I have a complex query that is dynamically assembled based upon search criteria. However, in its simplest form, it is still very slow. The main table it runs against has ~10M records. I ran an explain against a 'base' query and the first row of the explain looks bad (at least to a novice dba like me). I have read a couple tutorials about EXPLAIN, but I still am unsure how to fix the query. So, the first row of the results seems to indicate the problem, but I don't know what to do with it. I couldn't make a composite key that long even if I wanted to and some of the field names in that possible_keys column are not even in the patients table. Any help will be greatly appreciated.
id,select_type,table,type,possible_keys,key,key_len,ref,rows,Extra
1,SIMPLE,patients,range,"PRIMARY,location,appt_date,status,radiologist,contract,lastname,paperwork,images_archived,hash,created,document_attached,all_images_archived,last_image_archived,modality,study_uid,company,second_access,firstname,report_delivered,ssn,order_entry_status,dob,tech,doctor,mobile_facility,accession,location_appt_date,location_created,location_lastname,ref,person_seq",location_appt_date,55,NULL,573534,"Using index condition; Using where; Using temporary; Using filesort"
1,SIMPLE,receivable_transactions,ref,patient_seq,patient_seq,4,ris-dev.patients.seq,1,NULL
1,SIMPLE,patients_dispatch,ref,patient_seq,patient_seq,4,ris-dev.patients.seq,1,NULL
1,SIMPLE,mobile_facility,ref,"unique_index,name,location",unique_index,115,"ris-dev.patients.mobile_facility,const",1,"Using where"
1,SIMPLE,mobile_facility_service_areas,eq_ref,PRIMARY,PRIMARY,4,ris-dev.mobile_facility.service_area,1,NULL
Edit: same EXPLAIN, but reformatted to be easier to read:
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE patients range PRIMARY location_appt_date 55 NULL 573534 Using index condition; Using where; Using temporary; Using filesort
location
appt_date
status
radiologist
contract
lastname
paperwork
images_archived
hash
created
document_attached
all_images_archived
last_image_archived
modality
study_uid
company
second_access
firstname
report_delivered
ssn
order_entry_status
dob
tech
doctor
mobile_facility
accession
location_appt_date
location_created
location_lastname
ref
person_seq
1 SIMPLE receivable_transactions ref patient_seq patient_seq 4 ris-dev.patients.seq 1 NULL
1 SIMPLE patients_dispatch ref patient_seq patient_seq 4 ris-dev.patients.seq 1 NULL
1 SIMPLE mobile_facility ref unique_index unique_index 115 ris-dev.patients.mobile_facility,const 1 Using where
name
location
1 SIMPLE mobile_facility_service_areas eq_ref PRIMARY PRIMARY 4 ris-dev.mobile_facility.service_area 1 NULL
The explain is setup against the following query and table structures.
SELECT patients.fax_in_queue, patients.modality, patients.stat, patients.created, patients.seq, patients.lastname,
patients.firstname, patients.appt_date, patients.status, patients.contract, patients.location, patients.unique_hash,
patients.images_archived, patients.report_delivered, patients.doctor, patients.mobile_facility, patients.history,
patients.dob, patients.all_images_archived, patients.order_entry_status, patients.tech, patients.radiologist,
patients.last_image_archived, patients.state, patients.ss_comments, patients.completed, patients.report_status,
patients.have_paperwork, patients.facility_room_number, patients.facility_station_name, patients.facility_bed,
patients.findings_level, patients.document_attached, patients.study_start, patients.company, patients.accession,
patients.number_images, patients.client_number_images, patients.sex, patients.threshhold , GROUP_CONCAT(CONCAT(CONCAT(receivable_transactions.modifier, " "),
receivable_transactions.description) SEPARATOR ", ") AS rt_desc , patients_dispatch.seq AS doc_seq, patients_dispatch.requisition_last_sent,
patients_dispatch.requisition_signed_by_file_seq, patients_dispatch.requisition_signed, patients_dispatch.order_reason, patients_dispatch.order_comments,
patients_dispatch.order_taken, patients_dispatch.order_tech_last_notified, patients_dispatch.order_tech_in_transit, patients_dispatch.order_tech_in,
patients_dispatch.order_tech_out, patients_dispatch.order_tech_ack, patients_dispatch.addr1 AS d_addr1, patients_dispatch.addr2 AS d_addr2,
patients_dispatch.city AS d_city, patients_dispatch.state AS d_state, patients_dispatch.zip AS d_zip, CONCAT(patients.status, order_tech_out,
order_tech_in, order_tech_in_transit) as pseudo_status , mobile_facility.requisition_fax, mobile_facility.station_list, mobile_facility.address1 as mf_addr1,
mobile_facility.address2 as mf_addr2, mobile_facility.city as mf_city, mobile_facility.state as mf_state, mobile_facility.zip as mf_zip,
mobile_facility.phone as mf_phone, mobile_facility.phone2 as mf_phone2, mobile_facility_service_areas.name as mf_service_area
FROM patients LEFT JOIN receivable_transactions ON patients.seq = receivable_transactions.patient_seq
