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authorSergei Golubchik <sergii@pisem.net>2012-01-13 15:50:02 +0100
committerSergei Golubchik <sergii@pisem.net>2012-01-13 15:50:02 +0100
commit4f435bddfd44d40999f88685c61cc04e319d8d6c (patch)
treef9d0655a0d901b87f918a736741144b502cba3f6 /sql/sql_select.h
parent8c2bcdf85ff753bceeb5b235f3605e348e6f9e1d (diff)
parent6ca4ca7d37fed3b3da18666768de6a2f8c34bc7b (diff)
downloadmariadb-git-4f435bddfd44d40999f88685c61cc04e319d8d6c.tar.gz
5.3 merge
Diffstat (limited to 'sql/sql_select.h')
-rw-r--r--sql/sql_select.h365
1 files changed, 279 insertions, 86 deletions
diff --git a/sql/sql_select.h b/sql/sql_select.h
index 4b5e2903c1d..644828fa08c 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -2,7 +2,7 @@
#define SQL_SELECT_INCLUDED
/* Copyright (c) 2000, 2011, Oracle and/or its affiliates.
- Copyright (c) 2010, 2011, Monty Program Ab
+ Copyright (c) 2008-2011 Monty Program Ab
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -84,6 +84,8 @@ typedef struct keyuse_t {
bool is_for_hash_join() { return is_hash_join_key_no(key); }
} KEYUSE;
+#define NO_KEYPART ((uint)(-1))
+
class store_key;
const int NO_REF_PART= uint(-1);
@@ -165,6 +167,17 @@ enum enum_nested_loop_state
};
+/* Possible sj_strategy values */
+enum sj_strategy_enum
+{
+ SJ_OPT_NONE=0,
+ SJ_OPT_DUPS_WEEDOUT=1,
+ SJ_OPT_LOOSE_SCAN =2,
+ SJ_OPT_FIRST_MATCH =3,
+ SJ_OPT_MATERIALIZE =4,
+ SJ_OPT_MATERIALIZE_SCAN=5
+};
+
/* Values for JOIN_TAB::packed_info */
#define TAB_INFO_HAVE_VALUE 1
#define TAB_INFO_USING_INDEX 2
@@ -278,7 +291,16 @@ typedef struct st_join_table {
double partial_join_cardinality;
table_map dependent,key_dependent;
- uint use_quick,index;
+ /*
+ 1 - use quick select
+ 2 - use "Range checked for each record"
+ */
+ uint use_quick;
+ /*
+ Index to use. Note: this is valid only for 'index' access, but not range or
+ ref access.
+ */
+ uint index;
uint status; ///< Save status for cache
uint used_fields;
ulong used_fieldlength;
@@ -326,6 +348,8 @@ typedef struct st_join_table {
/* Variables for semi-join duplicate elimination */
SJ_TMP_TABLE *flush_weedout_table;
SJ_TMP_TABLE *check_weed_out_table;
+ /* for EXPLAIN only: */
+ SJ_TMP_TABLE *first_weedout_table;
/*
If set, means we should stop join enumeration after we've got the first
@@ -370,7 +394,7 @@ typedef struct st_join_table {
POSITION::sj_strategy field. This field is set up by the
fix_semijoin_strategies_for_picked_join_order.
