---
title: "WASM Procedures: Procedure Management"
---

# WASM Procedures: Procedure Management

:::caution[Planned design: not yet available in the server]
The current `heliosdb-full` server does not run WASM procedures. SQL that
would create or call one fails with SQLSTATE `0A000`. This page describes the
planned design for this upcoming feature. Only the [Go SDK](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_language_sdks/#go-sdk) is
published. Rust, JavaScript and Python examples are illustrations: no SDK
package exists for those languages. See the
[Quick Start](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_quick_start/) for what works today.

The SQL on this page, including `CREATE SECURITY PROFILE`, the
`SECURITY PROFILE` clause, syscall filters and `ALTER PROCEDURE` options,
is the planned syntax; the current server does not accept it.
:::

**Documentation Home > User Guides > Features > Procedure Management**

---

## Overview

This guide covers the complete lifecycle of WASM procedures in HeliosDB, including creation, updating, versioning, calling, and managing procedures through SQL and application code.

**Related Sections:**
- [Quick Start](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_quick_start/) - Get started with WASM procedures
- [Security Model](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_security_model/) - Security profiles and capabilities
- [Performance](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_performance/) - Optimization techniques
- [Monitoring](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_monitoring/) - Tracking procedure execution

---

## Procedure Management

### Creating Procedures

#### SQL Syntax

```sql
-- Planned syntax for the upcoming WASM procedures feature; the current server does not accept it.
CREATE [OR REPLACE] PROCEDURE procedure_name (
    parameter1 type1,
    parameter2 type2,
    ...
)
[RETURNS return_type]
LANGUAGE wasm
[SECURITY PROFILE 'profile_name']
[DESCRIPTION 'procedure description']
AS source;
```

#### Examples

**From file:**
```sql
-- Planned syntax for the upcoming WASM procedures feature; the current server does not accept it.
CREATE PROCEDURE calculate_discount(
    order_total DECIMAL(10,2),
    tier VARCHAR(20)
)
RETURNS DECIMAL(10,2)
LANGUAGE wasm
SECURITY PROFILE 'standard'
DESCRIPTION 'Calculate customer discount based on tier'
AS '/opt/procedures/discount.wasm';
```

**From binary:**
```sql
-- Planned syntax for the upcoming WASM procedures feature; the current server does not accept it.
CREATE PROCEDURE process_order(order_id BIGINT)
LANGUAGE wasm
AS BYTEA '\x00\x61\x73\x6d...'; -- WASM binary in hex
```

**With custom security:**
```sql
-- Planned syntax for the upcoming WASM procedures feature; the current server does not accept it.
CREATE PROCEDURE sync_external_data()
LANGUAGE wasm
SECURITY PROFILE 'elevated'
AS '/opt/procedures/sync.wasm';
```

### Updating Procedures

#### Hot Reload (Zero Downtime)

```sql
-- Planned syntax for the upcoming WASM procedures feature; the current server does not accept it.
ALTER PROCEDURE calculate_discount
SET SOURCE '/opt/procedures/discount_v2.wasm';
```

HeliosDB performs zero-downtime updates:
1. Compiles new WASM module
2. Waits for in-flight executions to complete
3. Swaps to new version
4. Keeps old version for rollback

#### Update Security Profile

```sql
-- Planned syntax for the upcoming WASM procedures feature; the current server does not accept it.
ALTER PROCEDURE my_procedure
SET SECURITY PROFILE 'elevated';
```

#### Update Metadata

```sql
-- Planned syntax for the upcoming WASM procedures feature; the current server does not accept it.
ALTER PROCEDURE my_procedure
SET DESCRIPTION 'Updated description';
```

### Dropping Procedures

```sql
-- Drop procedure
DROP PROCEDURE calculate_discount;

-- Drop if exists
DROP PROCEDURE IF EXISTS calculate_discount;

-- Drop cascade (removes dependencies)
DROP PROCEDURE calculate_discount CASCADE;
```

