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Commit ca6c4cc3 authored by psergey@psergey.(none)'s avatar psergey@psergey.(none)
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Added index_merge access method

parent 0466c250
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Showing with 1247 additions and 158 deletions
BitKeeper/etc/logging_ok
View file @ ca6c4cc3
......@@ -95,6 +95,7 @@ peter@linux.local
peter@mysql.com
peterg@mysql.com
pgulutzan@linux.local
psergey@psergey.(none)
ram@gw.udmsearch.izhnet.ru
ram@mysql.r18.ru
ram@ram.(none)
......
sql/opt_ft.cc
View file @ ca6c4cc3
......@@ -26,7 +26,7 @@
** Create a FT or QUICK RANGE based on a key
****************************************************************************/
QUICK_SELECT *get_ft_or_quick_select_for_ref(TABLE *table, JOIN_TAB *tab)
QUICK_RANGE_SELECT *get_ft_or_quick_select_for_ref(TABLE *table, JOIN_TAB *tab)
{
if (tab->type == JT_FT)
return new FT_SELECT(table, &tab->ref);
......
sql/opt_ft.h
View file @ ca6c4cc3
......@@ -24,17 +24,18 @@
#pragma interface /* gcc class implementation */
#endif
class FT_SELECT: public QUICK_SELECT {
class FT_SELECT: public QUICK_RANGE_SELECT {
public:
TABLE_REF *ref;
FT_SELECT(TABLE *table, TABLE_REF *tref) :
QUICK_SELECT (table,tref->key,1), ref(tref) { init(); }
QUICK_RANGE_SELECT (table,tref->key,1), ref(tref) { init(); }
int init() { return error=file->ft_init(); }
int init() { QUICK_RANGE_SELECT::init(); return (error=file->ft_init()); }
int get_next() { return error=file->ft_read(record); }
int get_type() { return QS_TYPE_FULLTEXT; }
};
QUICK_SELECT *get_ft_or_quick_select_for_ref(TABLE *table, JOIN_TAB *tab);
QUICK_RANGE_SELECT *get_ft_or_quick_select_for_ref(TABLE *table, JOIN_TAB *tab);
#endif
sql/opt_range.cc
View file @ ca6c4cc3
......@@ -267,14 +267,17 @@ public:
SEL_ARG *clone_tree();
};
class SEL_IMERGE;
class SEL_TREE :public Sql_alloc
{
public:
enum Type { IMPOSSIBLE, ALWAYS, MAYBE, KEY, KEY_SMALLER } type;
SEL_TREE(enum Type type_arg) :type(type_arg) {}
SEL_TREE() :type(KEY) { bzero((char*) keys,sizeof(keys));}
SEL_TREE() :type(KEY), keys_map(0) { bzero((char*) keys,sizeof(keys));}
SEL_ARG *keys[MAX_KEY];
key_map keys_map; /* bitmask of non-NULL elements in keys */
List<SEL_IMERGE> merges; /* possible ways to read rows using index_merge */
};
......@@ -301,10 +304,19 @@ static ha_rows check_quick_keys(PARAM *param,uint index,SEL_ARG *key_tree,
char *min_key,uint min_key_flag,
char *max_key, uint max_key_flag);
static QUICK_SELECT *get_quick_select(PARAM *param,uint index,
SEL_ARG *key_tree);
QUICK_RANGE_SELECT *get_quick_select(PARAM *param,uint index,
SEL_ARG *key_tree, MEM_ROOT *alloc = NULL);
static int get_quick_select_params(SEL_TREE *tree, PARAM& param,
key_map& needed_reg, TABLE *head,
bool index_read_can_be_used,
double* read_time,
ha_rows* records,
SEL_ARG*** key_to_read);
#ifndef DBUG_OFF
static void print_quick(QUICK_SELECT *quick,key_map needed_reg);
void print_quick_sel_imerge(QUICK_INDEX_MERGE_SELECT *quick,
key_map needed_reg);
void print_quick_sel_range(QUICK_RANGE_SELECT *quick,key_map needed_reg);
#endif
static SEL_TREE *tree_and(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2);
static SEL_TREE *tree_or(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2);
......@@ -312,16 +324,234 @@ static SEL_ARG *sel_add(SEL_ARG *key1,SEL_ARG *key2);
static SEL_ARG *key_or(SEL_ARG *key1,SEL_ARG *key2);
static SEL_ARG *key_and(SEL_ARG *key1,SEL_ARG *key2,uint clone_flag);
static bool get_range(SEL_ARG **e1,SEL_ARG **e2,SEL_ARG *root1);
static bool get_quick_keys(PARAM *param,QUICK_SELECT *quick,KEY_PART *key,
bool get_quick_keys(PARAM *param,QUICK_RANGE_SELECT *quick,KEY_PART *key,
SEL_ARG *key_tree,char *min_key,uint min_key_flag,
char *max_key,uint max_key_flag);
static bool eq_tree(SEL_ARG* a,SEL_ARG *b);
static SEL_ARG null_element(SEL_ARG::IMPOSSIBLE);
static bool null_part_in_key(KEY_PART *key_part, const char *key, uint length);
bool sel_trees_can_be_ored(SEL_TREE *tree1, SEL_TREE *tree2, PARAM* param);
/*
SEL_IMERGE is a list of possible ways to do index merge, i.e. it is
a condition in the following form:
(t_1||t_2||...||t_N) && (next)
where all t_i are SEL_TREEs, next is another SEL_IMERGE and no pair
(t_i,t_j) contains SEL_ARGS for the same index.
SEL_TREE contained in SEL_IMERGE always has merges=NULL.
This class relies on memory manager to do the cleanup.
*/
class SEL_IMERGE : public Sql_alloc
{
enum { PREALLOCED_TREES= 10};
public:
SEL_TREE *trees_prealloced[PREALLOCED_TREES];
SEL_TREE **trees; /* trees used to do index_merge */
SEL_TREE **trees_next; /* last of these trees */
SEL_TREE **trees_end; /* end of allocated space */
SEL_ARG ***best_keys; /* best keys to read in SEL_TREEs */
SEL_IMERGE() :
trees(&trees_prealloced[0]),
trees_next(trees),
trees_end(trees + PREALLOCED_TREES)
{}
int or_sel_tree(PARAM *param, SEL_TREE *tree);
int or_sel_tree_with_checks(PARAM *param, SEL_TREE *new_tree);
int or_sel_imerge_with_checks(PARAM *param, SEL_IMERGE* imerge);
};
/*
Add SEL_TREE to this index_merge without any checks,
NOTES
This function implements the following:
(x_1||...||x_N) || t = (x_1||...||x_N||t), where x_i, t are SEL_TREEs
RETURN
0 - OK
-1 - Out of memory.
*/
int SEL_IMERGE::or_sel_tree(PARAM *param, SEL_TREE *tree)
{
if (trees_next == trees_end)
{
const int realloc_ratio= 2; /* Double size for next round */
uint old_elements= (trees_end - trees);
uint old_size= sizeof(SEL_TREE**) * old_elements;
uint new_size= old_size * realloc_ratio;
SEL_TREE **new_trees;
if (!(new_trees= (SEL_TREE**)alloc_root(param->mem_root, new_size)))
return -1;
memcpy(new_trees, trees, old_size);
trees= new_trees;
trees_next= trees + old_elements;
trees_end= trees + old_elements * realloc_ratio;
}
*(trees_next++)= tree;
return 0;
}
/*
Perform OR operation on this SEL_IMERGE and supplied SEL_TREE new_tree,
combining new_tree with one of the trees in this SEL_IMERGE if they both
have SEL_ARGs for the same key.
