[Feature/Perf] Ottimizzazioni bulk pre-discovery, batch deletion sync e supporto OLE DB / Salesforce client_credentials

## Bulk Pre-Discovery e riduzione query SQLite/SOQL

### KeyAssociationService — FindAssociationsByKeyValuesBulkAsync (nuovo)
- Aggiunta query bulk 'WHERE KeyValue IN (...)' per recuperare N associazioni con 1 sola query SQLite
  (chunking a 500 chiavi per rispettare il limite ~999 parametri di SQLite)
- Aggiunta interfaccia IKeyAssociationService e delegata in DataConnectionCredentialService / IDataConnectionCredentialService

### AssociationService — BatchFindOrCreateAssociationsAsync (nuovo)
- Nuovo metodo bulk che sostituisce i loop per-record durante l'analisi composite:
  1) 1 query SQLite bulk per tutte le chiavi
  2) Per le chiavi non trovate: SOQL 'IN (...)' su Salesforce in chunk da 200 via BatchExecuteQueriesAsync
     (ceil(K/25) HTTP Composite call invece di K singole)
  3) Salvataggio parallelo delle associazioni pre-discovery scoperte
- Fallback per-record automatico per client REST non Salesforce
- Aggiornata interfaccia IAssociationService con documentazione XML completa

### DataCoupler.razor.cs — STEP A/B nel flusso COMPOSITE
- Pre-Discovery spostata FUORI dal loop parallelo (STEP A, prima dell'analisi)
- associationsByKey pre-popolato con BatchFindOrCreateAssociationsAsync
- STEP B: il loop parallelo usa TryGetValue O(1) invece di query async per record
- Rimozione blocco ~40 righe di per-record lookup / fallback duplicati

## Salesforce Composite API — Batch Delete e Patch

### SalesforceServiceClient — metodi batch (nuovi)
- BatchDeleteEntitiesAsync: elimina N record con ceil(N/25) Composite call invece di N
- BatchPatchSingleFieldAsync: aggiorna un singolo campo su N record tramite BatchUpdateEntitiesAsync

### DeletionSyncService — refactoring batch
- ExecuteBatchedSalesforceDeletionsAsync: orchestrazione batch per Delete / Deactivate / Mark su Salesforce
- ExecuteSequentialDeletionsAsync: loop sequenziale esistente estratto in metodo riutilizzabile
- Dispatcher: Salesforce -> batch Composite, altri client REST -> sequenziale

## Supporto OLE DB (database)

### DatabaseSchemaProviderFactory
- Aggiunto case DatabaseType.OleDb -> new OleDbSchemaProvider() nel factory switch

### DatabaseMethod.cs
- Aggiunto metodo IsOleDbConnection() (parallelo a IsOdbcConnection())
- Query validation e manager temporaneo estesi a OLE DB oltre che ODBC
- GetLimitedQuery: aggiunto case OleDb -> 'SELECT TOP N FROM (subquery)'

## Salesforce OAuth2 — fix client_credentials

### CredentialService.cs
- Aggiunto 'GrantType' alla HashSet serviceSpecificKeys per preservarlo nella serializzazione AdditionalParameters

### DataConnectionCredentialService.cs
- Refactored BuildRestServiceOptions in helper statico riutilizzato da entrambi i metodi GetRestServiceOptions
- Mapping coerente ClientId/ClientSecret/GrantType per Salesforce (allineato a DataConnectionFactory)
- TestSalesforceOAuthLogin: branch esplicito per client_credentials (no username/password/token)
  con validazione preventiva ClientId+ClientSecret obbligatori
- Log flow label (password|client_credentials) in tutti i messaggi di autenticazione

## VS Code tasks

### .vscode/tasks.json
- Rimosso task generico 'Publish Data_Coupler'
- Aggiunti due task separati: win-x64 e win-x86, entrambi SingleFile + Self-Contained + ReadyToRun

.vscode/tasks.json

@@ -29,17 +29,39 @@
 			}
 		},
 		{
-			"label": "Publish Data_Coupler",
+			"label": "Publish Data_Coupler Temp SingleFile Self-Contained Ready-To-Run win-x64",
+			"detail": "Publish the Data Coupler 64-bit with a Single File, Self Contained, Ready-To-Run",
 			"type": "shell",
 			"command": "dotnet",
 			"args": [
 				"publish",
-				"--configuration",
+				"Data_Coupler/Data_Coupler.csproj",
-				"Release",
+				"-c", "Release",
-				"--output",
+				"-r", "win-x64",
-				"${workspaceFolder}/publish",
+				"--self-contained", "true",
-				"--project",
+				"-p:PublishSingleFile=true",
-				"Data_Coupler/Data_Coupler.csproj"
+				"-p:PublishReadyToRun=true",
+				"-p:PublishTrimmed=false",
+				"-o", "C:\\Temp\\Publish\\Data_Coupler"
+			],
+			"group": "build",
+			"problemMatcher": []
+		},
+		{
+			"label": "Publish Data_Coupler Temp SingleFile Self-Contained Ready-To-Run win-x86",
+			"detail": "Publish the Data Coupler 32-bit with a Single File, Self Contained, Ready-To-Run",
+			"type": "shell",
+			"command": "dotnet",
+			"args": [
+				"publish",
+				"Data_Coupler/Data_Coupler.csproj",
+				"-c", "Release",
+				"-r", "win-x86",
+				"--self-contained", "true",
+				"-p:PublishSingleFile=true",
+				"-p:PublishReadyToRun=true",
+				"-p:PublishTrimmed=false",
+				"-o", "C:\\Temp\\Publish\\Data_Coupler_x86"
 			],
 			"group": "build",
 			"problemMatcher": []

CredentialManager/Services/CredentialService.cs

@@ -810,7 +810,7 @@ public class CredentialService : ICredentialService
                     {
                         "CompanyDatabase", "Language", "Version", "UseTrustedConnection",
                         "SecurityToken", "ClientId", "ClientSecret", "ApiVersion",
-                        "IsSandbox", "UseSoapApi", "RefreshToken", "AccessToken", "TokenExpiry"
+                        "IsSandbox", "UseSoapApi", "GrantType", "RefreshToken", "AccessToken", "TokenExpiry"
                     };
                     
                     foreach (var param in additionalParams)

CredentialManager/Services/IKeyAssociationService.cs

@@ -112,6 +112,16 @@ public interface IKeyAssociationService
     /// </summary>
     Task<KeyAssociation?> FindAssociationByKeyValueParallelAsync(string keyValue);
 
+    /// <summary>
+    /// Versione bulk: ricerca in un colpo solo tutte le associazioni attive per la combinazione
+    /// (KeyValue ∈ keyValues, DestinationEntity, RestCredentialName) usando una query SQL IN(...).
+    /// Riduce drasticamente le query SQLite quando si processano molti record.
+    /// </summary>
+    Task<Dictionary<string, KeyAssociation>> FindAssociationsByKeyValuesBulkAsync(
+        IEnumerable<string> keyValues,
+        string destinationEntity,
+        string restCredentialName);
+
     /// <summary>
     /// Versione thread-safe per operazioni parallele - Elimina associazione
     /// </summary>

CredentialManager/Services/KeyAssociationService.cs

@@ -358,6 +358,63 @@ public class KeyAssociationService : IKeyAssociationService
         }
     }
 
