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This is first cset for WL#1394 "Optimize index merge when all involved index ranges include only values with equal keys"

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The main idea is to exploit the fact that key scans for "key=const" return ordered sequences of rowids.
This commit is contained in:
sergefp@mysql.com
2004-05-13 01:38:40 +04:00
parent b2efad935b
commit a46d7542c9
28 changed files with 3720 additions and 500 deletions
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56
mysys/my_bitmap.c
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@@ -330,3 +330,59 @@ void bitmap_union(MY_BITMAP *map, const MY_BITMAP *map2)
bitmap_unlock(map);
}
/*
Get number of set bits in the bitmap
*/
uint bitmap_bits_set(const MY_BITMAP *map)
{
uchar *m= map->bitmap,
*end= map->bitmap+map->bitmap_size;
uint res= 0;
DBUG_ASSERT(map->bitmap);
bitmap_lock((MY_BITMAP *)map);
while (m < end)
{
res+= my_count_bits_ushort(*m++);
}
bitmap_unlock((MY_BITMAP *)map);
return res;
}
/*
Return number of first zero bit or MY_BIT_NONE if all bits are set.
*/
uint bitmap_get_first(const MY_BITMAP *map)
{
uchar *bitmap=map->bitmap;
uint bit_found = MY_BIT_NONE;
uint bitmap_size=map->bitmap_size*8;
uint i;
DBUG_ASSERT(map->bitmap);
bitmap_lock((MY_BITMAP *)map);
for (i=0; i < bitmap_size ; i++, bitmap++)
{
if (*bitmap != 0xff)
{ /* Found slot with free bit */
uint b;
for (b=0; ; b++)
{
if (!(*bitmap & (1 << b)))
{
bit_found = (i*8)+b;
break;
}
}
break; /* Found bit */
}
}
bitmap_unlock((MY_BITMAP *)map);
return bit_found;
}