[SHOW] EXPLAIN UPDATE/DELETE, code re-structuring

- Let Query Plan Footprint store join buffer type 
  in binary form, not string.
- Same for LooseScan type.

sql/opt_qpf.cc

@@ -489,7 +489,17 @@ void QPF_table_access::append_tag_name(String *str, enum Extra_tag tag)
     case ET_USING_JOIN_BUFFER:
     {
       str->append(extra_tag_text[tag]);
-      str->append(join_buffer_type);
+
+      str->append(STRING_WITH_LEN(" ("));
+      const char *buffer_type= bka_type.incremental ? "incremental" : "flat";
+      str->append(buffer_type);
+      str->append(STRING_WITH_LEN(", "));
+      str->append(bka_type.join_alg);
+      str->append(STRING_WITH_LEN(" join"));
+      str->append(STRING_WITH_LEN(")"));
+      if (bka_type.mrr_type.length())
+        str->append(bka_type.mrr_type);
+
       break;
     }
     case ET_FIRST_MATCH:
@@ -507,7 +517,8 @@ void QPF_table_access::append_tag_name(String *str, enum Extra_tag tag)
     case ET_USING_INDEX_FOR_GROUP_BY:
     {
       str->append(extra_tag_text[tag]);
-      str->append(loose_scan_type);
+      if (loose_scan_is_scanning)
+        str->append(" (scanning)");
       break;
     }
     default:

sql/opt_qpf.h

@@ -272,6 +272,15 @@ enum Extra_tag
 };
 
 
+typedef struct st_qpf_bka_type
+{
+  bool incremental;
+  const char *join_alg;
+  StringBuffer<64> mrr_type;
+
+} QPF_BKA_TYPE;
+
+
 /*
   Query Plan Footprint for a JOIN_TAB.
 */
@@ -329,7 +338,7 @@ class QPF_table_access : public Sql_alloc
   StringBuffer<64> quick_info;
 
   // Valid if ET_USING_INDEX_FOR_GROUP_BY is present
-  StringBuffer<64> loose_scan_type;
+  bool loose_scan_is_scanning;
   
   // valid with ET_RANGE_CHECKED_FOR_EACH_RECORD
   key_map range_checked_map;
@@ -338,7 +347,8 @@ class QPF_table_access : public Sql_alloc
   StringBuffer<64> mrr_type;
 
   // valid with ET_USING_JOIN_BUFFER
-  StringBuffer<64> join_buffer_type;
+  //StringBuffer<64> join_buffer_type;
+  QPF_BKA_TYPE bka_type;
   
   //TABLE *firstmatch_table;
   StringBuffer<64> firstmatch_table_name;

sql/opt_range.h

@@ -944,11 +944,7 @@ class QUICK_GROUP_MIN_MAX_SELECT : public QUICK_SELECT_I
   void dbug_dump(int indent, bool verbose);
 #endif
   bool is_agg_distinct() { return have_agg_distinct; }
-  virtual void append_loose_scan_type(String *str) 
-  {
-    if (is_index_scan)
-      str->append(STRING_WITH_LEN(" (scanning)"));
-  }
+  bool loose_scan_is_scanning() { return is_index_scan; }
 };
 
 

sql/sql_join_cache.cc

@@ -2568,34 +2568,26 @@ enum_nested_loop_state JOIN_CACHE::join_null_complements(bool skip_last)
     none
 */ 
 
-void JOIN_CACHE::print_explain_comment(String *str)
+void JOIN_CACHE::save_qpf(struct st_qpf_bka_type *qpf)
 {
-  str->append(STRING_WITH_LEN(" ("));
-  const char *buffer_type= prev_cache ? "incremental" : "flat";
-  str->append(buffer_type);
-  str->append(STRING_WITH_LEN(", "));
+  qpf->incremental= test(prev_cache);
 