+    /// <summary>
+    /// Bulk lookup delle associazioni: una sola query con WHERE KeyValue IN (...).
+    /// Per N chiavi sostituisce fino a 2N query SQLite del flusso per-record.
+    /// </summary>
+    public async Task<Dictionary<string, KeyAssociation>> FindAssociationsByKeyValuesBulkAsync(
+        IEnumerable<string> keyValues,
+        string destinationEntity,
+        string restCredentialName)
+    {
+        var distinctKeys = keyValues
+            .Where(k => !string.IsNullOrEmpty(k))
+            .Distinct()
+            .ToList();
+
+        if (distinctKeys.Count == 0)
+            return new Dictionary<string, KeyAssociation>(StringComparer.Ordinal);
+
+        try
+        {
+            // SQLite ha un limite hardcoded di ~999 parametri per query: chunk per sicurezza.
+            const int chunkSize = 500;
+            var result = new Dictionary<string, KeyAssociation>(StringComparer.Ordinal);
+
+            for (int i = 0; i < distinctKeys.Count; i += chunkSize)
+            {
+                var chunk = distinctKeys.Skip(i).Take(chunkSize).ToList();
+
+                var associations = await _context.KeyAssociations
+                    .AsNoTracking()
+                    .Where(ka => ka.IsActive &&
+                                 ka.DestinationEntity == destinationEntity &&
+                                 ka.RestCredentialName == restCredentialName &&
+                                 chunk.Contains(ka.KeyValue))
+                    .ToListAsync();
+
+                // Se ci sono duplicati (KeyValue ripetuto), tieni il più recente
+                foreach (var assoc in associations
+                    .GroupBy(a => a.KeyValue)
+                    .Select(g => g.OrderByDescending(a => a.UpdatedAt ?? a.CreatedAt).First()))
+                {
+                    result[assoc.KeyValue] = assoc;
+                }
+            }
+
+            _logger.LogDebug("BULK: Ricerca associazioni completata - {Found}/{Total} match per {Entity}/{Credential}",
+                result.Count, distinctKeys.Count, destinationEntity, restCredentialName);
+
+            return result;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "BULK: Errore nella ricerca bulk delle associazioni ({Count} chiavi, Entity={Entity})",
+                distinctKeys.Count, destinationEntity);
+            throw;
+        }
+    }
+
     /// <summary>
     /// Versione thread-safe per operazioni parallele - Delete association
     /// </summary>

DataConnection/CredentialManagement/Interfaces/IDataConnectionCredentialService.cs

@@ -85,6 +85,14 @@ public interface IDataConnectionCredentialService
     Task<KeyAssociation?> FindKeyAssociationByValueParallelAsync(string keyValue);
     Task<bool> DeleteKeyAssociationParallelAsync(int id);
 
+    /// <summary>
+    /// Bulk lookup associazioni - una sola query SQLite per N chiavi.
+    /// </summary>
+    Task<Dictionary<string, KeyAssociation>> FindKeyAssociationsByValuesBulkAsync(
+        IEnumerable<string> keyValues,
+        string destinationEntity,
+        string restCredentialName);
+
     // Deletion synchronization operations
     Task<int> MarkDeletedAssociationsAsync(List<string> sourceKeyValues, string destinationEntity, string restCredentialName);
     Task<List<KeyAssociation>> GetPendingDeletionsAsync(string destinationEntity, string restCredentialName);

DataConnection/CredentialManagement/Services/DataConnectionCredentialService.cs

@@ -168,16 +168,7 @@ public class DataConnectionCredentialService : IDataConnectionCredentialService
         if (credential == null)
             throw new InvalidOperationException($"REST API credential '{credentialName}' not found");
 
-        var options = new DataConnection.REST.Configuration.RestServiceOptions
+        var options = BuildRestServiceOptions(credential);
-        {
-            BaseUrl = credential.BaseUrl,
-            ApiKey = credential.ApiKey,
-            Username = credential.Username,
-            Password = credential.Password,
-            AuthToken = credential.AuthToken,
-            TimeoutSeconds = credential.TimeoutSeconds,
-            IgnoreSslErrors = credential.IgnoreSslErrors
-        };
 
         _logger.LogDebug("Created RestServiceOptions for credential: {Name} ({BaseUrl})",
             credentialName, credential.BaseUrl);
@@ -191,19 +182,42 @@ public class DataConnectionCredentialService : IDataConnectionCredentialService
         if (credential == null)
             throw new InvalidOperationException($"REST API credential with ID '{credentialId}' not found");
 
+        var options = BuildRestServiceOptions(credential);
+
+        _logger.LogDebug("Created RestServiceOptions for credential ID: {Id} ({BaseUrl})",
+            credentialId, credential.BaseUrl);
+        return options;
+    }
+
+    private static DataConnection.REST.Configuration.RestServiceOptions BuildRestServiceOptions(RestApiCredential credential)
+    {
         var options = new DataConnection.REST.Configuration.RestServiceOptions
         {
             BaseUrl = credential.BaseUrl,
-            ApiKey = credential.ApiKey,
             Username = credential.Username,
             Password = credential.Password,
-            AuthToken = credential.AuthToken,
             TimeoutSeconds = credential.TimeoutSeconds,
             IgnoreSslErrors = credential.IgnoreSslErrors
         };
 
-        _logger.LogDebug("Created RestServiceOptions for credential ID: {Id} ({BaseUrl})",
+        // Mapping coerente con DataConnectionFactory.CreateRestServiceClientAsync
-            credentialId, credential.BaseUrl);
+        switch (credential.ServiceType)
+        {
+            case RestServiceType.Salesforce:
+                options.ApiKey = credential.ClientId;
+                options.AuthToken = credential.ClientSecret;
+                options.SalesforceGrantType = credential.GrantType;
+                break;
+            case RestServiceType.SapB1ServiceLayer:
+                options.ApiKey = credential.CompanyDatabase;
+                options.AuthToken = credential.AuthToken;
+                break;
+            default:
+                options.ApiKey = credential.ApiKey;
+                options.AuthToken = credential.AuthToken;
+                break;
+        }
+
         return options;
     }
 
@@ -550,8 +564,8 @@ public class DataConnectionCredentialService : IDataConnectionCredentialService
     {
         try
         {
-            _logger.LogInformation("Testing Salesforce authentication for {Name} ({BaseUrl})",
+            _logger.LogInformation("Testing Salesforce authentication for {Name} ({BaseUrl}, GrantType={GrantType})",
-                credential.Name, credential.BaseUrl);
+                credential.Name, credential.BaseUrl, credential.GrantType);
 
             _logger.LogDebug("Salesforce credential details: Username={Username}, HasPassword={HasPassword}, HasSecurityToken={HasSecurityToken}, HasClientId={HasClientId}, HasClientSecret={HasClientSecret}",
                 credential.Username, !string.IsNullOrEmpty(credential.Password), !string.IsNullOrEmpty(credential.SecurityToken),
@@ -560,23 +574,42 @@ public class DataConnectionCredentialService : IDataConnectionCredentialService
             using var httpClient = new HttpClient();
             httpClient.Timeout = TimeSpan.FromSeconds(credential.TimeoutSeconds);
 
-            // Test di autenticazione OAuth2
             var tokenUrl = credential.BaseUrl.TrimEnd('/') + "/services/oauth2/token";
-            var tokenData = new List<KeyValuePair<string, string>>
+            List<KeyValuePair<string, string>> tokenData;
-            {
+            string flowLabel;
-                new("grant_type", "password"),
-                new("username", credential.Username ?? "")
-            };
 
