---
title: "blobexpansion drop-columns"
slug: "blobexpansion-drop-columns"
tags: ["5.5"]
updated: 2026-10-27T23:00:54Z
published: 2026-10-27T23:00:54Z
canonical: "docs.vastdata.com/blobexpansion-drop-columns"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# blobexpansion drop-columns

This command removes (drops) fields from being parsed from Kafka events. The column in the target database table remains, and any data in the column for messages parsed prior to it being dropped remains. Parsing of subsequent messages will not include the dropped fields.

## Usage

```plaintext
vcli: admin> blobexpansion drop-columns --database-name DATABASE
                                        --table-name TABLE 
                                        --arrow-schema ARROW_SCHEMA
                                       [--tenant-id TENANT]
                                       [--source-column-name SOURCE_COLUMN]
                                       [--remove-copy-source-column REMOVE_COPY_SOURCE]
```

## Required Parameters

| `--database-name DATABASE` | Kafka bucket name containing the source topic |
| --- | --- |
| `--table-name TABLE` | Source Kafka topic name |
| `--arrow-schema ARROW_SCHEMA` | Comma-separated list of fields of in the source of form name-type to discontinue parsing to the target, Example `--arrow-schema id,int, status-string` |

## Options

| `--tenant-id TENANT` | Tenant ID (optional) |
| --- | --- |
| `--source-column-name SOURCE_COLUMN` | Source column name (defaults to 'value') |
| `--remove-copy-source-column` | If set, discontinues copying the source json blob to the target table. |

## Example

This example shows the `blobexpansion drop-columns` command with sample values.

```plaintext
vcli: admin> blobexpansion drop-columns --tenant-id <integer> --database-name kafka_bucket --table-name my_topic --source-column-name value --arrow-schema col1-string,col2-int --remove-copy-source-column
```