*/
- uint sj_strategy;
+ enum sj_strategy_enum sj_strategy;
uint n_sj_tables;
@@ -502,12 +526,221 @@ end_write_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
bool end_of_records);
+struct st_position;
+
+class Semi_join_strategy_picker
+{
+public:
+ /* Called when starting to build a new join prefix */
+ virtual void set_empty() = 0;
+
+ /*
+ Update internal state after another table has been added to the join
+ prefix
+ */
+ virtual void set_from_prev(struct st_position *prev) = 0;
+
+ virtual bool check_qep(JOIN *join,
+ uint idx,
+ table_map remaining_tables,
+ const JOIN_TAB *new_join_tab,
+ double *record_count,
+ double *read_time,
+ table_map *handled_fanout,
+ sj_strategy_enum *strategy,
+ struct st_position *loose_scan_pos) = 0;
+
+ virtual void mark_used() = 0;
+
+ virtual ~Semi_join_strategy_picker() {}
+};
+
+
+/*
+ Duplicate Weedout strategy optimization state
+*/
+
+class Duplicate_weedout_picker : public Semi_join_strategy_picker
+{
+ /* The first table that the strategy will need to handle */
+ uint first_dupsweedout_table;
+
+ /*
+ Tables that we will need to have in the prefix to do the weedout step
+ (all inner and all outer that the involved semi-joins are correlated with)
+ */
+ table_map dupsweedout_tables;
+
+ bool is_used;
+public:
+ void set_empty()
+ {
+ dupsweedout_tables= 0;
+ first_dupsweedout_table= MAX_TABLES;
+ is_used= FALSE;
+ }
+ void set_from_prev(struct st_position *prev);
+
+ bool check_qep(JOIN *join,
+ uint idx,
+ table_map remaining_tables,
+ const JOIN_TAB *new_join_tab,
+ double *record_count,
+ double *read_time,
+ table_map *handled_fanout,
+ sj_strategy_enum *stratey,
+ struct st_position *loose_scan_pos);
+
+ void mark_used() { is_used= TRUE; }
+ friend void fix_semijoin_strategies_for_picked_join_order(JOIN *join);
+};
+
+
+class Firstmatch_picker : public Semi_join_strategy_picker
+{
+ /*
+ Index of the first inner table that we intend to handle with this
+ strategy
+ */
+ uint first_firstmatch_table;
+ /*
+ Tables that were not in the join prefix when we've started considering
+ FirstMatch strategy.
+ */
+ table_map first_firstmatch_rtbl;
+ /*
+ Tables that need to be in the prefix before we can calculate the cost
+ of using FirstMatch strategy.
+ */
+ table_map firstmatch_need_tables;
+
+ bool is_used;
+
+ bool in_firstmatch_prefix() { return (first_firstmatch_table != MAX_TABLES); }
+ void invalidate_firstmatch_prefix() { first_firstmatch_table= MAX_TABLES; }
+public:
+ void set_empty()
+ {
+ invalidate_firstmatch_prefix();
+ is_used= FALSE;
+ }
+
+ void set_from_prev(struct st_position *prev);
+ bool check_qep(JOIN *join,
+ uint idx,
+ table_map remaining_tables,
+ const JOIN_TAB *new_join_tab,
+ double *record_count,
+ double *read_time,
+ table_map *handled_fanout,
+ sj_strategy_enum *strategy,
+ struct st_position *loose_scan_pos);
+
+ void mark_used() { is_used= TRUE; }
+ friend void fix_semijoin_strategies_for_picked_join_order(JOIN *join);
+};
+
+
+class LooseScan_picker : public Semi_join_strategy_picker
+{
+ /* The first (i.e. driving) table we're doing loose scan for */
+ uint first_loosescan_table;
+ /*
+ Tables that need to be in the prefix before we can calculate the cost
+ of using LooseScan strategy.
+ */
+ table_map loosescan_need_tables;
+
+ /*
+ keyno - Planning to do LooseScan on this key. If keyuse is NULL then
+ this is a full index scan, otherwise this is a ref+loosescan
+ scan (and keyno matches the KEUSE's)
+ MAX_KEY - Not doing a LooseScan
+ */
+ uint loosescan_key; // final (one for strategy instance )
+ uint loosescan_parts; /* Number of keyparts to be kept distinct */
+
+ bool is_used;
+public:
+ void set_empty()
+ {
+ first_loosescan_table= MAX_TABLES;
+ is_used= FALSE;
+ }
+
+ void set_from_prev(struct st_position *prev);
+ bool check_qep(JOIN *join,
+ uint idx,
+ table_map remaining_tables,
+ const JOIN_TAB *new_join_tab,
+ double *record_count,
+ double *read_time,
+ table_map *handled_fanout,
+ sj_strategy_enum *strategy,
+ struct st_position *loose_scan_pos);
+ void mark_used() { is_used= TRUE; }
+
+ friend class Loose_scan_opt;
+ friend void best_access_path(JOIN *join,
+ JOIN_TAB *s,
+ table_map remaining_tables,
+ uint idx,
+ bool disable_jbuf,
+ double record_count,
+ struct st_position *pos,
+ struct st_position *loose_scan_pos);
+ friend bool get_best_combination(JOIN *join);
+ friend int setup_semijoin_dups_elimination(JOIN *join, ulonglong options,
+ uint no_jbuf_after);
+ friend void fix_semijoin_strategies_for_picked_join_order(JOIN *join);
+};
+
+
+class Sj_materialization_picker : public Semi_join_strategy_picker
+{
+ bool is_used;
+
+ /* The last inner table (valid once we're after it) */
+ uint sjm_scan_last_inner;
+ /*
+ Tables that we need to have in the prefix to calculate the correct cost.
