node, qt: inline `DEFAULT_DB_CACHE`

diff --git a/src/node/caches.cpp b/src/node/caches.cpp
index c25b3e9a..6eb2c0a3 100644
--- a/src/node/caches.cpp
+++ b/src/node/caches.cpp
@@ -41,7 +41,7 @@ uint64_t GetDefaultDBCache()
             return HIGH_DEFAULT_DBCACHE;
         }
     }
-    return DEFAULT_DB_CACHE;
+    return DEFAULT_KERNEL_CACHE;
 }
 
 uint64_t CalculateDbCacheBytes(const ArgsManager& args)
diff --git a/src/node/caches.h b/src/node/caches.h
index 756dfa37..14056a25 100644
--- a/src/node/caches.h
+++ b/src/node/caches.h
@@ -14,8 +14,6 @@
 
 class ArgsManager;
 
-//! -dbcache default (bytes)
-static constexpr uint64_t DEFAULT_DB_CACHE{DEFAULT_KERNEL_CACHE};
 //! Reserved non-dbcache memory usage.
 static constexpr uint64_t DBCACHE_WARNING_RESERVED_RAM{2_GiB};
 
@@ -34,7 +32,7 @@ CacheSizes CalculateCacheSizes(const ArgsManager& args, size_t n_indexes = 0);
 constexpr bool ShouldWarnOversizedDbCache(uint64_t dbcache, uint64_t total_ram) noexcept
 {
     const uint64_t available_ram{total_ram > DBCACHE_WARNING_RESERVED_RAM ? total_ram - DBCACHE_WARNING_RESERVED_RAM : 0};
-    const uint64_t cap{std::max<uint64_t>(DEFAULT_DB_CACHE, (available_ram / 4) * 3)};
+    const uint64_t cap{std::max(DEFAULT_KERNEL_CACHE, (available_ram / 4) * 3)};
     return dbcache > cap;
 }
 
diff --git a/src/qt/optionsmodel.cpp b/src/qt/optionsmodel.cpp
index 49e3c4b8..9f540c87 100644
--- a/src/qt/optionsmodel.cpp
+++ b/src/qt/optionsmodel.cpp
@@ -732,7 +732,7 @@ void OptionsModel::checkAndMigrate()
         // see https://github.com/bitcoin/bitcoin/pull/8273
         // force people to upgrade to the new value if they are using 100MB
         if (settingsVersion < 130000 && settings.contains("nDatabaseCache") && settings.value("nDatabaseCache").toLongLong() == 100)
-            settings.setValue("nDatabaseCache", qint64(DEFAULT_DB_CACHE / 1_MiB));
+            settings.setValue("nDatabaseCache", qint64(DEFAULT_KERNEL_CACHE / 1_MiB));
 
         settings.setValue(strSettingsVersionKey, CLIENT_VERSION);
     }
diff --git a/src/test/caches_tests.cpp b/src/test/caches_tests.cpp
index 15820a79..1291eb33 100644
--- a/src/test/caches_tests.cpp
+++ b/src/test/caches_tests.cpp
@@ -27,8 +27,8 @@ BOOST_AUTO_TEST_CASE(oversized_dbcache_warning)
     BOOST_CHECK(!ShouldWarnOversizedDbCache(MIN_DBCACHE_BYTES, 1_GiB));
 
     // Below DBCACHE_WARNING_RESERVED_RAM the existing fixed default dominates.
-    CheckDbCacheWarnThreshold(DEFAULT_DB_CACHE, 1_GiB);
-    CheckDbCacheWarnThreshold(DEFAULT_DB_CACHE, DBCACHE_WARNING_RESERVED_RAM);
+    CheckDbCacheWarnThreshold(DEFAULT_KERNEL_CACHE, 1_GiB);
+    CheckDbCacheWarnThreshold(DEFAULT_KERNEL_CACHE, DBCACHE_WARNING_RESERVED_RAM);
 
     // Above DBCACHE_WARNING_RESERVED_RAM the warning fires at 75% of the headroom.
     CheckDbCacheWarnThreshold(((3_GiB - DBCACHE_WARNING_RESERVED_RAM) / 4) * 3, 3_GiB);