Not yet done for ODBC tables.
modified:
  storage/connect/connect.cc
  storage/connect/ha_connect.cc
  storage/connect/ha_connect.h
  storage/connect/mycat.cc
  storage/connect/plgdbsem.h
  storage/connect/reldef.h
  storage/connect/tabdos.h
  storage/connect/tabmysql.cpp
  storage/connect/tabmysql.h
  storage/connect/tabodbc.cpp
  storage/connect/tabodbc.h
  storage/connect/xindex.cpp
  storage/connect/xtable.h

- Return error in "info" on Cardinality error.
modified:
  storage/connect/ha_connect.cc