1

I have a database system with a fairly complex dashboard query. First of all the details.

Data model:

DROP TABLE IF EXISTS `contract`;
CREATE TABLE IF NOT EXISTS `contract` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `organisation_id` int(11) NOT NULL,
  `code` varchar(3) NOT NULL,
  `moh_code` varchar(20) NOT NULL,
  `moh_number` varchar(20) NOT NULL,
  `moh_variation` varchar(20) NOT NULL,
  `description` mediumtext NOT NULL,
  `start` datetime NOT NULL,
  `finish` datetime NOT NULL,
  `cities` text,
  `is_support_contract` tinyint(1) DEFAULT NULL,
  `is_intensive` tinyint(1) DEFAULT NULL,
  `moh_team_type` varchar(4) DEFAULT NULL,
  `moh_team_setting` varchar(1) DEFAULT NULL,
  `moh_service_type` varchar(2) DEFAULT NULL,
  `moh_target_population` int(4) DEFAULT NULL,
  `moh_facility_id` varchar(10) DEFAULT NULL,
  `moh_open_date` datetime DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`),
  KEY `organisation_id_idx` (`organisation_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=10 ;

-- --------------------------------------------------------

--
-- Table structure for table `peer_engagement`
--

DROP TABLE IF EXISTS `peer_engagement`;
CREATE TABLE IF NOT EXISTS `peer_engagement` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `peer_id` int(11) NOT NULL,
  `ps_number_id` int(11) NOT NULL,
  `service_organisation_id` int(11) DEFAULT NULL,
  `past_service_disengaged` datetime DEFAULT NULL,
  `key_worker_id` int(11) DEFAULT NULL,
  `iss_clinical_service_id` int(11) DEFAULT NULL,
  `iss_psychiatrist_id` int(11) DEFAULT NULL,
  `iss_service_coordinator_id` int(11) DEFAULT NULL,
  `iss_declined_courier_back_address` varchar(255) DEFAULT NULL,
  `waitinglist_support_suggestions_made` mediumtext,
  `waiting_psw_id` int(11) DEFAULT NULL,
  `declined_waiting_what_support_avail` mediumtext,
  `referral_source_id` int(11) DEFAULT NULL,
  `iss_referred_by` int(11) DEFAULT NULL,
  `record_entered_by` int(11) NOT NULL,
  `record_entered` datetime NOT NULL,
  `waiting_list_priority_id` int(11) DEFAULT NULL,
  `assigned_psw_id` int(11) DEFAULT NULL,
  `assigned` datetime DEFAULT NULL,
  `assigned_by` int(11) DEFAULT NULL,
  `assigned_effective` datetime DEFAULT NULL,
  `last_reengaged` datetime DEFAULT NULL,
  `last_reengaged_id` int(11) DEFAULT NULL,
  `disengagement_started` datetime DEFAULT NULL,
  `disengagement_target` datetime DEFAULT NULL,
  `disengagement_type_id` int(11) DEFAULT NULL,
  `disengagement_comments` mediumtext,
  `status_id` int(11) DEFAULT NULL,
  `closed` datetime DEFAULT NULL,
  `closed_by` int(11) DEFAULT NULL,
  `is_intensive` varchar(5) DEFAULT NULL,
  `heard_about_us_id` int(11) DEFAULT NULL,
  `primhd_referral_no` varchar(50) DEFAULT NULL,
  `moved_to_and_delete_id` int(4) DEFAULT NULL,
  `deleted_date` datetime DEFAULT NULL,
  `is_gp_only` tinyint(4) NOT NULL,
  `referral_to_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`),
  KEY `peer_id_idx` (`peer_id`),
  KEY `ps_number_id_idx` (`ps_number_id`),
  KEY `service_organisation_id_idx` (`service_organisation_id`),
  KEY `key_worker_id_idx` (`key_worker_id`),
  KEY `iss_clinical_service_id_idx` (`iss_clinical_service_id`),
  KEY `iss_psychiatrist_id_idx` (`iss_psychiatrist_id`),
  KEY `iss_service_coordinator_id_idx` (`iss_service_coordinator_id`),
  KEY `referral_source_id_idx` (`referral_source_id`),
  KEY `iss_referred_by_idx` (`iss_referred_by`),
  KEY `record_entered_by_idx` (`record_entered_by`),
  KEY `waiting_psw_id_idx` (`waiting_psw_id`),
  KEY `waiting_list_priority_id_idx` (`waiting_list_priority_id`),
  KEY `assigned_psw_id_idx` (`assigned_psw_id`),
  KEY `assigned_by_idx` (`assigned_by`),
  KEY `last_reengaged_id_idx` (`last_reengaged_id`),
  KEY `disengagement_type_id_idx` (`disengagement_type_id`),
  KEY `status_id_idx` (`status_id`),
  KEY `closed_by_idx` (`closed_by`),
  KEY `peer_engagement_heard_about_us_id_fk` (`heard_about_us_id`),
  KEY `moved_to_and_delete_id_foreign_key` (`moved_to_and_delete_id`),
  KEY `deleted_date` (`deleted_date`),
  KEY `disengagement_target` (`disengagement_target`),
  KEY `peer_engagement_referral_to_id_fk` (`referral_to_id`),
  KEY `is_intensive` (`is_intensive`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=1502 ;

