# Workflow
> Workflow is a feature that allow you can use some pre-defined functions to complete some tasks. For example, you can use ExternalBuildIndex workflow to build in
---
LLMS index: [llms.txt](/llms.txt)
---
## Overview
Workflow is a feature that allow you can use some pre-defined functions to complete some tasks. For example, you can use [`ExternalBuildIndex`](#ExternalBuildIndex) workflow to build index externally for your Postgres cluster. There are some advantages of using workflow:
- **Out Of Box**: You can use the pre-defined functions to complete some tasks without writing any code.
- **Accelerate Tasks**: You can use a server with a higher resource configuration than the PostgreSQL cluster to accelerate the task.
- **Cluster Stability**: The workflow is executed in a separate server, which will not affect the stability of the PostgreSQL cluster.
- **Low Cost**: You do not need to pay continuously like a database for high configuration resources for short-term tasks.
## Supported Workflows
Supported workflows are as follows:
- [ExternalBuildIndex](#ExternalBuildIndex)
### ExternalBuildIndex {#ExternalBuildIndex}
The `ExternalBuildIndex` workflow is used to build vchord index externally for your Postgres cluster, details can be found [here](/docs/usage/external-build/).
In dashboard, you can click the `Create Workflow` button to create a new workflow.
You need to specify the following information:
- **Workflow Name**: A unique name for your workflow.
- **Option**: The option for `ExternalBuildIndex` workflow
- **Table**: The table where the vector is located
- **Column**: Vector column name
- **Dimension**: The dimension of the vector
- **Lists**: KMeans n list
- **DistanceMetric**: The distance metric for the vector
- **DistanceMetricCosine**: Cosine distance
- **DistanceMetricL2**: Euclidean distance
- **DistanceMetricDot**: Dot product distance
After submitting the workflow, the workflow will be in the `Running` status. The workflow will be unavailable during the running process. The running process may take a few minutes to complete. After the running process is completed, the workflow will be in the `Succeeded` status. You can list all the workflows in the dashboard.
You can check the detail of every step in the workflow detail page.
When the workflow is in the `Succeeded` status, you can validate the index is ready to use.
```shell
$ psql 'postgres://vectorchord_user:C8bTXXFi2vxA@vectorchord-oews3hvirnsq3vi7.us-east-1-dev.aws.vectorchord.com:5432/vectorchord?sslmode=require'
psql (15.3, server 16.5)
WARNING: psql major version 15, server major version 16.
Some psql features might not work.
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compression: off)
Type "help" for help.
vectorchord=# EXPLAIN ANALYZE SELECT * FROM sift ORDER BY embedding <-> '[12,47,14,25,2,3,4,7,14,122,90,7,0,0,6,14,0,24,122,22,2,4,6,0,0,10,93,10,6,6,0,0,122,31,9,23,19,9,8,56,122,100,29,19,3,0,0,25,3,9,43,59,76,32,0,0,8,6,10,7,24,58,1,1,81,23,32,68,14,19,10,23,122,13,2,1,4,9,86,122,3,0,0,8,122,95,68,30,9,2,0,2,26,50,44,13,0,0,0,3,12,82,18,7,6,0,0,0,2,20,112,122,6,5,1,0,3,69,122,43,15,1,0,0,0,27,29,21]' LIMIT 5;
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Limit (cost=0.00..1.85 rows=5 width=532) (actual time=0.644..0.683 rows=5 loops=1)
-> Index Scan using sift_embedding_idx on sift (cost=0.00..73962.25 rows=200012 width=532) (actual time=0.643..0.681 rows=5 loops=1)
Order By: (embedding <-> '[12,47,14,25,2,3,4,7,14,122,90,7,0,0,6,14,0,24,122,22,2,4,6,0,0,10,93,10,6,6,0,0,122,31,9,23,19,9,8,56,122,100,29,19,3,0,0,25,3,9,43,59,76,32,0,0,8,6,10,7,24,58,1,1,81,23,32,68,14,19,10,23,122,13,2,1,4,9,86,122,3,0,0,8,122,95,68,30,9,2,0,2,26,50,44,13,0,0,0,3,12,82,18,7,6,0,0,0,2,20,112,122,6,5,1,0,3,69,122,43,15,1,0,0,0,27,29,21]'::vector)
Planning Time: 0.069 ms
Execution Time: 0.710 ms
(5 rows)
```