# PostGIS Remote Import

Import spatial data from external PostGIS databases.

## Overview

PostGIS remote import allows you to connect to external PostgreSQL/PostGIS databases and import spatial tables as datasets in Aurora GIS.

## Connection Setup

### Create Connection

1. Navigate to PostGIS import page
2. Click "New Connection"
3. Enter connection details:
   - **Host**: Database server address
   - **Port**: Database port (default: 5432)
   - **Database**: Database name
   - **Username**: Database username
   - **Password**: Database password
4. Test connection
5. Save connection

### Connection Management

- **Save Connections**: Store credentials securely (encrypted)
- **Test Connections**: Verify connectivity before import
- **Delete Connections**: Remove saved connections

## Import Process

### Step 1: Select Connection

Choose a saved PostGIS connection or enter new connection details.

### Step 2: Browse Database

Browse available schemas and tables:
- **Schemas**: List of database schemas
- **Tables**: Spatial tables in selected schema
- **Columns**: Table columns and geometry information

### Step 3: Configure Import

Set import options:
- **Schema**: Source schema name
- **Table**: Source table name
- **Geometry Column**: Geometry column name (auto-detected)
- **ID Column**: Primary key column (optional)
- **Update Mode**: Replace, append, or upsert

### Step 4: Execute Import

Import can be:
- **Materialized**: Copy data to local database
- **Foreign Table**: Create foreign table (read-only, live connection)

## Import Modes

### Materialized Import

Full data copy to local database:
- **Pros**: Fast queries, no external dependency
- **Cons**: Data duplication, requires refresh for updates
- **Use Case**: Static datasets, analysis workflows

### Foreign Table Import

Live connection to external database:
- **Pros**: Always current, no data duplication
- **Cons**: Requires external connection, slower queries
- **Use Case**: Frequently updated data, large datasets

## Update Modes

### Replace

Replace all existing data:
- Delete existing data
- Import all source data
- Use for complete refresh

### Append

Add new data to existing:
- Keep existing data
- Add new records
- Use for incremental updates

### Upsert

Update existing, insert new:
- Requires key columns
- Updates matching records
- Inserts new records
- Use for incremental updates with changes

## Scheduled Imports

Set up recurring imports:

1. Configure import
2. Set schedule:
   - **Daily**: Run at specified time
   - **Weekly**: Run on specified day
   - **Monthly**: Run on specified date
3. Configure update mode
4. Save schedule

## Refresh Import

Manually refresh existing imports:

1. Navigate to import history
2. Select import to refresh
3. Click "Refresh"
4. System re-imports data using original settings

## Connection Security

### Credential Storage

- Passwords encrypted in database
- Secure connection testing
- Access control per user

### Network Security

- Use SSL connections when available
- Configure firewall rules
- Use VPN for remote databases

## Example: Materialized Import

```json
{
  "connection_id": 1,
  "schema": "public",
  "table": "parcels",
  "geometry_column": "geom",
  "id_column": "parcel_id",
  "update_mode": "replace",
  "materialize": true
}
```

## Example: Foreign Table Import

```json
{
  "connection_id": 1,
  "schema": "public",
  "table": "parcels",
  "geometry_column": "geom",
  "materialize": false
}
```

## Troubleshooting

### Common Issues

**Connection failed**
- Verify host, port, database name
- Check network connectivity
- Verify credentials
- Check firewall rules

**Table not found**
- Verify schema name
- Check table exists
- Verify user permissions

**Geometry column not detected**
- Ensure PostGIS extension enabled
- Check geometry column type
- Verify spatial reference system

**Import timeout**
- Check table size
- Use materialized import for large tables
- Consider filtering data

## Related Documentation

- [Vector Import](vector.md)
- [Raster Import](raster.md)
- [ESRI Import](esri.md)
- [Configuration Guide](../configuration.md)