-- --------------------------------------------------------

--
-- Table structure for table `peer_number`
--

DROP TABLE IF EXISTS `peer_number`;
CREATE TABLE IF NOT EXISTS `peer_number` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `ps_number` varchar(5) NOT NULL,
  `contract_id` int(11) NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`),
  KEY `contract_id_idx` (`contract_id`),
  KEY `ps_number` (`ps_number`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=75981 ;

-- --------------------------------------------------------

--
-- Table structure for table `person`
--

DROP TABLE IF EXISTS `person`;
CREATE TABLE IF NOT EXISTS `person` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` bigint(20) DEFAULT NULL,
  `name` varchar(100) NOT NULL,
  `suite` varchar(100) DEFAULT NULL,
  `hnr_street` varchar(200) NOT NULL,
  `suburb` varchar(50) NOT NULL,
  `city` varchar(50) NOT NULL,
  `postcode` varchar(5) NOT NULL,
  `manual_address_entry` tinyint(1) DEFAULT NULL,
  `current_living_situation_id` int(11) DEFAULT NULL,
  `dhb_area_id` int(11) DEFAULT NULL,
  `email` varchar(120) DEFAULT NULL,
  `phone_daytime` varchar(25) DEFAULT NULL,
  `phone_evening` varchar(25) DEFAULT NULL,
  `mobile` varchar(25) DEFAULT NULL,
  `fax` varchar(25) DEFAULT NULL,
  `emergency_contact_details` text,
  `notes` mediumtext,
  `dob` date DEFAULT NULL,
  `nhi` varchar(7) DEFAULT NULL,
  `gender_id` int(11) DEFAULT NULL,
  `ethnicity_id` int(11) DEFAULT NULL,
  `team_leader_id` int(11) DEFAULT NULL,
  `organisation_id` int(11) DEFAULT NULL,
  `role` varchar(100) DEFAULT NULL,
  `type` varchar(255) NOT NULL,
  `postal_address` varchar(200) DEFAULT NULL,
  `start_date` date DEFAULT NULL,
  `deleted_date` datetime DEFAULT NULL,
  `moved_to_and_delete_id` int(4) DEFAULT NULL,
  `employment_situation_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`),
  KEY `user_id_idx` (`user_id`),
  KEY `current_living_situation_id_idx` (`current_living_situation_id`),
  KEY `dhb_area_id_idx` (`dhb_area_id`),
  KEY `gender_id_idx` (`gender_id`),
  KEY `team_leader_id_idx` (`team_leader_id`),
  KEY `organisation_id_idx` (`organisation_id`),
  KEY `moved_to_and_delete_id_foreign_key_person` (`moved_to_and_delete_id`),
  KEY `person_employment_situation_id_fk` (`employment_situation_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=2377 ;

--
-- Constraints for dumped tables
--

--
-- Constraints for table `contract`
--
ALTER TABLE `contract`
  ADD CONSTRAINT `contract_organisation_id_organisation_id` FOREIGN KEY (`organisation_id`) REFERENCES `organisation` (`id`);

--
-- Constraints for table `peer_engagement`
--
ALTER TABLE `peer_engagement`
  ADD CONSTRAINT `moved_to_and_delete_id_foreign_key` FOREIGN KEY (`moved_to_and_delete_id`) REFERENCES `peer_engagement` (`id`),
  ADD CONSTRAINT `peer_engagement_assigned_by_person_id` FOREIGN KEY (`assigned_by`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `peer_engagement_assigned_psw_id_person_id` FOREIGN KEY (`assigned_psw_id`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `peer_engagement_closed_by_person_id` FOREIGN KEY (`closed_by`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `peer_engagement_disengagement_type_id_disengagement_type_id` FOREIGN KEY (`disengagement_type_id`) REFERENCES `disengagement_type` (`id`),
  ADD CONSTRAINT `peer_engagement_heard_about_us_id_fk` FOREIGN KEY (`heard_about_us_id`) REFERENCES `heard_about_us` (`id`),
  ADD CONSTRAINT `peer_engagement_iss_clinical_service_id_organisation_id` FOREIGN KEY (`iss_clinical_service_id`) REFERENCES `organisation` (`id`),
  ADD CONSTRAINT `peer_engagement_iss_psychiatrist_id_person_id` FOREIGN KEY (`iss_psychiatrist_id`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `peer_engagement_iss_referred_by_person_id` FOREIGN KEY (`iss_referred_by`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `peer_engagement_iss_service_coordinator_id_person_id` FOREIGN KEY (`iss_service_coordinator_id`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `peer_engagement_key_worker_id_person_id` FOREIGN KEY (`key_worker_id`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `peer_engagement_last_reengaged_id_peer_number_id` FOREIGN KEY (`last_reengaged_id`) REFERENCES `peer_number` (`id`),
  ADD CONSTRAINT `peer_engagement_peer_id_person_id` FOREIGN KEY (`peer_id`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `peer_engagement_ps_number_id_peer_number_id` FOREIGN KEY (`ps_number_id`) REFERENCES `peer_number` (`id`),
  ADD CONSTRAINT `peer_engagement_record_entered_by_person_id` FOREIGN KEY (`record_entered_by`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `peer_engagement_referral_source_id_referral_source_id` FOREIGN KEY (`referral_source_id`) REFERENCES `referral_source` (`id`),
  ADD CONSTRAINT `peer_engagement_referral_to_id_fk` FOREIGN KEY (`referral_to_id`) REFERENCES `referral_to` (`id`),
  ADD CONSTRAINT `peer_engagement_service_organisation_id_organisation_id` FOREIGN KEY (`service_organisation_id`) REFERENCES `organisation` (`id`),
  ADD CONSTRAINT `peer_engagement_status_id_status_id` FOREIGN KEY (`status_id`) REFERENCES `status` (`id`),
  ADD CONSTRAINT `peer_engagement_waiting_psw_id_person_id` FOREIGN KEY (`waiting_psw_id`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `pwwi` FOREIGN KEY (`waiting_list_priority_id`) REFERENCES `waiting_list_priority` (`id`);

--
-- Constraints for table `peer_number`
--
ALTER TABLE `peer_number`
  ADD CONSTRAINT `peer_number_contract_id_contract_id` FOREIGN KEY (`contract_id`) REFERENCES `contract` (`id`);

--
-- Constraints for table `person`
--
ALTER TABLE `person`
  ADD CONSTRAINT `moved_to_and_delete_id_foreign_key_person` FOREIGN KEY (`moved_to_and_delete_id`) REFERENCES `person` (`id`),
  ADD CONSTRAINT `person_current_living_situation_id_current_living_situation_id` FOREIGN KEY (`current_living_situation_id`) REFERENCES `current_living_situation` (`id`),
  ADD CONSTRAINT `person_dhb_area_id_contract_id` FOREIGN KEY (`dhb_area_id`) REFERENCES `contract` (`id`),
  ADD CONSTRAINT `person_employment_situation_id_fk` FOREIGN KEY (`employment_situation_id`) REFERENCES `employment_situation` (`id`),
  ADD CONSTRAINT `person_gender_id_gender_id` FOREIGN KEY (`gender_id`) REFERENCES `gender` (`id`),
  ADD CONSTRAINT `person_organisation_id_organisation_id` FOREIGN KEY (`organisation_id`) REFERENCES `organisation` (`id`),
  ADD CONSTRAINT `person_team_leader_id_person_id` FOREIGN KEY (`team_leader_id`) REFERENCES `person` (`id`);

Query:

