refactor(patients) remove subquery from search

This commit updates the SQL used to search for patients, it also updates
the structure of the table to INDEX and FULLTEXT INDEX columns that are
frequently searched on. This update greatly reduces the number of rows
that must be accessed by the search query, reducing the time required
and working to improve the performance on lower end hardware.

server/controllers/medical/patients/index.js

@@ -374,9 +374,9 @@ function searchByName(req, res, next) {
  */
 function find(options) {
   // ensure epected options are parsed appropriately as binary
-  db.convert(options, ['patient_group_uuid']);
+  db.convert(options, ['patient_group_uuid', 'debtor_group_uuid']);
 
-  const filters = new FilterParser(options, { tableAlias: 'q' });
+  const filters = new FilterParser(options, { tableAlias: 'p' });
   const sql = patientEntityQuery(options.detailed);
 
   filters.fullText('display_name');
@@ -389,11 +389,16 @@ function find(options) {
   filters.period('defaultPeriod', 'registration_date');
 
   const patientGroupStatement =
-    '(SELECT COUNT(uuid) FROM assignation_patient where patient_uuid = q.uuid AND patient_group_uuid = ?) = 1';
+    '(SELECT COUNT(uuid) FROM assignation_patient where patient_uuid = p.uuid AND patient_group_uuid = ?) = 1';
   filters.custom('patient_group_uuid', patientGroupStatement);
+  filters.equals('debtor_group_uuid', 'group_uuid', 'd');
+
+  const referenceStatement =
+    `CONCAT_WS('.', '${identifiers.PATIENT.key}', proj.abbr, p.reference) = ?`;
+  filters.custom('reference', referenceStatement);
 
   // @TODO Support ordering query (reference support for limit)?
-  filters.setOrder('ORDER BY q.registration_date DESC');
+  filters.setOrder('ORDER BY p.registration_date DESC');
 
   // applies filters and limits to defined sql, get parameters in correct order
   const query = filters.applyQuery(sql);
@@ -407,40 +412,30 @@ function patientEntityQuery(detailed) {
   // if the find should included detailed results
   if (detailed) {
     detailedColumns = `
-      , q.abbr, q.father_name, q.mother_name, q.profession, q.employer, q.hospital_no,
-      q.spouse, q.spouse_profession, q.spouse_employer, q.religion, q.marital_status,
-      q.phone, q.email, q.address_1, q.address_2, BUID(q.origin_location_id) as origin_location_id,
-      BUID(q.current_location_id) as current_location_id, q.registration_date, q.title, q.notes, q.text,
-      q.account_id, BUID(q.price_list_uuid) as price_list_uuid, q.is_convention, q.locked
+      , proj.abbr, p.father_name, p.mother_name, p.profession, p.employer,
+      p.spouse, p.spouse_profession, p.spouse_employer, p.religion, p.marital_status,
+      p.phone, p.email, p.address_1, p.address_2, BUID(p.origin_location_id) as origin_location_id,
+      BUID(p.current_location_id) as current_location_id, p.registration_date, p.title, p.notes, d.text,
+      dg.account_id, BUID(dg.price_list_uuid) as price_list_uuid, dg.is_convention, dg.locked
     `;
   }
 
