fix comments

Author: montywi

sql/sql_base.cc

@@ -8041,7 +8041,7 @@ void make_leaves_list(THD *thd, List<TABLE_LIST> &list, TABLE_LIST *tables,
  from_clause Top-level list of table references in the FROM clause
  tables Table list (select_lex->table_list)
  leaves List of join table leaves list (select_lex->leaf_tables)
- refresh It is onle refresh for subquery
+ refresh It is only refresh for subquery
  select_insert It is SELECT ... INSERT command
  full_table_list a parameter to pass to the make_leaves_list function
 

sql/sql_select.cc

@@ -756,12 +756,11 @@ JOIN::prepare(Item ***rref_pointer_array,
  }
 
  table_count= select_lex->leaf_tables.elements;
- 
+
  TABLE_LIST *tbl;
  List_iterator_fast<TABLE_LIST> li(select_lex->leaf_tables);
  while ((tbl= li++))
  {
- //table_count++; /* Count the number of tables in the join. */
  /*
  If the query uses implicit grouping where the select list contains both
  aggregate functions and non-aggregate fields, any non-aggregated field
@@ -805,8 +804,9 @@ JOIN::prepare(Item ***rref_pointer_array,
  thd->lex->allow_sum_func|= (nesting_map)1 << select_lex_arg->nest_level;
  select_lex->having_fix_field= 1;
  /*
- Wrap alone field in HAVING clause in case it will be outer field of subquery
- which need persistent pointer on it, but having could be changed by optimizer
+ Wrap alone field in HAVING clause in case it will be outer field
+ of subquery which need persistent pointer on it, but having
+ could be changed by optimizer
  */
  if (having->type() == Item::REF_ITEM &&
  ((Item_ref *)having)->ref_type() == Item_ref::REF)
@@ -1099,8 +1099,8 @@ JOIN::optimize_inner()
  before 'optimize' from upper query 'optimize' to allow semijoin
  conversion happened (which done in the same way.
  */
- if(select_lex->first_cond_optimization &&
- conds && conds->walk(&Item::exists2in_processor, 0, (uchar *)thd))
+ if (select_lex->first_cond_optimization &&
+  conds && conds->walk(&Item::exists2in_processor, 0, (uchar *)thd))
  DBUG_RETURN(1);
  /*
 TODO: make view to decide if it is possible to write to WHERE directly or make Semi-Joins able to process ON condition if it is possible
@@ -2536,9 +2536,10 @@ void JOIN::exec_inner()
  }
 
  /*
- Evaluate all constant expressions with subqueries in the ORDER/GROUP clauses
- to make sure that all subqueries return a single row. The evaluation itself
- will trigger an error if that is not the case.
+ Evaluate all constant expressions with subqueries in the
+ ORDER/GROUP clauses to make sure that all subqueries return a
+ single row. The evaluation itself will trigger an error if that is
+ not the case.
  */
  if (exec_const_order_group_cond.elements &&
  !(select_options & SELECT_DESCRIBE))
@@ -2763,7 +2764,6 @@ void JOIN::exec_inner()
 (curr_join->tmp_all_fields1.elements-
  curr_join->tmp_fields_list1.elements);
 
- 
  if (exec_tmp_table2)
 curr_tmp_table= exec_tmp_table2;
  else
@@ -2878,7 +2878,6 @@ void JOIN::exec_inner()
  if (curr_tmp_table->distinct)
  curr_join->select_distinct=0;	/* Each row is unique */
 
