WL#3732 Information schema optimization

client/mysqldump.c:
  table type compare is changed to case insensitive
mysql-test/r/information_schema.result:
  test result
mysql-test/r/information_schema_db.result:
  result fix
mysql-test/suite/ndb/r/ndb_alter_table.result:
  result fix
mysql-test/suite/ndb/r/ndb_temporary.result:
  result fix
mysql-test/t/information_schema.test:
  test case
sql/ha_ndbcluster.cc:
  char* variables are changed to LEX_STRING
sql/ha_ndbcluster.h:
  char* variables are changed to LEX_STRING
sql/ha_ndbcluster_binlog.cc:
  char* variables are changed to LEX_STRING
sql/handler.cc:
  char* variables are changed to LEX_STRING
sql/handler.h:
  char* variables are changed to LEX_STRING
sql/sql_base.cc:
  Modified functions which are used during open table process
  according to table opening method and requested_object.
sql/sql_select.cc:
  Add support for I_S tables into select_describe() function
sql/sql_show.cc:
  1. Added initialization of 'open_method' to 'st_field_info' structs.
  2. Added initialization of 'i_s_requested_object' to 'ST_SCHEMA_TABLE' structs.
  3. New function which calculates database name and table name values 
     from 'where' condition if it's possible
     void get_lookup_field_values(THD *thd, COND *cond, TABLE_LIST *table,
                                  LOOKUP_FIELD_VALUES *lookup_field_vals);
  4. New function which set table open method
     setup_table_open_method(TABLE_LIST *tables,
                             ST_SCHEMA_TABLE *schema_table,
                             enum enum_schema_tables schema_table_idx)
  5. New function
     int make_db_list(THD *thd, List<LEX_STRING> *files,
                      LOOKUP_FIELD_VALUES *lookup_field_vals,
                      bool *with_i_schema)
  6. New function
     int make_table_name_list(THD *thd, List<LEX_STRING> *files, LEX *lex,
                              LOOKUP_FIELD_VALUES *lookup_field_vals,
                              bool with_i_schema, LEX_STRING *db_name)
  7. Modified 'get_all_tables' function according to new schema(see wl#3732).
sql/sql_show.h:
  char* variables are changed to LEX_STRING
sql/table.cc:
  Modified functions which are used during open table process
  according to table opening method and requested_object.
sql/table.h:
  1. added new constants(open_method)
  #define SKIP_OPEN_TABLE 0
  #define OPEN_FRM_ONLY   1
  #define OPEN_FULL_TABLE 2
      
  2. Added new field 'open_method' into struct st_field_info;
     uint open_method;
      
  3. Added new field into ST_SCHEMA_TABLE struct
     uint i_s_requested_object;  /* the object we need to open(TABLE | VIEW) */.
  4. Added new field to TABLE_LIST struct.
     uint i_s_requested_object;
     This field is set from ST_SCHEMA_TABLE.i_s_requested_object
     for processed table before opening.
      
  5. Added new fields to TABLE_LIST struct, used for 'explain select' for I_S table
     bool has_db_lookup_value;
     bool has_table_lookup_value;
     uint table_open_method;
sql/unireg.h:
  added new constants

1 files changed, 76 insertions, 30 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 9ea67af1bf9..2d383ee1bfc 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1625,6 +1625,10 @@ JOIN::exec()
     DBUG_VOID_RETURN;
   }
 
+  if ((this->select_lex->options & OPTION_SCHEMA_TABLE) &&
+      get_schema_tables_result(this, PROCESSED_BY_JOIN_EXEC))
+    DBUG_VOID_RETURN;
+
   if (select_options & SELECT_DESCRIBE)
   {
     /*
@@ -1670,13 +1674,6 @@ JOIN::exec()
   */
   curr_join->examined_rows= 0;
 
-  if ((curr_join->select_lex->options & OPTION_SCHEMA_TABLE) &&
-      !thd->lex->describe &&
-      get_schema_tables_result(curr_join, PROCESSED_BY_JOIN_EXEC))
-  {
-    DBUG_VOID_RETURN;
-  }
-
   /* Create a tmp table if distinct or if the sort is too complicated */
   if (need_tmp)
   {
@@ -12929,7 +12926,6 @@ create_sort_index(THD *thd, JOIN *join, ORDER *order,
 
   /* Fill schema tables with data before filesort if it's necessary */
   if ((join->select_lex->options & OPTION_SCHEMA_TABLE) &&
-      !thd->lex->describe &&
       get_schema_tables_result(join, PROCESSED_BY_CREATE_SORT_INDEX))
     goto err;
 
