# Attach an Unlimited Storage Database Using Point-in-Time Recovery (PITR)

> **📝 Note**: PITR is not available in all editions of SingleStore. For more information, see [SingleStore Helios Editions](https://docs.singlestore.com/cloud/getting-started-with-singlestore-helios/about-singlestore-helios/singlestore-helios-editions.md).

The following example demonstrates how to restore an unlimited storage database. The Setup section contains the prerequisite steps needed to create the database and milestones, prior to performing the restore.

## Setup

1\. Create the unlimited storage database `bottomless_db`.

```sql
CREATE DATABASE bottomless_db;
```

2\. Make some updates to `bottomless_db`. In this example, you update the database by creating a table and inserting some data:

```sql
USE bottomless_db;
CREATE TABLE t(a INT);
INSERT INTO t(a) VALUES (10);
INSERT INTO t(a) VALUES (20);
```

3\. Create a milestone (a restore point):

```sql
CREATE MILESTONE "after_second_insert" FOR bottomless_db;
```

4\. Make more updates to `bottomless_db`:

```sql
INSERT INTO t(a) VALUES (30);
INSERT INTO t(a) VALUES (40);
```

Create a second milestone:

```sql
CREATE MILESTONE "after_fourth_insert" FOR bottomless_db;
```

## Perform the Restore

Suppose the values `30` and `40` were inserted into `t` in error. You now want to restore the database to the milestone `after_second_insert`. Detach the database to bring it offline:

```sql
DETACH DATABASE bottomless_db;
```

Then attach the database at the restore point:

```sql
ATTACH DATABASE bottomless_db AT MILESTONE "after_second_insert";
```

You can restore to any point in time for which all the data is available on an object store. It is not necessary to restore to a named milestone.

A database cannot be restored to a PITR milestone taken before the database was dropped. This is because [DROP DATABASE](https://docs.singlestore.com/cloud/reference/sql-reference/data-definition-language-ddl/drop-database.md) removes the PITR history.

## Daylight Saving Time Ambiguity in PITR

When you do a PITR using the following timestamp format,

```sql
ATTACH DATABASE x_db AT TIME 'YYYY-MM-DD HH:MM:SS';
```

the engine uses the server timezone. This can create ambiguity when daylight saving time (DST) changes time by one hour. For example, if you input the time as 1:05AM, was that before or after DST?  The time used by the engine and the user scripts may not match.

The solution is to use Unix time stamps or alternatively, use milestones to avoid this problem.

## Online PITR

The standard approach to PITR is offline because you must detach and then attach the database. As a result, the database cannot be accessed between those two operations. However, for some scenarios, you may not want to take the database offline, but you still want to do a PITR to a new database and manually copy some lost data back to the source database. 

***

Modified at: July 31, 2024

Source: [/cloud/manage-data/database-storage/attach-an-unlimited-storage-database-using-point-in-time-recovery-pitr/](https://docs.singlestore.com/cloud/manage-data/database-storage/attach-an-unlimited-storage-database-using-point-in-time-recovery-pitr/)

(An index of the documentation is available at /llms.txt)