Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://amazonaws-china.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# SVV\$1DISKUSAGE
<a name="r_SVV_DISKUSAGE"></a>

Amazon Redshift creates the SVV\$1DISKUSAGE system view by joining the STV\$1TBL\$1PERM and STV\$1BLOCKLIST tables. The SVV\$1DISKUSAGE view contains information about data allocation for the tables in a database.

Use aggregate queries with SVV\$1DISKUSAGE, as the following examples show, to determine the number of disk blocks allocated per database, table, slice, or column. Each data block uses 1 MB. You can also use [STV\$1PARTITIONS](r_STV_PARTITIONS.md) to view summary information about disk utilization.

SVV\$1DISKUSAGE is visible only to superusers. For more information, see [Visibility of data in system tables and views](cm_chap_system-tables.md#c_visibility-of-data).

**Note**  
This view is only available when querying provisioned clusters.

## Table columns
<a name="r_SVV_DISKUSAGE-table-rows"></a>

[\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/redshift/latest/dg/r_SVV_DISKUSAGE.html)

## Sample queries
<a name="r_SVV_DISKUSAGE-sample-queries"></a>

SVV\$1DISKUSAGE contains one row per allocated disk block, so a query that selects all the rows potentially returns a very large number of rows. We recommend using only aggregate queries with SVV\$1DISKUSAGE.

Return the highest number of blocks ever allocated to column 6 in the USERS table (the EMAIL column):

```
select db_id, trim(name) as tablename, max(blocknum)
from svv_diskusage
where name='users' and col=6
group by db_id, name;

db_id  | tablename | max
--------+-----------+-----
175857 | users     |   2
(1 row)
```

The following query returns similar results for all of the columns in a large 10-column table called SALESNEW. (The last three rows, for columns 10 through 12, are for the hidden metadata columns.) 

```
select db_id, trim(name) as tablename, col, tbl, max(blocknum)
from svv_diskusage
where name='salesnew'
group by db_id, name, col, tbl
order by db_id, name, col, tbl;

db_id  | tablename  | col |  tbl   | max
--------+------------+-----+--------+-----
175857 | salesnew   |   0 | 187605 | 154
175857 | salesnew   |   1 | 187605 | 154
175857 | salesnew   |   2 | 187605 | 154
175857 | salesnew   |   3 | 187605 | 154
175857 | salesnew   |   4 | 187605 | 154
175857 | salesnew   |   5 | 187605 |  79
175857 | salesnew   |   6 | 187605 |  79
175857 | salesnew   |   7 | 187605 | 302
175857 | salesnew   |   8 | 187605 | 302
175857 | salesnew   |   9 | 187605 | 302
175857 | salesnew   |  10 | 187605 |   3
175857 | salesnew   |  11 | 187605 |   2
175857 | salesnew   |  12 | 187605 | 296
(13 rows)
```