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MWL#17: Table elimination

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Address review feedback: 
- Change from Wave-based approach (a-la const table detection) to 
  building and walking functional dependency graph.
- Change from piggy-backing on ref-access code and KEYUSE structures
  to using our own expression analyzer.


sql/item.cc:
  MWL#17: Table elimination
  - Move from C-ish Field_processor_info to C++ ish and generic Field_enumerator
sql/item.h:
  MWL#17: Table elimination
  - Move from C-ish Field_processor_info to C++ ish and generic Field_enumerator
sql/sql_bitmap.h:
  MWL#17: Table elimination
  - Backport of Table_map_iterator from 6.0
This commit is contained in:
Sergey Petrunya
2009-08-13 02:34:21 +04:00
parent 5ecad03df9
commit 854bb82bd8
4 changed files with 1130 additions and 331 deletions
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33
sql/sql_bitmap.h
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@ -93,6 +93,34 @@ public:
}
};
/* An iterator to quickly walk over bits in unlonglong bitmap. */
class Table_map_iterator
{
ulonglong bmp;
uint no;
public:
Table_map_iterator(ulonglong t) : bmp(t), no(0) {}
int next_bit()
{
static const char last_bit[16]= {32, 0, 1, 0,
2, 0, 1, 0,
3, 0, 1, 0,
2, 0, 1, 0};
uint bit;
while ((bit= last_bit[bmp & 0xF]) == 32)
{
no += 4;
bmp= bmp >> 4;
if (!bmp)
return BITMAP_END;
}
bmp &= ~(1LL << bit);
return no + bit;
}
int operator++(int) { return next_bit(); }
enum { BITMAP_END= 64 };
};
template <> class Bitmap<64>
{
ulonglong map;
@ -136,5 +164,10 @@ public:
my_bool operator==(const Bitmap<64>& map2) const { return map == map2.map; }
char *print(char *buf) const { longlong2str(map,buf,16); return buf; }
ulonglong to_ulonglong() const { return map; }
class Iterator : public Table_map_iterator
{
public:
Iterator(Bitmap<64> &bmp) : Table_map_iterator(bmp.map) {}
};
};