LEFT JOIN patients_dispatch ON patients.seq = patients_dispatch.patient_seq
LEFT JOIN mobile_facility ON patients.location = mobile_facility.location AND patients.mobile_facility = mobile_facility.name
LEFT JOIN mobile_facility_service_areas ON mobile_facility.service_area = mobile_facility_service_areas.seq
WHERE patients.location = "XYZCompany" AND ((patients.appt_date >= '2020-03-19' AND patients.appt_date <= '2020-03-19 23:59:59')
OR (patients.appt_date <= '2020-03-19' AND patients.status < 'X'))
GROUP BY patients.seq DESC
ORDER BY patients.status, patients.order_entry_status, pseudo_status, patients.order_entry_status,patients.lastname);
CREATE TABLE `patients` (
`seq` int(11) NOT NULL AUTO_INCREMENT,
`person_seq` int(11) NOT NULL,
`firstname` varchar(20) NOT NULL DEFAULT '',
`lastname` varchar(30) NOT NULL DEFAULT '',
`middlename` varchar(20) NOT NULL DEFAULT '',
`ref` varchar(50) NOT NULL DEFAULT '',
`location` varchar(50) NOT NULL DEFAULT '',
`doctor` varchar(50) NOT NULL,
`radiologist` varchar(20) NOT NULL DEFAULT '',
`contract` varchar(50) NOT NULL,
`history` mediumtext NOT NULL,
`dob` varchar(15) NOT NULL DEFAULT '0000-00-00',
`appt_date` date NOT NULL DEFAULT '0000-00-00',
`status` tinyint(4) NOT NULL DEFAULT '0',
`tech` varchar(50) NOT NULL DEFAULT '',
`created` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
`ss_comments` mediumtext NOT NULL,
`mobile_facility` varchar(60) NOT NULL DEFAULT '',
`facility_room_number` varchar(50) NOT NULL,
`facility_bed` varchar(20) NOT NULL,
`facility_station_name` varchar(50) NOT NULL,
`stat` tinyint(4) NOT NULL DEFAULT '0',
`have_paperwork` tinyint(4) NOT NULL DEFAULT '0',
`completed` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
`sex` char(1) NOT NULL DEFAULT '',
`unique_hash` varchar(100) NOT NULL DEFAULT '',
`number_images` int(11) NOT NULL DEFAULT '0',
`client_number_images` int(11) NOT NULL,
`images_archived` tinyint(4) NOT NULL DEFAULT '0',
`completed_fax` varchar(10) NOT NULL DEFAULT '0' COMMENT 'This is the number the completed report is faxed to.',
`report_delivered` tinyint(4) NOT NULL DEFAULT '0',
`report_delivered_time` datetime NOT NULL,
`document_attached` tinyint(4) NOT NULL DEFAULT '0',
`modality` varchar(3) NOT NULL,
`last_image_archived` datetime NOT NULL,
`all_images_archived` tinyint(4) NOT NULL DEFAULT '0',
`fax_in_queue` varchar(12) NOT NULL,
`accession` varchar(100) NOT NULL,
`study_uid` varchar(100) NOT NULL,
`order_entry_status` tinyint(4) NOT NULL,
`compare_to` varchar(15) NOT NULL,
`state` varchar(3) NOT NULL,
`company` int(11) NOT NULL,
`second_access` varchar(50) NOT NULL,
`threshhold` datetime NOT NULL,
`report_status` tinyint(4) NOT NULL,
`second_id` varchar(50) NOT NULL,
`rad_alerted` tinyint(4) NOT NULL,
`assigned` datetime NOT NULL,
`findings_level` tinyint(4) NOT NULL,
`report_viewed` tinyint(4) NOT NULL,
`study_received` datetime NOT NULL,
`study_start` datetime NOT NULL,
`study_end` datetime NOT NULL,
`completed_email` varchar(50) NOT NULL,
`completed_send` varchar(255) NOT NULL,
`ssn` varchar(12) NOT NULL,
`exorder_number` varchar(30) NOT NULL,
`exvisit_number` varchar(30) NOT NULL,
`row_updated` timestamp NOT NULL ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`seq`),
KEY `location` (`location`),
KEY `appt_date` (`appt_date`),
KEY `status` (`status`),
KEY `radiologist` (`radiologist`),
KEY `contract` (`contract`),
KEY `lastname` (`lastname`),
KEY `paperwork` (`have_paperwork`),
KEY `images_archived` (`images_archived`),
KEY `hash` (`unique_hash`),
KEY `created` (`created`),
KEY `document_attached` (`document_attached`),
KEY `all_images_archived` (`all_images_archived`),
KEY `last_image_archived` (`last_image_archived`),
KEY `modality` (`modality`),
KEY `study_uid` (`study_uid`),
KEY `company` (`company`),
KEY `second_access` (`second_access`),
KEY `firstname` (`firstname`),
KEY `report_delivered` (`report_delivered`),
KEY `ssn` (`ssn`),
KEY `order_entry_status` (`order_entry_status`),
KEY `dob` (`dob`),
KEY `tech` (`tech`),
KEY `doctor` (`doctor`),
KEY `mobile_facility` (`mobile_facility`),
KEY `accession` (`accession`),
KEY `location_appt_date` (`location`,`appt_date`),
KEY `location_created` (`location`,`created`),
KEY `location_lastname` (`location`,`lastname`),
KEY `ref` (`ref`),
KEY `person_seq` (`person_seq`)
) ENGINE=InnoDB AUTO_INCREMENT=10242952 DEFAULT CHARSET=latin1;
CREATE TABLE `receivable_transactions` (
`seq` int(11) NOT NULL AUTO_INCREMENT,
`patient_seq` int(11) NOT NULL DEFAULT '0',
`cptcode` varchar(15) NOT NULL DEFAULT '',
`modifier` char(2) NOT NULL DEFAULT '',
`description` varchar(100) NOT NULL DEFAULT '',
`amount` decimal(6,2) NOT NULL DEFAULT '0.00',
`type` char(2) NOT NULL DEFAULT '',
`transaction` varchar(10) NOT NULL DEFAULT '',
`radiologist` varchar(20) NOT NULL DEFAULT '',
`status` tinyint(4) NOT NULL DEFAULT '0',
`completed` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
`created` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