SYNOPSIS
or_sel_tree_with_checks()
param PARAM from SQL_SELECT::test_quick_select
new_tree SEL_TREE with type KEY or KEY_SMALLER.
NOTES
This does the following:
(t_1||...||t_k)||new_tree =
either
= (t_1||...||t_k||new_tree)
or
= (t_1||....||(t_j|| new_tree)||...||t_k),
where t_i, y are SEL_TREEs.
new_tree is combined with the first t_j it has a SEL_ARG on common
key with. As a consequence of this, choice of keys to do index_merge
read may depend on the order of conditions in WHERE part of the query.
RETURN
0 OK
1 One of the trees was combined with new_tree to SEL_TREE::ALWAYS,
and (*this) should be discarded.
-1 An error occurred.
*/
int SEL_IMERGE::or_sel_tree_with_checks(PARAM *param, SEL_TREE *new_tree)
{
for (SEL_TREE** tree = trees;
tree != trees_next;
tree++)
{
if (sel_trees_can_be_ored(*tree, new_tree, param))
{
*tree = tree_or(param, *tree, new_tree);
if (!*tree)
return 1;
if (((*tree)->type == SEL_TREE::MAYBE) ||
((*tree)->type == SEL_TREE::ALWAYS))
return 1;
/* SEL_TREE::IMPOSSIBLE is impossible here */
return 0;
}
}
/* new tree cannot be combined with any of existing trees */
return or_sel_tree(param, new_tree);
}
/*
Perform OR operation on this index_merge and supplied index_merge list.
RETURN
0 - OK
1 - One of conditions in result is always TRUE and this SEL_IMERGE
should be discarded.
-1 - An error occurred
*/
int SEL_IMERGE::or_sel_imerge_with_checks(PARAM *param, SEL_IMERGE* imerge)
{
for (SEL_TREE** tree= imerge->trees;
tree != imerge->trees_next;
tree++)
{
if (or_sel_tree_with_checks(param, *tree))
return 1;
}
return 0;
}
/*
Perform AND operation on two index_merge lists, storing result in *im1.
*/
inline void imerge_list_and_list(List<SEL_IMERGE> *im1, List<SEL_IMERGE> *im2)
{
im1->concat(im2);
}
/*
Perform OR operation on 2 index_merge lists, storing result in first list.
NOTES
The following conversion is implemented:
(a_1 &&...&& a_N)||(b_1 &&...&& b_K) = AND_i,j(a_i || b_j) =>
=> (a_1||b_1).
i.e. all conjuncts except the first one are currently dropped.
This is done to avoid producing N*K ways to do index_merge.
If (a_1||b_1) produce a condition that is always true, NULL is
returned and index_merge is discarded. (while it is actually
possible to try harder).
As a consequence of this, choice of keys to do index_merge
read may depend on the order of conditions in WHERE part of
the query.
RETURN
0 OK, result is stored in *im1
other Error, both passed lists are unusable
*/
int imerge_list_or_list(PARAM *param,
List<SEL_IMERGE> *im1,
List<SEL_IMERGE> *im2)
{
SEL_IMERGE *imerge= im1->head();
im1->empty();
im1->push_back(imerge);
return imerge->or_sel_imerge_with_checks(param, im2->head());
}
/*
Perform OR operation on index_merge list and key tree.
RETURN
0 OK, result is stored in *im1
other Error
*/
int imerge_list_or_tree(PARAM *param,
List<SEL_IMERGE> *im1,
SEL_TREE *tree)
{
SEL_IMERGE *imerge;
List_iterator<SEL_IMERGE> it(*im1);
while((imerge= it++))
{
if (imerge->or_sel_tree_with_checks(param, tree))
it.remove();
}
return im1->is_empty();
}
/***************************************************************************
** Basic functions for SQL_SELECT and QUICK_SELECT
** Basic functions for SQL_SELECT and QUICK_RANGE_SELECT
***************************************************************************/
/* make a select from mysql info
......@@ -378,23 +608,34 @@ SQL_SELECT::~SQL_SELECT()
#undef index // Fix for Unixware 7
QUICK_SELECT::QUICK_SELECT(TABLE *table,uint key_nr,bool no_alloc)
:dont_free(0),error(0),index(key_nr),max_used_key_length(0),
used_key_parts(0), head(table), it(ranges),range(0)
QUICK_SELECT_I::QUICK_SELECT_I()
:max_used_key_length(0),
used_key_parts(0)
{}
QUICK_RANGE_SELECT::QUICK_RANGE_SELECT(TABLE *table,uint key_nr,bool no_alloc,
MEM_ROOT *parent_alloc)
:dont_free(0),error(0),it(ranges),range(0)
{
if (!no_alloc)
index= key_nr;
head= table;
if (!no_alloc && !parent_alloc)
{
init_sql_alloc(&alloc,1024,0); // Allocates everything here
my_pthread_setspecific_ptr(THR_MALLOC,&alloc);
}
else
bzero((char*) &alloc,sizeof(alloc));
file=head->file;
record=head->record[0];
init();
file= head->file;
record= head->record[0];
}
int QUICK_RANGE_SELECT::init()
{
return (error= file->index_init(index));
}
QUICK_SELECT::~QUICK_SELECT()
QUICK_RANGE_SELECT::~QUICK_RANGE_SELECT()
{
if (!dont_free)
{
......@@ -403,6 +644,42 @@ QUICK_SELECT::~QUICK_SELECT()
}
}
QUICK_INDEX_MERGE_SELECT::QUICK_INDEX_MERGE_SELECT(THD *thd, TABLE *table)
:cur_quick_it(quick_selects), index_merge(thd)
{
index= MAX_KEY;
head= table;
init_sql_alloc(&alloc,1024,0);
}
int QUICK_INDEX_MERGE_SELECT::init()
{
int error;
cur_quick_it.rewind();
cur_quick_select= cur_quick_it++;
if (error= index_merge.init(head))
return error;
return cur_quick_select->init();
}
void QUICK_INDEX_MERGE_SELECT::reset()
{
cur_quick_select->reset();
}
bool
QUICK_INDEX_MERGE_SELECT::push_quick_back(QUICK_RANGE_SELECT *quick_sel_range)
{
return quick_selects.push_back(quick_sel_range);
}
QUICK_INDEX_MERGE_SELECT::~QUICK_INDEX_MERGE_SELECT()
{
quick_selects.delete_elements();
free_root(&alloc,MYF(0));
}
QUICK_RANGE::QUICK_RANGE()
:min_key(0),max_key(0),min_length(0),max_length(0),
flag(NO_MIN_RANGE | NO_MAX_RANGE)
......@@ -581,6 +858,8 @@ int SQL_SELECT::test_quick_select(key_map keys_to_use, table_map prev_tables,
uint basflag;
uint idx;
double scan_time;
QUICK_INDEX_MERGE_SELECT *quick_imerge;
THD *thd= current_thd;
DBUG_ENTER("test_quick_select");
DBUG_PRINT("enter",("keys_to_use: %lu prev_tables: %lu const_tables: %lu",
(ulong) keys_to_use, (ulong) prev_tables,
......@@ -626,13 +905,13 @@ int SQL_SELECT::test_quick_select(key_map keys_to_use, table_map prev_tables,
param.keys=0;
param.mem_root= &alloc;
current_thd->no_errors=1; // Don't warn about NULL
thd->no_errors=1; // Don't warn about NULL
init_sql_alloc(&alloc,2048,0);
if (!(param.key_parts = (KEY_PART*) alloc_root(&alloc,
sizeof(KEY_PART)*
head->key_parts)))
{
current_thd->no_errors=0;
thd->no_errors=0;
free_root(&alloc,MYF(0)); // Return memory & allocator
DBUG_RETURN(0); // Can't use range
}
......@@ -675,10 +954,239 @@ int SQL_SELECT::test_quick_select(key_map keys_to_use, table_map prev_tables,
else if (tree->type == SEL_TREE::KEY ||
tree->type == SEL_TREE::KEY_SMALLER)
{
SEL_ARG **key,**end,**best_key=0;
/*
It is possible to use a quick select (but maybe it would be slower
than 'all' table scan).
