SQL: (0.6) Pruning for VERSIONING partitions [closes #97]

* based on RANGE pruning by COLUMNS (sys_trx_end) condition
* removed DEFAULT; AS OF NOW is always last; current VERSIONING as last non-empty (or first empty)
* Min/Max stats in TABLE_SHARE
* ALTER TABLE ADD PARTITION adds before AS OF NOW partition

1 files changed, 49 insertions, 16 deletions

diff --git a/sql/partition_element.h b/sql/partition_element.h
index e76558bf7ae..18276ef713e 100644
--- a/sql/partition_element.h
+++ b/sql/partition_element.h
@@ -90,38 +90,64 @@ typedef struct p_elem_val
 
 struct st_ddl_log_memory_entry;
 
-class Stat_timestampf : public Sql_alloc
+class Vers_field_stats : public Sql_alloc
 {
   static const uint buf_size= 4 + (TIME_SECOND_PART_DIGITS + 1) / 2;
   uchar min_buf[buf_size];
   uchar max_buf[buf_size];
   Field_timestampf min_value;
   Field_timestampf max_value;
+  mysql_rwlock_t lock;
 
 public:
-  Stat_timestampf(const char *field_name, TABLE_SHARE *share) :
+  Vers_field_stats(const char *field_name, TABLE_SHARE *share) :
     min_value(min_buf, NULL, 0, Field::NONE, field_name, share, 6),
     max_value(max_buf, NULL, 0, Field::NONE, field_name, share, 6)
   {
     min_value.set_max();
     memset(max_buf, 0, buf_size);
+    mysql_rwlock_init(key_rwlock_LOCK_vers_stats, &lock);
   }
-  void update(Field *from)
+  ~Vers_field_stats()
   {
-    from->update_min(&min_value, false);
-    from->update_max(&max_value, false);
+    mysql_rwlock_destroy(&lock);
+  }
+  bool update_unguarded(Field *from)
+  {
+    return
+      from->update_min(&min_value, false) +
+      from->update_max(&max_value, false);
+  }
+  bool update(Field *from)
+  {
+    mysql_rwlock_wrlock(&lock);
+    bool res= update_unguarded(from);
+    mysql_rwlock_unlock(&lock);
+    return res;
   }
   my_time_t min_time()
   {
-    return min_value.get_timestamp();
+    mysql_rwlock_rdlock(&lock);
+    my_time_t res= min_value.get_timestamp();
+    mysql_rwlock_unlock(&lock);
+    return res;
   }
   my_time_t max_time()
   {
-    return max_value.get_timestamp();
+    mysql_rwlock_rdlock(&lock);
+    my_time_t res= max_value.get_timestamp();
+    mysql_rwlock_unlock(&lock);
+    return res;
   }
 };
 
-class partition_element :public Sql_alloc {
+enum stat_trx_field
+{
+  STAT_TRX_END= 0
+};
+
+class partition_element :public Sql_alloc
+{
 public:
   List<partition_element> subpartitions;
   List<part_elem_value> list_val_list;
@@ -142,6 +168,7 @@ public:
   bool signed_flag;                          // Range value signed
   bool max_value;                            // MAXVALUE range
   uint32 id;
+  bool empty;
 
   enum elem_type
   {
@@ -151,7 +178,6 @@ public:
   };
 
   elem_type type;
-  Stat_timestampf *stat_trx_end;
 
   partition_element()
   : part_max_rows(0), part_min_rows(0), range_value(0),
@@ -162,10 +188,9 @@ public:
     nodegroup_id(UNDEF_NODEGROUP), has_null_value(FALSE),
     signed_flag(FALSE), max_value(FALSE),
     id(UINT32_MAX),
-    type(CONVENTIONAL),
-    stat_trx_end(NULL)
-  {
-  }
+    empty(true),
+    type(CONVENTIONAL)
+  {}
   partition_element(partition_element *part_elem)
   : part_max_rows(part_elem->part_max_rows),
     part_min_rows(part_elem->part_min_rows),
@@ -180,11 +205,19 @@ public:
     nodegroup_id(part_elem->nodegroup_id),
     has_null_value(FALSE),
     id(part_elem->id),
-    type(part_elem->type),
-    stat_trx_end(NULL)
+    empty(part_elem->empty),
+    type(part_elem->type)
+  {}
+  ~partition_element() {}
+
+  part_column_list_val& get_col_val(uint idx)
   {
+    DBUG_ASSERT(type != CONVENTIONAL);
+    DBUG_ASSERT(list_val_list.elements == 1);
+    part_elem_value *ev= static_cast<part_elem_value*>(list_val_list.first_node()->info);
+    DBUG_ASSERT(ev && ev->col_val_array);
+    return ev->col_val_array[idx];
   }
-  ~partition_element() {}
 };
 
 #endif /* PARTITION_ELEMENT_INCLUDED */