diff --git a/all.sas b/all.sas
index d1abba4..766e48e 100644
--- a/all.sas
+++ b/all.sas
@@ -3444,6 +3444,10 @@ run;
     located.  If not provided, is ignored.
   @param [out] outds= (0) The output table to load.  If not provided, will
     default to the table in the &ds parameter.
+  @param [in] flavour= (BASE) The SQL flavour to be applied to the output. Valid
+    options:
+    @li BASE (default) - suitable for regular proc sql
+    @li PGSQL - Used for Postgres databases
 
   <h4> SAS Macros </h4>
   @li mf_existfileref.sas
@@ -3455,18 +3459,29 @@ run;
   @author Allan Bowe (credit mjsq)
 **/
 
-%macro mp_ds2inserts(ds, outref=0,outlib=0,outds=0
+%macro mp_ds2inserts(ds, outref=0,outlib=0,outds=0,flavour=BASE
 )/*/STORE SOURCE*/;
 
 %if not %sysfunc(exist(&ds)) %then %do;
-  %put %str(WARN)ING:  &ds does not exist;
+  %put %str(WAR)NING:  &ds does not exist;
+  %return;
+%end;
+
+%if not %sysfunc(exist(&ds)) %then %do;
+  %put %str(WAR)NING:  &ds does not exist;
   %return;
 %end;
 
 %if %index(&ds,.)=0 %then %let ds=WORK.&ds;
 
+%let flavour=%upcase(&flavour);
+%if &flavour ne BASE and &flavour ne PGSQL %then %do;
+  %put %str(WAR)NING:  &flavour is not supported;
+  %return;
+%end;
+
 %if &outref=0 %then %do;
-  %put %str(WARN)ING:  Please provide a fileref;
+  %put %str(WAR)NING:  Please provide a fileref;
   %return;
 %end;
 %if %mf_existfileref(&outref)=0 %then %do;
@@ -3497,8 +3512,9 @@ select count(*) into: nobs TRIMMED from &ds;
   run;
 %end;
 
-%local varlist;
+%local varlist varlistcomma;
 %let varlist=%mf_getvarlist(&ds);
+%let varlistcomma=%mf_getvarlist(&ds,dlm=%str(,),quote=double);
 
 /* next, export data */
 data _null_;
@@ -3513,23 +3529,49 @@ data _null_;
     %let var=%scan(&varlist,&i);
     %let vtype=%mf_getvartype(&ds,&var);
     %if &i=1 %then %do;
-      put "insert into &outlib.&outds set ";
-      put "  &var="@;
+      %if &flavour=BASE %then %do;
+        put "insert into &outlib.&outds set ";
+        put "  &var="@;
+      %end;
+      %else %if &flavour=PGSQL %then %do;
+        _____str=cats(
+          "INSERT INTO &outlib.&outds ("
+          ,symget('varlistcomma')
+          ,") VALUES ("
+        );
+        put _____str;
+        put "  "@;
+      %end;
     %end;
     %else %do;
-      put "  ,&var="@;
+      %if &flavour=BASE %then %do;
+        put "  ,&var="@;
+      %end;
+      %else %if &flavour=PGSQL %then %do;
+        put "  ,"@;
+      %end;
     %end;
     %if &vtype=N %then %do;
-      /* @todo - deal with nulls in other db flavours */
-      /* from ._ to .z */
-      put &var;
+      %if &flavour=BASE %then %do;
+        put &var;
+      %end;
+      %else %if &flavour=PGSQL %then %do;
+        if missing(&var) then put 'NULL';
+        else put &var;
+      %end;
     %end;
     %else %do;
       _____str="'"!!trim(tranwrd(&var,"'","''"))!!"'";
       put _____str;
     %end;
   %end;
-  put ';';
+  %if &flavour=BASE %then %do;
+    put ';';
+  %end;
+  %else %if &flavour=PGSQL %then %do;
+    put ');';
+  %end;
+
   if _n_=&nobs then put /;
 run;
 
@@ -4355,12 +4397,13 @@ run;
       %mp_getddl(work,test,flavour=tsql,showlog=YES)
 
   <h4> SAS Macros </h4>
+  @li mf_existfileref.sas
   @li mp_getconstraints.sas
 
   @param lib libref of the library to create DDL for.  Should be assigned.
   @param ds dataset to create ddl for (optional)
-  @param fref= the fileref to which to write the DDL.  If not preassigned, will
-    be assigned to TEMP.
+  @param fref= the fileref to which to _append_ the DDL.  If it does not exist,
+    it will be created.
   @param flavour= The type of DDL to create (default=SAS). Supported=TSQL
   @param showlog= Set to YES to show the DDL in the log
   @param schema= Choose a preferred schema name (default is to use actual schema
@@ -4376,9 +4419,10 @@ run;
 )/*/STORE SOURCE*/;
 