SELECT p.id AS p__id, p.peer_id AS p__peer_id, p.ps_number_id AS p__ps_number_id, p.service_organisation_id AS p__service_organisation_id, p.past_service_disengaged AS p__past_service_disengaged, p.key_worker_id AS p__key_worker_id, p.is_gp_only AS p__is_gp_only, p.iss_clinical_service_id AS p__iss_clinical_service_id, p.iss_psychiatrist_id AS p__iss_psychiatrist_id, p.iss_service_coordinator_id AS p__iss_service_coordinator_id, p.iss_declined_courier_back_address AS p__iss_declined_courier_back_address, p.waitinglist_support_suggestions_made AS p__waitinglist_support_suggestions_made, p.waiting_psw_id AS p__waiting_psw_id, p.declined_waiting_what_support_avail AS p__declined_waiting_what_support_avail, p.referral_source_id AS p__referral_source_id, p.iss_referred_by AS p__iss_referred_by, p.record_entered_by AS p__record_entered_by, p.record_entered AS p__record_entered, p.waiting_list_priority_id AS p__waiting_list_priority_id, p.assigned_psw_id AS p__assigned_psw_id, p.assigned AS p__assigned, p.assigned_by AS p__assigned_by, p.assigned_effective AS p__assigned_effective, p.last_reengaged AS p__last_reengaged, p.last_reengaged_id AS p__last_reengaged_id, p.disengagement_started AS p__disengagement_started, p.disengagement_target AS p__disengagement_target, p.disengagement_type_id AS p__disengagement_type_id, p.disengagement_comments AS p__disengagement_comments, p.status_id AS p__status_id, p.closed AS p__closed, p.closed_by AS p__closed_by, p.is_intensive AS p__is_intensive, p.heard_about_us_id AS p__heard_about_us_id, p.primhd_referral_no AS p__primhd_referral_no, p.moved_to_and_delete_id AS p__moved_to_and_delete_id, p.deleted_date AS p__deleted_date, p.referral_to_id AS p__referral_to_id, p2.id AS p2__id, p2.user_id AS p2__user_id, p2.name AS p2__name, p2.suite AS p2__suite, p2.hnr_street AS p2__hnr_street, p2.suburb AS p2__suburb, p2.city AS p2__city, p2.postcode AS p2__postcode, p2.manual_address_entry AS p2__manual_address_entry, p2.postal_address AS p2__postal_address, p2.current_living_situation_id AS p2__current_living_situation_id, p2.employment_situation_id AS p2__employment_situation_id, p2.dhb_area_id AS p2__dhb_area_id, p2.email AS p2__email, p2.phone_daytime AS p2__phone_daytime, p2.phone_evening AS p2__phone_evening, p2.mobile AS p2__mobile, p2.fax AS p2__fax, p2.emergency_contact_details AS p2__emergency_contact_details, p2.notes AS p2__notes, p2.dob AS p2__dob, p2.nhi AS p2__nhi, p2.gender_id AS p2__gender_id, p2.team_leader_id AS p2__team_leader_id, p2.start_date AS p2__start_date, p2.organisation_id AS p2__organisation_id, p2.role AS p2__role, p2.type AS p2__type, p2.moved_to_and_delete_id AS p2__moved_to_and_delete_id, p2.deleted_date AS p2__deleted_date, p3.id AS p3__id, p3.user_id AS p3__user_id, p3.name AS p3__name, p3.suite AS p3__suite, p3.hnr_street AS p3__hnr_street, p3.suburb AS p3__suburb, p3.city AS p3__city, p3.postcode AS p3__postcode, p3.manual_address_entry AS p3__manual_address_entry, p3.postal_address AS p3__postal_address, p3.current_living_situation_id AS p3__current_living_situation_id, p3.employment_situation_id AS p3__employment_situation_id, p3.dhb_area_id AS p3__dhb_area_id, p3.email AS p3__email, p3.phone_daytime AS p3__phone_daytime, p3.phone_evening AS p3__phone_evening, p3.mobile AS p3__mobile, p3.fax AS p3__fax, p3.emergency_contact_details AS p3__emergency_contact_details, p3.notes AS p3__notes, p3.dob AS p3__dob, p3.nhi AS p3__nhi, p3.gender_id AS p3__gender_id, p3.team_leader_id AS p3__team_leader_id, p3.start_date AS p3__start_date, p3.organisation_id AS p3__organisation_id, p3.role AS p3__role, p3.type AS p3__type, p3.moved_to_and_delete_id AS p3__moved_to_and_delete_id, p3.deleted_date AS p3__deleted_date, p4.id AS p4__id, p4.ps_number AS p4__ps_number, p4.contract_id AS p4__contract_id, c.id AS c__id, c.organisation_id AS c__organisation_id, c.code AS c__code, c.moh_code AS c__moh_code, c.moh_team_type AS c__moh_team_type, c.moh_team_setting AS c__moh_team_setting, c.moh_service_type AS c__moh_service_type, c.moh_target_population AS c__moh_target_population, c.moh_facility_id AS c__moh_facility_id, c.moh_open_date AS c__moh_open_date, c.moh_number AS c__moh_number, c.moh_variation AS c__moh_variation, c.description AS c__description, c.start AS c__start, c.finish AS c__finish, c.cities AS c__cities, c.is_support_contract AS c__is_support_contract, c.is_intensive AS c__is_intensive, COALESCE(p2.name, p3.name) AS p2__0 
FROM peer_engagement p 
LEFT JOIN person p2 ON p.assigned_psw_id = p2.id 
LEFT JOIN person p3 ON p.waiting_psw_id = p3.id 
INNER JOIN peer_number p4 ON p.ps_number_id = p4.id 
INNER JOIN contract c ON p4.contract_id = c.id 
INNER JOIN person p5 ON p.peer_id = p5.id 
WHERE (p.is_intensive = 1 AND p.status_id in (0,1,2,3,4,5,7) 