@@ -15382,6 +15378,7 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
     {
       JOIN_TAB *tab=join->join_tab+i;
       TABLE *table=tab->table;
+      TABLE_LIST *table_list= tab->table->pos_in_table_list;
       char buff[512]; 
       char buff1[512], buff2[512], buff3[512];
       char keylen_str_buf[64];
@@ -15517,37 +15514,68 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
       }
       else
       {
-	item_list.push_back(item_null);
+        if (table_list->schema_table &&
+            table_list->schema_table->i_s_requested_object & OPTIMIZE_I_S_TABLE)
+        {
+          const char *tmp_buff;
+          int f_idx;
+          if (table_list->has_db_lookup_value)
+          {
+            f_idx= table_list->schema_table->idx_field1;
+            tmp_buff= table_list->schema_table->fields_info[f_idx].field_name;
+            tmp2.append(tmp_buff, strlen(tmp_buff), cs);
+          }          
+          if (table_list->has_table_lookup_value)
+          {
+            if (table_list->has_db_lookup_value)
+              tmp2.append(',');
+            f_idx= table_list->schema_table->idx_field2;
+            tmp_buff= table_list->schema_table->fields_info[f_idx].field_name;
+            tmp2.append(tmp_buff, strlen(tmp_buff), cs);
+          }
+          if (tmp2.length())
+            item_list.push_back(new Item_string(tmp2.ptr(),tmp2.length(),cs));
+          else
+            item_list.push_back(item_null);
+        }
+        else
+          item_list.push_back(item_null);
 	item_list.push_back(item_null);
 	item_list.push_back(item_null);
       }
       
       /* Add "rows" field to item_list. */
-      ha_rows examined_rows;
-      if (tab->select && tab->select->quick)
-        examined_rows= tab->select->quick->records;
-      else if (tab->type == JT_NEXT || tab->type == JT_ALL)
-        examined_rows= tab->table->file->records();
+      if (table_list->schema_table)
+      {
+        item_list.push_back(item_null);
+      }
       else
-        examined_rows=(ha_rows)join->best_positions[i].records_read; 
- 
-      item_list.push_back(new Item_int((longlong) (ulonglong) examined_rows, 
-                                       MY_INT64_NUM_DECIMAL_DIGITS));
-
-      /* Add "filtered" field to item_list. */
-      if (join->thd->lex->describe & DESCRIBE_EXTENDED)
       {
-        Item_float *filtered;
-        float f; 
-        if (examined_rows)
-          f= (float) (100.0 * join->best_positions[i].records_read /
-                      examined_rows);
+        ha_rows examined_rows;
+        if (tab->select && tab->select->quick)
+          examined_rows= tab->select->quick->records;
+        else if (tab->type == JT_NEXT || tab->type == JT_ALL)
+          examined_rows= tab->table->file->records();
         else
-          f= 0.0;
-        item_list.push_back((filtered= new Item_float(f)));
-        filtered->decimals= 2;
-      }
+          examined_rows=(ha_rows)join->best_positions[i].records_read; 
+ 
+        item_list.push_back(new Item_int((longlong) (ulonglong) examined_rows, 
+                                         MY_INT64_NUM_DECIMAL_DIGITS));
 
+        /* Add "filtered" field to item_list. */
+        if (join->thd->lex->describe & DESCRIBE_EXTENDED)
+        {
+          Item_float *filtered;
+          float f; 
+          if (examined_rows)
+            f= (float) (100.0 * join->best_positions[i].records_read /
+                        examined_rows);
+          else
+            f= 0.0;
+          item_list.push_back((filtered= new Item_float(f)));
+          filtered->decimals= 2;
+        }
+      }
 
       /* Build "Extra" field and add it to item_list. */
       my_bool key_read=table->key_read;
@@ -15615,6 +15643,24 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
               extra.append(STRING_WITH_LEN("; Using where"));
           }
 	}
+        if (table_list->schema_table &&
+            table_list->schema_table->i_s_requested_object & OPTIMIZE_I_S_TABLE)
+        {
+          if (!table_list->table_open_method)
+            extra.append(STRING_WITH_LEN("; Skip_open_table"));
+          else if (table_list->table_open_method == OPEN_FRM_ONLY)
+            extra.append(STRING_WITH_LEN("; Open_frm_only"));
+          else
+            extra.append(STRING_WITH_LEN("; Open_full_table"));
+          if (table_list->has_db_lookup_value &&
+              table_list->has_table_lookup_value)
+            extra.append(STRING_WITH_LEN("; Scanned 0 databases"));
+          else if (table_list->has_db_lookup_value ||
+                   table_list->has_table_lookup_value)
+            extra.append(STRING_WITH_LEN("; Scanned 1 database"));
+          else
+            extra.append(STRING_WITH_LEN("; Scanned all databases"));
+        }
 	if (key_read)
         {
           if (quick_type == QUICK_SELECT_I::QS_TYPE_GROUP_MIN_MAX)