diff --git a/pkg/db/db_init.go b/pkg/db/db_init.go
index 150b543b82c..b8eac1bdfca 100644
--- a/pkg/db/db_init.go
+++ b/pkg/db/db_init.go
@@ -6,89 +6,90 @@ import (
 
 func (d *dbConn) DBInit() {
 	db := d.db
-	_, err := db.Exec("CREATE TABLE IF NOT EXISTS studies" +
-		"(id CHAR(16) PRIMARY KEY, " +
-		"name VARCHAR(255), " +
-		"owner VARCHAR(255), " +
-		"optimization_type TINYINT, " +
-		"optimization_goal DOUBLE, " +
-		"parameter_configs TEXT, " +
-		"tags TEXT, " +
-		"objective_value_name VARCHAR(255), " +
-		"metrics TEXT, " +
-		"job_id TEXT)")
+	_, err := db.Exec(`CREATE TABLE IF NOT EXISTS studies
+		(id CHAR(16) PRIMARY KEY,
+		name VARCHAR(255),
+		owner VARCHAR(255),
+		optimization_type TINYINT,
+		optimization_goal DOUBLE,
+		parameter_configs TEXT,
+		tags TEXT,
+		objective_value_name VARCHAR(255),
+		metrics TEXT,
+		job_id TEXT)`)
 	if err != nil {
 		log.Fatalf("Error creating studies table: %v", err)
 	}
 
-	_, err = db.Exec("CREATE TABLE IF NOT EXISTS study_permissions" +
-		"(study_id CHAR(16) NOT NULL, " +
-		"access_permission VARCHAR(255), " +
-		"PRIMARY KEY (study_id, access_permission))")
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS study_permissions
+		(study_id CHAR(16) NOT NULL,
+		access_permission VARCHAR(255),
+		PRIMARY KEY (study_id, access_permission))`)
 	if err != nil {
 		log.Fatalf("Error creating study_permissions table: %v", err)
 	}
 
-	_, err = db.Exec("CREATE TABLE IF NOT EXISTS trials" +
-		"(id CHAR(16) PRIMARY KEY, " +
-		"study_id CHAR(16), " +
-		"parameters TEXT, " +
-		"objective_value VARCHAR(255), " +
-		"tags TEXT, " +
-		"FOREIGN KEY(study_id) REFERENCES studies(id))")
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS trials
+		(id CHAR(16) PRIMARY KEY,
+		study_id CHAR(16),
+		parameters TEXT,
+		objective_value VARCHAR(255),
+		tags TEXT,
+		FOREIGN KEY(study_id) REFERENCES studies(id))`)
 	if err != nil {
 		log.Fatalf("Error creating trials table: %v", err)
 	}
 
-	_, err = db.Exec("CREATE TABLE IF NOT EXISTS workers" +
-		"(id CHAR(16) PRIMARY KEY, " +
-		"study_id CHAR(16), " +
-		"trial_id CHAR(16), " +
-		"type VARCHAR(255), " +
-		"status TINYINT, " +
-		"template_path TEXT, " +
-		"tags TEXT, " +
-		"FOREIGN KEY(study_id) REFERENCES studies(id), " +
-		"FOREIGN KEY(trial_id) REFERENCES trials(id))")
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS workers
+		(id CHAR(16) PRIMARY KEY,
+		study_id CHAR(16),
+		trial_id CHAR(16),
+		type VARCHAR(255),
+		status TINYINT,
+		template_path TEXT,
+		tags TEXT,
+		FOREIGN KEY(study_id) REFERENCES studies(id),
+		FOREIGN KEY(trial_id) REFERENCES trials(id))`)
 	if err != nil {
 		log.Fatalf("Error creating workers table: %v", err)
 	}
 
-	_, err = db.Exec("CREATE TABLE IF NOT EXISTS worker_metrics" +
-		"(worker_id CHAR(16) NOT NULL, " +
-		"id INT AUTO_INCREMENT PRIMARY KEY, " +
-		"time DATETIME(6), " +
-		"name VARCHAR(255), " +
-		"value TEXT, " +
-		"is_objective TINYINT)")
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS worker_metrics
+		(worker_id CHAR(16) NOT NULL,
+		id INT AUTO_INCREMENT PRIMARY KEY,
+		time DATETIME(6),
+		name VARCHAR(255),
+		value TEXT,
+		is_objective TINYINT,
+		FOREIGN KEY (worker_id) REFERENCES workers(id) ON DELETE CASCADE)`)
 	if err != nil {
 		log.Fatalf("Error creating worker_metrics table: %v", err)
 	}
 
