# MARS-956: One-Time C2D MPEC Data Export from Operational Database to External Tables

## Overview
This package performs a one-time bulk export of C2D MPEC data from operational database tables (OU_C2D schema) to new external tables in OCI buckets. The export uses DATA_EXPORTER v2.7.5 with pRegisterExport parameter to move historical data to ODS bucket in CSV format with automatic file registration.

**Migration Strategy:**
- **Source**: OU_C2D schema tables (MPEC_ADMIN, MPEC_CONTENT, MPEC_CONTENT_CRITERION)  
- **Target**: ODS bucket (CSV format)
- **Registration**: Files automatically registered in A_SOURCE_FILE_RECEIVED
- **Template Compatibility**: Uses CT_ET_TEMPLATES.C2D_MPEC_* for column ordering

**Key Features:**
- Automatic file registration with pRegisterExport=TRUE
- Template table column order compliance
- Comprehensive verification and rollback capabilities
- ODS/C2D bucket path structure

## Contents
- `install_mars956.sql` - Master installation script with SPOOL logging
- `rollback_mars956.sql` - Master rollback script
- `00_MARS_956_*.sql` - Prerequisites check
- `01_MARS_956_*.sql` - Data export script
- `02_MARS_956_*.sql` - Export verification
- `03_MARS_956_*.sql` - Data integrity validation
- `91_MARS_956_*.sql` - Rollback scripts
- `99_MARS_956_*.sql` - Rollback verification

## Prerequisites
- Oracle Database 23ai with DBMS_CLOUD
- ADMIN user access (required for all MARS installations)
- DATA_EXPORTER package v2.7.5 or higher
- OU_C2D schema with populated MPEC tables
- CT_ET_TEMPLATES schema with C2D_MPEC_* template tables
- OCI bucket access credentials configured

## Data Structure

### Source Tables (OU_C2D schema)
- **MPEC_ADMIN**: 5 records with ETL keys 2001-2005
- **MPEC_CONTENT**: 5 records with ETL keys 2006-2008  
- **MPEC_CONTENT_CRITERION**: 9 records with ETL keys 2009-2010

### Template Tables (CT_ET_TEMPLATES schema)
- **C2D_MPEC_ADMIN**: 10 columns
- **C2D_MPEC_CONTENT**: 87 columns
- **C2D_MPEC_CONTENT_CRITERION**: 4 columns

### Target Structure (OCI ODS bucket)
```
mrds_data_dev/ODS/C2D/C2D_MPEC_ADMIN/*.csv
mrds_data_dev/ODS/C2D/C2D_MPEC_CONTENT/*.csv  
mrds_data_dev/ODS/C2D/C2D_MPEC_CONTENT_CRITERION/*.csv
```

## Enhanced Validation Framework

### Pre-Export Validation (Check 1-5)
1. **Source Table Analysis**: Comprehensive source table record counting with business rule validation
2. **Template Table Verification**: Ensures external table templates exist and are accessible  
3. **ETL Key Validation**: Verifies integrity of load history tracking keys (expected: 2001-2010)
4. **Schema Permissions**: Validates all required schema access permissions
5. **External Table Readiness**: Checks accessibility of target external tables (ODS.C2D_MPEC_*_ODS) with proper handling of empty states

### In-Export Validation
- **Pre-Export Record Count**: Source and target table counts before export begins
- **Live Progress Monitoring**: Real-time feedback during export operations
- **Post-Export Verification**: Immediate source vs target COUNT(*) comparison table
- **Error Handling**: Comprehensive error capture with detailed diagnostic information

### Post-Export Validation
- **Record Count Verification**: Detailed source vs target COUNT(*) comparison for all exported tables
- **File Registration Validation**: Confirms all exported files are properly registered in A_SOURCE_FILE_RECEIVED
- **Data Integrity Analysis**: Validates data structure and completeness using external table access
- **Delta Query Readiness**: Confirms external tables ready for operational delta queries
mrds_data_dev/ODS/C2D/C2D_MPEC_CONTENT/*.csv  
mrds_data_dev/ODS/C2D/C2D_MPEC_CONTENT_CRITERION/*.csv
```

## Installation

## Installation

### Prerequisites
**IMPORTANT**: External tables must already exist on the database (created via FILE_MANAGER procedures)

Required external tables in ODS schema:
- `ODS.C2D_MPEC_ADMIN_ODS`
- `ODS.C2D_MPEC_CONTENT_ODS`
- `ODS.C2D_MPEC_CONTENT_CRITERION_ODS`

If external tables don't exist, use `FILE_MANAGER.CREATE_EXTERNAL_TABLE` or `ODS.FILE_MANAGER_ODS.CREATE_EXTERNAL_TABLE` procedures to create them.

### Installation Command
```powershell
# Run as ADMIN user
cd c:\_git\MARS\wkcopy02\MARS_Packages\REL02_POST\MARS-956-NEW
sql "ADMIN/Cloudpass#34@ggmichalski_high" "@install_mars956.sql"

