validation: randomly compact chainstate

diff --git a/src/dbwrapper.cpp b/src/dbwrapper.cpp
index d51a347c..ffe6f267 100644
--- a/src/dbwrapper.cpp
+++ b/src/dbwrapper.cpp
@@ -256,7 +256,7 @@ CDBWrapper::CDBWrapper(const DBParams& params)
 
     if (params.options.force_compact) {
         LogInfo("Starting database compaction of %s", fs::PathToString(params.path));
-        DBContext().pdb->CompactRange(nullptr, nullptr);
+        CompactFull();
         LogInfo("Finished database compaction of %s", fs::PathToString(params.path));
     }
 
@@ -307,6 +307,8 @@ std::optional<std::string> CDBWrapper::GetProperty(const std::string& property)
     return std::nullopt;
 }
 
+void CDBWrapper::CompactFull() { DBContext().pdb->CompactRange(nullptr, nullptr); }
+
 size_t CDBWrapper::DynamicMemoryUsage() const
 {
     std::optional<size_t> parsed;
diff --git a/src/dbwrapper.h b/src/dbwrapper.h
index a5f63116..83da6feb 100644
--- a/src/dbwrapper.h
+++ b/src/dbwrapper.h
@@ -258,6 +258,9 @@ public:
 
     void WriteBatch(CDBBatch& batch, bool fSync = false);
 
+    //! Perform a blocking full compaction of the underlying LevelDB.
+    void CompactFull();
+
     //! Return a LevelDB property value, if available.
     std::optional<std::string> GetProperty(const std::string& property) const;
 
diff --git a/src/test/coins_tests.cpp b/src/test/coins_tests.cpp
index 847297e5..4c5ed748 100644
--- a/src/test/coins_tests.cpp
+++ b/src/test/coins_tests.cpp
@@ -1078,6 +1078,8 @@ BOOST_FIXTURE_TEST_CASE(coins_db_leveldb_layout, FlushTest)
     cache.Sync();
 
     BOOST_CHECK_EQUAL(level2_files(base), 0);
+    WITH_LOCK(::cs_main, base.CompactFull());
+    BOOST_CHECK_EQUAL(level2_files(base), 1);
 
     BOOST_CHECK(*Assert(base.GetCoin(outpoint)) == coin);
     BOOST_CHECK_EQUAL(base.GetBestBlock(), block_hash);
diff --git a/src/txdb.cpp b/src/txdb.cpp
index 7f45a7c0..62dc49a5 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -180,6 +180,14 @@ std::optional<std::string> CCoinsViewDB::GetDBProperty(const std::string& proper
     return m_db->GetProperty(property);
 }
 
+void CCoinsViewDB::CompactFull()
+{
+    AssertLockHeld(::cs_main);
+    LogDebug(BCLog::COINDB, "Starting chainstate compaction of %s", fs::PathToString(m_db_params.path));
+    m_db->CompactFull();
+    LogDebug(BCLog::COINDB, "Finished chainstate compaction of %s", fs::PathToString(m_db_params.path));
+}
+
 /** Specialization of CCoinsViewCursor to iterate over a CCoinsViewDB */
 class CCoinsViewDBCursor: public CCoinsViewCursor
 {
diff --git a/src/txdb.h b/src/txdb.h
index 827b36f3..648adc85 100644
--- a/src/txdb.h
+++ b/src/txdb.h
@@ -56,6 +56,9 @@ public:
     //! Dynamically alter the underlying leveldb cache size.
     void ResizeCache(size_t new_cache_size) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
+    //! Perform a blocking full compaction of the underlying LevelDB.
+    void CompactFull() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
+
     //! Return an underlying LevelDB property value, if available.
     std::optional<std::string> GetDBProperty(const std::string& property);
 };
diff --git a/src/validation.cpp b/src/validation.cpp
index 77e91999..df4bd867 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -113,6 +113,13 @@ const std::vector<std::string> CHECKLEVEL_DOC {
  * */
 static constexpr int PRUNE_LOCK_BUFFER{10};
 
+// Return whether the completed full flush should compact chainstate
+static bool ShouldCompactChainstate(bool in_ibd)
+{
+    static constexpr uint32_t flush_ratio{320}; // Roughly every 2 weeks with hourly flushes
+    return !in_ibd && FastRandomContext().randrange(flush_ratio) == 0;
+}
+
 TRACEPOINT_SEMAPHORE(validation, block_connected);
 TRACEPOINT_SEMAPHORE(utxocache, flush);
 TRACEPOINT_SEMAPHORE(mempool, replaced);
@@ -2825,9 +2832,17 @@ bool Chainstate::FlushStateToDisk(
             m_next_write = FastRandomContext().rand_uniform_delay(NodeClock::now() + DATABASE_WRITE_INTERVAL_MIN, range);
         }
     }
-    if (full_flush_completed && m_chainman.m_options.signals) {
-        // Update best block in wallet (so we can detect restored wallets).
-        m_chainman.m_options.signals->ChainStateFlushed(this->GetRole(), GetLocator(m_chain.Tip()));
+    if (full_flush_completed) {
+        if (m_chainman.m_options.signals) {
+            // Update best block in wallet (so we can detect restored wallets).
+            m_chainman.m_options.signals->ChainStateFlushed(this->GetRole(), GetLocator(m_chain.Tip()));
+        }
+
+        if (!m_chainman.m_interrupt && m_chainman.m_chainstates.size() == 1) { // Skip AssumeUTXO
+            if (ShouldCompactChainstate(m_chainman.IsInitialBlockDownload())) {
+                CoinsDB().CompactFull();
+            }
+        }
     }
     } catch (const std::runtime_error& e) {
         return FatalError(m_chainman.GetNotifications(), state, strprintf(_("System error while flushing: %s"), e.what()));