diff --git a/sql/CMakeLists.txt b/sql/CMakeLists.txt
index 8174cf609..f753e8f8b 100644
--- a/sql/CMakeLists.txt
+++ b/sql/CMakeLists.txt
@@ -93,8 +93,6 @@ endfunction()
 version_files("${PRE_UPDATE_FILES}" PRE_UPDATE_FILES_VERSIONED)
 version_files("${POST_UPDATE_FILES}" POST_UPDATE_FILES_VERSIONED)
 version_files("${PRE_INSTALL_SOURCE_FILES}" PRE_INSTALL_SOURCE_FILES_VERSIONED)
-version_files("${IMMUTABLE_API_SOURCE_FILES}"
-              IMMUTABLE_API_SOURCE_FILES_VERSIONED)
 version_files("${SOURCE_FILES}" SOURCE_FILES_VERSIONED)
 version_files("${MOD_FILES}" MOD_FILES_VERSIONED)
 version_files("updates/latest-dev.sql" LASTEST_MOD_VERSIONED)
@@ -122,7 +120,7 @@ endfunction()
 
 # Generate the extension file used with CREATE EXTENSION
 cat_files(
-  "${PRE_INSTALL_SOURCE_FILES_VERSIONED};${SOURCE_FILES_VERSIONED};${IMMUTABLE_API_SOURCE_FILES_VERSIONED};${NOTICE_FILE}"
+  "${PRE_INSTALL_SOURCE_FILES_VERSIONED};${SOURCE_FILES_VERSIONED};${NOTICE_FILE}"
   ${CMAKE_CURRENT_BINARY_DIR}/${INSTALL_FILE})
 add_custom_target(sqlfile ALL
                   DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${INSTALL_FILE})
diff --git a/sql/aggregates.sql b/sql/aggregates.sql
deleted file mode 100644
index a716512ec..000000000
--- a/sql/aggregates.sql
+++ /dev/null
@@ -1,59 +0,0 @@
--- This file and its contents are licensed under the Apache License 2.0.
--- Please see the included NOTICE for copyright information and
--- LICENSE-APACHE for a copy of the license.
-
--- This file is meant to contain aggregate functions that need to be created only
--- once and not recreated during updates.
--- There is no CREATE OR REPLACE AGGREGATE which means that the only way to replace
--- an aggregate is to DROP then CREATE which is problematic as it will fail
--- if the previous version of the aggregate has dependencies.
--- NOTE that WHEN CREATING NEW FUNCTIONS HERE you should also make sure they are
--- created in an update script so that both new users and people updating from a
--- previous version get the new function
-
-
---This aggregate returns the "first" element of the first argument when ordered by the second argument.
---Ex. first(temp, time) returns the temp value for the row with the lowest time
-CREATE AGGREGATE first(anyelement, "any") (
-    SFUNC = _timescaledb_internal.first_sfunc,
-    STYPE = internal,
-    COMBINEFUNC = _timescaledb_internal.first_combinefunc,
-    SERIALFUNC = _timescaledb_internal.bookend_serializefunc,
-    DESERIALFUNC = _timescaledb_internal.bookend_deserializefunc,
-    PARALLEL = SAFE,
-    FINALFUNC = _timescaledb_internal.bookend_finalfunc,
-    FINALFUNC_EXTRA
-);
-
---This aggregate returns the "last" element of the first argument when ordered by the second argument.
---Ex. last(temp, time) returns the temp value for the row with highest time
-CREATE AGGREGATE last(anyelement, "any") (
-    SFUNC = _timescaledb_internal.last_sfunc,
-    STYPE = internal,
-    COMBINEFUNC = _timescaledb_internal.last_combinefunc,
-    SERIALFUNC = _timescaledb_internal.bookend_serializefunc,
-    DESERIALFUNC = _timescaledb_internal.bookend_deserializefunc,
-    PARALLEL = SAFE,
-    FINALFUNC = _timescaledb_internal.bookend_finalfunc,
-    FINALFUNC_EXTRA
-);
-
--- This aggregate partitions the dataset into a specified number of buckets (nbuckets) ranging
--- from the inputted min to max values.
-CREATE AGGREGATE histogram (DOUBLE PRECISION, DOUBLE PRECISION, DOUBLE PRECISION, INTEGER) (
-    SFUNC = _timescaledb_internal.hist_sfunc,
-    STYPE = INTERNAL,
-    COMBINEFUNC = _timescaledb_internal.hist_combinefunc,
-    SERIALFUNC = _timescaledb_internal.hist_serializefunc,
-    DESERIALFUNC = _timescaledb_internal.hist_deserializefunc,
-    PARALLEL = SAFE,
-    FINALFUNC = _timescaledb_internal.hist_finalfunc,
-    FINALFUNC_EXTRA
-);
-
-CREATE AGGREGATE _timescaledb_internal.finalize_agg(agg_name TEXT,  inner_agg_collation_schema NAME,  inner_agg_collation_name NAME, inner_agg_input_types NAME[][], inner_agg_serialized_state BYTEA, return_type_dummy_val anyelement) (
-    SFUNC = _timescaledb_internal.finalize_agg_sfunc,
-    STYPE = internal,
-    FINALFUNC = _timescaledb_internal.finalize_agg_ffunc,
-    FINALFUNC_EXTRA
-);
diff --git a/sql/bookend.sql b/sql/bookend.sql
index 0ab77fa88..a30415f52 100644
--- a/sql/bookend.sql
+++ b/sql/bookend.sql
@@ -36,3 +36,37 @@ CREATE OR REPLACE FUNCTION _timescaledb_internal.bookend_deserializefunc(bytea,
 RETURNS internal
 AS '@MODULE_PATHNAME@', 'ts_bookend_deserializefunc'
 LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+
+-- We started using CREATE OR REPLACE AGGREGATE for aggregate creation once the syntax was fully supported
+-- as it is easier to support idempotent changes this way. This will allow for changes to functions supporting
+-- the aggregate, and, for instance, the definition and inclusion of inverse functions for window function
+-- support. However, it should still be noted that changes to the data structures used for the internal
+-- state of the aggregate must be backwards compatible and the old format must be accepted by any new functions
+-- in order for them to continue working with Continuous Aggregates, where old states may have been materialized.
