MySQL InnoDB query performance

Question

I'm trying to optimize a simple sql query that will be run over a ton of data lot of times.

This is the scenario:

• MySQL with InnoDB tables
• All fields used in where and join are Indexed. Tables have FK's.
• I don't need a whole cache of the query, but a cache of each table it's possible.
• Tables have much more reads that updates / inserts.

A real query:

SELECT one_field, another_field
FROM big_table 
INNER JOIN medium_table ON ( ... ) 
INNER JOIN small_table ON ( ... ) 
WHERE week >= #number AND week <= #number AND year >= #number AND year <= #number 
AND medium_table.indexed_field = #number
AND small_table.pk= #number

Some test results:

• Average query time: 2,3374s
• Test tables contains the tenth part of data (or even less) that real tables, like 75.000 rows for big_test_table.
• Query returns (in test cases) 6500 rows.
• Navicat says that 99.95% of query time is spended on "Sending data"
• I've tried with MyISAM, and the average query time was: 2,1898s

How can I improve the query or the database scheme?

It's better concatenate my year / week fields and in a [yearweek] indexed field?

In some benchmarks I see that MyISAM is faster than Innodb, but seems I have a little improvement:

http://www.mysqlperformanceblog.com/files/benchmarks/innodb-myisam-falcon.html
http://www.jortk.nl/2008/12/mysql-performance-benchmark-myisam-versus-innodb/

Is it worth lose FKs and go to MyISAM?

Thanks!

---

Updates:

Explain of the select:

1   SIMPLE  small_table const   PRIMARY PRIMARY 4   const   1   Using index
1   SIMPLE  medium_table    index_merge PRIMARY,Fk_small_table, Fk_indexed_field    Fk_small_table, Fk_indexed_field    5,5     250 Using intersect(Fk_small_table, Fk_indexed_field); Using where
1   SIMPLE  big_table   ref Fk_code_of_medium_table,week-year-compound-index    Fk_three    5   medium_table.primary_key    4   Using where

DB schema:

CREATE  TABLE IF NOT EXISTS `db`.`big_table` (
  `primary_key` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT ,
  `code_of_medium_table` INT UNSIGNED NULL ,
  `week` SMALLINT UNSIGNED NULL ,
  `year` YEAR NULL ,
   ......
  PRIMARY KEY (`primary_key`) ,
  INDEX `Fk_code_of_medium_table` (`code_of_medium_table` ASC) ,
  INDEX `In_week-year` (`week` ASC, `year` ASC) ,
  CONSTRAINT `Fk_code_of_medium_table`
    FOREIGN KEY (`code_of_medium_table` )
    REFERENCES `db`.`medium_table` (`code` )
    ON DELETE NO ACTION
    ON UPDATE NO ACTION,
ENGINE = InnoDB


CREATE  TABLE IF NOT EXISTS `db`.`medium_table` (
  `primary_key` INT UNSIGNED NOT NULL AUTO_INCREMENT ,
  .....
  `code_of_small_table` INT UNSIGNED NULL ,
  `indexed_field ` INT UNSIGNED NULL ,
  PRIMARY KEY (`primary_key`) ,
  INDEX `Fk_code_of_small_table` (`code_of_small_table` ASC) ,
  INDEX `Fk_indexed_field` (`another_field` ASC) ,
  CONSTRAINT `Fk_code_of_small_table`
    FOREIGN KEY (`code_of_small_table` )
    REFERENCES `db`.`small_table` (`code` )
    ON DELETE NO ACTION
    ON UPDATE NO ACTION,
  CONSTRAINT `Fk_indexed_field `
    FOREIGN KEY (`indexed_field ` )
    REFERENCES `db`.`other_table` (`code` )
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB


CREATE  TABLE IF NOT EXISTS `db`.`small_table` (
  `primary_key` INT UNSIGNED NOT NULL AUTO_INCREMENT ,
  .....
  PRIMARY KEY (`primary_key`) )
ENGINE = InnoDB

