diff --git a/configure/RULES.Db b/configure/RULES.Db
index 6a01ad19b..83058eb88 100644
--- a/configure/RULES.Db
+++ b/configure/RULES.Db
@@ -46,6 +46,17 @@ DBD += $(foreach type, $(CROSS_TARGET_OS_TYPES), $(DBD_$(type)))
 # DBD_RTEMS += abcRTEMS.dbd
 # DBD_solaris += abcSolaris.dbd
 #
+# ---------------------------------------------------
+# DBD concatination files
+
+COMMON_DBDCATS += $(addprefix $(COMMON_DIR)/,$(DBDCAT))
+DBDCAT_SOURCES += $(foreach file, $($*_DBD), $(DBDCAT_SOURCE) )
+DBDCAT_SOURCE = $(firstword $(wildcard $(file) $(foreach dir,  \
+    $(GENERIC_SRC_DIRS),$(addsuffix /$(file),$(dir)))) \
+    $(COMMON_DIR)/$(file))
+
+INSTALL_DBDS += $(addprefix $(INSTALL_DBD)/,$(DBDCAT))
+
 # ---------------------------------------------------
 
 DBDINC_NAME = $(patsubst %.h,%,$(patsubst %.dbd,%,$(DBDINC)))
@@ -173,7 +184,7 @@ endif
 
 inc : $(COMMON_INC) $(INSTALL_INC)
 
-build : $(COMMON_DBDS) $(COMMON_DBS) \
+build : $(COMMON_DBDS) $(COMMON_DBS) $(COMMON_DBDCATS) \
 	$(INSTALL_DBDS) $(INSTALL_DBS) \
 	$(DBDDEPENDS_FILES) $(TARGETS) \
 	$(INSTALL_DB_INSTALLS) $(INSTALL_DBD_INSTALLS)
@@ -368,8 +379,21 @@ $(COMMON_DIR)/%.dbd: ../%Include.dbd
 	$(DBEXPAND) $(DBDFLAGS) -o $(notdir $@) $<
 	@$(MV) $(notdir $@) $@
 
+# Make DBDCAT file x depend on x_DBD source files
+define  DBDCAT_template
+$$(COMMON_DIR)/$(1).dbd : ../Makefile $$(foreach file, $$($(1)_DBD),$$(DBDCAT_SOURCE) )
+endef
+$(foreach name,$(subst .dbd,,$(DBDCAT)), $(eval $(call DBDCAT_template,$(name))))
+
+$(COMMON_DBDCATS):$(COMMON_DIR)/%.dbd:
+	$(ECHO) "Creating dbd file $(notdir $@)"
+	@$(RM) $(notdir $@)
+	$(CAT) $(DBDCAT_SOURCES) > $(notdir $@)
+	#@$(CAT) $^ > $(notdir $@)
+	@$(MV) $(notdir $@) $@
+
 $(COMMON_DIR)/%.dbd:
-	$(ECHO) "Creating dbd file $(notdir $<)"
+	$(ECHO) "Creating dbd file $(notdir $@)"
 	@$(RM) $(notdir $@)
 	$(DBEXPAND) $(DBDFLAGS) -o $(notdir $@) $($*_DBD)
 	@$(MV) $(notdir $@) $@
diff --git a/configure/os/CONFIG.UnixCommon.Common b/configure/os/CONFIG.UnixCommon.Common
index 13044f914..6f3e81bc1 100644
--- a/configure/os/CONFIG.UnixCommon.Common
+++ b/configure/os/CONFIG.UnixCommon.Common
@@ -13,6 +13,7 @@ MV = mv
 RM = rm -f
 MKDIR = mkdir
 RMDIR = rm -rf
+CAT = cat
 
 # Allow site overrides
 -include $(CONFIG)/os/CONFIG_SITE.UnixCommon.Common
diff --git a/configure/os/CONFIG.win32-x86.Common b/configure/os/CONFIG.win32-x86.Common
index b30c9a69f..42937222d 100644
--- a/configure/os/CONFIG.win32-x86.Common
+++ b/configure/os/CONFIG.win32-x86.Common
@@ -16,6 +16,7 @@ RM = $(PERL) -MExtUtils::Command -e rm_f
 MKDIR = $(PERL) -MExtUtils::Command -e mkpath
 RMDIR = $(PERL) -MExtUtils::Command -e rm_rf
 NOP = $(PERL) -e ''
+CAT = $(PERL) -MExtUtils::Command -e cat
 
 WIND_HOST_TYPE = x86-win32
 OSITHREAD_USE_DEFAULT_STACK = NO
diff --git a/documentation/RELEASE_NOTES.html b/documentation/RELEASE_NOTES.html
index db20d167c..84c2b4be7 100644
--- a/documentation/RELEASE_NOTES.html
+++ b/documentation/RELEASE_NOTES.html
@@ -15,6 +15,24 @@ EPICS Base 3.15.0.x releases are not intended for use in production systems.</p>
 <h2 align="center">Changes between 3.15.0.1 and 3.15.0.2</h2>
 <!-- Insert new items immediately below here ... -->
 
+<h3>Concatenated database definition files</h3>
+
+<p>Database definition (dbd) files can now be concatenated during the EPICS build 
+into a created dbd file with the created dbd file then installed into 
+$(INSTALL_LOCATION)/dbd. The following lines in a Makefile will create a name.dbd 
+file containing a copy of lines from file1.dbd followed by lines from file2.dbd
+then file3.dbd and then install name.dbd into $(INSTALL_LOCATION)/dbd. NO dbd file 
+expansions will be done. 
+
+<blockquote> <pre>
+	DBDCAT += name.dbd
+	name_DBD += file1.dbd file2.dbd file3.dbd
+</pre></blockquote>
+
+The files file1.dbd, file2.dbd, and file3.dbd will be found if they exist in the 
+current directory, are created by the current Makefile, have fullpath name ,or 
+exist in a directory of the currently defined SRC_DIRS list.</p>
+
 <h3>On POSIX, attempt to lock all memory when running with FIFO scheduler</h3>
 
 <p>On POSIX systems, an IOC application's ability to meet timing deadlines is often
diff --git a/src/tools/dbdExpand.pl b/src/tools/dbdExpand.pl
index c9e10aa51..0f117bf70 100755
--- a/src/tools/dbdExpand.pl
+++ b/src/tools/dbdExpand.pl
@@ -34,6 +34,8 @@ if ($opt_D) {
     $dep = "\$(COMMON_DIR)/$dep";
 }
 
+exit 0 if (!@ARGV);
+
 while (@ARGV) {
     my $file = shift @ARGV;
     eval {