*/
SEL_ARG **best_key= 0;
ha_rows found_records;
double found_read_time= read_time;
if (!get_quick_select_params(tree, param, needed_reg, head, true,
&found_read_time, &found_records,
&best_key))
{
/*
Ok, quick select is better than 'all' table scan and we have its
parameters, so construct it.
*/
read_time= found_read_time;
records= found_records;
if ((quick= get_quick_select(&param,(uint) (best_key-tree->keys),
*best_key)) && (!quick->init()))
{
quick->records= records;
quick->read_time= read_time;
}
}
/*
btw, tree type SEL_TREE::INDEX_MERGE was not introduced
intentionally
*/
/* if no range select could be built, try using index_merge */
if (!quick && !tree->merges.is_empty())
{
DBUG_PRINT("info",("No range reads possible,"
" trying to construct index_merge"));
SEL_IMERGE *imerge;
SEL_IMERGE *min_imerge= NULL;
double min_imerge_cost= DBL_MAX;
ha_rows min_imerge_records;
List_iterator_fast<SEL_IMERGE> it(tree->merges);
while ((imerge= it++))
{
double imerge_cost= 0;
ha_rows imerge_total_records= 0;
double tree_read_time;
ha_rows tree_records;
imerge->best_keys=
(SEL_ARG***)alloc_root(&alloc,
(imerge->trees_next - imerge->trees)*
sizeof(void*));
for (SEL_TREE **ptree= imerge->trees;
ptree != imerge->trees_next;
ptree++)
{
tree_read_time= read_time;
if (get_quick_select_params(*ptree, param, needed_reg, head,
false,
&tree_read_time, &tree_records,
&(imerge->best_keys[ptree -
imerge->trees])))
goto imerge_fail;
imerge_cost += tree_read_time;
imerge_total_records += tree_records;
}
imerge_total_records= min(imerge_total_records,
head->file->records);
imerge_cost += imerge_total_records / TIME_FOR_COMPARE;
if (imerge_cost < min_imerge_cost)
{
min_imerge= imerge;
min_imerge_cost= imerge_cost;
min_imerge_records= imerge_total_records;
}
imerge_fail:;
}
if (!min_imerge)
goto end_free;
records= min_imerge_records;
/* ok, got minimal imerge, *min_imerge, with cost min_imerge_cost */
if (head->used_keys)
{
/* check if "ALL" +"using index" read would be faster */
int key_for_use= find_shortest_key(head, head->used_keys);
ha_rows total_table_records= (0 == head->file->records)? 1 :
head->file->records;
uint keys_per_block= (head->file->block_size/2/
(head->key_info[key_for_use].key_length+
head->file->ref_length) + 1);
double all_index_scan_read_time= ((double)(total_table_records+
keys_per_block-1)/
(double) keys_per_block);
DBUG_PRINT("info",
("'all' scan will be using key %d, read time %g",
key_for_use, all_index_scan_read_time));
if (all_index_scan_read_time < min_imerge_cost)
{
DBUG_PRINT("info",
("index merge would be slower, "
"will do full 'index' scan"));
goto end_free;
}
}
else
{
/* check if "ALL" would be faster */
if (read_time < min_imerge_cost)
{
DBUG_PRINT("info",
("index merge would be slower, "
"will do full table scan"));
goto end_free;
}
}
if (!(quick= quick_imerge= new QUICK_INDEX_MERGE_SELECT(thd, head)))
goto end_free;
quick->records= min_imerge_records;
quick->read_time= min_imerge_cost;
my_pthread_setspecific_ptr(THR_MALLOC, &quick_imerge->alloc);
QUICK_RANGE_SELECT *new_quick;
for (SEL_TREE **ptree = min_imerge->trees;
ptree != min_imerge->trees_next;
ptree++)
{
SEL_ARG **tree_best_key=
min_imerge->best_keys[ptree - min_imerge->trees];
if ((new_quick= get_quick_select(&param,
(uint)(tree_best_key-
(*ptree)->keys),
*tree_best_key,
&quick_imerge->alloc)))
{
new_quick->records= min_imerge_records;
new_quick->read_time= min_imerge_cost;
/*
QUICK_RANGE_SELECT::QUICK_RANGE_SELECT leaves THR_MALLOC
pointing to its allocator, restore it back
*/
//my_pthread_setspecific_ptr(THR_MALLOC,old_root);
quick_imerge->last_quick_select= new_quick;
if (quick_imerge->push_quick_back(new_quick))
{
delete new_quick;
delete quick;
quick= quick_imerge= NULL;
goto end_free;
}
}
else
{
delete quick;
quick= quick_imerge= NULL;
goto end_free;
}
}
free_root(&alloc,MYF(0));
my_pthread_setspecific_ptr(THR_MALLOC,old_root);
if (quick->init())
{
delete quick;
quick= quick_imerge= NULL;
DBUG_PRINT("error",
("Failed to allocate index merge structures,"
"falling back to full scan."));
}
else
{
/* with 'using filesort' quick->reset() is not called */
quick->reset();
}
goto end;
}
}
}
end_free:
free_root(&alloc,MYF(0)); // Return memory & allocator
my_pthread_setspecific_ptr(THR_MALLOC,old_root);
end:
thd->no_errors=0;
}
for (idx=0,key=tree->keys, end=key+param.keys ;
DBUG_EXECUTE("info",
{
if (quick_imerge)
print_quick_sel_imerge(quick_imerge, needed_reg);
else
print_quick_sel_range((QUICK_RANGE_SELECT*)quick, needed_reg);
}
);
/*
Assume that if the user is using 'limit' we will only need to scan
limit rows if we are using a key
*/
DBUG_RETURN(records ? test(quick) : -1);
}
/*
Calculate quick select read time, # of records, and best key to use
without constructing QUICK_SELECT
*/
static int get_quick_select_params(SEL_TREE *tree, PARAM& param,
key_map& needed_reg, TABLE *head,
bool index_read_can_be_used,
double* read_time, ha_rows* records,
SEL_ARG*** key_to_read)
{
int idx;
int result = 1;
/*
Note that there may be trees that have type SEL_TREE::KEY but contain
no key reads at all. For example, tree for expression "key1 is not null"
where key1 is defined as "not null".
*/
SEL_ARG **key,**end;
for (idx= 0,key=tree->keys, end=key+param.keys ;
key != end ;
key++,idx++)
{
......@@ -691,9 +1199,12 @@ int SQL_SELECT::test_quick_select(key_map keys_to_use, table_map prev_tables,
(*key)->maybe_flag)
needed_reg|= (key_map) 1 << keynr;
key_map usable_keys = index_read_can_be_used?
