diff --git a/sql/ckdb.sql b/sql/ckdb.sql
index f9bf6d73..aaa6eca7 100644
--- a/sql/ckdb.sql
+++ b/sql/ckdb.sql
@@ -251,6 +251,21 @@ CREATE TABLE sharesummary ( -- per workinfo for each user+worker
 );
 
 
+CREATE TABLE marks ( -- workinfoids to make workmarkers
+    poolinstance character varying(256) NOT NULL,
+    workinfoid bigint NOT NULL,
+    description character varying(256) DEFAULT ''::character varying NOT NULL,
+    marktype char NOT NULL, -- 'b'lock 'p'plns-begin 's'hift-begin 'e'=shift-end
+    status char NOT NULL,
+    createdate timestamp with time zone NOT NULL,
+    createby character varying(64) DEFAULT ''::character varying NOT NULL,
+    createcode character varying(128) DEFAULT ''::character varying NOT NULL,
+    createinet character varying(128) DEFAULT ''::character varying NOT NULL,
+    expirydate timestamp with time zone DEFAULT '6666-06-06 06:06:06+00',
+    PRIMARY KEY (poolinstance, workinfoid, expirydate)
+);
+
+
 CREATE TABLE workmarkers ( -- range of workinfo for share accounting
     markerid bigint NOT NULL,
     poolinstance character varying(256) NOT NULL,
@@ -263,7 +278,7 @@ CREATE TABLE workmarkers ( -- range of workinfo for share accounting
     createcode character varying(128) DEFAULT ''::character varying NOT NULL,
     createinet character varying(128) DEFAULT ''::character varying NOT NULL,
     expirydate timestamp with time zone DEFAULT '6666-06-06 06:06:06+00',
-    PRIMARY KEY (markerid)
+    PRIMARY KEY (markerid, expirydate)
 );
 
 
@@ -417,4 +432,4 @@ CREATE TABLE version (
     PRIMARY KEY (vlock)
 );
 
-insert into version (vlock,version) values (1,'0.9.4');
+insert into version (vlock,version) values (1,'0.9.5');
diff --git a/sql/v0.9.4-v0.9.5.sql b/sql/v0.9.4-v0.9.5.sql
new file mode 100644
index 00000000..c61a4e9c
--- /dev/null
+++ b/sql/v0.9.4-v0.9.5.sql
@@ -0,0 +1,41 @@
+SET SESSION AUTHORIZATION 'postgres';
+
+BEGIN transaction;
+
+DO $$
+DECLARE ver TEXT;
+BEGIN
+
+ UPDATE version set version='0.9.5' where vlock=1 and version='0.9.4';
+
+ IF found THEN
+  RETURN;
+ END IF;
+
+ SELECT version into ver from version
+  WHERE vlock=1;
+
+ RAISE EXCEPTION 'Wrong DB version - expect "0.9.4" - found "%"', ver;
+
+END $$;
+
+CREATE TABLE marks ( -- workinfoids to make workmarkers
+    poolinstance character varying(256) NOT NULL,
+    workinfoid bigint NOT NULL,
+    description character varying(256) DEFAULT ''::character varying NOT NULL,
+    marktype char NOT NULL, -- 'b'lock(end) 'p'plns-begin 's'hift-begin 'e'=shift-end
+    status char NOT NULL,
+    createdate timestamp with time zone NOT NULL,
+    createby character varying(64) DEFAULT ''::character varying NOT NULL,
+    createcode character varying(128) DEFAULT ''::character varying NOT NULL,
+    createinet character varying(128) DEFAULT ''::character varying NOT NULL,
+    expirydate timestamp with time zone DEFAULT '6666-06-06 06:06:06+00',
+    PRIMARY KEY (poolinstance, workinfoid, expirydate)
+);
+
+ALTER TABLE workmarkers DROP CONSTRAINT workmarkers_pkey;
+
+ALTER TABLE workmarkers ADD CONSTRAINT workmarkers_pkey
+ PRIMARY KEY (markerid, expirydate);
+
+END transaction;
diff --git a/src/ckdb.c b/src/ckdb.c
index 8f3357b5..11cead07 100644
--- a/src/ckdb.c
+++ b/src/ckdb.c
@@ -453,6 +453,11 @@ K_TREE *workmarkers_workinfoid_root;
 K_LIST *workmarkers_free;
 K_STORE *workmarkers_store;
 
+// MARKS
+K_TREE *marks_root;
+K_LIST *marks_free;
+K_STORE *marks_store;
+
 static char logname[512];
 static char *dbcode;
 
diff --git a/src/ckdb.h b/src/ckdb.h
index d6d3c49d..ab4fded8 100644
--- a/src/ckdb.h
+++ b/src/ckdb.h
@@ -51,7 +51,7 @@
  */
 
 #define DB_VLOCK "1"
-#define DB_VERSION "0.9.4"
+#define DB_VERSION "0.9.5"
 #define CKDB_VERSION DB_VERSION"-0.646"
 
 #define WHERE_FFL " - from %s %s() line %d"
@@ -1333,6 +1333,58 @@ extern K_STORE *workmarkers_store;
 #define MARKER_COMPLETE 'x'
 #define WMREADY(_status) (tolower(_status[0]) == MARKER_COMPLETE)
 
+// MARKS
+// TODO: implement
+typedef struct marks {
+	char *poolinstance;
+	int64_t workinfoid;
+	char *description;
+	char marktype[TXT_FLAG+1];
+	char status[TXT_FLAG+1];
+	HISTORYDATECONTROLFIELDS;
+} MARKS;
+
+/* Marks:
+ *  marktype is one of:
+ *   b - block end
+ *   p - pplns begin
+ *   s - shift begin (not yet used)
+ *   e - shift end (not yet used)
+ *  description should one one of
+ *   b - Block NNN stt
+ *   p - Payout NNN fin (where NNN is the block number of the payout)
+ *   s/e - to be decided
+ *
+ * WorkMarkers are from a begin workinfoid to an end workinfoid
+ *  the "-1" and "+1" below mean adding to or subtracting from
+ *  the workinfoid number
+ *
+ * Until we start using shifts:
+ *  WorkMarkers can be created up to ending in the largest 'p' "-1"
+ *  WorkMarkers will always be the smallest of:
+ *   Block NNN-1 "+1" to Block NNN
+ *   Block NNN "+1" to Payout MMM "-1"
+ *   Payout MMM to Block NNN
+ *   Payout MMM-1 to Payout MMM "-1"
+ * Thus to generate the WorkMarkers from the Marks:
+ *  Find the last 'p' with no matching workinfoidbegin
+ *  Then determine each previous WorkMarker based on each previous
+ *  mark, using the above rules and stop when we find one that already exists
+ */
+
+#define ALLOC_MARKS 1000
+#define LIMIT_MARKS 0
+#define INIT_MARKS(_item) INIT_GENERIC(_item, marks)
+#define DATA_MARKS(_var, _item) DATA_GENERIC(_var, _item, marks, true)
+#define DATA_MARKS_NULL(_var, _item) DATA_GENERIC(_var, _item, marks, false)
+
+extern K_TREE *marks_root;
+extern K_LIST *marks_free;
+extern K_STORE *marks_store;
+
+#define MARK_READY 'x'
+#define MREADY(_status) (tolower(_status[0]) == MARK_READY)
+
 extern void logmsg(int loglevel, const char *fmt, ...);
 extern void setnow(tv_t *now);
 extern void tick();