diff --git a/contrib/uuid-ossp/uuid-ossp.c b/contrib/uuid-ossp/uuid-ossp.c
index 88da168..9e9905b 100644
*** a/contrib/uuid-ossp/uuid-ossp.c
--- b/contrib/uuid-ossp/uuid-ossp.c
*************** pguuid_complain(uuid_rc_t rc)
*** 141,146 ****
--- 141,182 ----
  				 errmsg("OSSP uuid library failure: error code %d", rc)));
  }
  
+ /*
+  * We create a uuid_t object just once per session and re-use it for all
+  * operations in this module.  OSSP UUID caches the system MAC address and
+  * other state in this object.  Reusing the object has a number of benefits:
+  * saving the cycles needed to fetch the system MAC address over and over,
+  * reducing the amount of entropy we draw from /dev/urandom, and providing a
+  * positive guarantee that successive generated V1-style UUIDs don't collide.
+  * (On a machine fast enough to generate multiple UUIDs per microsecond,
+  * or whatever the system's wall-clock resolution is, we'd otherwise risk
+  * collisions whenever random initialization of the uuid_t's clock sequence
+  * value chanced to produce duplicates.)
+  *
+  * However: when we're doing V3 or V5 UUID creation, uuid_make needs two
+  * uuid_t objects, one holding the namespace UUID and one for the result.
+  * It's unspecified whether it's safe to use the same uuid_t for both cases,
+  * so let's cache a second uuid_t for use as the namespace holder object.
+  */
+ static uuid_t *
+ get_cached_uuid_t(int which)
+ {
+ 	static uuid_t *cached_uuid[2] = {NULL, NULL};
+ 
+ 	if (cached_uuid[which] == NULL)
+ 	{
+ 		uuid_rc_t	rc;
+ 
+ 		rc = uuid_create(&cached_uuid[which]);
+ 		if (rc != UUID_RC_OK)
+ 		{
+ 			cached_uuid[which] = NULL;
+ 			pguuid_complain(rc);
+ 		}
+ 	}
+ 	return cached_uuid[which];
+ }
+ 
  static char *
  uuid_to_string(const uuid_t *uuid)
  {
*************** string_to_uuid(const char *str, uuid_t *
*** 171,190 ****
  static Datum
  special_uuid_value(const char *name)
  {
! 	uuid_t	   *uuid;
  	char	   *str;
  	uuid_rc_t	rc;
  
- 	rc = uuid_create(&uuid);
- 	if (rc != UUID_RC_OK)
- 		pguuid_complain(rc);
  	rc = uuid_load(uuid, name);
  	if (rc != UUID_RC_OK)
  		pguuid_complain(rc);
  	str = uuid_to_string(uuid);
- 	rc = uuid_destroy(uuid);
- 	if (rc != UUID_RC_OK)
- 		pguuid_complain(rc);
  
  	return DirectFunctionCall1(uuid_in, CStringGetDatum(str));
  }
--- 207,220 ----
  static Datum
  special_uuid_value(const char *name)
  {
! 	uuid_t	   *uuid = get_cached_uuid_t(0);
  	char	   *str;
  	uuid_rc_t	rc;
  
  	rc = uuid_load(uuid, name);
  	if (rc != UUID_RC_OK)
  		pguuid_complain(rc);
  	str = uuid_to_string(uuid);
  
  	return DirectFunctionCall1(uuid_in, CStringGetDatum(str));
  }
*************** special_uuid_value(const char *name)
*** 193,212 ****
  static Datum
  uuid_generate_internal(int mode, const uuid_t *ns, const char *name, int len)
  {
! 	uuid_t	   *uuid;
  	char	   *str;
  	uuid_rc_t	rc;
  
- 	rc = uuid_create(&uuid);
- 	if (rc != UUID_RC_OK)
- 		pguuid_complain(rc);
  	rc = uuid_make(uuid, mode, ns, name);
  	if (rc != UUID_RC_OK)
  		pguuid_complain(rc);
  	str = uuid_to_string(uuid);
- 	rc = uuid_destroy(uuid);
- 	if (rc != UUID_RC_OK)
- 		pguuid_complain(rc);
  
  	return DirectFunctionCall1(uuid_in, CStringGetDatum(str));
  }
--- 223,236 ----
  static Datum
  uuid_generate_internal(int mode, const uuid_t *ns, const char *name, int len)
  {
! 	uuid_t	   *uuid = get_cached_uuid_t(0);
  	char	   *str;
  	uuid_rc_t	rc;
  
  	rc = uuid_make(uuid, mode, ns, name);
  	if (rc != UUID_RC_OK)
  		pguuid_complain(rc);
  	str = uuid_to_string(uuid);
  
  	return DirectFunctionCall1(uuid_in, CStringGetDatum(str));
  }
*************** uuid_generate_internal(int mode, const u
*** 215,240 ****
  static Datum
  uuid_generate_v35_internal(int mode, pg_uuid_t *ns, text *name)
  {
! 	uuid_t	   *ns_uuid;
! 	Datum		result;
! 	uuid_rc_t	rc;
  
! 	rc = uuid_create(&ns_uuid);
! 	if (rc != UUID_RC_OK)
! 		pguuid_complain(rc);
! 	string_to_uuid(DatumGetCString(DirectFunctionCall1(uuid_out, UUIDPGetDatum(ns))),
  				   ns_uuid);
  
! 	result = uuid_generate_internal(mode,
! 									ns_uuid,
! 									text_to_cstring(name),
! 									0);
! 
! 	rc = uuid_destroy(ns_uuid);
! 	if (rc != UUID_RC_OK)
! 		pguuid_complain(rc);
! 
! 	return result;
  }
  
  #else							/* !HAVE_UUID_OSSP */
--- 239,254 ----
  static Datum
  uuid_generate_v35_internal(int mode, pg_uuid_t *ns, text *name)
  {
! 	uuid_t	   *ns_uuid = get_cached_uuid_t(1);
  
! 	string_to_uuid(DatumGetCString(DirectFunctionCall1(uuid_out,
! 													   UUIDPGetDatum(ns))),
  				   ns_uuid);
  
! 	return uuid_generate_internal(mode,
! 								  ns_uuid,
! 								  text_to_cstring(name),
! 								  0);
  }
  
  #else							/* !HAVE_UUID_OSSP */