`report_meta_seq` int(11) NOT NULL DEFAULT '0',
`report_header` varchar(255) NOT NULL,
`report_body` blob NOT NULL,
`report_impression` mediumtext NOT NULL,
`report_hide` tinyint(4) NOT NULL,
`radiologist_group` varchar(50) NOT NULL,
`addendum` int(4) NOT NULL DEFAULT '0',
`addendum_type` varchar(20) NOT NULL,
`peer_review` int(4) NOT NULL DEFAULT '0',
`qa_reason` varchar(255) NOT NULL DEFAULT '',
`qa_agree` decimal(2,1) NOT NULL DEFAULT '0.0',
`findings` tinyint(4) NOT NULL,
`comments` mediumtext NOT NULL,
`company` int(11) NOT NULL,
`row_updated` timestamp NOT NULL ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`seq`),
KEY `patient_seq` (`patient_seq`),
KEY `cptcode` (`cptcode`),
KEY `transaction` (`transaction`),
KEY `type` (`type`),
KEY `created` (`created`),
KEY `radiologist` (`radiologist`),
KEY `status` (`status`),
KEY `report_meta_seq` (`report_meta_seq`),
KEY `Billing Check Dropdown` (`status`,`completed`),
KEY `qa_agree` (`qa_agree`),
KEY `peer_review` (`peer_review`),
KEY `addendum` (`addendum`),
KEY `company` (`company`),
KEY `completed` (`completed`)
) ENGINE=InnoDB AUTO_INCREMENT=9380351 DEFAULT CHARSET=latin1;
CREATE TABLE `patients_dispatch` (
`seq` int(11) NOT NULL AUTO_INCREMENT,
`patient_seq` int(11) NOT NULL,
`order_taken` datetime NOT NULL,
`order_taken_by` varchar(50) NOT NULL,
`order_person_calling` varchar(50) NOT NULL,
`order_supervising_physician` varchar(50) NOT NULL,
`order_trip_count` tinyint(4) NOT NULL,
`order_trip_count_max` tinyint(4) NOT NULL,
`order_trip_visit` tinyint(4) NOT NULL,
`order_tech_in` datetime NOT NULL,
`order_tech_out` datetime NOT NULL,
`order_ssn` varchar(12) NOT NULL,
`order_service_request_time` datetime NOT NULL,
`order_reason` varchar(255) NOT NULL,
`order_tech_ack` datetime NOT NULL,
`order_tech_assigned` datetime NOT NULL,
`order_tech_last_notified` datetime NOT NULL,
`requisition_last_sent` datetime NOT NULL,
`requisition_signed` datetime NOT NULL,
`requisition_signed_by` varchar(50) NOT NULL,
`requisition_signed_by_text` varchar(75) NOT NULL,
`requisition_signed_by_file_seq` int(11) NOT NULL,
`order_comments` mediumtext NOT NULL,
`order_tech_in_transit` datetime NOT NULL,
`fasting` tinyint(1) NOT NULL,
`collection_time` time DEFAULT NULL,
`addr1` varchar(100) NOT NULL,
`addr2` varchar(100) NOT NULL,
`city` varchar(30) NOT NULL,
`state` varchar(3) NOT NULL,
`zip` varchar(12) NOT NULL,
`phone` varchar(15) NOT NULL,
`mileage_start` int(11) NOT NULL,
`mileage_end` int(11) NOT NULL,
PRIMARY KEY (`seq`),
KEY `patient_seq` (`patient_seq`)
) ENGINE=InnoDB AUTO_INCREMENT=2261091 DEFAULT CHARSET=latin1;
CREATE TABLE `mobile_facility` (
`seq` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(60) NOT NULL,
`location` varchar(50) DEFAULT NULL,
`address1` varchar(50) NOT NULL,
`address2` varchar(50) NOT NULL,
`city` varchar(50) NOT NULL,
`state` varchar(2) NOT NULL,
`zip` varchar(10) NOT NULL,
`phone` varchar(15) NOT NULL,
`phone2` varchar(15) NOT NULL,
`fax` varchar(110) NOT NULL,
`rads_can_read` text NOT NULL,
`rads_cant_read` text NOT NULL,
`only_techs` text NOT NULL,
`never_modalities` varchar(255) NOT NULL COMMENT 'A serialized list of modalities a facility may not use.',
`station_list` mediumtext NOT NULL,
`email` varchar(255) NOT NULL,
`misc1` varchar(255) NOT NULL,
`latitude` float NOT NULL DEFAULT '0',
`longitude` float NOT NULL DEFAULT '0',
`affiliation` int(11) NOT NULL COMMENT 'mobile_facility_affiliations seq',
`branch` int(11) NOT NULL COMMENT 'mobile_facility_branches seq',
`service_area` int(11) NOT NULL COMMENT 'mobile_facility_service_areas seq',
`other_id` varchar(50) NOT NULL COMMENT 'Usually used for HL7',
`facility_type` varchar(2) DEFAULT NULL,
`no_stat` tinyint(1) NOT NULL DEFAULT '0' COMMENT 'Should the facility allow stat priority on patients?',
`facility_notes` varchar(512) DEFAULT NULL,
`requisition_fax` varchar(110) NOT NULL,
`report_template` text NOT NULL,
`all_orders_stat` tinyint(1) NOT NULL,
`sms_notification` varchar(15) NOT NULL,
`tat` varchar(10) NOT NULL,
`npi` varchar(15) NOT NULL,
`NMXR` tinyint(4) NOT NULL DEFAULT '0',
`billing_type` varchar(10) NOT NULL,
`salesman` varchar(75) NOT NULL,
`created_at` datetime NOT NULL,
`updated_at` datetime NOT NULL,
`default_bill_to` tinyint(4) NOT NULL DEFAULT '0',
PRIMARY KEY (`seq`),
UNIQUE KEY `unique_index` (`name`,`location`),
KEY `name` (`name`),
KEY `location` (`location`)
) ENGINE=InnoDB AUTO_INCREMENT=155104 DEFAULT CHARSET=latin1;
CREATE TABLE `mobile_facility_service_areas` (
`seq` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(50) NOT NULL,
`location` varchar(50) NOT NULL,
PRIMARY KEY (`seq`)
) ENGINE=InnoDB AUTO_INCREMENT=841 DEFAULT CHARSET=latin1;
It's only using the index on location, but that only narrows down the search to about a half a million rows. You'd like it to use an index to further narrow down by the appt_date.
However, the use of OR in your WHERE clause is causing a problem. It can't decide how to use the index.
