# MARS-835: One-Time CSDB Data Export from Operational Database to External Tables

## Overview
This package performs a one-time bulk export of CSDB data from operational database tables (OU_CSDB schema) to new external tables in OCI buckets. The export uses DATA_EXPORTER v2.4.0 with per-column date format handling to move historical data to either DATA bucket (CSV format) or HIST bucket (Parquet format with Hive-style partitioning).

**Migration Strategy:**
- **Split Export (2 tables)**: DEBT, DEBT_DAILY - Last 6 months → DATA (CSV), Older data → HIST (Parquet)
- **HIST Only (4 tables)**: INSTR_RAT_FULL, INSTR_DESC_FULL, ISSUER_RAT_FULL, ISSUER_DESC_FULL - All data → HIST (Parquet)

**Key Transformations:**
- Column rename: `A_ETL_LOAD_SET_FK` → `A_WORKFLOW_HISTORY_KEY` (all tables)
- Column removal: DEBT (2 columns), DEBT_DAILY (6 columns) not required in new structure

## Contents
- `install_mars835.sql` - Master installation script with SPOOL logging
- `rollback_mars835.sql` - Master rollback script
- `01_MARS_835_*.sql` - Individual installation scripts
- `91_MARS_835_*.sql` - Individual rollback scripts
- `track_package_versions.sql` - Package version tracking
- `verify_packages_version.sql` - Package verification

## Prerequisites
- Oracle Database 23ai
- ADMIN user access (required for all MARS installations)
- ENV_MANAGER v3.1.0+
- Required schema privileges

## Installation

### Option 1: Master Script (Recommended)
```powershell
# IMPORTANT: Execute as ADMIN user for proper privilege management
Get-Content "MARS_Packages/REL01_POST_DEACTIVATION/MARS-835/install_mars835.sql" | sql "ADMIN/Cloudpass#34@ggmichalski_high"

# Log file created: log/INSTALL_MARS_835_<PDB>_<timestamp>.log
```

### Option 2: Individual Scripts
```powershell
# IMPORTANT: Execute as ADMIN user
Get-Content "01_MARS_835_*.sql" | sql "ADMIN/Cloudpass#34@ggmichalski_high"
Get-Content "02_MARS_835_*.sql" | sql "ADMIN/Cloudpass#34@ggmichalski_high"
# ... etc
```

## Verification
```sql
-- Verify package versions
SELECT PACKAGE_NAME.GET_VERSION() FROM DUAL;

-- Check for errors (ADMIN user checks specific schema)
SELECT * FROM ALL_ERRORS 
WHERE OWNER = 'CT_MRDS'  -- Replace with target schema
  AND NAME = 'PACKAGE_NAME';

-- Verify no untracked changes
SELECT ENV_MANAGER.CHECK_PACKAGE_CHANGES('CT_MRDS', 'PACKAGE_NAME') FROM DUAL;
```

## Rollback
```powershell
# IMPORTANT: Execute as ADMIN user
Get-Content "MARS_Packages/REL01_POST_DEACTIVATION/MARS-835/rollback_mars835.sql" | sql "ADMIN/Cloudpass#34@ggmichalski_high"

**NOTE**: Rollback for data exports is **NOT RECOMMENDED** as it would delete exported files from OCI buckets. Only use rollback if export failed and needs to be restarted.
```

## Expected Changes

### Data Export Summary
**6 CSDB tables exported from OU_CSDB schema:**

**Group 1: Split DATA + HIST (Time Critical)**
1. **DEBT** - Last 6 months → DATA, Older → HIST
2. **DEBT_DAILY** - Last 6 months → DATA, Older → HIST

**Group 2: HIST Only (Weekend Bulk)**
3. **INSTR_RAT_FULL** - All data → HIST
4. **INSTR_DESC_FULL** - All data → HIST
5. **ISSUER_RAT_FULL** - All data → HIST
6. **ISSUER_DESC_FULL** - All data → HIST

