• Sergey Vojtovich's avatar
    MDEV-5675 - Performance: my_hash_sort_bin is called too often · b95c8ce5
    Sergey Vojtovich authored
    Reduced number of my_hash_sort_bin() calls from 4 to 1 per query.
    Reduced number of memory accesses done by my_hash_sort_bin().
    
    Details:
    - let MDL subsystem use pre-calculated hash value for hash
      inserts and deletes
    - let table cache use pre-calculated MDL hash value
    - MDL namespace is excluded from hash value calculation, so that
      hash value can be used by table cache as is
    - hash value for MDL is calculated as resulting hash value + MDL
      namespace
    - extended hash implementation to accept user defined hash function
    b95c8ce5
mdl.h 32.9 KB