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Add MRR counters: Handler_mrr_init, Handler_mrr_extra_rowid_sorts,

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Handler_mrr_extra_key_sorts.
This commit is contained in:
Sergey Petrunya
2012-01-23 23:35:52 +04:00
parent 9f60aa27f7
commit 2ae3fca465
5 changed files with 155 additions and 2 deletions
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77
mysql-test/r/myisam_mrr.result
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@@ -557,4 +557,81 @@ COUNT(alias2.f2)
set @@join_cache_level= @tmp_730133_jcl;
set @@optimizer_switch= @tmp_730133_os;
drop table t1;
#
# Test of MRR handler counters
#
flush status;
show status like 'Handler_mrr%';
Variable_name Value
Handler_mrr_extra_key_sorts 0
Handler_mrr_extra_rowid_sorts 0
Handler_mrr_init 0
create table t0 (a int);
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1 (a int, b int, filler char(200), key(a));
insert into t1
select A.a+10*B.a+100*C.a+1000*D.a, 123,'filler' from t0 A, t0 B, t0 C, t0 D;
explain select sum(b) from t1 where a < 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 8 Using index condition; Rowid-ordered scan
# This should show one MRR scan and no re-fills:
flush status;
select sum(b) from t1 where a < 10;
sum(b)
1230
show status like 'handler_mrr%';
Variable_name Value
Handler_mrr_extra_key_sorts 0
Handler_mrr_extra_rowid_sorts 0
Handler_mrr_init 1
set @mrr_buffer_size_save= @@mrr_buffer_size;
set mrr_buffer_size=128;
explain select sum(b) from t1 where a < 1600;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 1380 Using index condition; Rowid-ordered scan
# This should show one MRR scan and one extra rowid sort:
flush status;
select sum(b) from t1 where a < 1600;
sum(b)
196800
show status like 'handler_mrr%';
Variable_name Value
Handler_mrr_extra_key_sorts 0
Handler_mrr_extra_rowid_sorts 1
Handler_mrr_init 1
set @@mrr_buffer_size= @mrr_buffer_size_save;
#Now, let's check BKA:
set @join_cache_level_save= @@join_cache_level;
set @join_buffer_size_save= @@join_buffer_size;
set join_cache_level=6;
explain select sum(t1.b) from t0,t1 where t0.a=t1.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t0 ALL NULL NULL NULL NULL 10 Using where
1 SIMPLE t1 ref a a 5 test.t0.a 1 Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
flush status;
select sum(t1.b) from t0,t1 where t0.a=t1.a;
sum(t1.b)
1230
show status like 'handler_mrr%';
Variable_name Value
Handler_mrr_extra_key_sorts 0
Handler_mrr_extra_rowid_sorts 0
Handler_mrr_init 1
set join_buffer_size=10;
explain select sum(t1.b) from t0,t1 where t0.a=t1.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t0 ALL NULL NULL NULL NULL 10 Using where
1 SIMPLE t1 ref a a 5 test.t0.a 1 Using join buffer (flat, BKA join); Key-ordered Rowid-ordered scan
flush status;
select sum(t1.b) from t0,t1 where t0.a=t1.a;
sum(t1.b)
1230
show status like 'handler_mrr%';
Variable_name Value
Handler_mrr_extra_key_sorts 1
Handler_mrr_extra_rowid_sorts 1
Handler_mrr_init 2
set join_cache_level= @join_cache_level_save;
set join_buffer_size= @join_buffer_size_save;
drop table t0, t1;
set optimizer_switch= @myisam_mrr_tmp;