-
  curr_join->join_free();	/* Free quick selects */
 
  if (curr_join->select_distinct && ! curr_join->group_list)
@@ -11880,7 +11879,6 @@ void JOIN::cleanup(bool full)
  }
  }
  cleaned= true;
-
  }
  else
  {
@@ -16071,11 +16069,15 @@ void setup_tmp_table_column_bitmaps(TABLE *table, uchar *bitmaps)
  @param param a description used as input to create the table
  @param fields list of items that will be used to define
  column types of the table (also see NOTES)
- @param group TODO document
+ @param group Create an unique key over all group by fields.
+ This is used to retrive the row during
+ end_write_group() and update them.
  @param distinct should table rows be distinct
  @param save_sum_fields see NOTES
- @param select_options
- @param rows_limit
+ @param select_options Optiions for how the select is run.
+ See sql_priv.h for a list of options.
+ @param rows_limit Maximum number of rows to insert into the
+ temporary table
  @param table_alias possible name of the temporary table that can
  be used for name resolving; can be "".
 */
@@ -16375,9 +16377,9 @@ create_tmp_table(THD *thd, TMP_TABLE_PARAM *param, List<Item> &fields,
  /*
  If item->marker == 4 then we force create_tmp_field
  to create a 64-bit longs for BIT fields because HEAP
- tables can't index BIT fields directly. We do the same
- for distinct, as we want the distinct index to be
- usable in this case too.
+ tables can't index BIT fields directly. We do the
+ same for distinct, as we want the distinct index
+ to be usable in this case too.
  */
  item->marker == 4 || param->bit_fields_as_long,
  force_copy_fields,
@@ -16397,16 +16399,19 @@ create_tmp_table(THD *thd, TMP_TABLE_PARAM *param, List<Item> &fields,
  created temporary table is not to be used for subquery
  materialization.
 
- The reason is that for subqueries that require materialization as part
- of their plan, we create the 'external' temporary table needed for IN
- execution, after the 'internal' temporary table needed for grouping.
- Since both the external and the internal temporary tables are created
- for the same list of SELECT fields of the subquery, setting
- 'result_field' for each invocation of create_tmp_table overrides the
- previous value of 'result_field'.
-
- The condition below prevents the creation of the external temp table
- to override the 'result_field' that was set for the internal temp table.
+ The reason is that for subqueries that require
+ materialization as part of their plan, we create the
+ 'external' temporary table needed for IN execution, after
+ the 'internal' temporary table needed for grouping. Since
+ both the external and the internal temporary tables are
+ created for the same list of SELECT fields of the subquery,
+ setting 'result_field' for each invocation of
+ create_tmp_table overrides the previous value of
+ 'result_field'.
+
+ The condition below prevents the creation of the external
+ temp table to override the 'result_field' that was set for
+ the internal temp table.
  */
  if (!agg_item->result_field || !param->materialized_subquery)
  agg_item->result_field= new_field;
@@ -17710,6 +17715,7 @@ Next_select_func setup_end_select_func(JOIN *join)
  @retval
  -1 if error should be sent
 */
+
 static int
 do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
 {
@@ -17877,12 +17883,14 @@ int rr_sequential_and_unpack(READ_RECORD *info)
 
 
 /*
- Fill the join buffer with partial records, retrieve all full matches for them 
+ Fill the join buffer with partial records, retrieve all full matches for
+ them
 
  SYNOPSIS
  sub_select_cache()
- join pointer to the structure providing all context info for the query
- join_tab the first next table of the execution plan to be retrieved
+ join pointer to the structure providing all context info for the
+ query
+ join_tab the first next table of the execution plan to be retrieved
  end_records true when we need to perform final steps of the retrieval
 
  DESCRIPTION
@@ -21059,8 +21067,9 @@ create_sort_index(THD *thd, JOIN *join, ORDER *order,
  if (join->pre_sort_join_tab)
  {
  /*
- we've already been in this function, and stashed away the original access 
- method in join->pre_sort_join_tab, restore it now.
+ we've already been in this function, and stashed away the
+ original access method in join->pre_sort_join_tab, restore it
+ now.
  */
 
  /* First, restore state of the handler */
@@ -22795,11 +22804,11 @@ change_to_use_tmp_fields(THD *thd, Item **ref_pointer_array,
  if (!suv || !new_field)
  DBUG_RETURN(true); // Fatal error
  /*
- We are replacing the argument of Item_func_set_user_var
- after its value has been read. The argument's null_value
- should be set by now, so we must set it explicitly for the
- replacement argument since the null_value may be read
- without any preceding call to val_*().
+ We are replacing the argument of Item_func_set_user_var after
+ its value has been read. The argument's null_value should be
+ set by now, so we must set it explicitly for the replacement
+ argument since the null_value may be read without any
+ preceeding call to val_*().
  */
  new_field->update_null_value();
  List<Item> list;