   // @TODO Investigate if this origin alias table as 'q' does JOINs on every single patient row
   //       _before_selecting.
   // build the main part of the SQL query
   const sql = `
-    SELECT BUID(q.uuid) AS uuid, q.project_id, q.reference, q.display_name, BUID(q.debtor_uuid) as debtor_uuid,
-      q.sex, q.dob, q.registration_date, BUID(q.debtor_group_uuid) as debtor_group_uuid, q.hospital_no,
-      q.last_visit, q.userName, q.originVillageName, q.originSectorName ${detailedColumns}
-    FROM (
-      SELECT p.uuid, p.project_id, CONCAT_WS('.', '${identifiers.PATIENT.key}', proj.abbr, p.reference) AS reference,
-        p.display_name, p.debtor_uuid AS debtor_uuid, p.sex, p.dob, p.father_name, p.mother_name, p.profession,
-        p.employer, p.spouse, p.spouse_profession, p.spouse_employer, p.religion, p.marital_status, p.phone,
-        p.email, p.address_1, p.address_2, p.origin_location_id, p.current_location_id,
-        p.registration_date, p.title, p.notes, p.hospital_no, p.user_id, d.text, proj.abbr, dg.account_id,
-        dg.price_list_uuid as price_list_uuid, dg.is_convention, dg.locked, MAX(pv.start_date) AS last_visit,
-        dg.uuid AS debtor_group_uuid, u.display_name AS userName, originVillage.name AS originVillageName,
-        originSector.name AS originSectorName
-        FROM patient AS p
-        JOIN project AS proj ON p.project_id = proj.id
-        JOIN debtor AS d ON p.debtor_uuid = d.uuid
-        JOIN debtor_group AS dg ON d.group_uuid = dg.uuid
-        JOIN village as originVillage ON originVillage.uuid = p.origin_location_id
-        JOIN sector AS originSector on originVillage.sector_uuid = originSector.uuid
-        JOIN user AS u ON p.user_id = u.id
-        LEFT JOIN patient_visit AS pv ON pv.patient_uuid = p.uuid
-        GROUP BY p.uuid
-      ) AS q
+    SELECT BUID(p.uuid) AS uuid, p.project_id, CONCAT_WS('.', '${identifiers.PATIENT.key}', proj.abbr, p.reference) AS reference,
+      p.display_name, BUID(p.debtor_uuid) as debtor_uuid,
+      p.sex, p.dob, p.registration_date, BUID(d.group_uuid) as debtor_group_uuid, p.hospital_no,
+      u.display_name as userName, originVillage.name as originVillageName,
+      originSector.name as originSectorName ${detailedColumns}
+    FROM patient AS p
+      JOIN project AS proj ON p.project_id = proj.id
+      JOIN debtor AS d ON p.debtor_uuid = d.uuid
+      JOIN debtor_group AS dg ON d.group_uuid = dg.uuid
+      JOIN village as originVillage ON originVillage.uuid = p.origin_location_id
+      JOIN sector AS originSector on originVillage.sector_uuid = originSector.uuid
+      JOIN user AS u ON p.user_id = u.id
   `;
 
   return sql;

server/models/schema.sql

@@ -1096,7 +1096,7 @@ CREATE TABLE `patient` (
   `debtor_uuid`          BINARY(16) NOT NULL,
   `display_name`         VARCHAR(150) NOT NULL,
   `dob`                  DATE NOT NULL,
-  `dob_unknown_date`      BOOLEAN NOT NULL DEFAULT FALSE,
+  `dob_unknown_date`     BOOLEAN NOT NULL DEFAULT FALSE,
   `father_name`          VARCHAR(150),
   `mother_name`          VARCHAR(150),
   `profession`           VARCHAR(150),
@@ -1128,6 +1128,15 @@ CREATE TABLE `patient` (
   KEY `debtor_uuid` (`debtor_uuid`),
   KEY `origin_location_id` (`origin_location_id`),
   KEY `current_location_id` (`current_location_id`),
+
+  /* @TODO analyse performance implications of indexing frequently searched columns */
+  INDEX `registration_date` (`registration_date`),
+  INDEX `dob` (`dob`),
+  INDEX `sex` (`sex`), 
+
+  /* @TODO fulltext index may degrade INSERT performance over time */
+  FULLTEXT `display_name` (`display_name`),
+
   FOREIGN KEY (`project_id`) REFERENCES `project` (`id`),
   FOREIGN KEY (`debtor_uuid`) REFERENCES `debtor` (`uuid`) ON DELETE CASCADE ON UPDATE CASCADE,
   FOREIGN KEY (`current_location_id`) REFERENCES `village` (`uuid`) ON UPDATE CASCADE,