diff --git a/include/ircd/db/db.h b/include/ircd/db/db.h
index dadb06524..68d1bdc14 100644
--- a/include/ircd/db/db.h
+++ b/include/ircd/db/db.h
@@ -51,7 +51,7 @@ namespace ircd::db
 #include "cache.h"
 #include "opts.h"
 #include "column.h"
-#include "index.h"
+#include "domain.h"
 #include "cell.h"
 #include "row.h"
 #include "json.h"
diff --git a/include/ircd/db/index.h b/include/ircd/db/domain.h
similarity index 64%
rename from include/ircd/db/index.h
rename to include/ircd/db/domain.h
index 75179ab5d..c107faa6f 100644
--- a/include/ircd/db/index.h
+++ b/include/ircd/db/domain.h
@@ -13,30 +13,30 @@
 
 namespace ircd::db
 {
-	struct index;
+	struct domain;
 }
 
-/// An index is a glorified column; the database descriptor for this column
-/// must specify a prefix-extractor otherwise this index just behaves like
-/// a regular key/value column. Index is used to create iterable domains of
+/// An domain is a glorified column; the database descriptor for this column
+/// must specify a prefix-extractor otherwise this domain just behaves like
+/// a regular key/value column. domain is used to create iterable domains of
 /// a column which all share the same key-prefix.
 ///
-/// The index allows a concatenation of two strings to form a key. This con-
+/// The domain allows a concatenation of two strings to form a key. This con-
 /// catenated key is still unique for the column as a whole and is stored as
 /// the full concatenation -- however, as stated above the prefix function must
 /// be aware of how such a concatenation can be separated back into two
 /// strings.
 ///
-/// db::index allows the user to query for either just the first string, or
+/// db::domain allows the user to query for either just the first string, or
 /// the whole concatenation. In either case, the resulting iterator can move
 /// only around the keys and values within the domain of that first string.
 /// The iterator presents the user with it.first = second string only, thereby
 /// hiding the prefix allowing for easier iteration of the domain.
 ///
-/// Index is not good at reverse iteration due to limitations in RocksDB. Thus
+/// domain is not good at reverse iteration due to limitations in RocksDB. Thus
 /// it's better to just flip the comparator function for the column.
 ///
-struct ircd::db::index
+struct ircd::db::domain
 :column
 {
 	struct const_iterator_base;
@@ -58,42 +58,42 @@ struct ircd::db::index
 
 namespace ircd::db
 {
-	bool seek(index::const_iterator_base &, const string_view &);
-	bool seek(index::const_iterator_base &, const pos &);
+	bool seek(domain::const_iterator_base &, const string_view &);
+	bool seek(domain::const_iterator_base &, const pos &);
 }
 
-struct ircd::db::index::const_iterator_base
+struct ircd::db::domain::const_iterator_base
 :ircd::db::column::const_iterator_base
 {
-	friend class index;
+	friend class domain;
 
 	const value_type &operator*() const;
 	const value_type *operator->() const;
 
 	using column::const_iterator_base::const_iterator_base;
 
-	friend bool seek(index::const_iterator_base &, const string_view &);
-	friend bool seek(index::const_iterator_base &, const pos &);
+	friend bool seek(domain::const_iterator_base &, const string_view &);
+	friend bool seek(domain::const_iterator_base &, const pos &);
 };
 
-struct ircd::db::index::const_iterator
-:ircd::db::index::const_iterator_base
+struct ircd::db::domain::const_iterator
+:ircd::db::domain::const_iterator_base
 {
-	friend class index;
+	friend class domain;
 
 	const_iterator &operator++();
 	const_iterator &operator--();
 
-	using index::const_iterator_base::const_iterator_base;
+	using domain::const_iterator_base::const_iterator_base;
 };
 
-struct ircd::db::index::const_reverse_iterator
-:ircd::db::index::const_iterator_base
+struct ircd::db::domain::const_reverse_iterator
+:ircd::db::domain::const_iterator_base
 {
-	friend class index;
+	friend class domain;
 
 	const_reverse_iterator &operator++();
 	const_reverse_iterator &operator--();
 
-	using index::const_iterator_base::const_iterator_base;
+	using domain::const_iterator_base::const_iterator_base;
 };
diff --git a/include/ircd/m/dbs/event_horizon.h b/include/ircd/m/dbs/event_horizon.h
index d9eb37864..f6e0af73d 100644
--- a/include/ircd/m/dbs/event_horizon.h
+++ b/include/ircd/m/dbs/event_horizon.h
@@ -23,7 +23,7 @@ namespace ircd::m::dbs
 	std::tuple<event::idx> event_horizon_key(const string_view &amalgam);
 