-	_, err = db.Exec("CREATE TABLE IF NOT EXISTS worker_lastlogs" +
-		"(worker_id CHAR(16) PRIMARY KEY, " +
-		"time DATETIME(6), " +
-		"value TEXT)")
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS worker_lastlogs
+		(worker_id CHAR(16) PRIMARY KEY,
+		time DATETIME(6),
+		FOREIGN KEY (worker_id) REFERENCES workers(id) ON DELETE CASCADE)`)
 	if err != nil {
 		log.Fatalf("Error creating worker_lastlogs table: %v", err)
 	}
 
-	_, err = db.Exec("CREATE TABLE IF NOT EXISTS suggestion_param" +
-		"(id CHAR(16) PRIMARY KEY," +
-		"suggestion_algo TEXT, " +
-		"study_id CHAR(16), " +
-		"parameters TEXT, " +
-		"FOREIGN KEY(study_id) REFERENCES studies(id))")
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS suggestion_param
+		(id CHAR(16) PRIMARY KEY,
+		suggestion_algo TEXT,
+		study_id CHAR(16),
+		parameters TEXT,
+		FOREIGN KEY(study_id) REFERENCES studies(id))`)
 	if err != nil {
 		log.Fatalf("Error creating suggestion_param table: %v", err)
 	}
 
-	_, err = db.Exec("CREATE TABLE IF NOT EXISTS earlystop_param" +
-		"(id CHAR(16) PRIMARY KEY, " +
-		"earlystop_argo TEXT, " +
-		"study_id CHAR(16), " +
-		"parameters TEXT, " +
-		"FOREIGN KEY(study_id) REFERENCES studies(id))")
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS earlystop_param
+		(id CHAR(16) PRIMARY KEY,
+		earlystop_argo TEXT,
+		study_id CHAR(16),
+		parameters TEXT,
+		FOREIGN KEY(study_id) REFERENCES studies(id))`)
 	if err != nil {
 		log.Fatalf("Error creating earlystop_param table: %v", err)
 	}
diff --git a/pkg/db/interface.go b/pkg/db/interface.go
index 01e554e3ae4..61b27b418ff 100644
--- a/pkg/db/interface.go
+++ b/pkg/db/interface.go
@@ -455,18 +455,61 @@ func (d *dbConn) GetWorkerLogs(id string, opts *GetWorkerLogOpts) ([]*WorkerLog,
 	return result, nil
 }
 
-func (d *dbConn) getWorkerLastlog(id string, value *string) (*time.Time, error) {
-	var lastTimestamp string
+func (d *dbConn) getWorkerLastlogs(id string) (time.Time, []*WorkerLog, error) {
+	var timeStr string
+	var timeVal time.Time
 	var err error
 
-	if value != nil {
-		row := d.db.QueryRow("SELECT time, value FROM worker_lastlogs WHERE worker_id = ?", id)
-		err = row.Scan(&lastTimestamp, value)
-	} else {
-		row := d.db.QueryRow("SELECT time FROM worker_lastlogs WHERE worker_id = ?", id)
-		err = row.Scan(&lastTimestamp)
+	// Use LEFT JOIN to ensure a result even if there's no matching
+	// in worker_metrics.
+	rows, err := d.db.Query(
+		`SELECT worker_lastlogs.time, name, value FROM worker_lastlogs
+                 LEFT JOIN worker_metrics
+                 ON (worker_lastlogs.worker_id = worker_metrics.worker_id AND worker_lastlogs.time = worker_metrics.time)
+                 WHERE worker_lastlogs.worker_id = ?`, id)
+	if err != nil {
+		return timeVal, nil, err
 	}
 
+	var result []*WorkerLog
+	for rows.Next() {
+		log1 := new(WorkerLog)
+		var thisTime string
+		var name, value sql.NullString
+
+		err := rows.Scan(&thisTime, &name, &value)
+		if err != nil {
+			log.Printf("Error scanning log: %v", err)
+			continue
+		}
+		if timeStr == "" {
+			timeStr = thisTime
+			timeVal, err = time.Parse(mysqlTimeFmt, timeStr)
+			if err != nil {
+				log.Printf("Error parsing time %s: %v", timeStr, err)
+				return timeVal, nil, err
+			}
+		} else if timeStr != thisTime {
+			log.Printf("Unexpected query result %s != %s",
+				timeStr, thisTime)
+		}
+		log1.Time = timeVal
+		if !name.Valid {
+			continue
+		}
+		(*log1).Name = name.String
+		(*log1).Value = value.String
+		result = append(result, log1)
+	}
+	return timeVal, result, nil
+}
+
+func (d *dbConn) GetWorkerTimestamp(id string) (*time.Time, error) {
+	var lastTimestamp string
+
+	row := d.db.QueryRow("SELECT time FROM worker_lastlogs WHERE worker_id = ?", id)
+	err := row.Scan(&lastTimestamp)
+
 	switch {
 	case err == sql.ErrNoRows:
 		return nil, nil
@@ -483,10 +526,6 @@ func (d *dbConn) getWorkerLastlog(id string, value *string) (*time.Time, error)
 	}
 }
 
