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Implementation of SUM(DISTINCT), tests cases

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This commit is contained in:
konstantin@oak.local
2003-12-19 19:04:03 +03:00
parent 89b2ddcf3f
commit 7fdf6740c7
9 changed files with 834 additions and 35 deletions
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16
sql/sql_class.h
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@ -1207,8 +1207,13 @@ class user_var_entry
DTCollation collation;
};
/* Class for unique (removing of duplicates) */
/*
Unique -- class for unique (removing of duplicates).
Puts all values to the TREE. If the tree becomes too big,
it's dumped to the file. User can request sorted values, or
just iterate through them. In the last case tree merging is performed in
memory simultaneously with iteration, so it should be ~2-3x faster.
*/
class Unique :public Sql_alloc
{
@ -1222,10 +1227,10 @@ class Unique :public Sql_alloc
public:
ulong elements;
Unique(qsort_cmp2 comp_func, void * comp_func_fixed_arg,
Unique(qsort_cmp2 comp_func, void *comp_func_fixed_arg,
uint size_arg, ulong max_in_memory_size_arg);
~Unique();
inline bool unique_add(gptr ptr)
inline bool unique_add(void *ptr)
{
if (tree.elements_in_tree > max_elements && flush())
return 1;
@ -1234,6 +1239,9 @@ public:
bool get(TABLE *table);
void reset();
bool walk(tree_walk_action action, void *walk_action_arg);
friend int unique_write_to_file(gptr key, element_count count, Unique *unique);
friend int unique_write_to_ptrs(gptr key, element_count count, Unique *unique);
};