# Log file created: log/INSTALL_MARS_956_<PDB>_<timestamp>.log
```

### Alternative: Individual Scripts
```powershell
# Execute individual scripts for step-by-step validation
sql "ADMIN/Cloudpass#34@ggmichalski_high" "@00_MARS_956_pre_check_prerequisites.sql"
sql "ADMIN/Cloudpass#34@ggmichalski_high" "@01_MARS_956_export_c2d_mpec_data.sql"
sql "ADMIN/Cloudpass#34@ggmichalski_high" "@02_MARS_956_verify_exports.sql"
sql "ADMIN/Cloudpass#34@ggmichalski_high" "@03_MARS_956_verify_data_integrity.sql"
```

## Expected Results

### File Registration
- **9 CSV files** registered in A_SOURCE_FILE_RECEIVED
- **File naming pattern**: {ETL_KEY}_1_{TIMESTAMP}Z.csv
- **Processing status**: INGESTED
- **Total size**: ~0.33 KB

### Export Distribution
- **MPEC_ADMIN**: 3 files (ETL keys 2001-2005, 3 distinct keys)
- **MPEC_CONTENT**: 3 files (ETL keys 2006-2008, 3 distinct keys)
- **MPEC_CONTENT_CRITERION**: 3 files (ETL keys 2009-2010, 3 distinct keys)

### Duration
- **Expected**: 2-5 minutes (small datasets)
- **Actual**: ~16 seconds (based on testing)

## Verification

### Manual Verification
```sql
-- Check export results
SELECT COUNT(*) AS TOTAL_FILES FROM CT_MRDS.A_SOURCE_FILE_RECEIVED 
WHERE RECEPTION_DATE >= SYSDATE - 1/24 AND SOURCE_FILE_NAME LIKE '200%';

-- Check process logs
SELECT PROCESS_NAME, LOG_LEVEL, LOG_MESSAGE FROM CT_MRDS.A_PROCESS_LOG
WHERE PROCESS_NAME = 'MARS-956' ORDER BY LOG_TIMESTAMP DESC;
```

### Cloud Bucket Verification
```sql
-- List exported files in OCI bucket
SELECT object_name FROM TABLE(MRDS_LOADER.cloud_wrapper.list_objects(
    credential_name => 'DEF_CRED_ARN',
    location_uri => 'https://objectstorage.eu-frankfurt-1.oraclecloud.com/n/frtgjxu7zl7c/b/data/'
)) WHERE object_name LIKE 'ODS/C2D/C2D_MPEC_%';
```

## Rollback

### Full Rollback (if needed)
```powershell
cd c:\_git\MARS\wkcopy02\MARS_Packages\REL02_POST\MARS-956-NEW
sql "ADMIN/Cloudpass#34@ggmichalski_high" "@rollback_mars956.sql"
```

### Manual Rollback
```sql
-- Remove file registrations
DELETE FROM CT_MRDS.A_SOURCE_FILE_RECEIVED 
WHERE SOURCE_FILE_NAME LIKE '200%' AND RECEPTION_DATE >= SYSDATE - 7;

