# ALTER TABLE SQUASH PARTITIONS

ALTER TABLE SQUASH PARTITIONS SQL keyword reference documentation.

Merges partition parts back into the physical partition.

This SQL keyword is designed to use for downgrading QuestDB to a version earlier
than 7.2, when
[partition split](/docs/concepts/partitions/#partition-splitting-and-squashing)
is introduced. Squashing partition parts makes the database compatible with
earlier QuestDB versions.

## Syntax

```questdb-sql
ALTER TABLE tableName SQUASH PARTITIONS;
```

## Examples

The SQL keyword [SHOW PARTITIONS](/docs/query/sql/show/) can be used to
display partition split details.

For example, Let's consider the following table `x` containing split partitions:

```
SHOW PARTITIONS FROM x;
```

| index | partitionBy | name                     | minTimestamp                | maxTimestamp                | numRows | diskSize | diskSizeHuman | readOnly | active | attached | detached | attachable |
| ----- | ----------- | ------------------------ | --------------------------- | --------------------------- | ------- | -------- | ------------- | -------- | ------ | -------- | -------- | ---------- |
| 0     | DAY         | 2023-02-04               | 2023-02-04T00:00:00.000000Z | 2023-02-04T23:59:59.940000Z | 1440000 | 71281136 | 68.0 MiB      | FALSE    | FALSE  | TRUE     | FALSE    | FALSE      |
| 1     | DAY         | 2023-02-05               | 2023-02-05T00:00:00.000000Z | 2023-02-05T20:59:59.880000Z | 1259999 | 65388544 | 62.4 MiB      | FALSE    | FALSE  | TRUE     | FALSE    | FALSE      |
| 2     | DAY         | 2023-02-05T205959-880001 | 2023-02-05T20:59:59.940000Z | 2023-02-05T21:59:59.940000Z | 60002   | 83886080 | 80.0 MiB      | FALSE    | TRUE   | TRUE     | FALSE    | FALSE      |

The table is partition by day and there are two partitions for `2023-02-05` as a
result of partition split.

To merge the two partitions:

```questdb-sql
ALTER TABLE x SQUASH PARTITIONS;

SHOW PARTITIONS FROM x;
```

| index | partitionBy | name       | minTimestamp                | maxTimestamp                | numRows | diskSize | diskSizeHuman | readOnly | active | attached | detached | attachable |
| ----- | ----------- | ---------- | --------------------------- | --------------------------- | ------- | -------- | ------------- | -------- | ------ | -------- | -------- | ---------- |
| 0     | DAY         | 2023-02-04 | 2023-02-04T00:00:00.000000Z | 2023-02-04T23:59:59.940000Z | 1440000 | 71281136 | 68.0 MiB      | FALSE    | FALSE  | TRUE     | FALSE    | FALSE      |
| 1     | DAY         | 2023-02-05 | 2023-02-05T00:00:00.000000Z | 2023-02-05T21:59:59.940000Z | 1320001 | 65388544 | 62.4 MiB      | FALSE    | TRUE   | TRUE     | FALSE    | FALSE      |