+
+--This aggregate returns the "first" value of the first argument when ordered by the second argument.
+--Ex. first(temp, time) returns the temp value for the row with the lowest time
+CREATE OR REPLACE AGGREGATE first(anyelement, "any") (
+    SFUNC = _timescaledb_internal.first_sfunc,
+    STYPE = internal,
+    COMBINEFUNC = _timescaledb_internal.first_combinefunc,
+    SERIALFUNC = _timescaledb_internal.bookend_serializefunc,
+    DESERIALFUNC = _timescaledb_internal.bookend_deserializefunc,
+    PARALLEL = SAFE,
+    FINALFUNC = _timescaledb_internal.bookend_finalfunc,
+    FINALFUNC_EXTRA
+);
+
+--This aggregate returns the "last" value of the first argument when ordered by the second argument.
+--Ex. last(temp, time) returns the temp value for the row with highest time
+CREATE OR REPLACE AGGREGATE last(anyelement, "any") (
+    SFUNC = _timescaledb_internal.last_sfunc,
+    STYPE = internal,
+    COMBINEFUNC = _timescaledb_internal.last_combinefunc,
+    SERIALFUNC = _timescaledb_internal.bookend_serializefunc,
+    DESERIALFUNC = _timescaledb_internal.bookend_deserializefunc,
+    PARALLEL = SAFE,
+    FINALFUNC = _timescaledb_internal.bookend_finalfunc,
+    FINALFUNC_EXTRA
+);
diff --git a/sql/histogram.sql b/sql/histogram.sql
index bebc84968..414713080 100644
--- a/sql/histogram.sql
+++ b/sql/histogram.sql
@@ -26,3 +26,23 @@ CREATE OR REPLACE FUNCTION _timescaledb_internal.hist_finalfunc(state INTERNAL,
 RETURNS INTEGER[]
 AS '@MODULE_PATHNAME@', 'ts_hist_finalfunc'
 LANGUAGE C IMMUTABLE PARALLEL SAFE;
+
+-- We started using CREATE OR REPLACE AGGREGATE for aggregate creation once the syntax was fully supported
+-- as it is easier to support idempotent changes this way. This will allow for changes to functions supporting
+-- the aggregate, and, for instance, the definition and inclusion of inverse functions for window function
+-- support. However, it should still be noted that changes to the data structures used for the internal
+-- state of the aggregate must be backwards compatible and the old format must be accepted by any new functions
+-- in order for them to continue working with Continuous Aggregates, where old states may have been materialized.
+
+-- This aggregate partitions the dataset into a specified number of buckets (nbuckets) ranging
+-- from the inputted min to max values.
+CREATE OR REPLACE AGGREGATE histogram (DOUBLE PRECISION, DOUBLE PRECISION, DOUBLE PRECISION, INTEGER) (
+    SFUNC = _timescaledb_internal.hist_sfunc,
+    STYPE = INTERNAL,
+    COMBINEFUNC = _timescaledb_internal.hist_combinefunc,
+    SERIALFUNC = _timescaledb_internal.hist_serializefunc,
+    DESERIALFUNC = _timescaledb_internal.hist_deserializefunc,
+    PARALLEL = SAFE,
+    FINALFUNC = _timescaledb_internal.hist_finalfunc,
+    FINALFUNC_EXTRA
+);
diff --git a/sql/partialize_finalize.sql b/sql/partialize_finalize.sql
index 34a22785b..e3a97c074 100644
--- a/sql/partialize_finalize.sql
+++ b/sql/partialize_finalize.sql
@@ -17,3 +17,9 @@ RETURNS anyelement
 AS '@MODULE_PATHNAME@', 'ts_finalize_agg_ffunc'
 LANGUAGE C IMMUTABLE ;
 
+CREATE OR REPLACE AGGREGATE _timescaledb_internal.finalize_agg(agg_name TEXT,  inner_agg_collation_schema NAME,  inner_agg_collation_name NAME, inner_agg_input_types NAME[][], inner_agg_serialized_state BYTEA, return_type_dummy_val anyelement) (
+    SFUNC = _timescaledb_internal.finalize_agg_sfunc,
+    STYPE = internal,
+    FINALFUNC = _timescaledb_internal.finalize_agg_ffunc,
+    FINALFUNC_EXTRA
+);