Here's what I suggest:
Drop the index on location because it's redundant with the other indexes that have location as their first column.
Replace the index on location_appt_date with an index on location_appt_date_status.
ALTER TABLE patients
DROP KEY location,
DROP KEY location_appt_date,
ADD KEY location_appt_date_status (location, appt_date, status);
Refactor the query to use UNION instead of OR:
SELECT ... (all the columns you have) ...
FROM (
SELECT * FROM patients USE INDEX (location_appt_date_status)
WHERE location = 'XYZCompany' AND appt_date >= '2020-03-19' AND appt_date < '2020-03-20'
UNION
SELECT * FROM patients USE INDEX (location_appt_date_status)
WHERE location = 'XYZCompany' AND appt_date <= '2020-03-19' AND status < 'X'
) AS p
LEFT JOIN receivable_transactions FORCE INDEX (patient_seq)
ON p.seq = receivable_transactions.patient_seq
LEFT JOIN patients_dispatch FORCE INDEX (patient_seq)
ON p.seq = patients_dispatch.patient_seq
INNER JOIN mobile_facility FORCE INDEX (unique_index)
ON p.location = mobile_facility.location AND p.mobile_facility = mobile_facility.name
INNER JOIN mobile_facility_service_areas FORCE INDEX (PRIMARY)
ON mobile_facility.service_area = mobile_facility_service_areas.seq
GROUP BY p.seq
ORDER BY p.status, p.order_entry_status, pseudo_status, p.order_entry_status, p.lastname
You might not need all the USE INDEX() / FORCE INDEX() optimizer hints I used. I did those because I was testing with empty tables, and that can confuse the optimizer.
Let me focus on the part that affects optimization the most:
FROM patients AS p
LEFT JOIN receivable_transactions AS rt ON p.seq = rt.patient_seq
LEFT JOIN patients_dispatch AS pd ON p.seq = pd.patient_seq
LEFT JOIN mobile_facility AS mf ON p.location = mf.location
AND p.mobile_facility AS mf = mf.name
LEFT JOIN mobile_facility_service_areas AS sa ON mf.service_area = sa.seq
WHERE p.location = "XYZCompany"
AND ((p.appt_date >= '2020-03-19'
AND p.appt_date <= '2020-03-19 23:59:59')
OR (p.appt_date <= '2020-03-19'
AND p.status < 'X')
)
GROUP BY p.seq DESC
ORDER BY p.status, p.order_entry_status, pseudo_status, p.order_entry_status,
p.lastname);
The biggest issue is the OR. It often prevents most optimizations. The usual fix is to turn it into a UNION:
( SELECT ...
FROM .. JOIN ..
WHERE p.location = "XYZCompany"
AND p.appt_date >= '2020-03-19'
AND p.appt_date < '2020-03-19' + INTERVAL 1 DAY
...
)
UNION ALL
( SELECT ...
FROM .. JOIN ..
WHERE p.location = "XYZCompany"
AND p.appt_date <= '2020-03-19'
AND p.status < 'X'
...
)
Each select can benefit from this composite index on patients:
(location, appt_date, status)
The < 'X' is problematic because two ranges (appt_date and status) cannot both be used effectively. What are the possible values of status? If there is only one value before 'X', say 'M', then this would be much better: p.status = 'M' together with another index: (location, status, appt_date)
SELECT lots of stuff, then GROUP BY p.seq -- This is probably create strange results. (Search for ONLY_FULL_GROUP_BY for more discussion). It may be better to first get the patients.seq values (since that is all you are filtering on), then join to the other tables. This would eliminate the GROUP BY, or at least force you to deal with which row to fetch from each of the other tables.
range location_appt_date 55 573534 Using index condition; Using where; Using temporary; Using filesort -- says
55 = 2+50 (for varchar(50)) + 3 (for date) -- neither is NULL.
Based on the 55, I wonder if it is so well optimized that the OR->UNION is not needed.
"Using index condition" is internally called ICP (Index Condition Pushdown) if you want further understanding.
"Using filesort" may be an understatement -- There are probably two sorts, one for GROUP BY, one for ORDER BY. EXPLAIN FORMAT=JSON SELECT ... would make it clear. (And hence my hint that the GROUP BY should be avoided.
You have some redundant indexes (not relevant to much other than disk space): INDEX(a,b), INDEX(a) --> toss INDEX(a).
patients has an awful number of indexes.
The other tables seem to have adequate indexes for your query.
I have this query:
SELECT
c.*,
cv.views
FROM
content AS c
JOIN
content_views AS cv ON cv.content = c.record_num
WHERE
c.enabled = 1
ORDER BY
cv.views
Quite simple, but it's really slow... Is there a way to make it faster ?
This is my EXPLAIN:
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE c ref enabled_2,enabled enabled 4 const 23947 Using temporary; Using filesort
1 SIMPLE cv eq_ref PRIMARY PRIMARY 4 c.record_num 1
EDIT 2016-02-24
Please note that usually, I use a LIMIT so the number of records returned in the EXPLAIN isn't entirely accurate, however for the sake of simplicity and because the performance doesn't change with the LIMIT or without it, I have removed it.
As requested in the comments, this is the result of my SHOW CREATE TABLE. As you can see, one of my table is MyISAM while the other is InnoDB.