-            // Aggiungiamo password + security token se disponibile
+            if (credential.GrantType == CredentialManager.Models.SalesforceGrantType.ClientCredentials)
+            {
+                // Client Credentials flow — server-to-server, no user
+                if (string.IsNullOrEmpty(credential.ClientId) || string.IsNullOrEmpty(credential.ClientSecret))
+                {
+                    return (false, "Flusso client_credentials richiede ClientId e ClientSecret configurati.");
+                }
+
+                tokenData = new List<KeyValuePair<string, string>>
+                {
+                    new("grant_type", "client_credentials"),
+                    new("client_id", credential.ClientId),
+                    new("client_secret", credential.ClientSecret)
+                };
+                flowLabel = "client_credentials";
+            }
+            else
+            {
+                // Password flow (default)
                 var password = credential.Password ?? "";
                 if (!string.IsNullOrEmpty(credential.SecurityToken))
                 {
                     password += credential.SecurityToken;
                 }
-            tokenData.Add(new("password", password));
 
-            // Aggiungiamo client credentials se disponibili
+                tokenData = new List<KeyValuePair<string, string>>
+                {
+                    new("grant_type", "password"),
+                    new("username", credential.Username ?? ""),
+                    new("password", password)
+                };
+
                 if (!string.IsNullOrEmpty(credential.ClientId))
                 {
                     tokenData.Add(new("client_id", credential.ClientId));
@@ -585,24 +618,25 @@ public class DataConnectionCredentialService : IDataConnectionCredentialService
                 {
                     tokenData.Add(new("client_secret", credential.ClientSecret));
                 }
+                flowLabel = "password";
+            }
 
-            _logger.LogDebug("Posting to Salesforce token URL: {TokenUrl}", tokenUrl);
+            _logger.LogDebug("Posting to Salesforce token URL: {TokenUrl} (flow={Flow})", tokenUrl, flowLabel);
 
             var tokenContent = new FormUrlEncodedContent(tokenData);
             var response = await httpClient.PostAsync(tokenUrl, tokenContent);
 
             if (response.IsSuccessStatusCode)
             {
-                var responseContent = await response.Content.ReadAsStringAsync();
+                _logger.LogInformation("Salesforce authentication ({Flow}) successful for {Name}", flowLabel, credential.Name);
-                _logger.LogInformation("Salesforce authentication successful for {Name}", credential.Name);
+                return (true, $"Autenticazione Salesforce riuscita!\n\nDettagli:\n- Login URL: {credential.BaseUrl}\n- API Version: {credential.ApiVersion}\n- Sandbox: {credential.IsSandbox}\n- Tipo Auth: OAuth2 ({flowLabel})\n- Timeout: {credential.TimeoutSeconds}s");
-                return (true, $"Autenticazione Salesforce riuscita!\n\nDettagli:\n- Login URL: {credential.BaseUrl}\n- API Version: {credential.ApiVersion}\n- Sandbox: {credential.IsSandbox}\n- Tipo Auth: OAuth2\n- Timeout: {credential.TimeoutSeconds}s");
             }
             else
             {
                 var errorContent = await response.Content.ReadAsStringAsync();
-                _logger.LogWarning("Salesforce authentication failed for {Name}. Status: {StatusCode}, Response: {Response}",
+                _logger.LogWarning("Salesforce authentication ({Flow}) failed for {Name}. Status: {StatusCode}, Response: {Response}",
-                    credential.Name, response.StatusCode, errorContent);
+                    flowLabel, credential.Name, response.StatusCode, errorContent);
-                return (false, $"Autenticazione Salesforce fallita. Status: {response.StatusCode}\nDettagli: {errorContent}");
+                return (false, $"Autenticazione Salesforce ({flowLabel}) fallita. Status: {response.StatusCode}\nDettagli: {errorContent}");
             }
         }
         catch (HttpRequestException ex)
@@ -1074,6 +1108,14 @@ public class DataConnectionCredentialService : IDataConnectionCredentialService
         return await _keyAssociationService.FindAssociationByKeyValueParallelAsync(keyValue);
     }
 
+    public async Task<Dictionary<string, KeyAssociation>> FindKeyAssociationsByValuesBulkAsync(
+        IEnumerable<string> keyValues,
+        string destinationEntity,
+        string restCredentialName)
+    {
+        return await _keyAssociationService.FindAssociationsByKeyValuesBulkAsync(keyValues, destinationEntity, restCredentialName);
+    }
+
     public async Task<bool> DeleteKeyAssociationParallelAsync(int id)
     {
         return await _keyAssociationService.DeleteAssociationParallelAsync(id);

DataConnection/DB/EF/DatabaseSchemaProviderFactory.cs

@@ -19,7 +19,10 @@ public class DatabaseSchemaProviderFactory
     {
         return databaseType switch
         {
-            DatabaseType.SqlServer => new SqlServerSchemaProvider(),            DatabaseType.Odbc => new OdbcSchemaProvider(),            // Aggiungere qui altri provider quando implementati
+            DatabaseType.SqlServer => new SqlServerSchemaProvider(),
+            DatabaseType.Odbc => new OdbcSchemaProvider(),
+            DatabaseType.OleDb => new OleDbSchemaProvider(),
+            // Aggiungere qui altri provider quando implementati
             // DatabaseType.MySql => new MySqlSchemaProvider(),
             // DatabaseType.PostgreSql => new PostgreSqlSchemaProvider(),
             // DatabaseType.Oracle => new OracleSchemaProvider(),

DataConnection/REST/Implementations/SalesforceServiceClient.cs

@@ -126,13 +126,19 @@ namespace DataConnection.REST.Implementations
                 {
                     _accessToken = tokenResponse.AccessToken;
                     _instanceUrl = tokenResponse.InstanceUrl;
-                    _tokenExpiry = DateTime.UtcNow.AddSeconds(3600); // Salesforce doesn't always return expires_in
+
+                    // Se Salesforce restituisce expires_in (es. client_credentials), usalo con un margine di 60s;
+                    // altrimenti (password flow non restituisce expires_in) fallback al default 1h conservativo.
+                    var ttlSeconds = tokenResponse.ExpiresIn.HasValue && tokenResponse.ExpiresIn.Value > 60
+                        ? tokenResponse.ExpiresIn.Value - 60
+                        : 3600;
+                    _tokenExpiry = DateTime.UtcNow.AddSeconds(ttlSeconds);
 
                     _httpClient.DefaultRequestHeaders.Authorization =
                         new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", _accessToken);
 
-                    _logger.LogInformation("Salesforce authentication ({Flow}) successful. InstanceUrl={InstanceUrl}, TokenExpiry={Expiry}",
+                    _logger.LogInformation("Salesforce authentication ({Flow}) successful. InstanceUrl={InstanceUrl}, TokenExpiry={Expiry} (TTL {Ttl}s, server expires_in={ExpiresIn})",
-                        flowName, _instanceUrl, _tokenExpiry.ToLocalTime());
+                        flowName, _instanceUrl, _tokenExpiry.ToLocalTime(), ttlSeconds, tokenResponse.ExpiresIn?.ToString() ?? "null");
                     return true;
                 }
 
@@ -1616,6 +1622,13 @@ namespace DataConnection.REST.Implementations
 
             [JsonPropertyName("signature")]
             public string Signature { get; set; } = string.Empty;
+
+            /// <summary>
+            /// Durata di validità del token in secondi. Presente solo in alcuni flussi OAuth Salesforce
+            /// (es. client_credentials, JWT bearer); assente in altri (es. username/password) — in tal caso 0/null.
+            /// </summary>
+            [JsonPropertyName("expires_in")]
+            public int? ExpiresIn { get; set; }
         }
 
         private class SalesforceSObjectsResponse
@@ -2161,5 +2174,157 @@ namespace DataConnection.REST.Implementations
                 }).ToList();
             }
         }
+
+        /// <summary>
+        /// Elimina N record SObject in batch tramite Salesforce Composite API.
+        /// Riduce N HTTP calls a ceil(N/25), eseguite in parallelo.
+        /// </summary>
+        /// <param name="entityName">Nome SObject (es. "Account").</param>
+        /// <param name="entityIds">Lista di Id da eliminare.</param>
+        /// <param name="cancellationToken">Cancellation token.</param>
+        /// <returns>Risultato per ogni Id (Success/ErrorMessage).</returns>
+        public async Task<List<CompositeOperationResult>> BatchDeleteEntitiesAsync(
+            string entityName,
+            List<string> entityIds,
+            CancellationToken cancellationToken = default)
+        {
+            if (!IsAuthenticated())
+            {
+                _logger.LogDebug("Error: Not authenticated to Salesforce. Cannot perform batch delete.");
+                return new List<CompositeOperationResult>();
+            }
+
+            if (entityIds == null || entityIds.Count == 0)
+                return new List<CompositeOperationResult>();
+
+            const int maxBatchSize = 25;
+
+            var batches = new List<(List<string> batch, int startIndex, int batchNumber)>();
+            for (int i = 0; i < entityIds.Count; i += maxBatchSize)
+            {
+                var chunk = entityIds.Skip(i).Take(maxBatchSize).ToList();
+                batches.Add((chunk, i, (i / maxBatchSize) + 1));
+            }
+
+            _logger.LogDebug($"--- BatchDelete: {entityIds.Count} record in {batches.Count} batch (parallel) ---");
+
+            var batchTasks = batches.Select(async b =>
+                await ExecuteDeleteBatchAsync(entityName, b.batch, b.startIndex, cancellationToken));
+
+            var batchResults = await Task.WhenAll(batchTasks);
+
+            var allResults = new List<CompositeOperationResult>();
+            foreach (var r in batchResults) allResults.AddRange(r);
+
+            _logger.LogDebug($"All delete batches completed: {allResults.Count(r => r.Success)} success, {allResults.Count(r => !r.Success)} failed");
+            return allResults;
+        }
+
+        private async Task<List<CompositeOperationResult>> ExecuteDeleteBatchAsync(
+            string entityName,
+            List<string> batch,
+            int startIndex,
+            CancellationToken cancellationToken)
+        {
+            try
+            {
+                var compositeUri = $"{_instanceUrl}/services/data/v60.0/composite/";
+
+                var compositeRequest = new SalesforceCompositeRequest();
+                for (int i = 0; i < batch.Count; i++)
+                {
+                    var entityId = batch[i];
+                    compositeRequest.CompositeRequest.Add(new SalesforceCompositeSubRequest
+                    {
+                        Method = "DELETE",
+                        Url = $"/services/data/v60.0/sobjects/{entityName}/{entityId}",
+                        ReferenceId = $"delete_{startIndex + i}"
+                        // Body intenzionalmente null per DELETE
+                    });
+                }
+
+                var jsonContent = new StringContent(
+                    JsonSerializer.Serialize(compositeRequest, SalesforceJsonOptions),
+                    System.Text.Encoding.UTF8,
+                    "application/json");
+
+                var response = await _httpClient.PostAsync(compositeUri, jsonContent, cancellationToken);
+
+                if (!response.IsSuccessStatusCode)
+                {
+                    var errorContent = await response.Content.ReadAsStringAsync(cancellationToken);
+                    _logger.LogDebug($"Salesforce Batch Delete failed: {response.StatusCode} - {errorContent}");
+
+                    return batch.Select((id, idx) => new CompositeOperationResult
+                    {
+                        ReferenceId = $"delete_{startIndex + idx}",
+                        EntityId = id,
+                        Success = false,
+                        ErrorMessage = $"Batch operation failed: {response.StatusCode} - {errorContent}"
+                    }).ToList();
+                }
+
+                var responseContent = await response.Content.ReadAsStringAsync(cancellationToken);
+                var compositeResponse = JsonSerializer.Deserialize<SalesforceCompositeResponse>(responseContent, SalesforceJsonOptions);
+
+                var results = new List<CompositeOperationResult>();
+                if (compositeResponse?.CompositeResponse != null)
+                {
+                    for (int i = 0; i < compositeResponse.CompositeResponse.Count; i++)
+                    {
+                        var sub = compositeResponse.CompositeResponse[i];
+                        var originalId = i < batch.Count ? batch[i] : string.Empty;
+
+                        var result = new CompositeOperationResult
+                        {
+                            ReferenceId = sub.ReferenceId,
+                            EntityId = originalId,
+                            HttpStatusCode = sub.HttpStatusCode,
+                            // 204 No Content è la risposta di successo standard per DELETE
+                            Success = sub.HttpStatusCode >= 200 && sub.HttpStatusCode < 300
+                        };
+
+                        if (!result.Success)
+                            result.ErrorMessage = sub.Body?.ToString() ?? "Unknown error";
+
+                        results.Add(result);
+                    }
+                }
+
+                return results;
+            }
+            catch (Exception ex)
+            {
+                _logger.LogDebug($"Error during Salesforce batch delete: {ex.Message}");
+                return batch.Select((id, idx) => new CompositeOperationResult
+                {
+                    ReferenceId = $"delete_{startIndex + idx}",
+                    EntityId = id,
+                    Success = false,
+                    ErrorMessage = ex.Message
+                }).ToList();
+            }
+        }
+
+        
+
+        /// <summary>
+        /// Bulk PATCH per aggiornare un singolo campo (es. campo di tombstone/mark-as-deleted) su N record.
+        /// </summary>
+        public Task<List<CompositeOperationResult>> BatchPatchSingleFieldAsync(
+            string entityName,
+            IEnumerable<string> entityIds,
+            string fieldName,
+            object fieldValue,
+            CancellationToken cancellationToken = default)
+        {
+            var updates = entityIds
+                .Where(id => !string.IsNullOrEmpty(id))
+                .ToDictionary(
+                    id => id,
+                    _ => (Dictionary<string, object>)new Dictionary<string, object> { { fieldName, fieldValue } });
+
+            return BatchUpdateEntitiesAsync(entityName, updates, cancellationToken);
+        }
     }
 }

Data_Coupler/Extensions/DataCoupler/DatabaseMethod.cs

@@ -70,7 +70,6 @@ public partial class DataCoupler : ComponentBase
     /// <summary>
     /// Verifica se la credenziale database selezionata è di tipo ODBC
     /// </summary>
-    /// <returns>True se la credenziale è ODBC, altrimenti False</returns>
     protected bool IsOdbcConnection()
     {
         if (string.IsNullOrEmpty(selectedDatabaseCredential))
@@ -80,6 +79,18 @@ public partial class DataCoupler : ComponentBase
         return credential?.DatabaseType == DatabaseType.Odbc;
     }
 
+    /// <summary>
+    /// Verifica se la credenziale database selezionata è di tipo OLE DB
+    /// </summary>
+    protected bool IsOleDbConnection()
+    {
+        if (string.IsNullOrEmpty(selectedDatabaseCredential))
+            return false;
+
+        var credential = databaseCredentials.FirstOrDefault(c => c.Name == selectedDatabaseCredential);
+        return credential?.DatabaseType == DatabaseType.OleDb;
+    }
+    
     /// <summary>
     /// Gestisce il cambio di credenziale database selezionata
     /// </summary>
@@ -621,11 +632,12 @@ public partial class DataCoupler : ComponentBase
                 return;
             }
 
-            // Per ODBC, crea un database manager temporaneo se non esiste
+            // Per ODBC e OLE DB, crea un database manager temporaneo se non esiste
             var managerToUse = currentDatabaseManager;
-            if (managerToUse == null && IsOdbcConnection())
+            if (managerToUse == null && (IsOdbcConnection() || IsOleDbConnection()))
             {
-                Logger.LogInformation("Creando database manager temporaneo per validazione query ODBC");
+                Logger.LogInformation("Creando database manager temporaneo per validazione query {Type}",
+                    IsOdbcConnection() ? "ODBC" : "OLE DB");
                 tempManager = await ConnectionFactory.CreateDatabaseManagerAsync(selectedDatabaseCredential);
                 managerToUse = tempManager;
             }
@@ -661,8 +673,8 @@ public partial class DataCoupler : ComponentBase
 
                 Logger.LogInformation("Query validata con successo: {ColumnCount} colonne", queryColumns.Count);
                 
-                // Per ODBC, salva il manager se non era già presente
+                // Per ODBC e OLE DB, salva il manager temporaneo per riuso
-                if (IsOdbcConnection() && currentDatabaseManager == null && tempManager != null)
+                if ((IsOdbcConnection() || IsOleDbConnection()) && currentDatabaseManager == null && tempManager != null)
                 {
                     currentDatabaseManager = tempManager;
                     tempManager = null; // Non distruggerlo nel finally
@@ -747,6 +759,7 @@ public partial class DataCoupler : ComponentBase
         return databaseType switch
         {
             DatabaseType.SqlServer => $"SELECT TOP {limit} * FROM ({baseQuery}) AS subquery",
+            DatabaseType.OleDb => $"SELECT TOP {limit} * FROM ({baseQuery}) AS subquery",
             DatabaseType.Oracle => $"SELECT * FROM ({baseQuery}) WHERE ROWNUM <= {limit}",
             DatabaseType.MySql => $"{baseQuery} LIMIT {limit}",
             DatabaseType.PostgreSql => $"{baseQuery} LIMIT {limit}",

Data_Coupler/Pages/DataCoupler.razor.cs

@@ -3491,10 +3491,42 @@ public partial class DataCoupler : ComponentBase
             // Crea lista indicizzata per mantenere il record number
             var indexedRecords = records.Select((record, index) => new { Record = record, RecordNumber = index + 1 }).ToList();
 
-            Logger.LogInformation("COMPOSITE: Inizio analisi parallela di {RecordCount} record", indexedRecords.Count);
+            Logger.LogInformation("COMPOSITE: Inizio analisi di {RecordCount} record", indexedRecords.Count);
             var analysisStartTime = DateTime.UtcNow;
 
-            // Processa tutti i record in parallelo
+            // === STEP A: Bulk Pre-Discovery (1 query SQLite + poche SOQL IN invece di 2N+N) ===
+            var sourceKeysForBulk = new List<string>(indexedRecords.Count);
+            foreach (var idx in indexedRecords)
+            {
+                var key = GenerateSourceKey(idx.Record);
+                if (!string.IsNullOrEmpty(key))
+                    sourceKeysForBulk.Add(key);
+            }
+
+            Dictionary<string, KeyAssociation> associationsByKey = new(StringComparer.Ordinal);
+            if (currentUseRecordAssociations && !string.IsNullOrEmpty(currentSourceKeyField) && sourceKeysForBulk.Count > 0)
+            {
+                var commonRequest = new PreDiscoveryRequest
+                {
+                    SourceKeyField = currentSourceKeyField,
+                    DestinationEntity = currentEntityName,
+                    CredentialName = currentCredentialName,
+                    DestinationKeyField = GetEntityIdField(),
+                    FieldMappings = currentFieldMappings,
+                    RestClient = currentRestClient,
+                    EnablePreDiscovery = true,
+                    UseParallelMethod = true,
+                    IsScheduledTransfer = false
+                };
+
+                associationsByKey = await AssociationService.BatchFindOrCreateAssociationsAsync(
+                    sourceKeysForBulk, commonRequest);
+
+                Logger.LogInformation("COMPOSITE: Bulk Pre-Discovery completata - {Found}/{Total} associazioni risolte",
+                    associationsByKey.Count, sourceKeysForBulk.Count);
+            }
+
+            // === STEP B: Analisi locale parallela (no I/O) ===
             var processingTasks = indexedRecords.Select(async indexedRecord =>
             {
                 try
@@ -3513,48 +3545,7 @@ public partial class DataCoupler : ComponentBase
                     // Analizza le associazioni per capire se aggiornare, creare o saltare
                     if (currentUseRecordAssociations && !string.IsNullOrEmpty(sourceKey))
                     {
-                        Logger.LogDebug("COMPOSITE PARALLEL: Cerco associazione per KeyValue: '{KeyValue}', Entity: '{Entity}', Credential: '{Credential}'",
+                        associationsByKey.TryGetValue(sourceKey, out var existingAssociation);
-                            sourceKey, currentEntityName, currentCredentialName);
-
-                        // Usa i metodi paralleli per le operazioni di database
-                        var existingAssociation = await CredentialService.FindKeyAssociationByValueParallelAsync(
-                            sourceKey, currentEntityName, currentCredentialName);
-
-                        // FALLBACK: Se non troviamo l'associazione con tutti i parametri, proviamo solo con il KeyValue
-                        if (existingAssociation == null)
-                        {
-                            existingAssociation = await CredentialService.FindKeyAssociationByValueParallelAsync(sourceKey);
-                            if (existingAssociation != null)
-                            {
-                                // Verifica compatibilità
-                                if (existingAssociation.DestinationEntity != currentEntityName ||
-                                    existingAssociation.RestCredentialName != currentCredentialName)
-                                {
-                                    existingAssociation = null;
-                                }
-                            }
-                        }
-
-                        // 🔍 PRE-DISCOVERY: Usa il servizio centralizzato
-                        if (existingAssociation == null)
-                        {
-                            var preDiscoveryRequest = new PreDiscoveryRequest
-                            {
-                                SourceKey = sourceKey,
-                                SourceKeyField = currentSourceKeyField,
-                                DestinationEntity = currentEntityName,
-                                CredentialName = currentCredentialName,
-                                DestinationKeyField = GetEntityIdField(),
-                                FieldMappings = currentFieldMappings,
-                                RestClient = currentRestClient,
-                                CurrentDataHash = currentDataHash,
-                                EnablePreDiscovery = true,
-                                UseParallelMethod = true, // Usa metodi paralleli thread-safe
-                                IsScheduledTransfer = false
-                            };
-
-                            existingAssociation = await AssociationService.FindOrCreateAssociationAsync(preDiscoveryRequest);
-                        }
 
                         if (existingAssociation != null && existingAssociation.IsActive)
                         {

Data_Coupler/Services/AssociationService.cs

@@ -1,11 +1,13 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text;
 using System.Text.Json;
 using System.Threading.Tasks;
 using CredentialManager.Models;
 using CredentialManager.Services;
 using DataConnection.CredentialManagement.Interfaces;
+using DataConnection.REST.Implementations;
 using DataConnection.REST.Interfaces;
 using Microsoft.Extensions.Logging;
 
@@ -69,6 +71,227 @@ public class AssociationService : IAssociationService
         return null;
     }
 
+    /// <summary>
+    /// Versione bulk del find-or-create — vedi <see cref="IAssociationService.BatchFindOrCreateAssociationsAsync"/>.
+    /// </summary>
+    public async Task<Dictionary<string, KeyAssociation>> BatchFindOrCreateAssociationsAsync(
+        IEnumerable<string> sourceKeys,
+        PreDiscoveryRequest commonRequest)
+    {
+        if (commonRequest == null)
+            throw new ArgumentNullException(nameof(commonRequest));
+
+        var distinctKeys = sourceKeys
+            .Where(k => !string.IsNullOrEmpty(k))
+            .Distinct()
+            .ToList();
+
+        var result = new Dictionary<string, KeyAssociation>(StringComparer.Ordinal);
+        if (distinctKeys.Count == 0)
+            return result;
+
+        // STEP 1 — Bulk lookup nel DB locale (1 query SQLite invece di N)
+        Dictionary<string, KeyAssociation> localMatches;
+        try
+        {
+            localMatches = await _credentialService.FindKeyAssociationsByValuesBulkAsync(
+                distinctKeys, commonRequest.DestinationEntity, commonRequest.CredentialName);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "BULK PRE-DISCOVERY: bulk lookup locale fallito, fallback per-record");
+            // Fallback per-record (mantiene comportamento esistente in caso di problemi)
+            foreach (var key in distinctKeys)
+            {
+                var req = ClonePreDiscoveryRequest(commonRequest, key);
+                var found = await FindOrCreateAssociationAsync(req);
+                if (found != null) result[key] = found;
+            }
+            return result;
+        }
+
+        foreach (var kvp in localMatches)
+            result[kvp.Key] = kvp.Value;
+
+        var missingKeys = distinctKeys.Where(k => !result.ContainsKey(k)).ToList();
+
+        _logger.LogInformation("BULK PRE-DISCOVERY: {Local}/{Total} associazioni trovate localmente, {Missing} da cercare nella destinazione",
+            localMatches.Count, distinctKeys.Count, missingKeys.Count);
+
+        if (missingKeys.Count == 0 || !commonRequest.EnablePreDiscovery)
+            return result;
+
+        // STEP 2 — Pre-Discovery batched sulla destinazione REST
+        // Verifica che il campo chiave sia mappato
+        if (string.IsNullOrEmpty(commonRequest.SourceKeyField) ||
+            !commonRequest.FieldMappings.TryGetValue(commonRequest.SourceKeyField, out var mappedField))
+        {
+            _logger.LogWarning("BULK PRE-DISCOVERY: campo chiave '{SourceKeyField}' non mappato; skip discovery",
+                commonRequest.SourceKeyField);
+            return result;
+        }
+
+        // Solo SalesforceServiceClient supporta SOQL IN ottimizzata; per altri client si ricade al per-record.
+        if (commonRequest.RestClient is SalesforceServiceClient sfClient)
+        {
+            var discovered = await PerformBulkPreDiscoverySalesforceAsync(
+                sfClient, missingKeys, mappedField, commonRequest);
+
+            foreach (var kvp in discovered)
+                result[kvp.Key] = kvp.Value;
+        }
+        else
+        {
+            _logger.LogDebug("BULK PRE-DISCOVERY: client REST non Salesforce, fallback per-record per {Count} chiavi", missingKeys.Count);
+            foreach (var key in missingKeys)
+            {
+                var req = ClonePreDiscoveryRequest(commonRequest, key);
+                var found = await PerformPreDiscoveryAsync(req);
+                if (found != null) result[key] = found;
+            }
+        }
+
+        return result;
+    }
+
+    /// <summary>
+    /// Pre-Discovery batched specifica per Salesforce: usa SOQL <c>WHERE field IN (...)</c>
+    /// per recuperare in pochissime chiamate API tutti i record che matchano una qualsiasi delle chiavi mancanti.
+    /// </summary>
+    private async Task<Dictionary<string, KeyAssociation>> PerformBulkPreDiscoverySalesforceAsync(
+        SalesforceServiceClient sfClient,
+        List<string> missingKeys,
+        string mappedDestinationField,
+        PreDiscoveryRequest commonRequest)
+    {
+        var output = new Dictionary<string, KeyAssociation>(StringComparer.Ordinal);
+
+        // Chunk per stare sotto il limite SOQL/URL (~16 KB GET): ~200 valori per query
+        const int chunkSize = 200;
+        var queries = new List<string>();
+        for (int i = 0; i < missingKeys.Count; i += chunkSize)
+        {
+            var chunk = missingKeys.Skip(i).Take(chunkSize).ToList();
+
+            var sb = new StringBuilder();
+            sb.Append("SELECT Id, ");
+            sb.Append(mappedDestinationField);
+            sb.Append(" FROM ");
+            sb.Append(commonRequest.DestinationEntity);
+            sb.Append(" WHERE ");
+            sb.Append(mappedDestinationField);
+            sb.Append(" IN (");
+            sb.Append(string.Join(",", chunk.Select(v => $"'{v.Replace("'", "\\'")}'")));
+            sb.Append(')');
+
+            queries.Add(sb.ToString());
+        }
+
+        _logger.LogInformation("BULK PRE-DISCOVERY: {QueryCount} SOQL IN-query (~{ChunkSize} chiavi/query, Composite API ceil(N/25) HTTP call)",
+            queries.Count, chunkSize);
+
+        // BatchExecuteQueriesAsync raggruppa fino a 25 query in 1 Composite request
+        var batchResults = await sfClient.BatchExecuteQueriesAsync(queries);
+
+        // Indicizza i risultati per chiave: dal record letto leggiamo il valore di mappedDestinationField
+        var entityIdByKey = new Dictionary<string, string>(StringComparer.Ordinal);
+        foreach (var batchResult in batchResults.Where(r => r.Success && r.Records != null))
+        {
+            foreach (var record in batchResult.Records)
+            {
+                if (!record.TryGetValue(mappedDestinationField, out var keyVal) || keyVal == null)
+                    continue;
+
+                var keyStr = keyVal.ToString();
+                if (string.IsNullOrEmpty(keyStr))
+                    continue;
+
+                var idStr = ExtractDestinationId(record);
+                if (string.IsNullOrEmpty(idStr))
+                    continue;
+
+                // In caso di duplicati in Salesforce, prendiamo il primo
+                if (!entityIdByKey.ContainsKey(keyStr))
+                    entityIdByKey[keyStr] = idStr;
+            }
+        }
+
+        _logger.LogInformation("BULK PRE-DISCOVERY: trovati {Found}/{Missing} record esistenti nella destinazione",
+            entityIdByKey.Count, missingKeys.Count);
+
+        if (entityIdByKey.Count == 0)
+            return output;
+
+        // Salvataggio associazioni Pre-Discovery in parallelo
+        var saveTasks = entityIdByKey.Select(async kvp =>
+        {
+            try
+            {
+                var newAssoc = new KeyAssociation
+                {
+                    KeyValue = kvp.Key,
+                    SourceKeyField = commonRequest.SourceKeyField,
+                    DestinationKeyField = commonRequest.DestinationKeyField ?? "Id",
+                    MappedDestinationField = mappedDestinationField,
+                    DestinationEntity = commonRequest.DestinationEntity,
+                    DestinationId = kvp.Value,
+                    RestCredentialName = commonRequest.CredentialName,
+                    CreatedAt = DateTime.UtcNow,
+                    LastVerifiedAt = DateTime.UtcNow,
+                    IsActive = true,
+                    AdditionalInfo = JsonSerializer.Serialize(new Dictionary<string, object>
+                    {
+                        { "CreatedBy", "PreDiscovery" },
+                        { "DiscoveredAt", DateTime.UtcNow },
+                        { "MappingCount", commonRequest.FieldMappings.Count },
+                        { "BulkPreDiscovery", true },
+                        { "ScheduledTransfer", commonRequest.IsScheduledTransfer },
+                        { "SourceType", commonRequest.SourceType ?? string.Empty }
+                    })
+                };
+
+                var id = commonRequest.UseParallelMethod
+                    ? await _credentialService.SaveKeyAssociationParallelAsync(newAssoc)
+                    : await _credentialService.SaveKeyAssociationAsync(newAssoc);
+
+                newAssoc.Id = id;
+                return (kvp.Key, newAssoc);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "BULK PRE-DISCOVERY: errore nel salvataggio associazione per KeyValue '{KeyValue}'", kvp.Key);
+                return (kvp.Key, (KeyAssociation?)null);
+            }
+        });
+
+        var savedResults = await Task.WhenAll(saveTasks);
+        foreach (var (key, assoc) in savedResults)
+        {
+            if (assoc != null) output[key] = assoc;
+        }
+
+        return output;
+    }
+
+    private static PreDiscoveryRequest ClonePreDiscoveryRequest(PreDiscoveryRequest source, string sourceKey)
+    {
+        return new PreDiscoveryRequest
+        {
+            SourceKey = sourceKey,
+            SourceKeyField = source.SourceKeyField,
+            DestinationEntity = source.DestinationEntity,
+            CredentialName = source.CredentialName,
+            DestinationKeyField = source.DestinationKeyField,
+            FieldMappings = source.FieldMappings,
+            RestClient = source.RestClient,
+            CurrentDataHash = source.CurrentDataHash,
+            EnablePreDiscovery = source.EnablePreDiscovery,
+            UseParallelMethod = source.UseParallelMethod,
+            IsScheduledTransfer = source.IsScheduledTransfer,
+            SourceType = source.SourceType
+        };
+    }
+
     /// <summary>
     /// Verifica se un'associazione è stata creata dal Pre-Discovery
     /// controllando il campo AdditionalInfo
@@ -285,6 +508,22 @@ public interface IAssociationService
 {
     Task<KeyAssociation?> FindOrCreateAssociationAsync(PreDiscoveryRequest request);
     bool IsPreDiscoveryAssociation(KeyAssociation association);
+
+    /// <summary>
+    /// Versione bulk del find-or-create.
+    /// 1) Una sola query SQLite (WHERE KeyValue IN …) per recuperare le associazioni esistenti.
+    /// 2) Per le chiavi non trovate localmente, una manciata di SOQL "IN" su Salesforce
+    ///    (~200 chiavi per query, Composite API: ceil(K/25) HTTP call) invece di K chiamate singole.
+    /// 3) Le associazioni Pre-Discovery scoperte vengono salvate e restituite.
+    /// </summary>
+    /// <param name="sourceKeys">Lista (non vuota) dei valori chiave sorgente per tutti i record da analizzare.</param>
+    /// <param name="commonRequest">Parametri condivisi (entity, credential, restClient, mappings, ecc.).
+    ///   <see cref="PreDiscoveryRequest.SourceKey"/> e <see cref="PreDiscoveryRequest.CurrentDataHash"/>
+    ///   sono ignorati; vengono presi dal parametro <paramref name="sourceKeys"/>.</param>
+    /// <returns>Dizionario KeyValue → KeyAssociation (solo per chiavi trovate/create).</returns>
+    Task<Dictionary<string, KeyAssociation>> BatchFindOrCreateAssociationsAsync(
+        IEnumerable<string> sourceKeys,
+        PreDiscoveryRequest commonRequest);
 }
 