Explain statement

id  select_type table   type    possible_keys   key key_len ref rows    Extra
1   SIMPLE  p   ref peer_id_idx,ps_number_id_idx,status_id_idx,is_intensive,is_intensive_2  is_intensive    8   const   139 Using where
1   SIMPLE  p2  eq_ref  PRIMARY PRIMARY 4   mabel_mindandbody_co_nz.p.assigned_psw_id   1
1   SIMPLE  p3  eq_ref  PRIMARY PRIMARY 4   mabel_mindandbody_co_nz.p.waiting_psw_id    1
1   SIMPLE  p5  eq_ref  PRIMARY PRIMARY 4   mabel_mindandbody_co_nz.p.peer_id   1   
1   SIMPLE  p4  eq_ref  PRIMARY,contract_id_idx PRIMARY 4   mabel_mindandbody_co_nz.p.ps_number_id  1   
1   SIMPLE  c   eq_ref  PRIMARY PRIMARY 4   mabel_mindandbody_co_nz.p4.contract_id  1   

Configuration is default Ubuntu 12.04:

auto_increment_increment    1
auto_increment_offset   1
autocommit  ON
automatic_sp_privileges ON
back_log    50
basedir /usr
big_tables  OFF
binlog_cache_size   32768
binlog_direct_non_transactional_updates OFF
binlog_format   STATEMENT
binlog_stmt_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 NO_CHAIN
concurrent_insert   AUTO
connect_timeout 10
datadir /var/lib/mysql/
date_format %Y-%m-%d
datetime_format %Y-%m-%d %H:%i:%s
default_storage_engine  InnoDB
default_week_format 0
delay_key_write ON
delayed_insert_limit    100
delayed_insert_timeout  300
delayed_queue_size  1000
div_precision_increment 4
engine_condition_pushdown   ON
error_count 0
event_scheduler OFF
expire_logs_days    10
external_user   
flush   OFF
flush_time  0
foreign_key_checks  ON
ft_boolean_syntax   + -><()~*:""&|
ft_max_word_len 84
ft_min_word_len 4
ft_query_expansion_limit    20
ft_stopword_file    (built-in)
general_log OFF
general_log_file    /var/lib/mysql/mindandbody.log
group_concat_max_len    1024
have_compress   YES
have_crypt  YES
have_csv    YES
have_dynamic_loading    YES
have_geometry   YES
have_innodb YES
have_ndbcluster NO
have_openssl    DISABLED
have_partitioning   YES
have_profiling  YES
have_query_cache    YES
have_rtree_keys YES
have_ssl    DISABLED
have_symlink    YES
hostname    mindandbody
identity    0
ignore_builtin_innodb   OFF
init_connect    
init_file   
init_slave  
innodb_adaptive_flushing    ON
innodb_adaptive_hash_index  ON
innodb_additional_mem_pool_size 8388608
innodb_autoextend_increment 8
innodb_autoinc_lock_mode    1
innodb_buffer_pool_instances    1
innodb_buffer_pool_size 134217728
innodb_change_buffering all
innodb_checksums    ON
innodb_commit_concurrency   0
innodb_concurrency_tickets  500
innodb_data_file_path   ibdata1:10M:autoextend
innodb_data_home_dir    
innodb_doublewrite  ON
innodb_fast_shutdown    1
innodb_file_format  Antelope
innodb_file_format_check    ON
innodb_file_format_max  Antelope
innodb_file_per_table   OFF
innodb_flush_log_at_trx_commit  1
innodb_flush_method 
innodb_force_load_corrupted OFF
innodb_force_recovery   0
innodb_io_capacity  200
innodb_large_prefix OFF
innodb_lock_wait_timeout    50
innodb_locks_unsafe_for_binlog  OFF
innodb_log_buffer_size  8388608
Variable_name   Value
innodb_log_file_size    5242880
innodb_log_files_in_group   2
innodb_log_group_home_dir   ./
innodb_max_dirty_pages_pct  75
innodb_max_purge_lag    0
innodb_mirrored_log_groups  1
innodb_old_blocks_pct   37
innodb_old_blocks_time  0
innodb_open_files   300
innodb_print_all_deadlocks  OFF
innodb_purge_batch_size 20
innodb_purge_threads    0
innodb_random_read_ahead    OFF
innodb_read_ahead_threshold 56
innodb_read_io_threads  4
innodb_replication_delay    0
innodb_rollback_on_timeout  OFF
innodb_rollback_segments    128
innodb_spin_wait_delay  6
innodb_stats_method nulls_equal
innodb_stats_on_metadata    ON
innodb_stats_sample_pages   8
innodb_strict_mode  OFF
innodb_support_xa   ON
innodb_sync_spin_loops  30
innodb_table_locks  ON
innodb_thread_concurrency   0
innodb_thread_sleep_delay   10000
innodb_use_native_aio   OFF
innodb_use_sys_malloc   ON
innodb_version  5.5.37
innodb_write_io_threads 4
insert_id   0
interactive_timeout 28800
join_buffer_size    131072
keep_files_on_create    OFF
key_buffer_size 16777216
key_cache_age_threshold 300
key_cache_block_size    1024
key_cache_division_limit    100
large_files_support ON
large_page_size 0
large_pages OFF
last_insert_id  0
lc_messages en_US
lc_messages_dir /usr/share/mysql/english/
lc_time_names   en_US
license GPL
local_infile    ON
lock_wait_timeout   31536000
locked_in_memory    OFF
log OFF