CREATE TABLE `content` (
`title` varchar(255) NOT NULL DEFAULT '',
`filename` varchar(255) NOT NULL DEFAULT '',
`filename_2` varchar(255) NOT NULL,
`filename_3` varchar(255) NOT NULL,
`orig_filename` varchar(255) NOT NULL,
`trailer_filename` varchar(255) NOT NULL,
`thumbnail` varchar(255) NOT NULL DEFAULT '',
`embed` text NOT NULL,
`description` text NOT NULL,
`paysite` int(11) NOT NULL DEFAULT '0',
`keywords` varchar(255) NOT NULL,
`model` varchar(255) NOT NULL DEFAULT '',
`scheduled_date` date NOT NULL DEFAULT '0000-00-00',
`date_added` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
`encoded_date` datetime NOT NULL,
`rating` int(5) NOT NULL DEFAULT '0',
`length` int(11) NOT NULL DEFAULT '0',
`submitter` int(11) NOT NULL DEFAULT '0',
`ip` varchar(15) NOT NULL,
`approved` int(11) NOT NULL DEFAULT '0',
`hotlinked` varchar(1024) NOT NULL,
`plug_url` varchar(255) NOT NULL,
`enabled` int(11) NOT NULL DEFAULT '0',
`main_thumb` int(11) NOT NULL DEFAULT '3',
`xml` varchar(32) NOT NULL,
`photos` int(11) NOT NULL DEFAULT '0',
`mobile` varchar(255) NOT NULL,
`modeltmp` varchar(255) NOT NULL,
`movie_width` int(11) NOT NULL,
`movie_height` int(11) NOT NULL,
`token` varchar(255) DEFAULT NULL,
`source_thumb_url` varchar(255) NOT NULL,
`related` varchar(1024) NOT NULL,
`force_related` varchar(255) NOT NULL,
`record_num` int(11) NOT NULL AUTO_INCREMENT,
`webvtt_src` text NOT NULL,
`category_thumb` int(11) NOT NULL,
`related_date` date NOT NULL,
`publish_ready` tinyint(1) NOT NULL,
PRIMARY KEY (`record_num`),
KEY `encoded_date` (`encoded_date`,`photos`,`enabled`),
KEY `filename` (`filename`),
KEY `scheduled_date` (`scheduled_date`),
KEY `enabled_2` (`enabled`,`length`,`photos`),
KEY `enabled` (`enabled`,`encoded_date`,`photos`),
KEY `rating` (`rating`,`enabled`,`photos`),
KEY `token` (`token`),
KEY `submitter` (`submitter`),
FULLTEXT KEY `keywords` (`keywords`,`title`),
FULLTEXT KEY `title` (`title`),
FULLTEXT KEY `description` (`description`),
FULLTEXT KEY `keywords_2` (`keywords`)
) ENGINE=MyISAM AUTO_INCREMENT=124207 DEFAULT CHARSET=latin1
CREATE TABLE `content_views` (
`views` int(11) NOT NULL,
`content` int(11) NOT NULL,
PRIMARY KEY (`content`),
KEY `views` (`views`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
For this query:
SELECT c.*, cv.views
FROM content c JOIN
content_views cv
ON cv.content = c.record_num
WHERE c.enabled = 1
ORDER BY cv.views;
The best indexes are probably content(enabled, record_num) and content_views(content, views). I am guessing that the performance even with these indexes will be similar to what you have now.
I have a simple join between 3 mysql tables with 1613, 369, and 500 rows respectively. I believe I have everything indexed but the query is still taking 3 seconds or more. My query is:
SELECT
fe.pid, fe.encounter, s.Templates_ID
FROM
(form_encounter fe
JOIN em__structure s ON fe.pc_catid=s.Templates_ID
JOIN em__assemblies a ON s.Massemblies_ID=a.Massemblies_ID)
When I do an EXPLAIN on this I get the following, sorry for the format:
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE a index Massemblies_ID Massemblies_ID 4 NULL 651 Using index; Using temporary; Using filesort
1 SIMPLE s ref Templates_ID,Massemblies_ID Massemblies_ID 4 oaks_1410.a.Massemblies_ID 1
1 SIMPLE fe ref pc_catid pc_catid,4,oaks_1410.s.Templates_ID 100 Using where
Here are my 3 tables, I am trying to put every available clue in place to figure this out:
CREATE TABLE `form_encounter` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`date` datetime DEFAULT NULL,
`reason` longtext,
`facility` longtext,
`facility_id` int(11) NOT NULL DEFAULT '0',
`pid` bigint(20) DEFAULT NULL,
`encounter` bigint(20) DEFAULT NULL,
`onset_date` datetime DEFAULT NULL,
`sensitivity` varchar(30) DEFAULT NULL,
`pc_catid` int(11) NOT NULL DEFAULT '5' COMMENT 'event category from openemr_postcalendar_categories',
`last_stmt_date` date DEFAULT NULL,
`stmt_count` int(11) NOT NULL DEFAULT '0',
`provider_id` int(11) DEFAULT '0' COMMENT 'default and main provider for this visit',
`supervisor_id` int(11) DEFAULT '0' COMMENT 'supervising provider, if any, for this visit',
`invoice_refno` varchar(31) NOT NULL DEFAULT '',
`referral_source` varchar(31) NOT NULL DEFAULT '',
`billing_facility` int(11) NOT NULL DEFAULT '0',
`billing_status` int(11) DEFAULT '10' COMMENT 'see form_encounter_status_codes',
`billing_due_date` date DEFAULT NULL COMMENT 'date an encounter becomes due',
`last_level_billed` int(11) NOT NULL DEFAULT '0' COMMENT '0=none, 1=ins1, 2=ins2, etc',
`last_level_closed` int(11) NOT NULL DEFAULT '0' COMMENT '0=none, 1=ins1, 2=ins2, etc',
`billing_note` text,
`workmans_comp` varchar(1) DEFAULT 'N',
`workmans_comp_claim_number` varchar(40) DEFAULT NULL COMMENT 'workmans comp claim number',