### Bucket Destinations (DEV environment)
- **DATA Bucket**: `mrds_data_dev/ODS/CSDB/` (CSV format)
- **HIST Bucket**: `mrds_hist_dev/ARCHIVE/CSDB/` (Parquet with partitioning)

### Column Mappings
- **All tables**: `A_ETL_LOAD_SET_FK` renamed to `A_WORKFLOW_HISTORY_KEY`
- **DEBT**: Removed columns: `IDIRDEPOSITORY`, `VA_BONDDURATION`
- **DEBT_DAILY**: Removed columns: `STEPID`, `PROGRAMNAME`, `PROGRAMCEILING`, `PROGRAMSTATUS`, `ISSUERNACE21SECTOR`, `INSTRUMENTQUOTATIONBASIS`

## Testing

### Post-Export Verification

1. **Verify CSV files in DATA bucket** (DEBT, DEBT_DAILY - last 6 months):
```sql
-- Check exported files
SELECT object_name, bytes 
FROM TABLE(DBMS_CLOUD.LIST_OBJECTS(
    credential_name => 'DEF_CRED_ARN',
    location_uri => 'https://objectstorage.region.oraclecloud.com/n/namespace/b/mrds_data_dev/o/ODS/CSDB/'
)) WHERE object_name LIKE '%CSDB_DEBT%';
```

2. **Verify Parquet files in HIST bucket** (all 6 tables):
```sql
-- Check archived files with Hive partitioning
SELECT object_name, bytes 
FROM TABLE(DBMS_CLOUD.LIST_OBJECTS(
    credential_name => 'DEF_CRED_ARN',
    location_uri => 'https://objectstorage.region.oraclecloud.com/n/namespace/b/mrds_hist_dev/o/ARCHIVE/CSDB/'
)) WHERE object_name LIKE '%PARTITION_YEAR=%';
```

3. **Validate row counts match source tables**:
```sql
-- Compare counts between source and exported data
SELECT COUNT(*) FROM OU_CSDB.DEBT;
SELECT COUNT(*) FROM ODS.CSDB_DEBT_ODS;  -- External table pointing to DATA
SELECT COUNT(*) FROM ODS.CSDB_DEBT_ARCHIVE;  -- External table pointing to HIST
```

4. **Verify column mappings**:
```sql
-- Check A_WORKFLOW_HISTORY_KEY exists in exported data
SELECT A_WORKFLOW_HISTORY_KEY, COUNT(*) 
FROM ODS.CSDB_DEBT_ARCHIVE 
GROUP BY A_WORKFLOW_HISTORY_KEY;
```

## Known Issues

### Timing Constraints
- **DATA exports (DEBT, DEBT_DAILY)**: Must execute during parallel old+new loads phase after Production deployment
- **HIST exports (all 6 tables)**: Can run anytime, recommended for weekend bulk execution to avoid interference

### Environment-Specific Configuration
- Bucket names must be adjusted for each environment:
  - DEV: `mrds_data_dev`, `mrds_hist_dev`
  - TEST: `mrds_data_test`, `mrds_hist_test`  
  - PROD: `mrds_data_prod`, `mrds_hist_prod`

### Data Cutoff Date
- Export scripts use 6-month cutoff date calculated as `ADD_MONTHS(SYSDATE, -6)`
- Verify cutoff aligns with business requirements before execution

### One-Time Execution
- This is a **ONE-TIME data migration** package
- After successful execution, package should be **deactivated** (moved to REL01_POST_DEACTIVATION)
- Do not re-run unless explicitly required for data refresh

## Related
- **JIRA**: MARS-835 - CSDB Data Export to External Tables
- **Confluence**: FILE_MANAGER package - MRDS - Technical Team
- **Confluence**: Table Setup Guide for FILE PROCESSOR System
- **Source Schema**: OU_CSDB (Operational Database)
- **Target Schema**: ODS (External Tables)
- **Migration Type**: One-time bulk export (deactivated post-execution)

---

**Author:** Grzegorz Michalski  
**Date:** 2025-12-04  
**Version:** 1.0.0