmp, make_small(funp->fe->old_index), ep, dflags, off_heap);
+		    ep = enc_term(acmp, make_small(funp->fe->old_uniq), ep, dflags, off_heap);
 		    ep = enc_pid(acmp, funp->creator, ep, dflags);
 
 		fun_env:
@@ -1872,7 +1985,8 @@ enc_term(ErtsAtomCacheMap *acmp, Eterm obj, byte* ep, Uint32 dflags)
     return ep;
 }
 
-static Uint
+static
+Uint
 is_external_string(Eterm list, int* p_is_string)
 {
     Uint len = 0;
@@ -2162,13 +2276,13 @@ dec_term_atom_common:
 		    goto error;
 		}
 		ep += 4;
-		if ((cre = get_int8(ep)) >= MAX_CREATION) {
+		cre = get_int8(ep);
+		ep++;
+		if (!is_valid_creation(cre)) {
 		    goto error;
 		}
-		ep++;
-		cre = dec_set_creation(sysname,cre);
-		node = erts_find_or_insert_node(sysname, cre);
 
+		node = dec_get_node(sysname, cre);
 		if(node == erts_this_node) {
 		    *objp = make_internal_port(num);
 		}
@@ -2205,9 +2319,11 @@ dec_term_atom_common:
 		    goto error;
 		ep += 4;
 
-		if ((cre = get_int8(ep)) >= MAX_CREATION)
-		    goto error;
+		cre = get_int8(ep);
 		ep += 1;
+		if (!is_valid_creation(cre)) {
+		    goto error;
+		}
 		goto ref_ext_common;
 
 	    case NEW_REFERENCE_EXT:
@@ -2220,10 +2336,11 @@ dec_term_atom_common:
 		if ((ep = dec_atom(edep, ep, &sysname)) == NULL)
 		    goto error;
 
-		if ((cre = get_int8(ep)) >= MAX_CREATION)
-		    goto error;
+		cre = get_int8(ep);
 		ep += 1;
-
+		if (!is_valid_creation(cre)) {
+		    goto error;
+		}
 		r0 = get_int32(ep);
 		ep += 4;
 		if (r0 >= MAX_REFERENCE)
@@ -2231,8 +2348,7 @@ dec_term_atom_common:
 
 	    ref_ext_common:
 
