# SQL Server Collation Migration (UTF-8 / UTF-16) – Data Copy + Verification

This repository contains **two main scripts** to support a SQL Server 2022 migration scenario:

1. **Data copy (Variant B / Checkpointing)**: copies data from a source database into a target database **table-by-table** with restart capability.
2. **Verification / compare script**: compares source & target databases **without comparing row contents** (rowcounts + schema + programmable objects + principals).

> Intended usage: build a new target DB (e.g. UTF-8 collation), deploy schema, run copy, then verify.

## Repository layout

- `scripts/migrate_copy_checkpoint.sql`  
  Copy data source → target (restartable, per-table commit, FK-aware order, live progress output)

- `scripts/compare_source_target.sql`  
  Compare source vs target (**textual summaries + result sets**)  
  - Rowcounts per table
  - Column schema diffs
  - Views/Procs/Functions hash compare
  - Trigger hash compare
  - Users/Roles + Role memberships

- `docs/USAGE.md`  
  How to run the migration copy safely.

- `docs/VERIFY.md`  
  How to run and interpret the compare results.

## Quickstart

1. Open **SQL Server Management Studio** (SSMS)
2. Ensure target DB exists and schema is deployed
3. Run:
   - `scripts/migrate_copy_checkpoint.sql`
4. After successful copy, run:
   - `scripts/compare_source_target.sql`

Both scripts show **live progress output** in SSMS (Messages tab).

## Configuration

At the top of each script set:

- `@SourceDb` (default `sysdb_UTF8`)
- `@TargetDb` (default `sysdb_utf8_jr`)

## Notes

- The copy script disables triggers, constraints, and nonclustered indexes in target during load and re-enables them afterwards.
- The compare script uses hashes (SHA2_256) for object definitions to quickly detect differences.