MWL#121-124 DS-MRR support for key-ordered retrieval, etc

- Merge into 5.3-main

1 files changed, 22 insertions, 7 deletions

diff --git a/sql/handler.h b/sql/handler.h
index f76580b7082..d05709bbf3d 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -1281,9 +1281,9 @@ void get_sweep_read_cost(TABLE *table, ha_rows nrows, bool interrupted,
                          COST_VECT *cost);
 
 /*
-  The below two are not used (and not handled) in this milestone of this WL
-  entry because there seems to be no use for them at this stage of
-  implementation.
+  Indicates that all scanned ranges will be singlepoint (aka equality) ranges.
+  The ranges may not use the full key but all of them will use the same number
+  of key parts.
 */
 #define HA_MRR_SINGLE_POINT 1
 #define HA_MRR_FIXED_KEY  2
@@ -1325,6 +1325,16 @@ void get_sweep_read_cost(TABLE *table, ha_rows nrows, bool interrupted,
 */
 #define HA_MRR_NO_NULL_ENDPOINTS 128
 
+/*
+  The MRR user has materialized range keys somewhere in the user's buffer.
+  This can be used for optimization of the procedure that sorts these keys
+  since in this case key values don't have to be copied into the MRR buffer.
+
+  In other words, it is guaranteed that after RANGE_SEQ_IF::next() call the 
+  pointer in range->start_key.key will point to a key value that will remain 
+  there until the end of the MRR scan.
+*/
+#define HA_MRR_MATERIALIZED_KEYS 256
 
 
 /*
@@ -1815,14 +1825,19 @@ public:
   inline int ha_index_first(uchar * buf);
   inline int ha_index_last(uchar * buf);
   inline int ha_index_next_same(uchar *buf, const uchar *key, uint keylen);
+  /*
+    TODO: should we make for those functions non-virtual ha_func_name wrappers,
+    too?
+  */
   virtual ha_rows multi_range_read_info_const(uint keyno, RANGE_SEQ_IF *seq,
                                               void *seq_init_param, 
                                               uint n_ranges, uint *bufsz,
                                               uint *flags, COST_VECT *cost);
   virtual ha_rows multi_range_read_info(uint keyno, uint n_ranges, uint keys,
-                                        uint *bufsz, uint *flags, COST_VECT *cost);
+                                        uint key_parts, uint *bufsz, 
+                                        uint *flags, COST_VECT *cost);
   virtual int multi_range_read_init(RANGE_SEQ_IF *seq, void *seq_init_param,
-                                    uint n_ranges, uint mode,
+                                    uint n_ranges, uint mode, 
                                     HANDLER_BUFFER *buf);
   virtual int multi_range_read_next(char **range_info);
   virtual int read_range_first(const key_range *start_key,
@@ -2181,7 +2196,8 @@ public:
       TRUE    if the engine supports virtual columns
   */
   virtual bool check_if_supported_virtual_columns(void) { return FALSE;}
-
+  
+  TABLE* get_table() { return table; }
 protected:
   /* deprecated, don't use in new engines */
   inline void ha_statistic_increment(ulong SSV::*offset) const { }
@@ -2374,7 +2390,6 @@ private:
   virtual int rename_partitions(const char *path)
   { return HA_ERR_WRONG_COMMAND; }
   friend class ha_partition;
-  friend class DsMrr_impl;
 public:
   /* XXX to be removed, see ha_partition::partition_ht() */
   virtual handlerton *partition_ht() const