+ Basically, we need all inner tables and outer tables mentioned in the
+ semi-join's ON expression so we can correctly account for fanout.
+ */
+ table_map sjm_scan_need_tables;
+
+public:
+ void set_empty()
+ {
+ sjm_scan_need_tables= 0;
+ LINT_INIT(sjm_scan_last_inner);
+ is_used= FALSE;
+ }
+ void set_from_prev(struct st_position *prev);
+ bool check_qep(JOIN *join,
+ uint idx,
+ table_map remaining_tables,
+ const JOIN_TAB *new_join_tab,
+ double *record_count,
+ double *read_time,
+ table_map *handled_fanout,
+ sj_strategy_enum *strategy,
+ struct st_position *loose_scan_pos);
+ void mark_used() { is_used= TRUE; }
+
+ friend void fix_semijoin_strategies_for_picked_join_order(JOIN *join);
+};
+
+
/**
Information about a position of table within a join order. Used in join
optimization.
*/
typedef struct st_position
{
+ /* The table that's put into join order */
+ JOIN_TAB *table;
+
/*
The "fanout": number of output rows that will be produced (after
pushed down selection condition is applied) per each row combination of
@@ -521,7 +754,10 @@ typedef struct st_position
number the access method will be invoked.
*/
double read_time;
- JOIN_TAB *table;
+
+ /* Cumulative cost and record count for the join prefix */
+ COST_VECT prefix_cost;
+ double prefix_record_count;
/*
NULL - 'index' or 'range' or 'index_merge' or 'ALL' access is used.
@@ -531,14 +767,13 @@ typedef struct st_position
/* If ref-based access is used: bitmap of tables this table depends on */
table_map ref_depend_map;
-
- bool use_join_buffer;
-
-
- /* These form a stack of partial join order costs and output sizes */
- COST_VECT prefix_cost;
- double prefix_record_count;
-
+
+ /*
+ TRUE <=> join buffering will be used. At the moment this is based on
+ *very* imprecise guesses made in best_access_path().
+ */
+ bool use_join_buffer;
+
/*
Current optimization state: Semi-join strategy to be used for this
and preceding join tables.
@@ -551,7 +786,8 @@ typedef struct st_position
this applies to. The values of covered_preceding_positions->sj_strategy
must be ignored.
*/
- uint sj_strategy;
+ enum sj_strategy_enum sj_strategy;
+
/*
Valid only after fix_semijoin_strategies_for_picked_join_order() call:
if sj_strategy!=SJ_OPT_NONE, this is the number of subsequent tables that
@@ -559,67 +795,15 @@ typedef struct st_position
*/
uint n_sj_tables;
-/* LooseScan strategy members */
-
- /* The first (i.e. driving) table we're doing loose scan for */
- uint first_loosescan_table;
- /*
- Tables that need to be in the prefix before we can calculate the cost
- of using LooseScan strategy.
- */
- table_map loosescan_need_tables;
-
- /*
- keyno - Planning to do LooseScan on this key. If keyuse is NULL then
- this is a full index scan, otherwise this is a ref+loosescan
- scan (and keyno matches the KEUSE's)
- MAX_KEY - Not doing a LooseScan
- */
- uint loosescan_key; // final (one for strategy instance )
- uint loosescan_parts; /* Number of keyparts to be kept distinct */
-
-/* FirstMatch strategy */
- /*
- Index of the first inner table that we intend to handle with this
- strategy
- */
- uint first_firstmatch_table;
- /*
- Tables that were not in the join prefix when we've started considering
- FirstMatch strategy.
- */
- table_map first_firstmatch_rtbl;
- /*
- Tables that need to be in the prefix before we can calculate the cost
- of using FirstMatch strategy.