`prior_authorization_number` varchar(40) DEFAULT NULL COMMENT 'prior authorization number for workmans comp',
`auto_accident` varchar(1) DEFAULT 'N',
`auto_accident_state` varchar(2) DEFAULT NULL COMMENT 'auto accident state',
`other_accident` varchar(1) DEFAULT 'N',
`referral_provider_id` int(11) DEFAULT NULL,
`referral_provider_npi` varchar(10) DEFAULT NULL,
`signed_by` int(11) NOT NULL DEFAULT '0' COMMENT 'Provider who signed the encounter',
`pc_templateid` varchar(10) DEFAULT NULL COMMENT 'Physical exam template used for this encounter',
`pc_poptemplateid` int(10) unsigned DEFAULT NULL COMMENT 'Encounter template including data population',
`pc_poptemplatestatus` tinyint(1) unsigned DEFAULT NULL COMMENT 'Whether ecounter has been materially modified from template',
`deleted` tinyint(4) NOT NULL DEFAULT '0' COMMENT 'flag indicates form has been deleted',
PRIMARY KEY (`id`),
UNIQUE KEY `pid_encounter_unique` (`pid`,`encounter`) USING BTREE,
KEY `pc_catid` (`pc_catid`)
) ENGINE=InnoDB AUTO_INCREMENT=1614 DEFAULT CHARSET=latin1 ROW_FORMAT=DYNAMIC
Second table:
CREATE TABLE `em__structure` (
`ID` int(11) unsigned NOT NULL AUTO_INCREMENT,
`Templates_ID` int(11) unsigned DEFAULT NULL,
`Sections_ID` int(11) unsigned DEFAULT NULL,
`Idx` mediumint(4) unsigned DEFAULT '1',
`Massemblies_ID` int(5) unsigned NOT NULL DEFAULT '0',
`EditDate` timestamp NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`ID`),
KEY `Templates_ID` (`Templates_ID`),
KEY `Sections_ID` (`Sections_ID`),
KEY `Massemblies_ID` (`Massemblies_ID`)
) ENGINE=InnoDB
Third table:
CREATE TABLE `em__assemblies` (
`ID` int(11) unsigned NOT NULL AUTO_INCREMENT,
`Massemblies_ID` int(5) unsigned NOT NULL DEFAULT '0',
`Groupings_ID` int(11) unsigned DEFAULT NULL,
`Components_ID` int(11) unsigned DEFAULT NULL,
`Idx` mediumint(4) unsigned DEFAULT '1',
`Sex` char(1) DEFAULT NULL,
`Responsetypes_ID` int(11) DEFAULT NULL,
PRIMARY KEY (`ID`),
KEY `Groupings_ID` (`Groupings_ID`),
KEY `Components_ID` (`Components_ID`),
KEY `Responsetypes_ID` (`Responsetypes_ID`),
KEY `Massemblies_ID` (`Massemblies_ID`)
) ENGINE=InnoDB AUTO_INCREMENT=505 DEFAULT CHARSET=latin1
The joins are all on indexed integer keys.
I have this query that is running slow (16 seconds), it only has 44085 records in the biggest table. Any suggestions or anything that sticks out?
thanks for any help
SELECT u.`vid`, u.`userID`, u.`localConID`, u.`lastran`, u.`laststatus`,
u.`lastmessage`, u.`active`
,u.`autorundaily`, u.`autorunmonthly`, u.`fileslocation`
,c.`conid`, c.`fname`, c.`lname`, c.`homephone`, c.`cellphone` , c.`email` ,
DATE_FORMAT(u.`lastran`,'%d/%m/%y %k:%i') lastranFormatted, u.`retrys`
FROM virtual_alerts_users u
LEFT JOIN virtual_alerts_cons c ON c.referid = u.localConID
WHERE u.userID = 9581
When i do an explain i get::
id | select_type | table | type | possible_keys | key | key_len | ref | rows | extra
1 | SIMPLE | u | ALL | Index 3 | null | null | null | 459 | Using where
1 | SIMPLE | c | ALL | null | null | null | null | 44085 |
The tables look like::
CREATE TABLE `virtual_alerts_users` (
`vid` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT,
`userID` INT(11) NOT NULL DEFAULT '0',
`localConID` VARCHAR(10) NULL DEFAULT NULL,
`encrpytPW` VARCHAR(100) NULL DEFAULT NULL,
`lastran` TIMESTAMP NULL DEFAULT NULL,
`laststatus` INT(11) NULL DEFAULT NULL,
`lastmessage` TEXT NULL,
`active` TINYINT(4) NOT NULL DEFAULT '0',
`autorundaily` TINYINT(4) NOT NULL DEFAULT '0',
`autorunmonthly` TINYINT(4) NOT NULL DEFAULT '0',
`fileslocation` VARCHAR(512) NULL DEFAULT NULL,
`retrys` TINYINT(4) NULL DEFAULT '0',
PRIMARY KEY (`vid`),
UNIQUE INDEX `Index 2` (`localConID`),
INDEX `Index 3` (`userID`)
)
-
CREATE TABLE `virtual_alerts_cons` (
`conid` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT,
`userID` INT(11) UNSIGNED NOT NULL DEFAULT '0',
`vid` INT(11) UNSIGNED NOT NULL DEFAULT '0',
`fname` VARCHAR(50) NULL DEFAULT NULL,
`lname` VARCHAR(50) NULL DEFAULT NULL,
`referid` VARCHAR(10) NULL DEFAULT NULL,
`level` VARCHAR(2) NULL DEFAULT NULL,
`status` VARCHAR(2) NULL DEFAULT NULL,
`lang` VARCHAR(15) NULL DEFAULT NULL,
`homephone` VARCHAR(15) NULL DEFAULT NULL,
`cellphone` VARCHAR(15) NULL DEFAULT NULL,
`address` VARCHAR(255) NULL DEFAULT NULL,
`email` VARCHAR(255) NULL DEFAULT NULL,
`birthday_mon` TINYINT(4) NULL DEFAULT '0',
`birthday_day` TINYINT(4) NULL DEFAULT '0',
`anv_mon` TINYINT(4) NULL DEFAULT '0',
`anv_day` TINYINT(4) NULL DEFAULT '0',
`anv_cnt` TINYINT(4) NULL DEFAULT '0',
`lasthash` BIGINT(20) NULL DEFAULT '0',
`lastupdated` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`conid`),
UNIQUE INDEX `Index 3` (`userID`, `referid`),
INDEX `Index 2` (`userID`),
INDEX `Index 4` (`vid`)
)
You have no index on referid in virtual_alerts_cons, but you do have a combined index on userID and referid.
