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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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165
sql/opt_range.h
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@ -79,14 +79,18 @@ public:
TABLE *head;
/*
the only index this quick select uses, or MAX_KEY for
QUICK_INDEX_MERGE_SELECT
index this quick select uses, or MAX_KEY for quick selects
that use several indexes
*/
uint index;
uint index;
/* applicable iff index!= MAX_KEY */
uint max_used_key_length, used_key_parts;
QUICK_SELECT_I();
virtual ~QUICK_SELECT_I(){};
/**/
virtual int init() = 0;
virtual int reset(void) = 0;
virtual int get_next() = 0; /* get next record to retrieve */
@ -97,27 +101,64 @@ public:
QS_TYPE_RANGE = 0,
QS_TYPE_INDEX_MERGE = 1,
QS_TYPE_RANGE_DESC = 2,
QS_TYPE_FULLTEXT = 3
QS_TYPE_FULLTEXT = 3,
QS_TYPE_ROR_INTERSECT = 4,
QS_TYPE_ROR_UNION = 5,
};
/* Get type of this quick select - one of the QS_* values */
virtual int get_type() = 0;
/* Get type of this quick select - one of the QS_TYPE_* values */
virtual int get_type() = 0;
/*
Initialize this quick select as a child of a index union or intersection
scan. This call replaces init() call.
*/
virtual int init_ror_child_scan(bool reuse_handler)
{ DBUG_ASSERT(0); return 1; }
virtual void cleanup_ror_child_scan() { DBUG_ASSERT(0); }
virtual void save_last_pos(){};
/*
Fill key_names with list of keys this quick select used;
fill used_lenghth with correponding used lengths.
This is used by select_describe.
*/
virtual void fill_keys_and_lengths(String *key_names,
String *used_lengths)=0;
virtual bool check_if_keys_used(List<Item> *fields);
/*
rowid of last row retrieved by this quick select. This is used only
when doing ROR-index_merge selects
*/
byte *last_rowid;
byte *record;
#ifndef DBUG_OFF
/*
Print quick select information to DBUG_FILE. Caller is responsible
for locking DBUG_FILE before this call and unlocking it afterwards.
*/
virtual void dbug_dump(int indent, bool verbose)= 0;
#endif
};
struct st_qsel_param;
class SEL_ARG;
class QUICK_RANGE_SELECT : public QUICK_SELECT_I
class QUICK_RANGE_SELECT : public QUICK_SELECT_I
{
protected:
bool next,dont_free;
public:
int error;
handler *file;
byte *record;
protected:
friend void print_quick_sel_range(QUICK_RANGE_SELECT *quick,
const key_map* needed_reg);
handler *file;
bool free_file; /* if true, this quick select "owns" file and will free it */
protected:
friend
QUICK_RANGE_SELECT *get_quick_select_for_ref(THD *thd, TABLE *table,
struct st_table_ref *ref);
@ -131,17 +172,19 @@ protected:
MEM_ROOT *alloc);
friend class QUICK_SELECT_DESC;
friend class QUICK_INDEX_MERGE_SELECT;
friend class QUICK_ROR_INTERSECT_SELECT;
DYNAMIC_ARRAY ranges; /* ordered array of range ptrs */
QUICK_RANGE **cur_range; /* current element in ranges */
QUICK_RANGE *range;
MEM_ROOT alloc;
KEY_PART *key_parts;
int cmp_next(QUICK_RANGE *range);
int cmp_prev(QUICK_RANGE *range);
bool row_in_ranges();
public:
MEM_ROOT alloc;
QUICK_RANGE_SELECT(THD *thd, TABLE *table,uint index_arg,bool no_alloc=0,
MEM_ROOT *parent_alloc=NULL);
~QUICK_RANGE_SELECT();
@ -157,7 +200,16 @@ public:
