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docs/transactions-and-disposal.md

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+# Transactions and Disposal
+
+DynamORM manages connections, command pools, and transaction stacks internally.
+
+## Connection and Transaction Options
+
+`DynamicDatabaseOptions` controls behavior:
+
+- `SingleConnection`
+- `SingleTransaction`
+- `SupportSchema`
+- `SupportStoredProcedures`
+- `SupportNoLock`
+- `SupportTop` / `SupportLimitOffset` / `SupportFirstSkip`
+
+Typical setup:
+
+```csharp
+var options =
+    DynamicDatabaseOptions.SingleConnection |
+    DynamicDatabaseOptions.SingleTransaction |
+    DynamicDatabaseOptions.SupportLimitOffset |
+    DynamicDatabaseOptions.SupportSchema;
+```
+
+## Transaction Usage
+
+```csharp
+using (var db = new DynamicDatabase(factory, connectionString, options))
+using (var conn = db.Open())
+using (var tx = conn.BeginTransaction())
+using (var cmd = conn.CreateCommand())
+{
+    cmd.SetCommand("UPDATE users SET first = 'Ada' WHERE id = 1").ExecuteNonQuery();
+    tx.Commit();
+}
+```
+
+Global transaction mode is also available via `db.BeginTransaction()`.
+
+## Disposal Guarantees
+
+Current disposal behavior includes idempotent guards on key objects:
+
+- `DynamicDatabase`
+- `DynamicConnection`
+- `DynamicCommand`
+- `DynamicTransaction`
+- `DynamicTable`
+- builder and parser helpers
+
+This prevents repeated cleanup from throwing or re-disposing lower-level resources.
+
+## Pooling and Rollback Behavior
+
+Behavior validated by `DynamORM.Tests/Helpers/PoolingTests.cs`:
+
+- Disposing the database invalidates active commands.
+- Open transactions are rolled back during disposal when not committed.
+
+## Practices
+
+- Prefer `using` blocks for `DynamicDatabase`, connections, commands, transactions, and builders.
+- Do not manually re-dispose the same object from multiple ownership paths unless `IsDisposed` is checked.
+- Keep transaction scope short and explicit.