 /* check fileref is assigned */
-%if %sysfunc(fileref(&fref)) > 0 %then %do;
-  filename &fref temp;
+%if %mf_existfileref(&outref)=0 %then %do;
+  filename &outref temp ;
 %end;
+
 %if %length(&libref)=0 %then %let libref=WORK;
 %let flavour=%upcase(&flavour);
 
@@ -4457,7 +4501,7 @@ create table _data_ as
 %mend addConst;
 
 data _null_;
-  file &fref;
+  file &fref mod;
   put "/* DDL generated by &sysuserid on %sysfunc(datetime(),datetime19.) */";
 run;
 
@@ -5114,6 +5158,8 @@ create table &outds (rename=(
   @li mf_getvartype.sas
 
   @param [in] libds dataset to hash
+  @param [in] salt= Provide a salt (could be, for instance, the name of the
+    dataset). Max 32 chars.
   @param [out] outds= (work.mf_hashdataset) The output dataset to create. This
   will contain one column (hashkey) with one observation (a hex32.
   representation of the input hash)
@@ -5127,7 +5173,8 @@ create table &outds (rename=(
 
 %macro mp_hashdataset(
   libds,
-  outds=
+  outds=,
+  salt=
 )/*/STORE SOURCE*/;
   %if %mf_getattrn(&libds,NLOBS)=0 %then %do;
     %put %str(WARN)ING: Dataset &libds is empty;, or is not a dataset;
@@ -5147,7 +5194,7 @@ create table &outds (rename=(
     %let varlist=%mf_getvarlist(&libds);
     data &outds(rename=(&keyvar=hashkey) keep=&keyvar);
       length &prevkeyvar &keyvar $32;
-      retain &prevkeyvar;
+      retain &prevkeyvar "&salt";
       set &libds end=&lastvar;
       /* hash should include previous row */
       &keyvar=put(md5(&prevkeyvar
diff --git a/base/mp_ds2inserts.sas b/base/mp_ds2inserts.sas
index b964673..09e510a 100644
--- a/base/mp_ds2inserts.sas
+++ b/base/mp_ds2inserts.sas
@@ -20,6 +20,10 @@
     located.  If not provided, is ignored.
   @param [out] outds= (0) The output table to load.  If not provided, will
     default to the table in the &ds parameter.
+  @param [in] flavour= (BASE) The SQL flavour to be applied to the output. Valid
+    options:
+    @li BASE (default) - suitable for regular proc sql
+    @li PGSQL - Used for Postgres databases
 
   <h4> SAS Macros </h4>
   @li mf_existfileref.sas
@@ -31,18 +35,29 @@
   @author Allan Bowe (credit mjsq)
 **/
 
-%macro mp_ds2inserts(ds, outref=0,outlib=0,outds=0
+%macro mp_ds2inserts(ds, outref=0,outlib=0,outds=0,flavour=BASE
 )/*/STORE SOURCE*/;
 
 %if not %sysfunc(exist(&ds)) %then %do;
-  %put %str(WARN)ING:  &ds does not exist;
+  %put %str(WAR)NING:  &ds does not exist;
+  %return;
+%end;
+
+%if not %sysfunc(exist(&ds)) %then %do;
+  %put %str(WAR)NING:  &ds does not exist;
   %return;
 %end;
 
 %if %index(&ds,.)=0 %then %let ds=WORK.&ds;
 
+%let flavour=%upcase(&flavour);
+%if &flavour ne BASE and &flavour ne PGSQL %then %do;
+  %put %str(WAR)NING:  &flavour is not supported;
+  %return;
+%end;
+
 %if &outref=0 %then %do;
-  %put %str(WARN)ING:  Please provide a fileref;
+  %put %str(WAR)NING:  Please provide a fileref;
   %return;
 %end;
 %if %mf_existfileref(&outref)=0 %then %do;
@@ -73,8 +88,9 @@ select count(*) into: nobs TRIMMED from &ds;
   run;
 %end;
 
-%local varlist;
+%local varlist varlistcomma;
 %let varlist=%mf_getvarlist(&ds);
+%let varlistcomma=%mf_getvarlist(&ds,dlm=%str(,),quote=double);
 