int get_next();
bool reverse_sorted() { return 0; }
bool unique_key_range();
int init_ror_child_scan(bool reuse_handler);
void save_last_pos()
{
file->position(record);
};
int get_type() { return QS_TYPE_RANGE; }
void fill_keys_and_lengths(String *key_names, String *used_lengths);
#ifndef DBUG_OFF
virtual void dbug_dump(int indent, bool verbose);
#endif
};
@ -232,6 +284,11 @@ public:
bool reverse_sorted() { return false; }
bool unique_key_range() { return false; }
int get_type() { return QS_TYPE_INDEX_MERGE; }
void fill_keys_and_lengths(String *key_names, String *used_lengths);
bool check_if_keys_used(List<Item> *fields);
#ifndef DBUG_OFF
virtual void dbug_dump(int indent, bool verbose);
#endif
bool push_quick_back(QUICK_RANGE_SELECT *quick_sel_range);
@ -242,9 +299,6 @@ public:
List_iterator_fast<QUICK_RANGE_SELECT> cur_quick_it;
QUICK_RANGE_SELECT* cur_quick_select;
/* last element in quick_selects list */
QUICK_RANGE_SELECT* last_quick_select;
/* quick select that uses clustered primary key (NULL if none) */
QUICK_RANGE_SELECT* pk_quick_select;
@ -262,6 +316,87 @@ public:
READ_RECORD read_record;
};
/*
Rowid-Ordered Retrieval (ROR) index intersection quick select.
This quick select produces an intersection of records returned by several
QUICK_RANGE_SELECTs that return data ordered by rowid.
*/
class QUICK_ROR_INTERSECT_SELECT : public QUICK_SELECT_I
{
public:
QUICK_ROR_INTERSECT_SELECT(THD *thd, TABLE *table,
bool retrieve_full_rows,
MEM_ROOT *parent_alloc);
~QUICK_ROR_INTERSECT_SELECT();
int init();
int reset(void);
int get_next();
bool reverse_sorted() { return false; }
bool unique_key_range() { return false; }
int get_type() { return QS_TYPE_ROR_INTERSECT; }
void fill_keys_and_lengths(String *key_names, String *used_lengths);
bool check_if_keys_used(List<Item> *fields);
#ifndef DBUG_OFF
virtual void dbug_dump(int indent, bool verbose);
#endif
int init_ror_child_scan(bool reuse_handler);
bool push_quick_back(QUICK_RANGE_SELECT *quick_sel_range);
/* range quick selects this intersection consists of */
List<QUICK_RANGE_SELECT> quick_selects;
QUICK_RANGE_SELECT *cpk_quick;
MEM_ROOT alloc;
THD *thd;
bool reset_called;
bool need_to_fetch_row;
};
/*
Rowid-Ordered Retrieval index union select.
*/
class QUICK_ROR_UNION_SELECT : public QUICK_SELECT_I
{
public:
QUICK_ROR_UNION_SELECT(THD *thd, TABLE *table);
~QUICK_ROR_UNION_SELECT();
int init();
int reset(void);
int get_next();
bool reverse_sorted() { return false; }
bool unique_key_range() { return false; }
int get_type() { return QS_TYPE_ROR_UNION; }
void fill_keys_and_lengths(String *key_names, String *used_lengths);
bool check_if_keys_used(List<Item> *fields);
#ifndef DBUG_OFF
virtual void dbug_dump(int indent, bool verbose);
#endif
bool push_quick_back(QUICK_SELECT_I *quick_sel_range);
/* range quick selects this index_merge read consists of */
List<QUICK_SELECT_I> quick_selects;
QUEUE queue;
MEM_ROOT alloc;
THD *thd;
byte *cur_rowid;
byte *prev_rowid;
uint rowid_length;
bool reset_called;
bool have_prev_rowid;
private:
static int queue_cmp(void *arg, byte *val1, byte *val2);
};
class QUICK_SELECT_DESC: public QUICK_RANGE_SELECT
{
public: