Aggiunta documentazione Postgres DbContextPool

Author: Angelo Pirola

src/NET6CustomLibrary/Docs/README-DbContextPool-Postgres.md

@@ -0,0 +1,41 @@
+# Entity Framework Core DbContext Pool configuration for Postgres database
+
+
+## Configuration to add to the appsettings.json file
+
+```json
+"ConnectionStrings": {
+  "Default": "Host=[SERVER];Port=5432;Database=[DATABASE];Username=[USERNAME];Password=[PASSWORD]"
+},
+```
+
+<b>Note:</b> The default port for Postgres is 5432, but it can be changed as needed according to your needs.
+
+
+## Registering services at Startup
+
+```csharp
+public Startup(IConfiguration configuration)
+{
+  Configuration = configuration;
+}
+
+public IConfiguration Configuration { get; }
+	
+public void ConfigureServices(IServiceCollection services)
+{
+  //OMISSIS
+
+  var connectionString = Configuration.GetSection("ConnectionStrings").GetValue<string>("Default");
+
+  //OMISSIS
+
+  services.AddDbContextUsePostgres<MyDbContext>(connectionString, 3);
+}
+```
+
+<b>Note:</b>The value <b>3</b> indicates the number of attempts (retryOnFailure), in order to avoid transient errors.
+
+If you don't want to activate connection resiliency, set the value to <b>zero</b>.
+
+Finally you need to replace the <b>MyDbContext</b> value with the actual implementation of your DbContext