 /* next, export data */
 data _null_;
@@ -89,23 +105,49 @@ data _null_;
     %let var=%scan(&varlist,&i);
     %let vtype=%mf_getvartype(&ds,&var);
     %if &i=1 %then %do;
-      put "insert into &outlib.&outds set ";
-      put "  &var="@;
+      %if &flavour=BASE %then %do;
+        put "insert into &outlib.&outds set ";
+        put "  &var="@;
+      %end;
+      %else %if &flavour=PGSQL %then %do;
+        _____str=cats(
+          "INSERT INTO &outlib.&outds ("
+          ,symget('varlistcomma')
+          ,") VALUES ("
+        );
+        put _____str;
+        put "  "@;
+      %end;
     %end;
     %else %do;
-      put "  ,&var="@;
+      %if &flavour=BASE %then %do;
+        put "  ,&var="@;
+      %end;
+      %else %if &flavour=PGSQL %then %do;
+        put "  ,"@;
+      %end;
     %end;
     %if &vtype=N %then %do;
-      /* @todo - deal with nulls in other db flavours */
-      /* from ._ to .z */
-      put &var;
+      %if &flavour=BASE %then %do;
+        put &var;
+      %end;
+      %else %if &flavour=PGSQL %then %do;
+        if missing(&var) then put 'NULL';
+        else put &var;
+      %end;
     %end;
     %else %do;
       _____str="'"!!trim(tranwrd(&var,"'","''"))!!"'";
       put _____str;
     %end;
   %end;
-  put ';';
+  %if &flavour=BASE %then %do;
+    put ';';
+  %end;
+  %else %if &flavour=PGSQL %then %do;
+    put ');';
+  %end;
+
   if _n_=&nobs then put /;
 run;
 
diff --git a/base/mp_getddl.sas b/base/mp_getddl.sas
index be92303..4b7d400 100644
--- a/base/mp_getddl.sas
+++ b/base/mp_getddl.sas
@@ -16,12 +16,13 @@
       %mp_getddl(work,test,flavour=tsql,showlog=YES)
 
   <h4> SAS Macros </h4>
+  @li mf_existfileref.sas
   @li mp_getconstraints.sas
 
   @param lib libref of the library to create DDL for.  Should be assigned.
   @param ds dataset to create ddl for (optional)
-  @param fref= the fileref to which to write the DDL.  If not preassigned, will
-    be assigned to TEMP.
+  @param fref= the fileref to which to _append_ the DDL.  If it does not exist,
+    it will be created.
   @param flavour= The type of DDL to create (default=SAS). Supported=TSQL
   @param showlog= Set to YES to show the DDL in the log
   @param schema= Choose a preferred schema name (default is to use actual schema
@@ -37,9 +38,10 @@
 )/*/STORE SOURCE*/;
 
 /* check fileref is assigned */
-%if %sysfunc(fileref(&fref)) > 0 %then %do;
-  filename &fref temp;
+%if %mf_existfileref(&outref)=0 %then %do;
+  filename &outref temp ;
 %end;
+
 %if %length(&libref)=0 %then %let libref=WORK;
 %let flavour=%upcase(&flavour);
 
@@ -118,7 +120,7 @@ create table _data_ as
 %mend addConst;
 
 data _null_;
-  file &fref;
+  file &fref mod;
   put "/* DDL generated by &sysuserid on %sysfunc(datetime(),datetime19.) */";
 run;
 
diff --git a/base/mp_hashdataset.sas b/base/mp_hashdataset.sas
index d05ed94..1c05059 100644
--- a/base/mp_hashdataset.sas
+++ b/base/mp_hashdataset.sas
@@ -20,6 +20,8 @@
   @li mf_getvartype.sas
 
   @param [in] libds dataset to hash
+  @param [in] salt= Provide a salt (could be, for instance, the name of the
+    dataset). Max 32 chars.
   @param [out] outds= (work.mf_hashdataset) The output dataset to create. This
   will contain one column (hashkey) with one observation (a hex32.
   representation of the input hash)
@@ -33,7 +35,8 @@
 
 %macro mp_hashdataset(
   libds,
-  outds=
+  outds=,
+  salt=
 )/*/STORE SOURCE*/;
   %if %mf_getattrn(&libds,NLOBS)=0 %then %do;
     %put %str(WARN)ING: Dataset &libds is empty;, or is not a dataset;
@@ -53,7 +56,7 @@
     %let varlist=%mf_getvarlist(&libds);
     data &outds(rename=(&keyvar=hashkey) keep=&keyvar);
       length &prevkeyvar &keyvar $32;
-      retain &prevkeyvar;
+      retain &prevkeyvar "&salt";
       set &libds end=&lastvar;
       /* hash should include previous row */
       &keyvar=put(md5(&prevkeyvar