Variables output:

auto_increment_increment    1
auto_increment_offset   1
automatic_sp_privileges ON
back_log    50
basedir /usr/
bdb_cache_size  8384512
bdb_home    /var/lib/mysql/
bdb_log_buffer_size 262144
bdb_logdir  
bdb_max_lock    10000
bdb_shared_data OFF
bdb_tmpdir  /tmp/
binlog_cache_size   32768
bulk_insert_buffer_size 8388608
character_set_client    utf8
character_set_connection    utf8
character_set_database  latin1
character_set_filesystem    binary
character_set_results   utf8
character_set_server    latin1
character_set_system    utf8
character_sets_dir  /usr/share/mysql/charsets/
collation_connection    utf8_general_ci
collation_database  latin1_swedish_ci
collation_server    latin1_swedish_ci
completion_type 0
concurrent_insert   1
connect_timeout 10
datadir /var/lib/mysql/
date_format %Y-%m-%d
datetime_format %Y-%m-%d %H:%i:%s
default_week_format 0
delay_key_write ON
delayed_insert_limit    100
delayed_insert_timeout  300
delayed_queue_size  1000
div_precision_increment 4
keep_files_on_create    OFF
engine_condition_pushdown   OFF
expire_logs_days    0
flush   OFF
flush_time  0
ft_boolean_syntax   + -><()~*:""&|
ft_max_word_len 84
ft_min_word_len 4
ft_query_expansion_limit    20
ft_stopword_file    (built-in)
group_concat_max_len    1024
have_archive    NO
have_bdb    YES
have_blackhole_engine   NO
have_compress   YES
have_crypt  YES
have_csv    NO
have_dynamic_loading    YES
have_example_engine NO
have_federated_engine   NO
have_geometry   YES
have_innodb YES
have_isam   NO
have_merge_engine   YES
have_ndbcluster NO
have_openssl    DISABLED
have_ssl    DISABLED
have_query_cache    YES
have_raid   NO
have_rtree_keys YES
have_symlink    YES
hostname    EarnedBE002
init_connect    
init_file   
init_slave  
innodb_additional_mem_pool_size 1048576
innodb_autoextend_increment 8
innodb_buffer_pool_awe_mem_mb   0
innodb_buffer_pool_size 8388608
innodb_checksums    ON
innodb_commit_concurrency   0
innodb_concurrency_tickets  500
innodb_data_file_path   ibdata1:10M:autoextend
innodb_data_home_dir    
innodb_adaptive_hash_index  ON
innodb_doublewrite  ON
innodb_fast_shutdown    1
innodb_file_io_threads  4
innodb_file_per_table   OFF
innodb_flush_log_at_trx_commit  1
innodb_flush_method 
innodb_force_recovery   0
innodb_lock_wait_timeout    50
innodb_locks_unsafe_for_binlog  OFF
innodb_log_arch_dir 
innodb_log_archive  OFF
innodb_log_buffer_size  1048576
innodb_log_file_size    5242880
innodb_log_files_in_group   2
innodb_log_group_home_dir   ./
innodb_max_dirty_pages_pct  90
innodb_max_purge_lag    0
innodb_mirrored_log_groups  1
innodb_open_files   300
innodb_rollback_on_timeout  OFF
innodb_support_xa   ON
innodb_sync_spin_loops  20
innodb_table_locks  ON
innodb_thread_concurrency   8
innodb_thread_sleep_delay   10000
interactive_timeout 28800
join_buffer_size    131072
key_buffer_size 8384512
key_cache_age_threshold 300
key_cache_block_size    1024
key_cache_division_limit    100
language    /usr/share/mysql/english/
large_files_support ON
large_page_size 0
large_pages OFF
lc_time_names   en_US
license GPL
local_infile    ON
locked_in_memory    OFF
log OFF
log_bin OFF
log_bin_trust_function_creators OFF
log_error   
log_queries_not_using_indexes   OFF
log_slave_updates   OFF
log_slow_queries    OFF
log_warnings    1
long_query_time 10
low_priority_updates    OFF
lower_case_file_system  OFF
lower_case_table_names  0
max_allowed_packet  1048576
max_binlog_cache_size   18446744073709547520
max_binlog_size 1073741824
max_connect_errors  10
max_connections 100
max_delayed_threads 20
max_error_count 64
max_heap_table_size 16777216
max_insert_delayed_threads  20
max_join_size   18446744073709551615
max_length_for_sort_data    1024
max_prepared_stmt_count 16382
max_relay_log_size  0
max_seeks_for_key   18446744073709551615
max_sort_length 1024
max_sp_recursion_depth  0
max_tmp_tables  32
max_user_connections    0
max_write_lock_count    18446744073709551615
multi_range_count   256
myisam_data_pointer_size    6
myisam_max_sort_file_size   9223372036853727232
myisam_recover_options  OFF
myisam_repair_threads   1
myisam_sort_buffer_size 8388608
myisam_stats_method nulls_unequal
net_buffer_length   16384
net_read_timeout    30
net_retry_count 10
net_write_timeout   60
new OFF
old_passwords   OFF
open_files_limit    1024
optimizer_prune_level   1
optimizer_search_depth  62
pid_file    /var/run/mysqld/mysqld.pid
plugin_dir  
port    3306
preload_buffer_size 32768
profiling   OFF
profiling_history_size  15
protocol_version    10
query_alloc_block_size  8192
query_cache_limit   1048576
query_cache_min_res_unit    4096
query_cache_size    0
query_cache_type    ON
query_cache_wlock_invalidate    OFF
query_prealloc_size 8192
range_alloc_block_size  4096
read_buffer_size    131072
read_only   OFF
read_rnd_buffer_size    262144
relay_log   
relay_log_index 
relay_log_info_file relay-log.info
relay_log_purge ON
relay_log_space_limit   0
rpl_recovery_rank   0
secure_auth OFF
secure_file_priv    
server_id   0
skip_external_locking   ON
skip_networking OFF
skip_show_database  OFF
slave_compressed_protocol   OFF
slave_load_tmpdir   /tmp/
slave_net_timeout   3600
slave_skip_errors   OFF
slave_transaction_retries   10
slow_launch_time    2
socket  /var/lib/mysql/mysql.sock
sort_buffer_size    2097144
sql_big_selects ON
sql_mode    
sql_notes   ON
sql_warnings    OFF
ssl_ca  
ssl_capath  
ssl_cert    
ssl_cipher  
ssl_key 
storage_engine  MyISAM
sync_binlog 0
sync_frm    ON
system_time_zone    UTC
table_cache 64
table_lock_wait_timeout 50
table_type  MyISAM
thread_cache_size   0
thread_stack    262144
time_format %H:%i:%s
time_zone   SYSTEM
timed_mutexes   OFF
tmp_table_size  33554432
tmpdir  /tmp/
transaction_alloc_block_size    8192
transaction_prealloc_size   4096
tx_isolation    REPEATABLE-READ
updatable_views_with_limit  YES
version 5.0.77
version_bdb Sleepycat Software: Berkeley DB 4.1.24: (January 29, 2009)
version_comment Source distribution
version_compile_machine x86_64
version_compile_os  redhat-linux-gnu
wait_timeout    28800

