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Reduced size of POSITION

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Replaced Cost_estimate prefix_cost with a double as prefix_cost was
only used to store and retrive total prefix cost.

This also speeds up things (a bit) as don't have to call
Cost_estimate::total_cost() for every access to the prefix_cost.

Sizeof POSITION decreased from 304 to 256.
This commit is contained in:
Monty
2022-06-03 13:24:18 +03:00
committed by Oleg Smirnov
parent fbbc63453b
commit 1f0187ff8d
3 changed files with 12 additions and 13 deletions
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17
sql/opt_subselect.cc
View File

@@ -2895,7 +2895,7 @@ void optimize_semi_joins(JOIN *join, table_map remaining_tables, uint idx,
pos[-1].inner_tables_handled_with_other_sjs;
}
pos->prefix_cost.convert_from_cost(*current_read_time);
pos->prefix_cost= *current_read_time;
pos->prefix_record_count= *current_record_count;
{
@@ -3017,7 +3017,7 @@ void optimize_semi_joins(JOIN *join, table_map remaining_tables, uint idx,
update_sj_state(join, new_join_tab, idx, remaining_tables);
pos->prefix_cost.convert_from_cost(*current_read_time);
pos->prefix_cost= *current_read_time;
pos->prefix_record_count= *current_record_count;
pos->dups_producing_tables= dups_producing_tables;
}
@@ -3107,15 +3107,15 @@ bool Sj_materialization_picker::check_qep(JOIN *join,
else
{
/* This is SJ-Materialization with lookups */
Cost_estimate prefix_cost;
double prefix_cost;
signed int first_tab= (int)idx - mat_info->tables;
double prefix_rec_count;
double prefix_rec_count, mat_read_time;
Json_writer_object trace(join->thd);
trace.add("strategy", "SJ-Materialization");
if (first_tab < (int)join->const_tables)
{
prefix_cost.reset();
prefix_cost= 0;
prefix_rec_count= 1.0;
}
else
@@ -3124,9 +3124,8 @@ bool Sj_materialization_picker::check_qep(JOIN *join,
prefix_rec_count= join->positions[first_tab].prefix_record_count;
}
double mat_read_time= prefix_cost.total_cost();
mat_read_time=
COST_ADD(mat_read_time,
COST_ADD(prefix_cost,
COST_ADD(mat_info->materialization_cost.total_cost(),
COST_MULT(prefix_rec_count,
mat_info->lookup_cost.total_cost())));
@@ -3171,7 +3170,7 @@ bool Sj_materialization_picker::check_qep(JOIN *join,
}
else
{
prefix_cost= join->positions[first_tab - 1].prefix_cost.total_cost();
prefix_cost= join->positions[first_tab - 1].prefix_cost;
prefix_rec_count= join->positions[first_tab - 1].prefix_record_count;
}
@@ -3535,7 +3534,7 @@ bool Duplicate_weedout_picker::check_qep(JOIN *join,
}
else
{
dups_cost= join->positions[first_tab - 1].prefix_cost.total_cost();
dups_cost= join->positions[first_tab - 1].prefix_cost;
prefix_rec_count= join->positions[first_tab - 1].prefix_record_count;
temptable_rec_size= 8; /* This is not true but we'll make it so */
}

2
sql/sql_select.cc
View File

@@ -17945,7 +17945,7 @@ void optimize_wo_join_buffering(JOIN *join, uint first_tab, uint last_tab,
if (first_tab > join->const_tables)
{
cost= join->positions[first_tab - 1].prefix_cost.total_cost();
cost= join->positions[first_tab - 1].prefix_cost;
rec_count= join->positions[first_tab - 1].prefix_record_count;
}
else

6
sql/sql_select.h
View File

@@ -952,6 +952,9 @@ public:
double prefix_record_count;
/* Cost for the join prefix */
double prefix_cost;
/*
NULL - 'index' or 'range' or 'index_merge' or 'ALL' access is used.
Other - [eq_]ref[_or_null] access is used. Pointer to {t.keypart1 = expr}
@@ -983,9 +986,6 @@ public:
LooseScan_picker loosescan_picker;
Sj_materialization_picker sjmat_picker;
/* Cumulative cost and record count for the join prefix */
Cost_estimate prefix_cost;
/*
Current optimization state: Semi-join strategy to be used for this
and preceding join tables.