update timestamp format to use UnixNano

Author: kafka1991

buffer.go

@@ -553,8 +553,8 @@ func (b *buffer) TimestampColumn(name string, ts time.Time) *buffer {
 		return b
 	}
 	b.WriteByte('=')
-	b.writeInt(ts.UnixMicro())
-	b.WriteByte('t')
+	b.writeInt(ts.UnixNano())
+	b.WriteByte('n')
 	b.hasFields = true
 	return b
 }

buffer_test.go

@@ -117,7 +117,7 @@ func TestTimestampSerialization(t *testing.T) {
 			assert.NoError(t, err)
 
 			// Check the buffer
-			expected := []byte("my_test_table a_col=" + strconv.FormatInt(tc.val.UnixMicro(), 10) + "t\n")
+			expected := []byte("my_test_table a_col=" + strconv.FormatInt(tc.val.UnixNano(), 10) + "n\n")
 			assert.Equal(t, expected, buf.Messages())
 		})
 	}

integration_test.go

@@ -139,7 +139,7 @@ func setupQuestDB0(ctx context.Context, auth ilpAuthType, setupProxy bool) (*que
 	}
 	uniqueNetworkName := fmt.Sprintf("%s-%d", networkName, time.Now().UnixNano())
 	req := testcontainers.ContainerRequest{
-		Image:          "questdb/questdb:9.0.2",
+		Image:          "questdb/questdb:9.0.3",
 		ExposedPorts:   []string{"9000/tcp", "9009/tcp"},
 		WaitingFor:     wait.ForHTTP("/settings").WithPort("9000"),
 		Networks:       []string{uniqueNetworkName},