-- Remove process logs
DELETE FROM CT_MRDS.A_PROCESS_LOG 
WHERE PROCESS_NAME IN ('MARS-956', 'MARS-956-ROLLBACK') AND LOG_TIMESTAMP >= SYSDATE - 7;
```

## Troubleshooting

### Common Issues

1. **ORA-17008: Closed connection**
   - Use MCP SQLcl server instead of traditional SQLcl
   - Connection: `CT_MRDS@ggmichalski_high`

2. **No files registered**
   - Check DATA_EXPORTER package version (requires v2.7.5+)
   - Verify pRegisterExport=TRUE parameter

3. **Template table errors**
   - Ensure CT_ET_TEMPLATES.C2D_MPEC_* tables exist
   - Check column compatibility with source tables

4. **ETL key validation errors**
   - Verify A_ETL_LOAD_SET_FK values exist in CT_ODS.A_LOAD_HISTORY
   - Check ETL key range: 2001-2010

### Error Resolution
- Check `log/INSTALL_MARS_956_*.log` for detailed error information
- Review A_PROCESS_LOG table for runtime errors
- Use verification scripts to diagnose specific issues

### Common Validation Issues

#### External Table Access Errors
**Problem**: "✗ ERROR: Cannot access C2D_MPEC_*_ODS tables"
- **Cause**: Missing external table definitions or incorrect bucket paths
- **Solution**: Verify external tables exist and point to correct OCI bucket paths
- **Check**: `SELECT * FROM ODS.C2D_MPEC_ADMIN_ODS WHERE ROWNUM <= 1;`
- **Create**: Use `ODS.FILE_MANAGER_ODS.CREATE_EXTERNAL_TABLE` if tables don't exist

#### Record Count Mismatches  
**Problem**: Source vs target COUNT(*) differences in post-export validation
- **Cause**: Export failure, external table configuration, or bucket synchronization lag
- **Solution**: Wait 30-60 seconds and re-run verification script
- **Check**: Run `@03_MARS_956_verify_data_integrity.sql` again

#### Empty Source Tables
**Problem**: "⚠ WARNING: No source data found"
- **Cause**: Source tables not populated or incorrect schema permissions  
- **Solution**: Verify OU_C2D schema contains expected MPEC data
- **Check**: `SELECT COUNT(*) FROM OU_C2D.MPEC_ADMIN;` (should return 5)

#### ETL Key Validation Failures
**Problem**: ETL keys outside expected range 2001-2010
- **Cause**: Data inconsistency or load history corruption
- **Solution**: Review source data quality and CT_ODS.A_LOAD_HISTORY entries
- **Check**: Verify ETL key distribution in source tables

#### External Table Empty State Handling  
**Problem**: KUP-13023 or ORA-29913 errors during validation
- **Expected**: These errors are normal for empty external tables
- **Handling**: Pre-checks properly handle empty states as normal condition
- **Action**: No action required if source tables contain data

## Dependencies

### External Tables Setup (If Not Already Created)

If external tables don't exist, create them using FILE_MANAGER procedures:

```sql
-- Option 1: Using ODS.FILE_MANAGER_ODS (recommended - AUTHID DEFINER)
BEGIN
    ODS.FILE_MANAGER_ODS.CREATE_EXTERNAL_TABLE(
        pTableName => 'C2D_MPEC_ADMIN_ODS',
        pTemplateTableName => 'CT_ET_TEMPLATES.C2D_MPEC_ADMIN',
        pPrefix => 'ODS/C2D/C2D_MPEC_ADMIN',
        pBucketUri => CT_MRDS.ENV_MANAGER.gvDataBucketUri
    );
    
    ODS.FILE_MANAGER_ODS.CREATE_EXTERNAL_TABLE(
        pTableName => 'C2D_MPEC_CONTENT_ODS',
        pTemplateTableName => 'CT_ET_TEMPLATES.C2D_MPEC_CONTENT',
        pPrefix => 'ODS/C2D/C2D_MPEC_CONTENT',
        pBucketUri => CT_MRDS.ENV_MANAGER.gvDataBucketUri
    );
    
    ODS.FILE_MANAGER_ODS.CREATE_EXTERNAL_TABLE(
        pTableName => 'C2D_MPEC_CONTENT_CRITERION_ODS',
        pTemplateTableName => 'CT_ET_TEMPLATES.C2D_MPEC_CONTENT_CRITERION',
        pPrefix => 'ODS/C2D/C2D_MPEC_CONTENT_CRITERION',
        pBucketUri => CT_MRDS.ENV_MANAGER.gvDataBucketUri
    );
END;
/

-- Option 2: Using CT_MRDS.FILE_MANAGER (AUTHID CURRENT_USER - requires ODS context)
-- Connect as ODS user first
-- Then call CT_MRDS.FILE_MANAGER.CREATE_EXTERNAL_TABLE with same parameters
```

### Package Dependencies
- **CT_MRDS.DATA_EXPORTER** v2.7.5+ (with pRegisterExport support)
- **CT_MRDS.ENV_MANAGER** v3.1.0+
- **MRDS_LOADER.cloud_wrapper** (for OCI bucket access)

### Schema Dependencies  
- **OU_C2D**: Source data schema
- **CT_ET_TEMPLATES**: Template table definitions
- **CT_MRDS**: Process logging and configuration
- **CT_ODS**: ETL load history validation

### Infrastructure Dependencies
- **OCI Object Storage**: ODS bucket access
- **Database credentials**: DEF_CRED_ARN configured
- **Network connectivity**: Frankfurt region access

## Related MARS Issues
- **MARS-956**: C2D MPEC Historical Data Export (this package)
- **MARS-835**: CSDB Data Export (reference implementation)
- **Related**: DATA_EXPORTER package enhancements

## Support
For technical support or issues:
1. Check installation log files in `log/` directory
2. Review verification script outputs
3. Contact Database Team with specific error messages
4. Include A_PROCESS_LOG entries for debugging

---
**Package Version**: 1.0.0  
**Created**: 2026-02-12  
**Author**: System Generated (based on MARS-835 structure)  
**Status**: Ready for deployment