-func (d *dbConn) GetWorkerTimestamp(id string) (*time.Time, error) {
-	return d.getWorkerLastlog(id, nil)
-}
-
 func (d *dbConn) storeWorkerLog(workerID string, time string, metricsName string, metricsValue string, objectiveValueName string) error {
 	isObjective := 0
 	if metricsName == objectiveValueName {
@@ -502,9 +541,8 @@ func (d *dbConn) storeWorkerLog(workerID string, time string, metricsName string
 
 func (d *dbConn) StoreWorkerLogs(workerID string, logs []*api.MetricsLog) error {
 	var lasterr error
-	var lastValue string
 
-	dbT, err := d.getWorkerLastlog(workerID, &lastValue)
+	dbT, lastLogs, err := d.getWorkerLastlogs(workerID)
 	if err != nil {
 		log.Printf("Error getting last log timestamp: %v", err)
 	}
@@ -519,10 +557,14 @@ func (d *dbConn) StoreWorkerLogs(workerID string, logs []*api.MetricsLog) error
 		return err
 	}
 
+	// Store logs when
+	//   1. a log is newer than dbT, or,
+	//   2. a log is not yet in the DB when the timestamps are equal
 	var formattedTime string
-	var ls []string
+	var lastTime time.Time
 	for _, mlog := range logs {
 		metricsName := mlog.Name
+	logLoop:
 		for _, mv := range mlog.Values {
 			t, err := time.Parse(time.RFC3339Nano, mv.Time)
 			if err != nil {
@@ -530,48 +572,40 @@ func (d *dbConn) StoreWorkerLogs(workerID string, logs []*api.MetricsLog) error
 				lasterr = err
 				continue
 			}
-			if dbT != nil && !t.After(*dbT) {
+			if t.Before(dbT) {
 				// dbT is from mysql and has microsec precision.
 				// This code assumes nanosec fractions are rounded down.
 				continue
 			}
 			// use UTC as mysql DATETIME lacks timezone
 			formattedTime = t.UTC().Format(mysqlTimeFmt)
-			if dbT != nil {
-				// Parse again to get rounding effect
-				//reparsed_time, err := time.Parse(mysqlTimeFmt, formattedTime)
-				//if reparsed_time == *dbT {
-				//	if mv.Value == lastValue {
-				//	 stored_logs are already in DB
-				//	 This assignment ensures the remaining
-				//	 logs will be stored in DB.
-				//		dbT = nil
-				//		continue
-				//	}
-				//	// We don't know this is necessary or not yet.
-				//	stored_logs = append(stored_logs, &mv.Value)
-				//	continue
-				//}
-				// (reparsed_time > *dbT) can be assumed
-				err = d.storeWorkerLog(workerID,
-					dbT.UTC().Format(mysqlTimeFmt),
-					metricsName, mv.Value,
-					objectiveValueName)
+			if !dbT.IsZero() {
+				// Parse again to get rounding effect, otherwise
+				// the next comparison will be almost always false.
+				reparsed_time, err := time.Parse(mysqlTimeFmt, formattedTime)
 				if err != nil {
-					log.Printf("Error storing log %s: %v", mv.Value, err)
+					log.Printf("Error parsing time %s: %v", formattedTime, err)
 					lasterr = err
+					continue
 				}
-				dbT = nil
-			} else {
-				err = d.storeWorkerLog(workerID,
-					formattedTime,
-					metricsName, mv.Value,
-					objectiveValueName)
-				if err != nil {
-					log.Printf("Error storing log %s: %v", mv.Value, err)
-					lasterr = err
+				if reparsed_time == dbT {
+					for _, l := range lastLogs {
+						if l.Name == metricsName && l.Value == mv.Value {
+							continue logLoop
+						}
+					}
 				}
 			}
+			err = d.storeWorkerLog(workerID,
+				formattedTime,
+				metricsName, mv.Value,
+				objectiveValueName)
+			if err != nil {
+				log.Printf("Error storing log %s: %v", mv.Value, err)
+				lasterr = err
+			} else if t.After(lastTime) {
+				lastTime = t
+			}
 		}
 	}
 	if lasterr != nil {
@@ -579,9 +613,10 @@ func (d *dbConn) StoreWorkerLogs(workerID string, logs []*api.MetricsLog) error
 		// would be lost.
 		return lasterr
 	}
-	if len(ls) == 2 {
-		_, err = d.db.Exec("REPLACE INTO worker_lastlogs VALUES (?, ?, ?)",
-			workerID, formattedTime, ls[1])
+	if !lastTime.IsZero() {
+		formattedTime = lastTime.UTC().Format(mysqlTimeFmt)
+		_, err = d.db.Exec("REPLACE INTO worker_lastlogs VALUES (?, ?)",
+			workerID, formattedTime)
 	}
 	return err
 }