 	// event_id | event_idx
-	extern db::index event_horizon;
+	extern db::domain event_horizon;
 }
 
 namespace ircd::m::dbs::desc
diff --git a/include/ircd/m/dbs/event_refs.h b/include/ircd/m/dbs/event_refs.h
index df950168e..1d61f87e7 100644
--- a/include/ircd/m/dbs/event_refs.h
+++ b/include/ircd/m/dbs/event_refs.h
@@ -29,7 +29,7 @@ namespace ircd::m::dbs
 	};
 
 	// event_idx | ref_type, event_idx
-	extern db::index event_refs;
+	extern db::domain event_refs;
 
 	string_view
 	event_refs_key(const mutable_buffer &out,
diff --git a/include/ircd/m/dbs/event_sender.h b/include/ircd/m/dbs/event_sender.h
index de24264d9..4dc98ce00 100644
--- a/include/ircd/m/dbs/event_sender.h
+++ b/include/ircd/m/dbs/event_sender.h
@@ -23,7 +23,7 @@ namespace ircd::m::dbs
 	std::tuple<string_view, event::idx> event_sender_key(const string_view &amalgam);
 
 	// host | local, event_idx
-	extern db::index event_sender;
+	extern db::domain event_sender;
 }
 
 namespace ircd::m::dbs::desc
diff --git a/include/ircd/m/dbs/event_type.h b/include/ircd/m/dbs/event_type.h
index 901ff1b5c..62ac3cb05 100644
--- a/include/ircd/m/dbs/event_type.h
+++ b/include/ircd/m/dbs/event_type.h
@@ -22,7 +22,7 @@ namespace ircd::m::dbs
 	std::tuple<event::idx> event_type_key(const string_view &amalgam);
 
 	// type | event_idx => -
-	extern db::index event_type;
+	extern db::domain event_type;
 }
 
 namespace ircd::m::dbs::desc
diff --git a/include/ircd/m/dbs/room_events.h b/include/ircd/m/dbs/room_events.h
index e36fea282..da52b03ad 100644
--- a/include/ircd/m/dbs/room_events.h
+++ b/include/ircd/m/dbs/room_events.h
@@ -23,7 +23,7 @@ namespace ircd::m::dbs
 	std::pair<uint64_t, event::idx> room_events_key(const string_view &amalgam);
 
 	// room_id | depth, event_idx => node_id
-	extern db::index room_events;
+	extern db::domain room_events;
 }
 
 namespace ircd::m::dbs::desc
diff --git a/include/ircd/m/dbs/room_head.h b/include/ircd/m/dbs/room_head.h
index b2ecab547..b06dac576 100644
--- a/include/ircd/m/dbs/room_head.h
+++ b/include/ircd/m/dbs/room_head.h
@@ -22,7 +22,7 @@ namespace ircd::m::dbs
 	string_view room_head_key(const string_view &amalgam);
 
 	// room_id | event_id => event_idx
-	extern db::index room_head;
+	extern db::domain room_head;
 }
 
 namespace ircd::m::dbs::desc
diff --git a/include/ircd/m/dbs/room_joined.h b/include/ircd/m/dbs/room_joined.h
index 41e591d5a..5de3c2a56 100644
--- a/include/ircd/m/dbs/room_joined.h
+++ b/include/ircd/m/dbs/room_joined.h
@@ -23,7 +23,7 @@ namespace ircd::m::dbs
 	std::pair<string_view, string_view> room_joined_key(const string_view &amalgam);
 
 	// room_id | origin, member => event_idx
-	extern db::index room_joined;
+	extern db::domain room_joined;
 }
 
 namespace ircd::m::dbs::desc
diff --git a/include/ircd/m/dbs/room_state.h b/include/ircd/m/dbs/room_state.h
index c0550996c..e08abdb5e 100644
--- a/include/ircd/m/dbs/room_state.h
+++ b/include/ircd/m/dbs/room_state.h
@@ -23,7 +23,7 @@ namespace ircd::m::dbs
 	std::pair<string_view, string_view> room_state_key(const string_view &amalgam);
 
 	// room_id | type, state_key => event_idx
-	extern db::index room_state;
+	extern db::domain room_state;
 }
 
 namespace ircd::m::dbs::desc
diff --git a/include/ircd/m/dbs/room_state_space.h b/include/ircd/m/dbs/room_state_space.h
index a2a5b6d95..21fa5454d 100644
--- a/include/ircd/m/dbs/room_state_space.h
+++ b/include/ircd/m/dbs/room_state_space.h
@@ -30,7 +30,7 @@ namespace ircd::m::dbs
 	room_state_space_key_parts room_state_space_key(const string_view &amalgam);
 