-		cre = dec_set_creation(sysname, cre);
-		node = erts_find_or_insert_node(sysname, cre);
+		node = dec_get_node(sysname, cre);
 		if(node == erts_this_node) {
 		    RefThing *rtp = (RefThing *) hp;
 		    ref_num = (Uint32 *) (hp + REF_THING_HEAD_SIZE);
@@ -2560,6 +2676,66 @@ dec_term_atom_common:
 		}
 		break;
 	    }
+	case ATOM_INTERNAL_REF2:
+	    n = get_int16(ep);
+	    ep += 2;
+	    if (n >= atom_table_size()) {
+		goto error;
+	    }
+	    *objp = make_atom(n);
+	    break;
+	case ATOM_INTERNAL_REF3:
+	    n = get_int24(ep);
+	    ep += 3;
+	    if (n >= atom_table_size()) {
+		goto error;
+	    }
+	    *objp = make_atom(n);
+	    break;
+
+	case BINARY_INTERNAL_REF:
+	    {
+		ProcBin* pb = (ProcBin*) hp;
+		sys_memcpy(pb, ep, sizeof(ProcBin));
+		ep += sizeof(ProcBin);
+
+		erts_refc_inc(&pb->val->refc, 1);
+		hp += PROC_BIN_SIZE;
+		pb->next = off_heap->first;
+		off_heap->first = (struct erl_off_heap_header*)pb;
+		pb->flags = 0;
+		*objp = make_binary(pb);
+		break;
+	    }
+	case BIT_BINARY_INTERNAL_REF:
+	    {
+		Sint bitoffs = *ep++;
+		Sint bitsize = *ep++;
+		ProcBin* pb = (ProcBin*) hp;
+		ErlSubBin* sub;
+		sys_memcpy(pb, ep, sizeof(ProcBin));
+		ep += sizeof(ProcBin);
+
+		erts_refc_inc(&pb->val->refc, 1);
+		hp += PROC_BIN_SIZE;
+		pb->next = off_heap->first;
+		off_heap->first = (struct erl_off_heap_header*)pb;
+		pb->flags = 0;
+
+		sub = (ErlSubBin*)hp;
+		sub->thing_word = HEADER_SUB_BIN;
+		sub->size = pb->size - (bitoffs + bitsize + 7)/8;
+		sub->offs = 0;
+		sub->bitoffs = bitoffs;
+		sub->bitsize = bitsize;
+		sub->is_writable = 0;
+		sub->orig = make_binary(pb);
+
+		hp += ERL_SUB_BIN_SIZE;
+		*objp = make_binary(sub);
+		break;
+	    }
+
 	default:
 	error:
 	    /* UNDO:
@@ -2642,20 +2818,29 @@ encode_size_struct2(ErtsAtomCacheMap *acmp, Eterm obj, unsigned dflags)
 	case NIL_DEF:
 	    result++;
 	    break;
-	case ATOM_DEF: {
-	    int alen = atom_tab(atom_val(obj))->len;
-	    if ((MAX_ATOM_LENGTH <= 255 || alen <= 255)
-		&& (dflags & DFLAG_SMALL_ATOM_TAGS)) {
-		/* Make sure a SMALL_ATOM_EXT fits: SMALL_ATOM_EXT l t1 t2... */
-		result += 1 + 1 + alen;
+	case ATOM_DEF:
+	    if (dflags & DFLAGS_INTERNAL_TAGS) {
+		if (atom_val(obj) >= (1<<16)) {
+		    result += 1 + 3;
+		}
+		else {
+		    result += 1 + 2;
+		}
 	    }
 	    else {
-		/* Make sure an ATOM_EXT fits: ATOM_EXT l1 l0 t1 t2... */
-		result += 1 + 2 + alen;
+		int alen = atom_tab(atom_val(obj))->len;
+		if ((MAX_ATOM_LENGTH <= 255 || alen <= 255)
+		    && (dflags & DFLAG_SMALL_ATOM_TAGS)) {
+		    /* Make sure a SMALL_ATOM_EXT fits: SMALL_ATOM_EXT l t1 t2... */
+			result += 1 + 1 + alen;
+		}
+		else {
+		    /* Make sure an ATOM_EXT fits: ATOM_EXT l1 l0 t1 t2... */
+			result += 1 + 2 + alen;
+		}
+		insert_acache_map(acmp, obj);
 	    }
-	    insert_acache_map(acmp, obj);
 	    break;
-	}
 	case SMALL_DEF:
 	    {
 		Sint val = signed_val(obj);
@@ -2734,8 +2919,25 @@ encode_size_struct2(ErtsAtomCacheMap *acmp, Eterm obj, unsigned dflags)
 	    }
 	    break;
 	case BINARY_DEF:
+	    if (dflags & DFLAGS_INTERNAL_TAGS) {
+		ProcBin* pb = (ProcBin*) binary_val(obj);
+		Uint sub_extra = 0;
+		Uint tot_bytes = pb->size;
+		if (pb->thing_word == HEADER_SUB_BIN) {
+		    ErlSubBin* sub = (ErlSubBin*) pb;
+		    pb = (ProcBin*) binary_val(sub->orig);
+		    sub_extra = 2;  /* bitoffs and bitsize */
+		    tot_bytes += (sub->bitoffs + sub->bitsize+ 7) / 8;
+		}
+		if (pb->thing_word == HEADER_PROC_BIN
+		    && heap_bin_size(tot_bytes) > PROC_BIN_SIZE) {
+
+		    result += 1 + sub_extra + sizeof(ProcBin);
+		    break;
+		}
+	    }
 	    result += 1 + 4 + binary_size(obj) +
-		5;			/* For unaligned binary */
+		    5;			/* For unaligned binary */
 	    break;
 	case FUN_DEF:
 	    {
@@ -2807,7 +3009,7 @@ encode_size_struct2(ErtsAtomCacheMap *acmp, Eterm obj, unsigned dflags)
 }
 
 static Sint
-decoded_size(byte *ep, byte* endp, int no_refc_bins)
+decoded_size(byte *ep, byte* endp, int no_refc_bins, int internal_tags)
 {
     int heap_size = 0;
     int terms;
@@ -3017,6 +3219,29 @@ decoded_size(byte *ep, byte* endp, int no_refc_bins)
 		heap_size += ERL_FUN_SIZE + num_free;
 		break;
 	    }
+	case ATOM_INTERNAL_REF2:
+	    SKIP(2+atom_extra_skip);
+	    atom_extra_skip = 0;
+	    break;
+	case ATOM_INTERNAL_REF3:
+	    SKIP(3+atom_extra_skip);
+	    atom_extra_skip = 0;
+	    break;
+
+	case BINARY_INTERNAL_REF:
+	    if (!internal_tags) {
+		return -1;
+	    }
+	    SKIP(sizeof(ProcBin));
+	    heap_size += PROC_BIN_SIZE;
+	    break;
+	case BIT_BINARY_INTERNAL_REF:
+	    if (!internal_tags) {
+		return -1;
+	    }
+	    SKIP(2+sizeof(ProcBin));
+	    heap_size += PROC_BIN_SIZE + ERL_SUB_BIN_SIZE;
+	    break;
 	default:
 	    return -1;
 	}
diff --git a/erts/emulator/beam/external.h b/erts/emulator/beam/external.h
index cee48bbeb0..d8287b96a4 100644
--- a/erts/emulator/beam/external.h
+++ b/erts/emulator/beam/external.h
@@ -54,6 +54,10 @@
 
