diff --git a/db/src/bootstrap.rs b/db/src/bootstrap.rs
index 7d745347..4584284d 100644
--- a/db/src/bootstrap.rs
+++ b/db/src/bootstrap.rs
@@ -85,10 +85,10 @@ lazy_static! {
         ]
     };
 
-    pub static ref V1_PARTS: [(symbols::Keyword, i64, i64, i64); 3] = {
-            [(ns_keyword!("db.part", "db"), 0, USER0 - 1, (1 + V1_IDENTS.len()) as i64),
-             (ns_keyword!("db.part", "user"), USER0, TX0 - 1, USER0),
-             (ns_keyword!("db.part", "tx"), TX0, i64::max_value(), TX0),
+    pub static ref V1_PARTS: [(symbols::Keyword, i64, i64, i64, bool); 3] = {
+            [(ns_keyword!("db.part", "db"), 0, USER0 - 1, (1 + V1_IDENTS.len()) as i64, false),
+             (ns_keyword!("db.part", "user"), USER0, TX0 - 1, USER0, true),
+             (ns_keyword!("db.part", "tx"), TX0, i64::max_value(), TX0, false),
         ]
     };
 
@@ -277,7 +277,7 @@ fn symbolic_schema_to_assertions(symbolic_schema: &Value) -> Result<Vec<Value>>
 
 pub(crate) fn bootstrap_partition_map() -> PartitionMap {
     V1_PARTS.iter()
-            .map(|&(ref part, start, end, index)| (part.to_string(), Partition::new(start, end, index)))
+            .map(|&(ref part, start, end, index, allow_excision)| (part.to_string(), Partition::new(start, end, index, allow_excision)))
             .collect()
 }
 
diff --git a/db/src/db.rs b/db/src/db.rs
index 47b2057a..be350905 100644
--- a/db/src/db.rs
+++ b/db/src/db.rs
@@ -247,7 +247,7 @@ lazy_static! {
         r#"CREATE TABLE schema (e INTEGER NOT NULL, a SMALLINT NOT NULL, v BLOB NOT NULL, value_type_tag SMALLINT NOT NULL)"#,
         r#"CREATE INDEX idx_schema_unique ON schema (e, a, v, value_type_tag)"#,
         // TODO: store entid instead of ident for partition name.
-        r#"CREATE TABLE parts (part TEXT NOT NULL PRIMARY KEY, start INTEGER NOT NULL, end INTEGER NOT NULL, idx INTEGER NOT NULL)"#,
+        r#"CREATE TABLE parts (part TEXT NOT NULL PRIMARY KEY, start INTEGER NOT NULL, end INTEGER NOT NULL, idx INTEGER NOT NULL, allow_excision SMALLINT NOT NULL)"#,
         ]
     };
 }
@@ -299,7 +299,7 @@ pub fn create_current_version(conn: &mut rusqlite::Connection) -> Result<DB> {
     // This is necessary: `transact` will only UPDATE parts, not INSERT them if they're missing.
     for (part, partition) in db.partition_map.iter() {
         // TODO: Convert "keyword" part to SQL using Value conversion.
-        tx.execute("INSERT INTO parts (part, start, end, idx) VALUES (?, ?, ?, ?)", &[part, &partition.start, &partition.end, &partition.index])?;
+        tx.execute("INSERT INTO parts (part, start, end, idx, allow_excision) VALUES (?, ?, ?, ?, ?)", &[part, &partition.start, &partition.end, &partition.index, &partition.allow_excision])?;
     }
 
     // TODO: return to transact_internal to self-manage the encompassing SQLite transaction.
@@ -441,9 +441,9 @@ fn read_materialized_view(conn: &rusqlite::Connection, table: &str) -> Result<Ve
 
 /// Read the partition map materialized view from the given SQL store.
 fn read_partition_map(conn: &rusqlite::Connection) -> Result<PartitionMap> {
-    let mut stmt: rusqlite::Statement = conn.prepare("SELECT part, start, end, idx FROM parts")?;
+    let mut stmt: rusqlite::Statement = conn.prepare("SELECT part, start, end, idx, allow_excision FROM parts")?;
     let m = stmt.query_and_then(&[], |row| -> Result<(String, Partition)> {
-        Ok((row.get_checked(0)?, Partition::new(row.get_checked(1)?, row.get_checked(2)?, row.get_checked(3)?)))
+        Ok((row.get_checked(0)?, Partition::new(row.get_checked(1)?, row.get_checked(2)?, row.get_checked(3)?, row.get_checked(4)?)))
     })?.collect();
     m
 }
@@ -1280,7 +1280,7 @@ mod tests {
             // Add a fake partition to allow tests to do things like
             // [:db/add 111 :foo/bar 222]
             {
-                let fake_partition = Partition { start: 100, end: 2000, index: 1000 };
+                let fake_partition = Partition { start: 100, end: 2000, index: 1000, allow_excision: true };
                 parts.insert(":db.part/fake".into(), fake_partition);
             }
 
diff --git a/db/src/types.rs b/db/src/types.rs
index 39d221eb..f9404365 100644
--- a/db/src/types.rs
+++ b/db/src/types.rs
@@ -45,12 +45,14 @@ pub struct Partition {
     pub end: i64,
     /// The next entid to be allocated in the partition.
     pub index: i64,
+    /// `true` if entids in the partition can be excised with `:db/excise`.
+    pub allow_excision: bool,
 }
 
 impl Partition {
-    pub fn new(start: i64, end: i64, next: i64) -> Partition {
-        assert!(start <= next, "A partition represents a monotonic increasing sequence of entids.");
-        Partition { start: start, end: end, index: next }
+    pub fn new(start: i64, end: i64, index: i64, allow_excision: bool) -> Partition {
+        assert!(start <= index, "A partition represents a monotonic increasing sequence of entids.");
+        Partition { start, end, index, allow_excision }
     }
 
     pub fn contains_entid(&self, e: i64) -> bool {