(head->used_keys & ((key_map) 1 << keynr)) : 0;
found_records=check_quick_select(&param, idx, *key);
if (found_records != HA_POS_ERROR && found_records > 2 &&
head->used_keys & ((table_map) 1 << keynr) &&
usable_keys &&
(head->file->index_flags(keynr) & HA_KEY_READ_ONLY))
{
/*
......@@ -713,35 +1224,16 @@ int SQL_SELECT::test_quick_select(key_map keys_to_use, table_map prev_tables,
param.range_count,
found_records)+
(double) found_records / TIME_FOR_COMPARE);
if (read_time > found_read_time)
if (*read_time > found_read_time)
{
read_time=found_read_time;
records=found_records;
best_key=key;
*read_time= found_read_time;
*records= found_records;
*key_to_read= key;
result = 0;
}
}
}
if (best_key && records)
{
if ((quick=get_quick_select(&param,(uint) (best_key-tree->keys),
*best_key)))
{
quick->records=records;
quick->read_time=read_time;
}
}
}
}
free_root(&alloc,MYF(0)); // Return memory & allocator
my_pthread_setspecific_ptr(THR_MALLOC,old_root);
current_thd->no_errors=0;
}
DBUG_EXECUTE("info",print_quick(quick,needed_reg););
/*
Assume that if the user is using 'limit' we will only need to scan
limit rows if we are using a key
*/
DBUG_RETURN(records ? test(quick) : -1);
return result;
}
/* make a select tree of all keys in condition */
......@@ -911,6 +1403,7 @@ get_mm_parts(PARAM *param,Field *field, Item_func::Functype type,Item *value,
sel_arg=new SEL_ARG(SEL_ARG::MAYBE_KEY);// This key may be used later
sel_arg->part=(uchar) key_part->part;
tree->keys[key_part->key]=sel_add(tree->keys[key_part->key],sel_arg);
tree->keys_map |= 1 << key_part->key;
}
}
DBUG_RETURN(tree);
......@@ -1176,6 +1669,8 @@ tree_and(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2)
DBUG_RETURN(tree1);
}
bool trees_have_key = false;
key_map result_keys= 0;
/* Join the trees key per key */
SEL_ARG **key1,**key2,**end;
for (key1= tree1->keys,key2= tree2->keys,end=key1+param->keys ;
......@@ -1184,6 +1679,7 @@ tree_and(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2)
uint flag=0;
if (*key1 || *key2)
{
trees_have_key = true;
if (*key1 && !(*key1)->simple_key())
flag|=CLONE_KEY1_MAYBE;
if (*key2 && !(*key2)->simple_key())
......@@ -1192,17 +1688,57 @@ tree_and(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2)
if ((*key1)->type == SEL_ARG::IMPOSSIBLE)
{
tree1->type= SEL_TREE::IMPOSSIBLE;
break;
DBUG_RETURN(tree1);
}
result_keys |= 1 << (key1 - tree1->keys);
#ifdef EXTRA_DEBUG
(*key1)->test_use_count(*key1);
#endif
}
}
tree1->keys_map= result_keys;
/* dispose index_merge if there is a "range" option */
if (trees_have_key)
{
tree1->merges.empty();
DBUG_RETURN(tree1);
}
/* ok, both trees are index_merge trees */
imerge_list_and_list(&tree1->merges, &tree2->merges);
DBUG_RETURN(tree1);
}
/*
Check if two SEL_TREES can be combined into one without using index_merge
*/
bool sel_trees_can_be_ored(SEL_TREE *tree1, SEL_TREE *tree2, PARAM* param)
{
key_map common_keys= tree1->keys_map & tree2->keys_map;
DBUG_ENTER("sel_trees_can_be_ored");
if (!common_keys)
DBUG_RETURN(false);
/* trees have a common key, check if they refer to same key part */
SEL_ARG **key1,**key2;
for (uint key_no=0; key_no < param->keys; key_no++, common_keys= common_keys >> 1)
{
if (common_keys & 1)
{
key1= tree1->keys + key_no;
key2= tree2->keys + key_no;
if ((*key1)->part == (*key2)->part)
{
DBUG_RETURN(true);
}
}
}
DBUG_RETURN(false);
}
static SEL_TREE *
tree_or(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2)
......@@ -1219,21 +1755,63 @@ tree_or(PARAM *param,SEL_TREE *tree1,SEL_TREE *tree2)
if (tree2->type == SEL_TREE::MAYBE)
DBUG_RETURN(tree2);
SEL_TREE *result= 0;
key_map result_keys= 0;
if (sel_trees_can_be_ored(tree1, tree2, param))
{
/* Join the trees key per key */
SEL_ARG **key1,**key2,**end;
SEL_TREE *result=0;
for (key1= tree1->keys,key2= tree2->keys,end=key1+param->keys ;
for (key1= tree1->keys,key2= tree2->keys,end= key1+param->keys ;
key1 != end ; key1++,key2++)
{
*key1=key_or(*key1,*key2);
if (*key1)
{
result=tree1; // Added to tree1
result_keys |= 1 << (key1 - tree1->keys);
#ifdef EXTRA_DEBUG
(*key1)->test_use_count(*key1);
#endif
}
}
if (result)
result->keys_map= result_keys;
}
else
{
/* ok, two trees have KEY type but cannot be used without index merge */
if (tree1->merges.is_empty() && tree2->merges.is_empty())
{
SEL_IMERGE *merge;
/* both trees are "range" trees, produce new index merge structure */
if (!(result= new SEL_TREE()) || !(merge= new SEL_IMERGE()) ||
(result->merges.push_back(merge)) ||
(merge->or_sel_tree(param, tree1)) ||
(merge->or_sel_tree(param, tree2)))
result= NULL;
else
result->type= tree1->type;
}
else if (!tree1->merges.is_empty() && !tree2->merges.is_empty())
{
if (imerge_list_or_list(param, &tree1->merges, &tree2->merges))
result= new SEL_TREE(SEL_TREE::ALWAYS);
else
result= tree1;
}
else
{
/* one tree is index merge tree and another is range tree */
if (tree1->merges.is_empty())
swap(SEL_TREE*, tree1, tree2);
/* add tree2 to tree1->merges, checking if it collapses to ALWAYS */
if (imerge_list_or_tree(param, &tree1->merges, tree2))
result= new SEL_TREE(SEL_TREE::ALWAYS);
else
result= tree1;
}
}
DBUG_RETURN(result);
}
......@@ -2201,14 +2779,17 @@ check_quick_keys(PARAM *param,uint idx,SEL_ARG *key_tree,
/****************************************************************************
** change a tree to a structure to be used by quick_select
** This uses it's own malloc tree
** The caller should call QUICK_SELCT::init for returned quick select
****************************************************************************/
static QUICK_SELECT *
get_quick_select(PARAM *param,uint idx,SEL_ARG *key_tree)
QUICK_RANGE_SELECT *
get_quick_select(PARAM *param,uint idx,SEL_ARG *key_tree,
MEM_ROOT *parent_alloc)
{
QUICK_SELECT *quick;
QUICK_RANGE_SELECT *quick;
DBUG_ENTER("get_quick_select");
if ((quick=new QUICK_SELECT(param->table,param->real_keynr[idx])))
if ((quick=new QUICK_RANGE_SELECT(param->table,param->real_keynr[idx],
test(parent_alloc),
parent_alloc)))
{
if (quick->error ||
get_quick_keys(param,quick,param->key[idx],key_tree,param->min_key,0,