To force MySQL to use that, change your join condition to:
LEFT JOIN
virtual_alerts_cons c
ON
c.referid = u.localConID
AND
c.userId = u.userID
Alternatively, you could create an additional index on referid.
The table virtual_alerts_con doesn't have the right kind of index for referid.
CREATE TABLE `virtual_alerts_cons` (
`conid` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT,
`userID` INT(11) UNSIGNED NOT NULL DEFAULT '0',
`vid` INT(11) UNSIGNED NOT NULL DEFAULT '0',
`fname` VARCHAR(50) NULL DEFAULT NULL,
`lname` VARCHAR(50) NULL DEFAULT NULL,
`referid` VARCHAR(10) NULL DEFAULT NULL,
`level` VARCHAR(2) NULL DEFAULT NULL,
`status` VARCHAR(2) NULL DEFAULT NULL,
`lang` VARCHAR(15) NULL DEFAULT NULL,
`homephone` VARCHAR(15) NULL DEFAULT NULL,
`cellphone` VARCHAR(15) NULL DEFAULT NULL,
`address` VARCHAR(255) NULL DEFAULT NULL,
`email` VARCHAR(255) NULL DEFAULT NULL,
`birthday_mon` TINYINT(4) NULL DEFAULT '0',
`birthday_day` TINYINT(4) NULL DEFAULT '0',
`anv_mon` TINYINT(4) NULL DEFAULT '0',
`anv_day` TINYINT(4) NULL DEFAULT '0',
`anv_cnt` TINYINT(4) NULL DEFAULT '0',
`lasthash` BIGINT(20) NULL DEFAULT '0',
`lastupdated` TIMESTAMP NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`conid`),
UNIQUE INDEX `Index 3` (`userID`, `referid`),
INDEX `Index 2` (`userID`),
INDEX `Index 5` (`referid`),
INDEX `Index 4` (`vid`)
)
You can also probably change the query to something like this
SELECT u.`vid`, u.`userID`, u.`localConID`, u.`lastran`, u.`laststatus`,
u.`lastmessage`, u.`active`
,u.`autorundaily`, u.`autorunmonthly`, u.`fileslocation`
,c.`conid`, c.`fname`, c.`lname`, c.`homephone`, c.`cellphone` , c.`email` ,
DATE_FORMAT(u.`lastran`,'%d/%m/%y %k:%i') lastranFormatted, u.`retrys`
FROM virtual_alerts_users u
LEFT JOIN virtual_alerts_cons c ON c.referid = u.localConID AND c.userId = 9581
WHERE u.userID = 9581
That will probably take advantage of the Index 3 with both userId and referid.
The explain plan shows you that it is scanning all the rows of the virtual_alerts_con table because it can't use any indexes. Your "Index 3" isn't helping because its a multi-column index. There are restrictions on how you use multi-column indexes.
If you have an index with A, B, C, you can't search on just column C. You can search with just A, or A+B, or A+B+C.
I have written a query and optimized it to extent i can. But still query takes 3 minutes to give output.
Please find the below query.
SELECT ps_product.id_product,ps_product_lang.name,pa.id_product_attribute,
pa.`ean13` AS `a_ean13`,MAX(IF((agl.name LIKE "Color"),al.name,'')) AS Color,
MAX(IF((agl.name LIKE "Size"),al.name,'')) AS Size,
ps_product.price,
ps_product_lang.`description`,`ps_product_lang`.`description_short`,`ps_product_lang`.`meta_description`,
`ps_product_lang`.`meta_keywords`,`ps_product_lang`.`meta_title`,pa.`default_on`,
ps_product.`additional_shipping_cost`,
pa.`reference`,
pa.`price`
FROM
`ps_product`
JOIN ps_product_lang ON ps_product_lang.id_product = ps_product.id_product
join ps_product_attribute pa on pa.`id_product` = ps_product.id_product
LEFT JOIN ps_product_attribute_combination pac ON pac.id_product_attribute = pa.id_product_attribute
LEFT JOIN ps_attribute a ON a.id_attribute = pac.id_attribute
LEFT JOIN ps_attribute_group ag ON ag.id_attribute_group = a.id_attribute_group
LEFT JOIN ps_attribute_lang al ON (a.id_attribute = al.id_attribute AND al.id_lang = 1)
LEFT JOIN ps_attribute_group_lang agl ON (ag.id_attribute_group = agl.id_attribute_group AND agl.id_lang = 1)
GROUP BY pa.id_product_attribute ORDER BY ps_product.id_product;
Here is the explain command output
id select_type table type possible_keys key key_len ref rows Extra
------ ----------- --------------- ------ --------------------------------------------------------------------------- ------------------------------------------ ------- ------------------------------- ------ ---------------------------------
1 SIMPLE ps_product ALL PRIMARY (NULL) (NULL) (NULL) 11378 Using temporary; Using filesort
1 SIMPLE pa ref product_attribute_product,product_default product_attribute_product 4 catalog.ps_product.id_product 2
1 SIMPLE pac ref id_product_attribute id_product_attribute 4 catalog.pa.id_product_attribute 1 Using index
1 SIMPLE a eq_ref PRIMARY PRIMARY 4 catalog.pac.id_attribute 1
1 SIMPLE ag eq_ref PRIMARY PRIMARY 4 catalog.a.id_attribute_group 1 Using index
1 SIMPLE al ref id_lang,ps_attribute_lang_lang_idx,ps_attribute_lang_attribute_idx ps_attribute_lang_attribute_idx 4 catalog.a.id_attribute 1
1 SIMPLE agl ref ps_attribute_group_lang_attributegroup_idx,ps_attribute_group_lang_lang_idx ps_attribute_group_lang_attributegroup_idx 4 catalog.ag.id_attribute_group 1
1 SIMPLE ps_product_lang ref ps_product_lang_product_lang_shop,ps_product_lang_product_idx ps_product_lang_product_lang_shop 4 catalog.ps_product.id_product 3
Is there any way i can improve performance.
