Cache file->index_flags(index, 0, 1) in table->key_info[index].index_flags

The reason for this is that we call file->index_flags(index, 0, 1)
multiple times in best_access_patch()when optimizing a table.
For example, in InnoDB, the calls is not trivial (4 if's and 2 assignments)
Now the function is inlined and is just a memory reference.

Other things:
- handler::is_clustering_key() and pk_is_clustering_key() are now inline.
- Added TABLE::can_use_rowid_filter() to simplify some code.
- Test if we should use a rowid_filter only if can_use_rowid_filter() is
  true.
- Added TABLE::is_clustering_key() to avoid a memory reference.
- Simplify some code using the fact that HA_KEYREAD_ONLY is true implies
  that HA_CLUSTERED_INDEX is false.
- Added DBUG_ASSERT to TABLE::best_range_rowid_filter() to ensure we
  do not call it with a clustering key.
- Reorginized elements in struct st_key to get better memory alignment.
- Updated ha_innobase::index_flags() to not have
  HA_DO_RANGE_FILTER_PUSHDOWN for clustered index

1 files changed, 15 insertions, 0 deletions

diff --git a/sql/sql_class.h b/sql/sql_class.h
index 95cf1275ee1..10f67fe0777 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -7430,6 +7430,21 @@ inline void handler::set_table(TABLE* table_arg)
   costs= &table_arg->s->optimizer_costs;
 }
 
+inline bool handler::pk_is_clustering_key(uint index) const
+{
+   /*
+     We have to check for MAX_INDEX as table->s->primary_key can be
+     MAX_KEY in the case where there is no primary key.
+   */
+   return index != MAX_KEY && is_clustering_key(index);
+}
+
+inline bool handler::is_clustering_key(uint index) const
+{
+  DBUG_ASSERT(index != MAX_KEY);
+  return table->is_clustering_key(index);
+}
+
 inline int handler::ha_ft_read(uchar *buf)
 {
   int error= ft_read(buf);