......@@ -2220,7 +2801,8 @@ get_quick_select(PARAM *param,uint idx,SEL_ARG *key_tree)
else
{
quick->key_parts=(KEY_PART*)
memdup_root(&quick->alloc,(char*) param->key[idx],
memdup_root(parent_alloc? parent_alloc : &quick->alloc,
(char*) param->key[idx],
sizeof(KEY_PART)*
param->table->key_info[param->real_keynr[idx]].key_parts);
}
......@@ -2232,9 +2814,8 @@ get_quick_select(PARAM *param,uint idx,SEL_ARG *key_tree)
/*
** Fix this to get all possible sub_ranges
*/
static bool
get_quick_keys(PARAM *param,QUICK_SELECT *quick,KEY_PART *key,
bool
get_quick_keys(PARAM *param,QUICK_RANGE_SELECT *quick,KEY_PART *key,
SEL_ARG *key_tree,char *min_key,uint min_key_flag,
char *max_key, uint max_key_flag)
{
......@@ -2343,7 +2924,7 @@ get_quick_keys(PARAM *param,QUICK_SELECT *quick,KEY_PART *key,
Return 1 if there is only one range and this uses the whole primary key
*/
bool QUICK_SELECT::unique_key_range()
bool QUICK_RANGE_SELECT::unique_key_range()
{
if (ranges.elements == 1)
{
......@@ -2380,16 +2961,22 @@ static bool null_part_in_key(KEY_PART *key_part, const char *key, uint length)
** Create a QUICK RANGE based on a key
****************************************************************************/
QUICK_SELECT *get_quick_select_for_ref(TABLE *table, TABLE_REF *ref)
QUICK_RANGE_SELECT *get_quick_select_for_ref(TABLE *table, TABLE_REF *ref)
{
table->file->index_end(); // Remove old cursor
QUICK_SELECT *quick=new QUICK_SELECT(table, ref->key, 1);
QUICK_RANGE_SELECT *quick=new QUICK_RANGE_SELECT(table, ref->key, 1);
KEY *key_info = &table->key_info[ref->key];
KEY_PART *key_part;
uint part;
if (!quick)
return 0;
if (quick->init())
{
delete quick;
return 0;
}
if (cp_buffer_from_ref(ref))
{
if (current_thd->is_fatal_error)
......@@ -2427,11 +3014,204 @@ err:
return 0;
}
INDEX_MERGE::INDEX_MERGE(THD *thd_arg) :
dont_save(false), thd(thd_arg)
{}
String *INDEX_MERGE::Item_rowid::val_str(String *str)
{
str->set_quick((char*)head->file->ref, head->file->ref_length, collation.collation);
return str;
}
/*
Initialize index_merge operation.
RETURN
0 - OK
other - error.
*/
int INDEX_MERGE::init(TABLE *table)
{
DBUG_ENTER("INDEX_MERGE::init");
head= table;
if (!(rowid_item= new Item_rowid(table)))
DBUG_RETURN(1);
tmp_table_param.copy_field= 0;
tmp_table_param.end_write_records= HA_POS_ERROR;
tmp_table_param.group_length= table->file->ref_length;
tmp_table_param.group_parts= 1;
tmp_table_param.group_null_parts= 0;
tmp_table_param.hidden_field_count= 0;
tmp_table_param.field_count= 0;
tmp_table_param.func_count= 1;
tmp_table_param.sum_func_count= 0;
tmp_table_param.quick_group= 1;
bzero(&order, sizeof(ORDER));
order.item= (Item**)&rowid_item;
order.asc= 1;
fields.push_back(rowid_item);
temp_table= create_tmp_table(thd,
&tmp_table_param,
fields,
&order,
false,
0,
SELECT_DISTINCT,
HA_POS_ERROR,
(char *)"");
DBUG_RETURN(!temp_table);
}
/*
Check if record with ROWID record_pos has already been processed and
if not - store the ROWID value.
RETURN
0 - record has not been processed yet
1 - record has already been processed.
-1 - an error occurred and query processing should be terminated.
Error code is stored in INDEX_MERGE::error
*/
int INDEX_MERGE::check_record_in()
{
return (dont_save)?
check_record() :
put_record();
}
/*
Stop remembering records in check().
(this should be called just before the last key scan)
RETURN
0 - OK
1 - error occurred initializing table index.
*/
int INDEX_MERGE::start_last_quick_select()
{
int result= 0;
if (!temp_table->uniques)
{
dont_save= true;
result= temp_table->file->index_init(0);
}
return result;
}
inline int INDEX_MERGE::put_record()
{
DBUG_ENTER("INDEX_MERGE::put_record");
copy_funcs(tmp_table_param.items_to_copy);
if ((error= temp_table->file->write_row(temp_table->record[0])))
{
if (error == HA_ERR_FOUND_DUPP_KEY ||
error == HA_ERR_FOUND_DUPP_UNIQUE)
DBUG_RETURN(1);
DBUG_PRINT("info",
("Error writing row to temp. table: %d, converting to myisam",
error));
if (create_myisam_from_heap(current_thd, temp_table, &tmp_table_param,
error,1))
{
DBUG_PRINT("info", ("Table conversion failed, bailing out"));
DBUG_RETURN(-1);
}
}
DBUG_RETURN(0);
}
inline int INDEX_MERGE::check_record()
{
int result= 1;
DBUG_ENTER("INDEX_MERGE::check_record");
if ((error= temp_table->file->index_read(temp_table->record[0],
head->file->ref,
head->file->ref_length,
HA_READ_KEY_EXACT)))
{
if (error != HA_ERR_KEY_NOT_FOUND)
result= -1;
else
result= 0;
}
DBUG_RETURN(result);
}
INDEX_MERGE::~INDEX_MERGE()
{
if (temp_table)
{
DBUG_PRINT("info", ("Freeing temp. table"));
free_tmp_table(current_thd, temp_table);
}
/* rowid_item is freed automatically */
list_node* node;
node= fields.first_node();
fields.remove(&node);
}
int QUICK_INDEX_MERGE_SELECT::get_next()
{
int result;
int put_result;
DBUG_ENTER("QUICK_INDEX_MERGE_SELECT::get_next");
do
{
while ((result= cur_quick_select->get_next()) == HA_ERR_END_OF_FILE)
{
cur_quick_select= cur_quick_it++;
if (!cur_quick_select)
break;
cur_quick_select->init();
cur_quick_select->reset();
if (last_quick_select == cur_quick_select)
{
if ((result= index_merge.start_last_quick_select()))
DBUG_RETURN(result);
}
}
if (result)
{
/*
table read error (including HA_ERR_END_OF_FILE on last quick select
in index_merge)
*/
DBUG_RETURN(result);
}
cur_quick_select->file->position(cur_quick_select->record);
put_result= index_merge.check_record_in();
}while(put_result == 1); /* While record is processed */
DBUG_RETURN((put_result != -1) ? result : index_merge.error);
}
/* get next possible record using quick-struct */
int QUICK_SELECT::get_next()
int QUICK_RANGE_SELECT::get_next()
{
DBUG_ENTER("get_next");
DBUG_ENTER("QUICK_RANGE_SELECT::get_next");
for (;;)
{
......@@ -2518,7 +3298,7 @@ int QUICK_SELECT::get_next()
Returns 0 if key <= range->max_key
*/
int QUICK_SELECT::cmp_next(QUICK_RANGE *range_arg)
int QUICK_RANGE_SELECT::cmp_next(QUICK_RANGE *range_arg)
{
if (range_arg->flag & NO_MAX_RANGE)
return 0; /* key can't be to large */
......@@ -2559,8 +3339,9 @@ int QUICK_SELECT::cmp_next(QUICK_RANGE *range_arg)
for now, this seems to work right at least.