 /// <summary>

Data_Coupler/Services/DeletionSyncService.cs

@@ -1,5 +1,6 @@
 using CredentialManager.Models;
 using DataConnection.CredentialManagement.Interfaces;
+using DataConnection.REST.Implementations;
 using DataConnection.REST.Interfaces;
 using Microsoft.Extensions.Logging;
 
@@ -79,76 +80,18 @@ public class DeletionSyncService : IDeletionSyncService
             _logger.LogInformation("Trovate {Count} cancellazioni in attesa di sincronizzazione", 
                 pendingDeletions.Count);
 
-            // Step 3: Esegui le cancellazioni nella destinazione
+            // Step 3: Esegui le cancellazioni nella destinazione.
-            foreach (var deletion in pendingDeletions)
+            // Per Salesforce usiamo le Composite API in batch (ceil(N/25) HTTP call invece di N);
+            // per gli altri client REST manteniamo il loop sequenziale (nessun batch supportato).
+            if (restClient is SalesforceServiceClient salesforceClient)
             {
-                try
+                await ExecuteBatchedSalesforceDeletionsAsync(
-                {
+                    salesforceClient, destinationEntity, pendingDeletions, options, result);
-                    bool syncSuccess = false;
-                    string errorMessage = "";
-
-                    switch (options.Action)
-                    {
-                        case DeletionAction.Delete:
-                            // Elimina fisicamente il record
-                            syncSuccess = await DeleteRecordAsync(
-                                restClient, destinationEntity, deletion.DestinationId);
-                            break;
-
-                        case DeletionAction.Deactivate:
-                            // Marca il record come inattivo
-                            syncSuccess = await DeactivateRecordAsync(
-                                restClient, destinationEntity, deletion.DestinationId);
-                            break;
-
-                        case DeletionAction.Mark:
-                            // Imposta un campo personalizzato
-                            if (string.IsNullOrEmpty(options.MarkField) || string.IsNullOrEmpty(options.MarkValue))
-                            {
-                                errorMessage = "MarkField e MarkValue devono essere specificati per DeletionAction.Mark";
-                                _logger.LogWarning(errorMessage);
-                                result.Errors.Add($"KeyValue: {deletion.KeyValue} - {errorMessage}");
-                                continue;
-                            }
-
-                            syncSuccess = await MarkRecordAsync(
-                                restClient, destinationEntity, deletion.DestinationId,
-                                options.MarkField, options.MarkValue);
-                            break;
-
-                        default:
-                            errorMessage = $"Azione di cancellazione non supportata: {options.Action}";
-                            _logger.LogWarning(errorMessage);
-                            result.Errors.Add($"KeyValue: {deletion.KeyValue} - {errorMessage}");
-                            continue;
-                    }
-
-                    if (syncSuccess)
-                    {
-                        // Marca la cancellazione come sincronizzata
-                        await _credentialService.MarkDeletionSyncedAsync(deletion.Id);
-                        result.DeletedRecordsSynced++;
-
-                        _logger.LogInformation(
-                            "Cancellazione sincronizzata: KeyValue={KeyValue}, DestinationId={DestinationId}, Action={Action}",
-                            deletion.KeyValue, deletion.DestinationId, options.Action);
             }
             else
             {
-                        result.SyncErrors++;
+                await ExecuteSequentialDeletionsAsync(
-                        var error = $"Errore nella sincronizzazione della cancellazione per KeyValue: {deletion.KeyValue}";
+                    restClient, destinationEntity, pendingDeletions, options, result);
-                        result.Errors.Add(error);
-                        _logger.LogWarning(error);
-                    }
-                }
-                catch (Exception ex)
-                {
-                    result.SyncErrors++;
-                    var error = $"Errore durante la sincronizzazione della cancellazione per KeyValue: {deletion.KeyValue} - {ex.Message}";
-                    result.Errors.Add(error);
-                    _logger.LogError(ex, "Errore nella sincronizzazione della cancellazione per {KeyValue}", 
-                        deletion.KeyValue);
-                }
             }
 
             result.IsSuccess = result.SyncErrors == 0;
@@ -170,6 +113,183 @@ public class DeletionSyncService : IDeletionSyncService
         return result;
     }
 
