Optimizer Debugging With GDB

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Some useful things for debugging optimizer code with gdb.

Printing current partial join prefix

best_access_path() is a function that adds another table to the join prefix.

When in or around that function, the following can be useful:

A macro to print the join prefix already constructed:

define bap_print_prefix
  set $i=0
  while ($i < idx)
    p join->positions[$i++].table->table->alias.Ptr
  end
end

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