*/
QUICK_SELECT_DESC::QUICK_SELECT_DESC(QUICK_SELECT *q, uint used_key_parts)
: QUICK_SELECT(*q), rev_it(rev_ranges)
QUICK_SELECT_DESC::QUICK_SELECT_DESC(QUICK_RANGE_SELECT *q,
uint used_key_parts)
: QUICK_RANGE_SELECT(*q), rev_it(rev_ranges)
{
bool not_read_after_key = file->table_flags() & HA_NOT_READ_AFTER_KEY;
QUICK_RANGE *r;
......@@ -2827,7 +3608,23 @@ print_key(KEY_PART *key_part,const char *key,uint used_length)
}
}
static void print_quick(QUICK_SELECT *quick,key_map needed_reg)
void print_quick_sel_imerge(QUICK_INDEX_MERGE_SELECT *quick,
key_map needed_reg)
{
DBUG_ENTER("print_param");
if (! _db_on_ || !quick)
DBUG_VOID_RETURN;
List_iterator_fast<QUICK_RANGE_SELECT> it(quick->quick_selects);
QUICK_RANGE_SELECT* quick_range_sel;
while ((quick_range_sel= it++))
{
print_quick_sel_range(quick_range_sel, needed_reg);
}
DBUG_VOID_RETURN;
}
void print_quick_sel_range(QUICK_RANGE_SELECT *quick,key_map needed_reg)
{
QUICK_RANGE *range;
DBUG_ENTER("print_param");
......
sql/opt_range.h
View file @ ca6c4cc3
......@@ -65,41 +65,198 @@ class QUICK_RANGE :public Sql_alloc {
}
};
class INDEX_MERGE;
class QUICK_SELECT {
/*
Quick select interface.
This class is parent for all QUICK_*_SELECT and FT_SELECT classes.
*/
class QUICK_SELECT_I
{
public:
ha_rows records; /* estimate of # of records to be retrieved */
double read_time; /* time to perform this retrieval */
TABLE *head;
/*
the only index this quick select uses, or MAX_KEY for
QUICK_INDEX_MERGE_SELECT
*/
uint index;
uint max_used_key_length, used_key_parts;
QUICK_SELECT_I();
virtual ~QUICK_SELECT_I(){};
virtual int init() = 0;
virtual void reset(void) = 0;
virtual int get_next() = 0; /* get next record to retrieve */
virtual bool reverse_sorted() = 0;
virtual bool unique_key_range() { return false; }
enum {
QS_TYPE_RANGE = 0,
QS_TYPE_INDEX_MERGE = 1,
QS_TYPE_RANGE_DESC = 2,
QS_TYPE_FULLTEXT = 3
};
/* Get type of this quick select - one of the QS_* values */
virtual int get_type() = 0;
};
struct st_qsel_param;
class SEL_ARG;
class QUICK_RANGE_SELECT : public QUICK_SELECT_I
{
protected:
bool next,dont_free;
public:
int error;
uint index, max_used_key_length, used_key_parts;
TABLE *head;
handler *file;
byte *record;
protected:
friend void print_quick_sel_range(QUICK_RANGE_SELECT *quick,
key_map needed_reg);
friend QUICK_RANGE_SELECT *get_quick_select_for_ref(TABLE *table,
struct st_table_ref *ref);
friend bool get_quick_keys(struct st_qsel_param *param,
QUICK_RANGE_SELECT *quick,KEY_PART *key,
SEL_ARG *key_tree,char *min_key,uint min_key_flag,
char *max_key, uint max_key_flag);
friend QUICK_RANGE_SELECT *get_quick_select(struct st_qsel_param*,uint idx,
SEL_ARG *key_tree,
MEM_ROOT *alloc);
friend class QUICK_SELECT_DESC;
List<QUICK_RANGE> ranges;
List_iterator<QUICK_RANGE> it;
QUICK_RANGE *range;
MEM_ROOT alloc;
KEY_PART *key_parts;
ha_rows records;
double read_time;
int cmp_next(QUICK_RANGE *range);
public:
QUICK_RANGE_SELECT(TABLE *table,uint index_arg,bool no_alloc=0,
MEM_ROOT *parent_alloc=NULL);
~QUICK_RANGE_SELECT();
QUICK_SELECT(TABLE *table,uint index_arg,bool no_alloc=0);
virtual ~QUICK_SELECT();
void reset(void) { next=0; it.rewind(); }
int init() { return error=file->index_init(index); }
virtual int get_next();
virtual bool reverse_sorted() { return 0; }
int cmp_next(QUICK_RANGE *range);
int init();
int get_next();
bool reverse_sorted() { return 0; }
bool unique_key_range();
int get_type() { return QS_TYPE_RANGE; }
};
/*
Helper class for keeping track of rows that have been passed to output
in index_merge access method.
NOTES
Current implementation uses a temporary table to store ROWIDs of rows that
have been passed to output. In the future it might be changed to use more
efficient mechanisms, like Unique class.
*/
class INDEX_MERGE
{
public:
INDEX_MERGE(THD *thd_arg);
~INDEX_MERGE();
int init(TABLE *table);
int check_record_in();
int start_last_quick_select();
int error;
private:
/* The only field in temporary table */
class Item_rowid : public Item_str_func
{
TABLE *head; /* source table */
public:
Item_rowid(TABLE *table) : head(table)
{
max_length= table->file->ref_length;
collation.set(&my_charset_bin);
};
const char *func_name() const { return "rowid"; }
bool const_item() const { return 0; }
String *val_str(String *);
void fix_length_and_dec()
{}
};
/* Check if record has been processed and save it if it wasn't */
inline int put_record();
/* Check if record has been processed without saving it */
inline int check_record();
/* If true, check_record_in does't store ROWIDs it is passed. */
bool dont_save;
THD *thd;
TABLE *head; /* source table */
TABLE *temp_table; /* temp. table used for values storage */
TMP_TABLE_PARAM tmp_table_param; /* temp. table creation parameters */
Item_rowid *rowid_item; /* the only field in temp. table */
List<Item> fields; /* temp. table fields list
(the only element is rowid_item) */
ORDER order; /* key for temp. table (rowid_item) */
};
/*
Index merge quick select.
It is implemented as a container for several QUICK_RANGE_SELECTs.
*/
class QUICK_INDEX_MERGE_SELECT : public QUICK_SELECT_I
{
public:
QUICK_INDEX_MERGE_SELECT(THD *thd, TABLE *table);
~QUICK_INDEX_MERGE_SELECT();
int init();
void reset(void);
int get_next();
bool reverse_sorted() { return false; }
bool unique_key_range() { return false; }
int get_type() { return QS_TYPE_INDEX_MERGE; }
bool push_quick_back(QUICK_RANGE_SELECT *quick_sel_range);
/* range quick selects this index_merge read consists of */
List<QUICK_RANGE_SELECT> quick_selects;
/* quick select which is currently used for rows retrieval */
List_iterator_fast<QUICK_RANGE_SELECT> cur_quick_it;
QUICK_RANGE_SELECT* cur_quick_select;
/*
Last element in quick_selects list.
INDEX_MERGE::start_last_quick_select is called before retrieving
rows for it.
