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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
View File

@ -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;

52
mysql-test/t/myisam_mrr.test
View File

@ -268,5 +268,57 @@ set @@join_cache_level= @tmp_730133_jcl;
set @@optimizer_switch= @tmp_730133_os;
drop table t1;
--echo #
--echo # Test of MRR handler counters
--echo #
flush status;
show status like 'Handler_mrr%';
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;
--echo # This should show one MRR scan and no re-fills:
flush status;
select sum(b) from t1 where a < 10;
show status like 'handler_mrr%';
set @mrr_buffer_size_save= @@mrr_buffer_size;
--disable_warnings
set mrr_buffer_size=128;
--enable_warnings
explain select sum(b) from t1 where a < 1600;
--echo # This should show one MRR scan and one extra rowid sort:
flush status;
select sum(b) from t1 where a < 1600;
show status like 'handler_mrr%';
set @@mrr_buffer_size= @mrr_buffer_size_save;
--echo #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;
flush status;
select sum(t1.b) from t0,t1 where t0.a=t1.a;
show status like 'handler_mrr%';
--disable_warnings
set join_buffer_size=10;
--enable_warnings
explain select sum(t1.b) from t0,t1 where t0.a=t1.a;
flush status;
select sum(t1.b) from t0,t1 where t0.a=t1.a;
show status like 'handler_mrr%';
set join_cache_level= @join_cache_level_save;
set join_buffer_size= @join_buffer_size_save;
drop table t0, t1;
## This must be last line in the file:
set optimizer_switch= @myisam_mrr_tmp;

21
sql/multi_range_read.cc
View File

@ -466,6 +466,10 @@ void Mrr_ordered_index_reader::resume_read()
/**
Fill the buffer with (lookup_tuple, range_id) pairs and sort
@return
0 OK, the buffer is non-empty and sorted
HA_ERR_END_OF_FILE Source exhausted, the buffer is empty.
*/
int Mrr_ordered_index_reader::refill_buffer(bool initial)
@ -502,6 +506,13 @@ int Mrr_ordered_index_reader::refill_buffer(bool initial)
if (source_exhausted && key_buffer->is_empty())
DBUG_RETURN(HA_ERR_END_OF_FILE);
if (!initial)
{
/* This is a non-initial buffer fill and we've got a non-empty buffer */
THD *thd= current_thd;
status_var_increment(thd->status_var.ha_mrr_extra_key_sorts);
}
key_buffer->sort((key_buffer->type() == Lifo_buffer::FORWARD)?
(qsort2_cmp)Mrr_ordered_index_reader::compare_keys_reverse :
(qsort2_cmp)Mrr_ordered_index_reader::compare_keys,
@ -576,6 +587,7 @@ int Mrr_ordered_rndpos_reader::init(handler *h_arg,
int Mrr_ordered_rndpos_reader::refill_buffer(bool initial)
{
int res;
bool first_call= initial;
DBUG_ENTER("Mrr_ordered_rndpos_reader::refill_buffer");
if (index_reader_exhausted)
@ -593,6 +605,14 @@ int Mrr_ordered_rndpos_reader::refill_buffer(bool initial)
initial= FALSE;
index_reader_needs_refill= FALSE;
}
if (!first_call && !index_reader_exhausted)
{
/* Ok, this was a successful buffer refill operation */
THD *thd= current_thd;
status_var_increment(thd->status_var.ha_mrr_extra_rowid_sorts);
}
DBUG_RETURN(res);
}
@ -825,7 +845,6 @@ int DsMrr_impl::dsmrr_init(handler *h_arg, RANGE_SEQ_IF *seq_funcs,
strategy= disk_strategy= &reader_factory.ordered_rndpos_reader;
}
if (is_mrr_assoc)
status_var_increment(thd->status_var.ha_multi_range_read_init_count);
full_buf= buf->buffer;

3
sql/mysqld.cc
View File

@ -8303,6 +8303,9 @@ SHOW_VAR status_vars[]= {
{"Handler_write", (char*) offsetof(STATUS_VAR, ha_write_count), SHOW_LONG_STATUS},
{"Handler_tmp_update", (char*) offsetof(STATUS_VAR, ha_tmp_update_count), SHOW_LONG_STATUS},
{"Handler_tmp_write", (char*) offsetof(STATUS_VAR, ha_tmp_write_count), SHOW_LONG_STATUS},
{"Handler_mrr_init", (char*) offsetof(STATUS_VAR, ha_multi_range_read_init_count), SHOW_LONG_STATUS},
{"Handler_mrr_extra_rowid_sorts", (char*) offsetof(STATUS_VAR, ha_mrr_extra_rowid_sorts), SHOW_LONG_STATUS},
{"Handler_mrr_extra_key_sorts", (char*) offsetof(STATUS_VAR, ha_mrr_extra_key_sorts), SHOW_LONG_STATUS},
{"Key", (char*) &show_default_keycache, SHOW_FUNC},
{"Last_query_cost", (char*) offsetof(STATUS_VAR, last_query_cost), SHOW_DOUBLE_STATUS},
{"Max_used_connections", (char*) &max_used_connections, SHOW_LONG},

2
sql/sql_class.h
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@ -578,6 +578,8 @@ typedef struct system_status_var
BatchedKeyAccess.
*/
ulong ha_multi_range_read_init_count;
ulong ha_mrr_extra_key_sorts;
ulong ha_mrr_extra_rowid_sorts;
ulong ha_rollback_count;
ulong ha_update_count;