log_bin OFF
log_bin_trust_function_creators OFF
log_error   
log_output  FILE
log_queries_not_using_indexes   ON
log_slave_updates   OFF
log_slow_queries    OFF
log_warnings    1
long_query_time 10.000000
low_priority_updates    OFF
lower_case_file_system  OFF
lower_case_table_names  0
max_allowed_packet  16777216
max_binlog_cache_size   18446744073709547520
max_binlog_size 104857600
max_binlog_stmt_cache_size  18446744073709547520
max_connect_errors  10
max_connections 60
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_long_data_size  16777216
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
metadata_locks_cache_size   1024
min_examined_row_limit  0
multi_range_count   256
myisam_data_pointer_size    6
myisam_max_sort_file_size   9223372036853727232
myisam_mmap_size    18446744073709551615
myisam_recover_options  BACKUP
myisam_repair_threads   1
myisam_sort_buffer_size 8388608
myisam_stats_method nulls_unequal
myisam_use_mmap OFF
net_buffer_length   16384
net_read_timeout    30
net_retry_count 10
net_write_timeout   60
Variable_name   Value
new OFF
old OFF
old_alter_table OFF
old_passwords   OFF
open_files_limit    1024
optimizer_prune_level   1
optimizer_search_depth  62
optimizer_switch    index_merge=on,index_merge_union=on,index_merge_so...
performance_schema  OFF
performance_schema_events_waits_history_long_size   10000
performance_schema_events_waits_history_size    10
performance_schema_max_cond_classes 80
performance_schema_max_cond_instances   1000
performance_schema_max_file_classes 50
performance_schema_max_file_handles 32768
performance_schema_max_file_instances   10000
performance_schema_max_mutex_classes    200
performance_schema_max_mutex_instances  1000000
performance_schema_max_rwlock_classes   30
performance_schema_max_rwlock_instances 1000000
performance_schema_max_table_handles    100000
performance_schema_max_table_instances  50000
performance_schema_max_thread_classes   50
performance_schema_max_thread_instances 1000
pid_file    /var/run/mysqld/mysqld.pid
plugin_dir  /usr/lib/mysql/plugin/
port    3306
preload_buffer_size 32768
profiling   OFF
profiling_history_size  15
protocol_version    10
proxy_user  
pseudo_slave_mode   OFF
pseudo_thread_id    205661
query_alloc_block_size  8192
query_cache_limit   1048576
query_cache_min_res_unit    4096
query_cache_size    16777216
query_cache_type    ON
query_cache_wlock_invalidate    OFF
query_prealloc_size 8192
rand_seed1  0
rand_seed2  0
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_recovery  OFF
relay_log_space_limit   0
report_host 
report_password 
report_port 3306
report_user 
rpl_recovery_rank   0
secure_auth OFF
secure_file_priv    
server_id   0
skip_external_locking   ON
skip_name_resolve   OFF
skip_networking OFF
skip_show_database  OFF
slave_compressed_protocol   OFF
slave_exec_mode STRICT
slave_load_tmpdir   /tmp
slave_max_allowed_packet    1073741824
slave_net_timeout   3600
slave_skip_errors   OFF
slave_transaction_retries   10
slave_type_conversions  
slow_launch_time    2
slow_query_log  OFF
slow_query_log_file /var/lib/mysql/mindandbody-slow.log
socket  /var/run/mysqld/mysqld.sock
sort_buffer_size    2097152
sql_auto_is_null    OFF
sql_big_selects ON
sql_big_tables  OFF
sql_buffer_result   OFF
sql_log_bin ON
sql_log_off OFF
sql_low_priority_updates    OFF
sql_max_join_size   18446744073709551615
sql_mode    
sql_notes   ON
sql_quote_show_create   ON
sql_safe_updates    OFF
sql_select_limit    18446744073709551615
sql_slave_skip_counter  0
sql_warnings    OFF
ssl_ca  
ssl_capath  
ssl_cert    
ssl_cipher  
ssl_key 
storage_engine  InnoDB
stored_program_cache    256
Variable_name   Value
sync_binlog 0
sync_frm    ON
sync_master_info    0
sync_relay_log  0
sync_relay_log_info 0
system_time_zone    NZDT
table_definition_cache  400
table_open_cache    256
thread_cache_size   8
thread_concurrency  10
thread_handling one-thread-per-connection
thread_stack    196608
time_format %H:%i:%s
time_zone   SYSTEM
timed_mutexes   OFF
timestamp   1441749665
tmp_table_size  16777216
tmpdir  /tmp
transaction_alloc_block_size    8192
transaction_prealloc_size   4096
tx_isolation    REPEATABLE-READ
unique_checks   ON
updatable_views_with_limit  YES
version 5.5.37-0ubuntu0.12.04.1
version_comment (Ubuntu)
version_compile_machine x86_64
version_compile_os  debian-linux-gnu
wait_timeout    28800
warning_count   0