---

With the index proposed by ypercube, at moment, this is the fastest query (2,107s avg):

SELECT SQL_NO_CACHE int_field, varchar_field 
FROM big_table 
INNER JOIN medium_table ON ( ... ) 
INNER JOIN small_table  ON ( ... ) 
WHERE  week BETWEEN #number AND #number 
AND year BETWEEN #number AND #number 
AND small_table.pk = 248
AND medium_table.indexed_field = #number

Answer 1

I hope you find the following links and previous answers of mine of interest.

I wish I could provide you with a specific answer to your problem but I dont have the time to get my head completely around your schema: naming conventions are so bad, lack of useful information, inconsistencies etc, etc...

However, you should find the solution to your problem below and it's nothing to do with switching to the less performant myisam engine !

A snippet from one of the answers below:

You should read the following and learn a little bit about the advantages of a well designed innodb table and how best to use clustered indexes - only available with innodb !

Clustered indexes:

http://dev.mysql.com/doc/refman/5.0/en/innodb-index-types.html

http://www.xaprb.com/blog/2006/07/04/how-to-exploit-mysql-index-optimizations/

Previous answers of mine:

60 million entries, select entries from a certain month. How to optimize database?

MySQL and NoSQL: Help me to choose the right one

How to avoid "Using temporary" in many-to-many queries?

Optimal MySQL settings for queries that deliver large amounts of data?

Hope this helps :)

Answer 2

(EDITED)

A (year, week) or (week, year) index in big_table would definitely help this query.

I see you already have the second one, (week, year). I would prefer the first one but for this query it would not make much difference, if any.

---

I would add:

• a composite index (code_of_medium_table, year, week) in the big_table and

• a composite index (code_of_small_table, indexed_field) in the medium_table.

Can you try it and post again the query plan?

---

Or (year, week, code_of_medium_table) and (indexed_field, code_of_small_table).