 	// room_id | type, state_key, depth, event_idx => --
-	extern db::index room_state_space;
+	extern db::domain room_state_space;
 }
 
 namespace ircd::m::dbs::desc
diff --git a/include/ircd/m/room/messages.h b/include/ircd/m/room/messages.h
index 609822662..df9c4b5a1 100644
--- a/include/ircd/m/room/messages.h
+++ b/include/ircd/m/room/messages.h
@@ -46,7 +46,7 @@ namespace ircd::m
 struct ircd::m::room::messages
 {
 	m::room room;
-	db::index::const_iterator it;
+	db::domain::const_iterator it;
 	event::fetch _event;
 
   public:
diff --git a/ircd/db.cc b/ircd/db.cc
index f580fca22..d27ce3bc6 100644
--- a/ircd/db.cc
+++ b/ircd/db.cc
@@ -4995,13 +4995,13 @@ const
 //
 
 const ircd::db::gopts
-ircd::db::index::applied_opts
+ircd::db::domain::applied_opts
 {
 	{ get::PREFIX }
 };
 
 bool
-ircd::db::seek(index::const_iterator_base &it,
+ircd::db::seek(domain::const_iterator_base &it,
                const pos &p)
 {
 	switch(p)
@@ -5021,21 +5021,21 @@ ircd::db::seek(index::const_iterator_base &it,
 			break;
 	}
 
-	it.opts |= index::applied_opts;
+	it.opts |= domain::applied_opts;
 	return seek(static_cast<column::const_iterator_base &>(it), p);
 }
 
 bool
-ircd::db::seek(index::const_iterator_base &it,
+ircd::db::seek(domain::const_iterator_base &it,
                const string_view &p)
 {
-	it.opts |= index::applied_opts;
+	it.opts |= domain::applied_opts;
 	return seek(static_cast<column::const_iterator_base &>(it), p);
 }
 
-ircd::db::index::const_iterator
-ircd::db::index::begin(const string_view &key,
-                       gopts opts)
+ircd::db::domain::const_iterator
+ircd::db::domain::begin(const string_view &key,
+                        gopts opts)
 {
 	const_iterator ret
 	{
@@ -5046,9 +5046,9 @@ ircd::db::index::begin(const string_view &key,
 	return ret;
 }
 
-ircd::db::index::const_iterator
-ircd::db::index::end(const string_view &key,
-                     gopts opts)
+ircd::db::domain::const_iterator
+ircd::db::domain::end(const string_view &key,
+                      gopts opts)
 {
 	const_iterator ret
 	{
@@ -5063,13 +5063,13 @@ ircd::db::index::end(const string_view &key,
 
 /// NOTE: RocksDB says they don't support reverse iteration over a prefix range
 /// This means we have to forward scan to the end and then walk back! Reverse
-/// iterations of an index shoud only be used for debugging and statistics! The
-/// index should be ordered the way it will be primarily accessed using the
+/// iterations of a domain should only be used for debugging and statistics! The
+/// domain should be ordered the way it will be primarily accessed using the
 /// comparator. If it will be accessed in different directions, make another
-/// index column.
-ircd::db::index::const_reverse_iterator
-ircd::db::index::rbegin(const string_view &key,
-                        gopts opts)
+/// domain column.
+ircd::db::domain::const_reverse_iterator
+ircd::db::domain::rbegin(const string_view &key,
+                         gopts opts)
 {
 	const_reverse_iterator ret
 	{
@@ -5082,9 +5082,9 @@ ircd::db::index::rbegin(const string_view &key,
 	return ret;
 }
 
-ircd::db::index::const_reverse_iterator
-ircd::db::index::rend(const string_view &key,
-                      gopts opts)
+ircd::db::domain::const_reverse_iterator
+ircd::db::domain::rend(const string_view &key,
+                       gopts opts)
 {
 	const_reverse_iterator ret
 	{
@@ -5101,8 +5101,8 @@ ircd::db::index::rend(const string_view &key,
 // const_iterator
 //
 
-ircd::db::index::const_iterator &
-ircd::db::index::const_iterator::operator--()
+ircd::db::domain::const_iterator &
+ircd::db::domain::const_iterator::operator--()
 {
 	if(likely(bool(*this)))
 		seek(*this, pos::PREV);
@@ -5112,8 +5112,8 @@ ircd::db::index::const_iterator::operator--()
 	return *this;
 }
 
