> For the complete documentation index, see [llms.txt](https://upsolver.gitbook.io/content/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://upsolver.gitbook.io/content/reference-1/monitoring/system-catalog/information-schema/columns.md).

# Columns

The **columns** system table includes information about all the columns within all the tables created in your organization. 

From a worksheet within Upsolver, run the following query: 

```sql
SELECT * 
FROM system.information_schema.columns;
-- If you have a lot of columns, you can use LIMIT to reduce the result set 
-- LIMIT 50; 
```

The **system.information\_schema.columns** table includes the following columns:

<table><thead><tr><th width="246">Column</th><th width="129.33333333333331">Type</th><th>Description</th></tr></thead><tbody><tr><td>catalog</td><td>string</td><td>The name of the catalog used to store the parent table.</td></tr><tr><td>data_type</td><td>string</td><td>The type that was automatically inferred by  Upsolver when the data was ingested, or the type that was specified by the user who created the table.</td></tr><tr><td>first_seen_on</td><td>datetime</td><td>This is the date and time when data first arrives in the column.</td></tr><tr><td>is_primary_key</td><td>Boolean</td><td>Returns <strong>TRUE</strong> or <strong>FALSE</strong> to indicate if this is a primary key column. </td></tr><tr><td>last_seen_on</td><td>datetime</td><td>The date and time when data last arrived in this column. </td></tr><tr><td>name</td><td>string</td><td>The name of the column that was inferred on initial ingestion by Upsolver or defined by the user on creation.</td></tr><tr><td>schema</td><td>string</td><td>The name of the schema in which the parent table was created.</td></tr><tr><td>table</td><td>string</td><td>The name of the table that was defined by the user on creation.</td></tr><tr><td><p>type_evolution</p><p>[ </p><p>       data_type (string),</p><p>       first_seen_on (string),</p><p>       last_seen_on (string)</p><p>]</p></td><td>string</td><td><p>The history of data type changes discovered during ingestion. Upsolver automatically detects a changed type within a column and records the previous type, and when it was first and last seen. For more information, </p><p>see <a href="/spaces/KpsWQIZ3OMa5ck6PLmO4/pages/o2mv8flFgqMCxJlOZ7vd">Schema Detection and Evolution</a>.</p></td></tr></tbody></table>

{% hint style="info" %}
For more information on tables and columns, please refer to the [Tables](/content/reference-1/sql-commands/tables.md) SQL command reference.&#x20;
{% endhint %}


---

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