- */
- table_map firstmatch_need_tables;
-
- bool in_firstmatch_prefix() { return (first_firstmatch_table != MAX_TABLES); }
- void invalidate_firstmatch_prefix() { first_firstmatch_table= MAX_TABLES; }
-
-/* Duplicate Weedout strategy */
- /* The first table that the strategy will need to handle */
- uint first_dupsweedout_table;
- /*
- Tables that we will need to have in the prefix to do the weedout step
- (all inner and all outer that the involved semi-joins are correlated with)
- */
- table_map dupsweedout_tables;
-
-/* SJ-Materialization-Scan strategy */
- /* The last inner table (valid once we're after it) */
- uint sjm_scan_last_inner;
- /*
- Tables that we need to have in the prefix to calculate the correct cost.
- Basically, we need all inner tables and outer tables mentioned in the
- semi-join's ON expression so we can correctly account for fanout.
- */
- table_map sjm_scan_need_tables;
-
table_map prefix_dups_producing_tables;
-} POSITION;
+ table_map inner_tables_handled_with_other_sjs;
+
+ Duplicate_weedout_picker dups_weedout_picker;
+ Firstmatch_picker firstmatch_picker;
+ LooseScan_picker loosescan_picker;
+ Sj_materialization_picker sjmat_picker;
+} POSITION;
typedef struct st_rollup
{
@@ -631,18 +815,6 @@ typedef struct st_rollup
} ROLLUP;
-#define SJ_OPT_NONE 0
-#define SJ_OPT_DUPS_WEEDOUT 1
-#define SJ_OPT_LOOSE_SCAN 2
-#define SJ_OPT_FIRST_MATCH 3
-#define SJ_OPT_MATERIALIZE 4
-#define SJ_OPT_MATERIALIZE_SCAN 5
-
-inline bool sj_is_materialize_strategy(uint strategy)
-{
- return strategy >= SJ_OPT_MATERIALIZE;
-}
-
class JOIN_TAB_RANGE: public Sql_alloc
{
public:
@@ -750,6 +922,7 @@ public:
*/
bool sort_and_group;
bool first_record,full_join, no_field_update;
+ bool hash_join;
bool do_send_rows;
table_map const_table_map;
/*
@@ -810,7 +983,7 @@ public:
they produce.
*/
table_map cur_dups_producing_tables;
-
+
/* We also maintain a stack of join optimization states in * join->positions[] */
/******* Join optimization state members end *******/
/*
@@ -935,6 +1108,7 @@ public:
COND *conds; // ---"---
Item *conds_history; // store WHERE for explain
COND *outer_ref_cond; ///<part of conds containing only outer references
+ COND *pseudo_bits_cond; // part of conds containing special bita
TABLE_LIST *tables_list; ///<hold 'tables' parameter of mysql_select
List<TABLE_LIST> *join_list; ///< list of joined tables in reverse order
COND_EQUAL *cond_equal;
@@ -1061,7 +1235,7 @@ public:
rollup.state= ROLLUP::STATE_NONE;
no_const_tables= FALSE;
- outer_ref_cond= 0;
+ outer_ref_cond= pseudo_bits_cond= NULL;
in_to_exists_where= NULL;
in_to_exists_having= NULL;
}
@@ -1151,6 +1325,25 @@ public:
return test(allowed_join_cache_types & JOIN_CACHE_HASHED_BIT) &&
max_allowed_join_cache_level > JOIN_CACHE_HASHED_BIT;
}
+ /*
+ Check if we need to create a temporary table.
+ This has to be done if all tables are not already read (const tables)
+ and one of the following conditions holds:
+ - We are using DISTINCT (simple distinct's are already optimized away)
+ - We are using an ORDER BY or GROUP BY on fields not in the first table
+ - We are using different ORDER BY and GROUP BY orders
+ - The user wants us to buffer the result.
+ When the WITH ROLLUP modifier is present, we cannot skip temporary table
+ creation for the DISTINCT clause just because there are only const tables.
+ */
+ bool test_if_need_tmp_table()
+ {
+ return ((const_tables != table_count &&
+ ((select_distinct || !simple_order || !simple_group) ||
+ (group_list && order) ||
+ test(select_options & OPTION_BUFFER_RESULT))) ||
+ (rollup.state != ROLLUP::STATE_NONE && select_distinct));
+ }
bool choose_subquery_plan(table_map join_tables);
void get_partial_cost_and_fanout(int end_tab_idx,
table_map filter_map,