Here are the create statements.
CREATE TABLE `ps_product` (
`id_product` int(10) unsigned NOT NULL AUTO_INCREMENT,
`id_supplier` int(10) unsigned DEFAULT NULL,
`id_manufacturer` int(10) unsigned DEFAULT NULL,
`id_category_default` int(10) unsigned DEFAULT NULL,
`id_shop_default` int(10) unsigned NOT NULL DEFAULT '1',
`id_tax_rules_group` int(11) unsigned NOT NULL,
`on_sale` tinyint(1) unsigned NOT NULL DEFAULT '0',
`online_only` tinyint(1) unsigned NOT NULL DEFAULT '0',
`ean13` varchar(13) DEFAULT NULL,
`upc` varchar(12) DEFAULT NULL,
`ecotax` decimal(17,6) NOT NULL DEFAULT '0.000000',
`quantity` int(10) NOT NULL DEFAULT '0',
`minimal_quantity` int(10) unsigned NOT NULL DEFAULT '1',
`price` decimal(20,6) NOT NULL DEFAULT '0.000000',
`wholesale_price` decimal(20,6) NOT NULL DEFAULT '0.000000',
`unity` varchar(255) DEFAULT NULL,
`unit_price_ratio` decimal(20,6) NOT NULL DEFAULT '0.000000',
`additional_shipping_cost` decimal(20,2) NOT NULL DEFAULT '0.00',
`reference` varchar(32) DEFAULT NULL,
`supplier_reference` varchar(32) DEFAULT NULL,
`location` varchar(64) DEFAULT NULL,
`width` decimal(20,6) NOT NULL DEFAULT '0.000000',
`height` decimal(20,6) NOT NULL DEFAULT '0.000000',
`depth` decimal(20,6) NOT NULL DEFAULT '0.000000',
`weight` decimal(20,6) NOT NULL DEFAULT '0.000000',
`out_of_stock` int(10) unsigned NOT NULL DEFAULT '2',
`quantity_discount` tinyint(1) DEFAULT '0',
`customizable` tinyint(2) NOT NULL DEFAULT '0',
`uploadable_files` tinyint(4) NOT NULL DEFAULT '0',
`text_fields` tinyint(4) NOT NULL DEFAULT '0',
`active` tinyint(1) unsigned NOT NULL DEFAULT '0',
`available_for_order` tinyint(1) NOT NULL DEFAULT '1',
`available_date` date NOT NULL,
`condition` enum('new','used','refurbished') NOT NULL DEFAULT 'new',
`show_price` tinyint(1) NOT NULL DEFAULT '1',
`indexed` tinyint(1) NOT NULL DEFAULT '0',
`visibility` enum('both','catalog','search','none') NOT NULL DEFAULT 'both',
`cache_is_pack` tinyint(1) NOT NULL DEFAULT '0',
`cache_has_attachments` tinyint(1) NOT NULL DEFAULT '0',
`is_virtual` tinyint(1) NOT NULL DEFAULT '0',
`cache_default_attribute` int(10) unsigned DEFAULT NULL,
`date_add` datetime NOT NULL,
`date_upd` datetime NOT NULL,
`advanced_stock_management` tinyint(1) NOT NULL DEFAULT '0',
`style_guide_url` varchar(100) DEFAULT NULL,
`sequence` int(10) DEFAULT '0',
`a_createddate` datetime DEFAULT NULL,
`a_createdby` bigint(20) DEFAULT NULL,
`a_modifieddate` datetime DEFAULT NULL,
`a_modifiedby` bigint(20) DEFAULT NULL,
PRIMARY KEY (`id_product`),
KEY `product_supplier` (`id_supplier`),
KEY `product_manufacturer` (`id_manufacturer`),
KEY `id_category_default` (`id_category_default`),
KEY `indexed` (`indexed`),
KEY `date_add` (`date_add`),
KEY `ps_product.active_ind` (`active`)
)
and
CREATE TABLE `ps_product_lang` (
`a_productlangid` int(11) NOT NULL AUTO_INCREMENT,
`id_product` int(10) unsigned NOT NULL,
`id_shop` int(11) unsigned NOT NULL DEFAULT '1',
`id_lang` int(10) unsigned NOT NULL,
`description` text,
`description_short` text,
`link_rewrite` varchar(128) NOT NULL,
`meta_description` varchar(255) DEFAULT NULL,
`meta_keywords` varchar(255) DEFAULT NULL,
`meta_title` varchar(128) DEFAULT NULL,
`name` varchar(128) NOT NULL,
`available_now` varchar(255) DEFAULT NULL,
`available_later` varchar(255) DEFAULT NULL,
`a_createddate` datetime DEFAULT NULL,
`a_createdby` bigint(20) DEFAULT NULL,
`a_modifieddate` datetime DEFAULT NULL,
`a_modifiedby` bigint(20) DEFAULT NULL,
PRIMARY KEY (`a_productlangid`,`id_product`,`id_shop`,`id_lang`),
UNIQUE KEY `ps_product_lang_product_lang_shop` (`id_product`,`id_shop`,`id_lang`),
KEY `id_lang` (`id_lang`),
KEY `name` (`name`),
KEY `ps_product_lang_product_idx` (`id_product`),
KEY `ps_product_lang_shop_idx` (`id_shop`),
CONSTRAINT `ps_product_lang_lang` FOREIGN KEY (`id_lang`) REFERENCES `ps_lang` (`id_lang`) ON DELETE NO ACTION ON UPDATE NO ACTION,
CONSTRAINT `ps_product_lang_product` FOREIGN KEY (`id_product`) REFERENCES `ps_product` (`id_product`) ON DELETE NO ACTION ON UPDATE NO ACTION,
CONSTRAINT `ps_product_lang_shop` FOREIGN KEY (`id_shop`) REFERENCES `ps_shop` (`id_shop`) ON DELETE NO ACTION ON UPDATE NO ACTION
)