 #define DIST_HEADER       'D'
 #define ATOM_CACHE_REF    'R'
+#define ATOM_INTERNAL_REF2 'I'
+#define ATOM_INTERNAL_REF3 'K'
+#define BINARY_INTERNAL_REF 'J'
+#define BIT_BINARY_INTERNAL_REF 'L'
 #define COMPRESSED        'P'
 
 #if 0
@@ -156,7 +160,9 @@ Uint erts_encode_dist_ext_size(Eterm, Uint32, ErtsAtomCacheMap *);
 void erts_encode_dist_ext(Eterm, byte **, Uint32, ErtsAtomCacheMap *);
 
 Uint erts_encode_ext_size(Eterm);
+Uint erts_encode_ext_size_ets(Eterm);
 void erts_encode_ext(Eterm, byte **);
+byte* erts_encode_ext_ets(Eterm, byte *, struct erl_off_heap_header** ext_off_heap);
 
 #ifdef ERTS_WANT_EXTERNAL_TAGS
 ERTS_GLB_INLINE void erts_peek_dist_header(ErtsDistHeaderPeek *, byte *, Uint);
@@ -172,7 +178,9 @@ Sint erts_decode_dist_ext_size(ErtsDistExternal *, int);
 Eterm erts_decode_dist_ext(Eterm **, ErlOffHeap *, ErtsDistExternal *);
 
 Sint erts_decode_ext_size(byte*, Uint, int);
+Sint erts_decode_ext_size_ets(byte*, Uint);
 Eterm erts_decode_ext(Eterm **, ErlOffHeap *, byte**);
+Eterm erts_decode_ext_ets(Eterm **, ErlOffHeap *, byte*);
 
 Eterm erts_term_to_binary(Process* p, Eterm Term, int level, Uint flags);
 
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 12536f6cde..89c6625550 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -522,6 +522,7 @@ union erl_off_heap_ptr {
     struct erl_fun_thing* fun;
     struct external_thing_* ext;
     Eterm* ep;
+    void* voidp;
 };
 
 /* arrays that get malloced at startup */
diff --git a/erts/emulator/beam/packet_parser.c b/erts/emulator/beam/packet_parser.c
index 5bcd567b5f..a66d60aa22 100644
--- a/erts/emulator/beam/packet_parser.c
+++ b/erts/emulator/beam/packet_parser.c
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 2008-2009. All Rights Reserved.
+ * Copyright Ericsson AB 2008-2010. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -47,11 +47,6 @@
                              (((unsigned char*) (s))[1] << 8) | \
                              (((unsigned char*) (s))[0]))
 
-#define put_int24(s, x) ((((unsigned char*)(s))[0] = ((x) >> 16) & 0xff), \
-                         (((unsigned char*)(s))[1] = ((x) >> 8) & 0xff), \
-                         (((unsigned char*)(s))[2] = (x) & 0xff))
-
-
 #if !defined(__WIN32__) && !defined(HAVE_STRNCASECMP)
 #define STRNCASECMP my_strncasecmp
 
@@ -833,7 +828,7 @@ int packet_parse_ssl(const char* buf, int len,
         char prefix[4];
         /* <<1:8,Length:24,Data/binary>> */
         prefix[0] = 1;
-        put_int24(&prefix[1],len-3);
+        put_int24(len-3,&prefix[1]);
         return pcb->ssl_tls(arg, 22, major, minor, buf+3, len-3, prefix, sizeof(prefix));
     } 
     else {
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index 93203a08a9..0d15272aa8 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -1166,6 +1166,15 @@ void* sys_calloc2(Uint, Uint);
                             ((char*)(s))[3] = (char)(i)         & 0xff;} \
                         while (0)
 
+#define get_int24(s) ((((unsigned char*) (s))[0] << 16) | \
+                      (((unsigned char*) (s))[1] << 8)  | \
+                      (((unsigned char*) (s))[2]))
+
+#define put_int24(i, s) do {((char*)(s))[0] = (char)((i) >> 16) & 0xff;  \
+                            ((char*)(s))[1] = (char)((i) >> 8)  & 0xff;  \
+                            ((char*)(s))[2] = (char)(i)         & 0xff;} \
+                        while (0)
+
 #define get_int16(s) ((((unsigned char*)  (s))[0] << 8) | \
                       (((unsigned char*)  (s))[1]))
 
@@ -1179,6 +1188,7 @@ void* sys_calloc2(Uint, Uint);
 
 #define put_int8(i, s) do {((unsigned char*)(s))[0] = (i) & 0xff;} while (0)
 
+
 /*
  * Use DEBUGF as you would use printf, but use double parentheses:
  *