diff --git a/storage/clickhousespanstore/heap.go b/storage/clickhousespanstore/heap.go
index b7005e83..95956888 100644
--- a/storage/clickhousespanstore/heap.go
+++ b/storage/clickhousespanstore/heap.go
@@ -12,10 +12,11 @@ var (
 )
 
 type heapItem struct {
-	startTime time.Time
-	worker    *WriteWorker
+	pushTime time.Time
+	worker   *WriteWorker
 }
 
+// workerHeap is a heap for WriteWorkers where worker's push time is the key.
 type workerHeap struct {
 	elems   *[]*heapItem
 	indexes map[*WriteWorker]int
@@ -31,8 +32,8 @@ func newWorkerHeap(cap int) workerHeap {
 
 func (workerHeap workerHeap) AddWorker(worker *WriteWorker) {
 	heap.Push(workerHeap, heapItem{
-		worker:    worker,
-		startTime: time.Now(),
+		worker:   worker,
+		pushTime: time.Now(),
 	})
 }
 
@@ -56,7 +57,7 @@ func (workerHeap workerHeap) Len() int {
 }
 
 func (workerHeap workerHeap) Less(i, j int) bool {
-	return (*workerHeap.elems)[i].startTime.Before((*workerHeap.elems)[j].startTime)
+	return (*workerHeap.elems)[i].pushTime.Before((*workerHeap.elems)[j].pushTime)
 }
 
 func (workerHeap workerHeap) Swap(i, j int) {
diff --git a/storage/clickhousespanstore/params.go b/storage/clickhousespanstore/params.go
index cea92c82..08f7943c 100644
--- a/storage/clickhousespanstore/params.go
+++ b/storage/clickhousespanstore/params.go
@@ -7,6 +7,7 @@ import (
 	"github.com/hashicorp/go-hclog"
 )
 
+// WriteParams contains parameters that are shared between WriteWorker`s
 type WriteParams struct {
 	logger     hclog.Logger
 	db         *sql.DB
diff --git a/storage/clickhousespanstore/pool.go b/storage/clickhousespanstore/pool.go
index 36200b5d..9ee55325 100644
--- a/storage/clickhousespanstore/pool.go
+++ b/storage/clickhousespanstore/pool.go
@@ -10,6 +10,9 @@ import (
 
 const maxSpanCount int = 10000000
 
+// WriteWorkerPool is a worker pool for writing batches of spans.
+// Given a new batch, WriteWorkerPool creates a new WriteWorker.
+// If the number of currently processed spans if more than maxSpanCount, then the oldest worker is removed.
 type WriteWorkerPool struct {
 	params *WriteParams
 
@@ -19,9 +22,8 @@ type WriteWorkerPool struct {
 
 	totalSpanCount int
 	mutex          sync.Mutex
-	// TODO: rewrite on using heap
-	workers    workerHeap
-	workerDone chan *WriteWorker
+	workers        workerHeap
+	workerDone     chan *WriteWorker
 }
 
 func NewWorkerPool(params *WriteParams) WriteWorkerPool {
@@ -31,8 +33,7 @@ func NewWorkerPool(params *WriteParams) WriteWorkerPool {
 		done:    sync.WaitGroup{},
 		batches: make(chan []*model.Span),
 
-		mutex: sync.Mutex{},
-		// TODO: decide on size
+		mutex:      sync.Mutex{},
 		workers:    newWorkerHeap(100),
 		workerDone: make(chan *WriteWorker),
 	}
diff --git a/storage/clickhousespanstore/worker.go b/storage/clickhousespanstore/worker.go
index 782c53a1..a18efa26 100644
--- a/storage/clickhousespanstore/worker.go
+++ b/storage/clickhousespanstore/worker.go
@@ -14,6 +14,9 @@ import (
 
 var delays = []int{2, 3, 5, 8}
 
+// WriteWorker writes spans to CLickHouse.
+// Given a batch of spans, WriteWorker attempts to write them to database.
+// Interval in seconds between attempts changes due to delays slice, then it remains the same as the last value in delays.
 type WriteWorker struct {
 	params *WriteParams