*/
QUICK_RANGE_SELECT* last_quick_select;
/*
Used to keep track of what records have been already passed to output
when doing index_merge access (NULL means no index_merge)
*/
INDEX_MERGE index_merge;
MEM_ROOT alloc;
};
class QUICK_SELECT_DESC: public QUICK_SELECT
class QUICK_SELECT_DESC: public QUICK_RANGE_SELECT
{
public:
QUICK_SELECT_DESC(QUICK_SELECT *q, uint used_key_parts);
QUICK_SELECT_DESC(QUICK_RANGE_SELECT *q, uint used_key_parts);
int get_next();
bool reverse_sorted() { return 1; }
int get_type() { return QS_TYPE_RANGE_DESC; }
private:
int cmp_prev(QUICK_RANGE *range);
bool range_reads_after_key(QUICK_RANGE *range);
......@@ -114,7 +271,7 @@ private:
class SQL_SELECT :public Sql_alloc {
public:
QUICK_SELECT *quick; // If quick-select used
QUICK_SELECT_I *quick; // If quick-select used
COND *cond; // where condition
TABLE *head;
IO_CACHE file; // Positions to used records
......@@ -134,6 +291,6 @@ class SQL_SELECT :public Sql_alloc {
bool force_quick_range=0);
};
QUICK_SELECT *get_quick_select_for_ref(TABLE *table, struct st_table_ref *ref);
QUICK_RANGE_SELECT *get_quick_select_for_ref(TABLE *table, struct st_table_ref *ref);
#endif
sql/sql_class.cc
View file @ ca6c4cc3
......@@ -537,8 +537,8 @@ int THD::send_explain_fields(select_result *result)
item->maybe_null=1;
field_list.push_back(item=new Item_empty_string("key",NAME_LEN));
item->maybe_null=1;
field_list.push_back(item=new Item_return_int("key_len",3,
MYSQL_TYPE_LONGLONG));
field_list.push_back(item=new Item_empty_string("key_len",
NAME_LEN*MAX_KEY));
item->maybe_null=1;
field_list.push_back(item=new Item_empty_string("ref",
NAME_LEN*MAX_REF_PARTS));
......
sql/sql_list.h
View file @ ca6c4cc3
......@@ -135,6 +135,12 @@ public:
last= &first;
return tmp->info;
}
inline void concat(base_list *list)
{
*last= list->first;
last= list->last;
elements+= list->elements;
}
inline list_node* last_node() { return *last; }
inline list_node* first_node() { return first;}
inline void *head() { return first->info; }
......@@ -255,6 +261,7 @@ public:
}
empty();
}
inline void concat(List<T> *list) { base_list::concat(list); }
};
......
sql/sql_select.cc
View file @ ca6c4cc3
......@@ -32,7 +32,8 @@
const char *join_type_str[]={ "UNKNOWN","system","const","eq_ref","ref",
"MAYBE_REF","ALL","range","index","fulltext",
"ref_or_null","simple_in","index_in"
"ref_or_null","simple_in","index_in",
"index_merge"
};
static void optimize_keyuse(JOIN *join, DYNAMIC_ARRAY *keyuse_array);
......@@ -114,7 +115,6 @@ static int join_read_next_same_or_null(READ_RECORD *info);
static COND *make_cond_for_table(COND *cond,table_map table,
table_map used_table);
static Item* part_of_refkey(TABLE *form,Field *field);
static uint find_shortest_key(TABLE *table, key_map usable_keys);
static bool test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,
ha_rows select_limit, bool no_changes);
static int create_sort_index(THD *thd, JOIN *join, ORDER *order,
......@@ -6473,7 +6473,7 @@ static int test_if_order_by_key(ORDER *order, TABLE *table, uint idx,
return reverse;
}
static uint find_shortest_key(TABLE *table, key_map usable_keys)
uint find_shortest_key(TABLE *table, key_map usable_keys)
{
uint min_length= (uint) ~0;
uint best= MAX_KEY;
......@@ -6601,6 +6601,9 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
}
else if (select && select->quick) // Range found by opt_range
{
/* assume results are not ordered when index merge is used */
if (select->quick->get_type() == QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)
DBUG_RETURN(0);
ref_key= select->quick->index;
ref_key_parts= select->quick->used_key_parts;
}
......@@ -6635,6 +6638,10 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
}
else
{
/*
We have verified above that select->quick is not
index_merge quick select.
*/
select->quick->index= new_ref_key;
select->quick->init();
}
......@@ -6656,10 +6663,13 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
*/
if (!select->quick->reverse_sorted())
{
if (table->file->index_flags(ref_key) & HA_NOT_READ_PREFIX_LAST)
if (table->file->index_flags(ref_key) & HA_NOT_READ_PREFIX_LAST ||
(select->quick->get_type() ==
QUICK_SELECT_I::QS_TYPE_INDEX_MERGE))
DBUG_RETURN(0); // Use filesort
// ORDER BY range_key DESC
QUICK_SELECT_DESC *tmp=new QUICK_SELECT_DESC(select->quick,
QUICK_SELECT_DESC *tmp=new QUICK_SELECT_DESC((QUICK_RANGE_SELECT*)(select->quick),
used_key_parts);
if (!tmp || tmp->error)
{
......@@ -6794,8 +6804,11 @@ create_sort_index(THD *thd, JOIN *join, ORDER *order,
{
select->quick=tab->quick;
tab->quick=0;
/* We can only use 'Only index' if quick key is same as ref_key */
if (table->key_read && (uint) tab->ref.key != select->quick->index)
/*
We can only use 'Only index' if quick key is same as ref_key
and in index_merge 'Only index' cannot be used
*/
if (table->key_read && ((uint) tab->ref.key != select->quick->index))
{
table->key_read=0;
table->file->extra(HA_EXTRA_NO_KEYREAD);
......@@ -8598,12 +8611,15 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
JOIN_TAB *tab=join->join_tab+i;
TABLE *table=tab->table;
char buff[512],*buff_ptr=buff;
char buff1[512], buff2[512];
char buff1[512], buff2[512], buff3[512];
char keylen_str_buf[64];
char derived_name[64];
String tmp1(buff1,sizeof(buff1),cs);
String tmp2(buff2,sizeof(buff2),cs);
String tmp3(buff3,sizeof(buff3),cs);
tmp1.length(0);
tmp2.length(0);
tmp3.length(0);
item_list.empty();
item_list.push_back(new Item_int((int32)
......@@ -8612,7 +8628,13 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
strlen(join->select_lex->type),
cs));
if (tab->type == JT_ALL && tab->select && tab->select->quick)
tab->type= JT_RANGE;
{
if (tab->select->quick->get_type() ==
QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)
tab->type = JT_INDEX_MERGE;
else
tab->type = JT_RANGE;
}
if (table->derived_select_number)
{
/* Derived table name generation */
......@@ -8646,10 +8668,14 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
if (tab->ref.key_parts)
{
KEY *key_info=table->key_info+ tab->ref.key;
register uint length;
item_list.push_back(new Item_string(key_info->name,
strlen(key_info->name),
system_charset_info));
item_list.push_back(new Item_int((int32) tab->ref.key_length));
length= longlong2str(tab->ref.key_length, keylen_str_buf, 10) -
keylen_str_buf;
item_list.push_back(new Item_string(keylen_str_buf, length,
system_charset_info));
for (store_key **ref=tab->ref.key_copy ; *ref ; ref++)
{
if (tmp2.length())
......@@ -8661,18 +8687,60 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
else if (tab->type == JT_NEXT)
{
KEY *key_info=table->key_info+ tab->index;
register uint length;
item_list.push_back(new Item_string(key_info->name,
strlen(key_info->name),cs));
item_list.push_back(new Item_int((int32) key_info->key_length));
length= longlong2str(key_info->key_length, keylen_str_buf, 10) -
keylen_str_buf;
item_list.push_back(new Item_string(keylen_str_buf,
length,
system_charset_info));
item_list.push_back(item_null);
}
else if (tab->select && tab->select->quick)
{
KEY *key_info=table->key_info+ tab->select->quick->index;
item_list.push_back(new Item_string(key_info->name,
strlen(key_info->name),cs));
item_list.push_back(new Item_int((int32) tab->select->quick->
max_used_key_length));
if (tab->select->quick->get_type() ==
QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)
{
QUICK_INDEX_MERGE_SELECT *quick_imerge=
(QUICK_INDEX_MERGE_SELECT*)tab->select->quick;
QUICK_RANGE_SELECT *quick;
List_iterator_fast<QUICK_RANGE_SELECT> it(quick_imerge->
quick_selects);
while ((quick= it++))
{
KEY *key_info= table->key_info + quick->index;
register uint length;
if (tmp3.length())
tmp3.append(',');
tmp3.append(key_info->name);
if (tmp2.length())
tmp2.append(',');
length= longlong2str(quick->max_used_key_length, keylen_str_buf,
10) -
keylen_str_buf;
tmp2.append(keylen_str_buf, length);
}
}
else
{
KEY *key_info= table->key_info + tab->select->quick->index;
register uint length;
tmp3.append(key_info->name);
length= longlong2str(tab->select->quick->max_used_key_length,
keylen_str_buf, 10) -
keylen_str_buf;
tmp2.append(keylen_str_buf, length);
}
item_list.push_back(new Item_string(tmp3.ptr(),tmp3.length(),cs));
item_list.push_back(new Item_string(tmp2.ptr(),tmp2.length(),cs));
item_list.push_back(item_null);
}
else
......