### Calling Procedures

#### Direct Call

```sql
-- Simple call
CALL calculate_discount(1000.00, 'gold');

-- Call with result
SELECT calculate_discount(1000.00, 'gold') AS discount;

-- Use in query
SELECT
    order_id,
    total,
    calculate_discount(total, customer_tier) AS discount
FROM orders;
```

#### Prepared Call

```sql
PREPARE discount_calc AS
    SELECT calculate_discount($1, $2);

EXECUTE discount_calc(1000.00, 'gold');
```

#### Application Integration

**Python:**
```python
import psycopg2

conn = psycopg2.connect("dbname=heliosdb")
cursor = conn.cursor()

# Call procedure
cursor.execute("SELECT calculate_discount(%s, %s)", (1000.00, 'gold'))
discount = cursor.fetchone()[0]

print(f"Discount: ${discount:.2f}")
```

**Node.js:**
```javascript
const { Client } = require('pg');

const client = new Client({ database: 'heliosdb' });
await client.connect();

const result = await client.query(
    'SELECT calculate_discount($1, $2)',
    [1000.00, 'gold']
);

console.log(`Discount: $${result.rows[0].calculate_discount}`);
```

**Java:**
```java
Connection conn = DriverManager.getConnection("jdbc:postgresql://localhost/heliosdb");
CallableStatement stmt = conn.prepareCall("{? = call calculate_discount(?, ?)}");
stmt.registerOutParameter(1, Types.DECIMAL);
stmt.setDouble(2, 1000.00);
stmt.setString(3, "gold");
stmt.execute();

double discount = stmt.getDouble(1);
System.out.println("Discount: $" + discount);
```

### Versioning

HeliosDB supports procedure versioning for safe deployments:

```sql
-- Planned syntax for the upcoming WASM procedures feature; the current server does not accept it.
-- Create version 1
CREATE PROCEDURE my_procedure@v1(x INT)
LANGUAGE wasm
AS '/path/to/v1.wasm';

-- Create version 2
CREATE PROCEDURE my_procedure@v2(x INT, y INT)
LANGUAGE wasm
AS '/path/to/v2.wasm';

-- Call specific version
SELECT my_procedure@v1(100);
SELECT my_procedure@v2(100, 200);

-- Update default version
ALTER PROCEDURE my_procedure
SET DEFAULT VERSION 'v2';

-- Now calls v2 by default
SELECT my_procedure(100, 200);
```

### Listing Procedures

```sql
-- List all procedures
SELECT * FROM heliosdb_procedures;

-- Filter by language
SELECT name, created_at, size_bytes
FROM heliosdb_procedures
WHERE language = 'wasm';

-- View procedure details
SELECT * FROM heliosdb_procedure_info WHERE name = 'calculate_discount';
```

**Output:**
```
name                | language | security_profile | size_bytes | created_at          | last_modified
--------------------|----------|------------------|------------|---------------------|-------------------
calculate_discount  | wasm     | standard         | 45231      | 2025-11-01 10:00:00 | 2025-11-01 14:30:00
process_order       | wasm     | elevated         | 67890      | 2025-11-01 11:00:00 | 2025-11-01 11:00:00
```

---

## Key Takeaways

1. **Flexible Deployment**: Load procedures from files or inline binary data
2. **Zero-Downtime Updates**: Hot reload procedures without service interruption
3. **Version Control**: Support multiple versions of procedures simultaneously
4. **Universal Access**: Call procedures from SQL queries or any PostgreSQL-compatible client
5. **Comprehensive Metadata**: Track procedure information through system catalogs

## Next Steps

- **[Performance Optimization](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_performance/)** - Optimize procedure execution
- **[Monitoring & Debugging](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_monitoring/)** - Track and debug procedures
- **[Advanced Topics](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_advanced_topics/)** - Advanced features and patterns

---

**Navigation:** [← Use Cases](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_use_cases/) | [Index](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_user_guide/) | [Performance →](https://www.heliosdb.com/docs/full/guides/features/wasm_procedures_performance/)