-ircd::db::index::const_iterator &
-ircd::db::index::const_iterator::operator++()
+ircd::db::domain::const_iterator &
+ircd::db::domain::const_iterator::operator++()
 {
 	if(likely(bool(*this)))
 		seek(*this, pos::NEXT);
@@ -5123,8 +5123,8 @@ ircd::db::index::const_iterator::operator++()
 	return *this;
 }
 
-ircd::db::index::const_reverse_iterator &
-ircd::db::index::const_reverse_iterator::operator--()
+ircd::db::domain::const_reverse_iterator &
+ircd::db::domain::const_reverse_iterator::operator--()
 {
 	if(likely(bool(*this)))
 		seek(*this, pos::NEXT);
@@ -5134,8 +5134,8 @@ ircd::db::index::const_reverse_iterator::operator--()
 	return *this;
 }
 
-ircd::db::index::const_reverse_iterator &
-ircd::db::index::const_reverse_iterator::operator++()
+ircd::db::domain::const_reverse_iterator &
+ircd::db::domain::const_reverse_iterator::operator++()
 {
 	if(likely(bool(*this)))
 		seek(*this, pos::PREV);
@@ -5145,8 +5145,8 @@ ircd::db::index::const_reverse_iterator::operator++()
 	return *this;
 }
 
-const ircd::db::index::const_iterator_base::value_type &
-ircd::db::index::const_iterator_base::operator*()
+const ircd::db::domain::const_iterator_base::value_type &
+ircd::db::domain::const_iterator_base::operator*()
 const
 {
 	const auto &prefix
@@ -5158,7 +5158,7 @@ const
 	column::const_iterator_base::operator*();
 	string_view &key{val.first};
 
-	// When there's no prefixing this index column is just
+	// When there's no prefixing this domain column is just
 	// like a normal column. Otherwise, we remove the prefix
 	// from the key the user will end up seeing.
 	if(prefix.has && prefix.has(key))
@@ -5171,8 +5171,8 @@ const
 	return val;
 }
 
-const ircd::db::index::const_iterator_base::value_type *
-ircd::db::index::const_iterator_base::operator->()
+const ircd::db::domain::const_iterator_base::value_type *
+ircd::db::domain::const_iterator_base::operator->()
 const
 {
 	return &this->operator*();
diff --git a/ircd/m_dbs.cc b/ircd/m_dbs.cc
index 3da2e0302..774504971 100644
--- a/ircd/m_dbs.cc
+++ b/ircd/m_dbs.cc
@@ -185,15 +185,15 @@ ircd::m::dbs::init::init(const string_view &servername,
 	// Construct global convenience references for the metadata columns
 	event_idx = db::column{*events, desc::events__event_idx.name};
 	event_json = db::column{*events, desc::events__event_json.name};
-	event_refs = db::index{*events, desc::events__event_refs.name};
-	event_horizon = db::index{*events, desc::events__event_horizon.name};
-	event_sender = db::index{*events, desc::events__event_sender.name};
-	event_type = db::index{*events, desc::events__event_type.name};
-	room_head = db::index{*events, desc::events__room_head.name};
-	room_events = db::index{*events, desc::events__room_events.name};
-	room_joined = db::index{*events, desc::events__room_joined.name};
-	room_state = db::index{*events, desc::events__room_state.name};
-	room_state_space = db::index{*events, desc::events__room_state_space.name};
+	event_refs = db::domain{*events, desc::events__event_refs.name};
+	event_horizon = db::domain{*events, desc::events__event_horizon.name};
+	event_sender = db::domain{*events, desc::events__event_sender.name};
+	event_type = db::domain{*events, desc::events__event_type.name};
+	room_head = db::domain{*events, desc::events__room_head.name};
+	room_events = db::domain{*events, desc::events__room_events.name};
+	room_joined = db::domain{*events, desc::events__room_joined.name};
+	room_state = db::domain{*events, desc::events__room_state.name};
+	room_state_space = db::domain{*events, desc::events__room_state_space.name};
 	state_node = db::column{*events, desc::events__state_node.name};
 }
 
diff --git a/ircd/m_room.cc b/ircd/m_room.cc
index ac1f83a7b..547bcafb9 100644
--- a/ircd/m_room.cc
+++ b/ircd/m_room.cc
@@ -3267,7 +3267,7 @@ bool
 ircd::m::room::origins::has(const string_view &origin)
 const
 {
-	db::index &index
+	db::domain &index
 	{
 		dbs::room_joined
 	};
@@ -3340,7 +3340,7 @@ bool
 ircd::m::room::origins::_for_each(const origins &origins,
                                   const closure_bool &view)
 {
-	db::index &index
+	db::domain &index
 	{
 		dbs::room_joined
 	};