-  const char *join_alg="";
   switch (get_join_alg()) {
   case BNL_JOIN_ALG:
-    join_alg= "BNL";
+    qpf->join_alg= "BNL";
     break;
   case BNLH_JOIN_ALG:
-    join_alg= "BNLH";
+    qpf->join_alg= "BNLH";
     break;
   case BKA_JOIN_ALG:
-    join_alg= "BKA";
+    qpf->join_alg= "BKA";
     break;
   case BKAH_JOIN_ALG:
-    join_alg= "BKAH";
+    qpf->join_alg= "BKAH";
     break;
   default:
     DBUG_ASSERT(0);
   }
-
-  str->append(join_alg);
-  str->append(STRING_WITH_LEN(" join"));
-  str->append(STRING_WITH_LEN(")"));
 }
 
 /**
@@ -2621,18 +2613,17 @@ static void add_mrr_explain_info(String *str, uint mrr_mode, handler *file)
   }
 }
 
-
-void JOIN_CACHE_BKA::print_explain_comment(String *str)
+void JOIN_CACHE_BKA::save_qpf(struct st_qpf_bka_type *qpf)
 {
-  JOIN_CACHE::print_explain_comment(str); 
-  add_mrr_explain_info(str, mrr_mode, join_tab->table->file);
+  JOIN_CACHE::save_qpf(qpf); 
+  add_mrr_explain_info(&qpf->mrr_type, mrr_mode, join_tab->table->file);
 }
 
 
-void JOIN_CACHE_BKAH::print_explain_comment(String *str)
+void JOIN_CACHE_BKAH::save_qpf(struct st_qpf_bka_type *qpf)
 {
-  JOIN_CACHE::print_explain_comment(str); 
-  add_mrr_explain_info(str, mrr_mode, join_tab->table->file);
+  JOIN_CACHE::save_qpf(qpf); 
+  add_mrr_explain_info(&qpf->mrr_type, mrr_mode, join_tab->table->file);
 }
 
 

sql/sql_join_cache.h

@@ -63,6 +63,7 @@ typedef struct st_cache_field {
 
 class JOIN_TAB_SCAN;
 
+struct st_qpf_bka_type;
 
 /*
   JOIN_CACHE is the base class to support the implementations of 
@@ -657,7 +658,7 @@ class JOIN_CACHE :public Sql_alloc
   enum_nested_loop_state join_records(bool skip_last);
 
   /* Add a comment on the join algorithm employed by the join cache */
-  virtual void print_explain_comment(String *str);
+  virtual void save_qpf(struct st_qpf_bka_type *qpf);
 
   THD *thd();
 
@@ -1335,7 +1336,7 @@ class JOIN_CACHE_BKA :public JOIN_CACHE
   /* Check index condition of the joined table for a record from BKA cache */
   bool skip_index_tuple(range_id_t range_info);
 
-  void print_explain_comment(String *str);
+  void save_qpf(struct st_qpf_bka_type *qpf);
 };
 
 
@@ -1426,5 +1427,5 @@ class JOIN_CACHE_BKAH :public JOIN_CACHE_BNLH
   /* Check index condition of the joined table for a record from BKAH cache */
   bool skip_index_tuple(range_id_t range_info);
 
-  void print_explain_comment(String *str);
+  void save_qpf(struct st_qpf_bka_type *qpf);
 };

sql/sql_select.cc

@@ -22907,7 +22907,7 @@ int JOIN::save_qpf(QPF_query *output, bool need_tmp_table, bool need_order,
             QUICK_GROUP_MIN_MAX_SELECT *qgs= 
               (QUICK_GROUP_MIN_MAX_SELECT *) tab->select->quick;
             qpt->push_extra(ET_USING_INDEX_FOR_GROUP_BY);
-            qgs->append_loose_scan_type(&qpt->loose_scan_type);
+            qpt->loose_scan_is_scanning= qgs->loose_scan_is_scanning();
           }
           else
             qpt->push_extra(ET_USING_INDEX);
@@ -22979,9 +22979,8 @@ int JOIN::save_qpf(QPF_query *output, bool need_tmp_table, bool need_order,
         if (tab->cache)
 	{
           qpt->push_extra(ET_USING_JOIN_BUFFER);
-          tab->cache->print_explain_comment(&qpt->join_buffer_type);
+          tab->cache->save_qpf(&qpt->bka_type);
         }
-        
       }
       
       if (saved_join_tab)