How can I determine if any of my my.ini settings (or lack thereof) reducs the speed of my query unnecessarily?

1 Answer 1

3

A PRIMARY KEY is a UNIQUE KEY; remove the second of these:

PRIMARY KEY (`id`),
UNIQUE KEY `id` (`id`),

You might gets a slight performance improvement by adding this composite index to peer_engagement:

INDEX(is_intensive, status_id)

innodb_buffer_pool_size 134217728

change to about 70% of available RAM unless you are running in a small VM.

join_buffer_size 131072

changing to 1M might help.

Please provide EXPLAIN SELECT ....

LIMIT without an ORDER BY? The engine is free to give you whichever 20 rows it feels like. However, with an ORDER BY may make it slower.

That's an awfully lot of fields to be fetching at once.

Since some of the fields are TEXT, certain optimizations are turned off.

8
  • 70% of RAM also on an Apache/Mysql shared machine?
    – automatem
    Sep 9, 2015 at 2:17
  • INDEX(is_intensive, status_id) brings it from 9000ms to ca 900ms!
    – automatem
    Sep 9, 2015 at 2:22
  • 70% after allowing for any other apps.
    – Rick James
    Sep 9, 2015 at 2:31
  • 900ms -- I have a saying "You can't tune your way out of a performance problem". The add-on is that indexes, query modifications, even app redesign may be needed. You were lucky - add just one index. (I did not see any other useful index prospects.)
    – Rick James
    Sep 9, 2015 at 2:35
  • I have added explain statement. I have also changed query slightly to display slower case where is_intensive is 1. In my opinion this should be faster as is_intensive=1 is a smaller data set.
    – automatem
    Sep 9, 2015 at 2:38

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