sql/sql_select.h
View file @ ca6c4cc3
......@@ -76,7 +76,7 @@ typedef struct st_join_cache {
enum join_type { JT_UNKNOWN,JT_SYSTEM,JT_CONST,JT_EQ_REF,JT_REF,JT_MAYBE_REF,
JT_ALL, JT_RANGE, JT_NEXT, JT_FT, JT_REF_OR_NULL,
JT_SIMPLE_IN, JT_INDEX_IN};
JT_SIMPLE_IN, JT_INDEX_IN, JT_INDEX_MERGE};
class JOIN;
......@@ -85,7 +85,7 @@ typedef struct st_join_table {
KEYUSE *keyuse; /* pointer to first used key */
SQL_SELECT *select;
COND *select_cond;
QUICK_SELECT *quick;
QUICK_SELECT_I *quick;
Item *on_expr;
const char *info;
byte *null_ref_key;
......@@ -307,6 +307,7 @@ void copy_fields(TMP_TABLE_PARAM *param);
void copy_funcs(Item **func_ptr);
bool create_myisam_from_heap(THD *thd, TABLE *table, TMP_TABLE_PARAM *param,
int error, bool ignore_last_dupp_error);
uint find_shortest_key(TABLE *table, key_map usable_keys);
/* functions from opt_sum.cc */
int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds);
......
sql/sql_test.cc
View file @ ca6c4cc3
......@@ -179,9 +179,39 @@ TEST_join(JOIN *join)
" quick select checked for each record (keys: %d)\n",
(int) tab->select->quick_keys);
else if (tab->select->quick)
fprintf(DBUG_FILE," quick select used on key %s, length: %d\n",
{
int quick_type= tab->select->quick->get_type();
if ((quick_type == QUICK_SELECT_I::QS_TYPE_RANGE) ||
(quick_type == QUICK_SELECT_I::QS_TYPE_RANGE_DESC))
{
fprintf(DBUG_FILE,
" quick select used on key %s, length: %d\n",
form->key_info[tab->select->quick->index].name,
tab->select->quick->max_used_key_length);
}
else if (quick_type == QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)
{
QUICK_INDEX_MERGE_SELECT *quick_imerge=
(QUICK_INDEX_MERGE_SELECT*)tab->select->quick;
QUICK_RANGE_SELECT *quick;
fprintf(DBUG_FILE,
" index_merge quick select used\n");
List_iterator_fast<QUICK_RANGE_SELECT> it(quick_imerge->quick_selects);
while ((quick = it++))
{
fprintf(DBUG_FILE,
" range quick select: key %s, length: %d\n",
form->key_info[quick->index].name,
quick->max_used_key_length);
}
}
else
{
fprintf(DBUG_FILE,
" quick select of unknown nature used\n");
}
}
else
VOID(fputs(" select used\n",DBUG_FILE));
}
......
sql/sql_union.cc
View file @ ca6c4cc3
......@@ -117,6 +117,7 @@ int st_select_lex_unit::prepare(THD *thd, select_result *sel_result,
{
SELECT_LEX *lex_select_save= thd->lex.current_select;
SELECT_LEX *select_cursor;
SELECT_LEX *sl;
DBUG_ENTER("st_select_lex_unit::prepare");
if (prepared)
......@@ -185,7 +186,7 @@ int st_select_lex_unit::prepare(THD *thd, select_result *sel_result,
union_result->not_describe=1;
union_result->tmp_table_param=tmp_table_param;
for (SELECT_LEX *sl= select_cursor; sl; sl= sl->next_select())
for (sl= select_cursor; sl; sl= sl->next_select())
{
JOIN *join= new JOIN(thd, sl->item_list,
sl->options | thd->options | SELECT_NO_UNLOCK,
......
sql/sql_update.cc
View file @ ca6c4cc3
......@@ -171,10 +171,18 @@ int mysql_update(THD *thd,
init_ftfuncs(thd, &thd->lex.select_lex, 1);
/* Check if we are modifying a key that we are used to search with */
if (select && select->quick)
{
if (select->quick->get_type() != QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)
{
used_index= select->quick->index;
used_key_is_modified= (!select->quick->unique_key_range() &&
check_if_key_used(table,
(used_index=select->quick->index),
fields));
check_if_key_used(table,used_index,fields));
}
else
{
used_key_is_modified= true;
}
}
else if ((used_index=table->file->key_used_on_scan) < MAX_KEY)
used_key_is_modified=check_if_key_used(table, used_index, fields);
else
......@@ -688,8 +696,26 @@ static bool safe_update_on_fly(JOIN_TAB *join_tab, List<Item> *fields)
case JT_ALL:
/* If range search on index */
if (join_tab->quick)
return !check_if_key_used(table, join_tab->quick->index,
*fields);
{
if (join_tab->quick->get_type() != QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)
{
return !check_if_key_used(table,join_tab->quick->index,*fields);
}
else
{
QUICK_INDEX_MERGE_SELECT *qsel_imerge=
(QUICK_INDEX_MERGE_SELECT*)(join_tab->quick);
List_iterator_fast<QUICK_RANGE_SELECT> it(qsel_imerge->quick_selects);
QUICK_RANGE_SELECT *quick;
while ((quick= it++))
{
if (check_if_key_used(table, quick->index, *fields))
return 0;
}
return 1;
}
}
/* If scanning in clustered key */
if ((table->file->table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
table->primary_key < MAX_KEY)
......
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