+    /// <summary>
+    /// Esegue le cancellazioni in batch via Salesforce Composite API.
+    /// Riduce N round-trip HTTP a ceil(N/25) batch in parallelo.
+    /// </summary>
+    private async Task ExecuteBatchedSalesforceDeletionsAsync(
+        SalesforceServiceClient salesforceClient,
+        string destinationEntity,
+        List<KeyAssociation> pendingDeletions,
+        DeletionSyncOptions options,
+        DeletionSyncResult result)
+    {
+        // Per Mark serve MarkField e MarkValue: validazione preventiva (un solo log)
+        if (options.Action == DeletionAction.Mark &&
+            (string.IsNullOrEmpty(options.MarkField) || string.IsNullOrEmpty(options.MarkValue)))
+        {
+            const string err = "MarkField e MarkValue devono essere specificati per DeletionAction.Mark";
+            _logger.LogWarning(err);
+            foreach (var d in pendingDeletions)
+            {
+                result.SyncErrors++;
+                result.Errors.Add($"KeyValue: {d.KeyValue} - {err}");
+            }
+            return;
+        }
+
+        // Mappa entityId → KeyAssociation per ricostruire l'associazione dal risultato batch
+        var deletionsById = pendingDeletions
+            .Where(d => !string.IsNullOrEmpty(d.DestinationId))
+            .GroupBy(d => d.DestinationId)
+            .ToDictionary(g => g.Key, g => g.First()); // se duplicati, prima occorrenza
+
+        var entityIds = deletionsById.Keys.ToList();
+        if (entityIds.Count == 0)
+            return;
+
+        _logger.LogInformation("DELETION SYNC (Salesforce batched): {Count} record, action={Action}",
+            entityIds.Count, options.Action);
+
+        List<DataConnection.REST.Implementations.SalesforceServiceClient.CompositeOperationResult> batchResults;
+        try
+        {
+            switch (options.Action)
+            {
+                case DeletionAction.Delete:
+                    batchResults = await salesforceClient.BatchDeleteEntitiesAsync(destinationEntity, entityIds);
+                    break;
+
+                case DeletionAction.Deactivate:
+                    // Aggiorna IsActive/Active = false in batch.
+                    // Non sappiamo a priori quale dei due campi esista sull'SObject: proviamo IsActive,
+                    // se Salesforce ritorna errore il record verrà segnalato come fallito.
+                    var deactivateUpdates = entityIds.ToDictionary(
+                        id => id,
+                        _ => (Dictionary<string, object>)new Dictionary<string, object>
+                        {
+                            { "IsActive", false }
+                        });
+                    batchResults = await salesforceClient.BatchUpdateEntitiesAsync(destinationEntity, deactivateUpdates);
+                    break;
+
+                case DeletionAction.Mark:
+                    batchResults = await salesforceClient.BatchPatchSingleFieldAsync(
+                        destinationEntity, entityIds, options.MarkField!, options.MarkValue!);
+                    break;
+
+                default:
+                    _logger.LogWarning("DELETION SYNC: azione non supportata: {Action}", options.Action);
+                    foreach (var d in pendingDeletions)
+                    {
+                        result.SyncErrors++;
+                        result.Errors.Add($"KeyValue: {d.KeyValue} - Azione non supportata: {options.Action}");
+                    }
+                    return;
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "DELETION SYNC: errore nell'esecuzione del batch Salesforce");
+            foreach (var d in pendingDeletions)
+            {
+                result.SyncErrors++;
+                result.Errors.Add($"KeyValue: {d.KeyValue} - {ex.Message}");
+            }
+            return;
+        }
+
+        // Aggiorna lo stato delle cancellazioni in DB in parallelo per i record sincronizzati con successo
+        var markSyncedTasks = new List<Task>();
+        foreach (var br in batchResults)
+        {
+            if (!deletionsById.TryGetValue(br.EntityId ?? string.Empty, out var deletion))
+                continue;
+
+            if (br.Success)
+            {
+                result.DeletedRecordsSynced++;
+                markSyncedTasks.Add(_credentialService.MarkDeletionSyncedAsync(deletion.Id));
+                _logger.LogDebug(
+                    "DELETION SYNC: KeyValue={KeyValue}, DestinationId={DestinationId}, Action={Action} OK",
+                    deletion.KeyValue, deletion.DestinationId, options.Action);
+            }
+            else
+            {
+                result.SyncErrors++;
+                var msg = $"KeyValue: {deletion.KeyValue} - {br.ErrorMessage ?? "Unknown error"}";
+                result.Errors.Add(msg);
+                _logger.LogWarning("DELETION SYNC fallita: {Msg}", msg);
+            }
+        }
+
+        if (markSyncedTasks.Count > 0)
+            await Task.WhenAll(markSyncedTasks);
+    }
+
+    /// <summary>
+    /// Fallback sequenziale per client REST non Salesforce.
+    /// </summary>
+    private async Task ExecuteSequentialDeletionsAsync(
+        IRestServiceClient restClient,
+        string destinationEntity,
+        List<KeyAssociation> pendingDeletions,
+        DeletionSyncOptions options,
+        DeletionSyncResult result)
+    {
+        foreach (var deletion in pendingDeletions)
+        {
+            try
+            {
+                bool syncSuccess = false;
+                string errorMessage = "";
+
+                switch (options.Action)
+                {
+                    case DeletionAction.Delete:
+                        syncSuccess = await DeleteRecordAsync(restClient, destinationEntity, deletion.DestinationId);
+                        break;
+                    case DeletionAction.Deactivate:
+                        syncSuccess = await DeactivateRecordAsync(restClient, destinationEntity, deletion.DestinationId);
+                        break;
+                    case DeletionAction.Mark:
+                        if (string.IsNullOrEmpty(options.MarkField) || string.IsNullOrEmpty(options.MarkValue))
+                        {
+                            errorMessage = "MarkField e MarkValue devono essere specificati per DeletionAction.Mark";
+                            _logger.LogWarning(errorMessage);
+                            result.Errors.Add($"KeyValue: {deletion.KeyValue} - {errorMessage}");
+                            continue;
+                        }
+                        syncSuccess = await MarkRecordAsync(restClient, destinationEntity, deletion.DestinationId,
+                            options.MarkField, options.MarkValue);
+                        break;
+                    default:
+                        errorMessage = $"Azione di cancellazione non supportata: {options.Action}";
+                        _logger.LogWarning(errorMessage);
+                        result.Errors.Add($"KeyValue: {deletion.KeyValue} - {errorMessage}");
+                        continue;
+                }
+
+                if (syncSuccess)
+                {
+                    await _credentialService.MarkDeletionSyncedAsync(deletion.Id);
+                    result.DeletedRecordsSynced++;
+                }
+                else
+                {
+                    result.SyncErrors++;
+                    result.Errors.Add($"Errore nella sincronizzazione della cancellazione per KeyValue: {deletion.KeyValue}");
+                }
+            }
+            catch (Exception ex)
+            {
+                result.SyncErrors++;
+                result.Errors.Add($"KeyValue: {deletion.KeyValue} - {ex.Message}");
+                _logger.LogError(ex, "Errore nella sincronizzazione della cancellazione per {KeyValue}", deletion.KeyValue);
+            }
+        }
+    }
+
     /// <summary>
     /// Elimina fisicamente un record dalla destinazione
     /// </summary>

Data_Coupler/Services/ScheduledProfileExecutionService.cs

@@ -895,10 +895,45 @@ public class ScheduledProfileExecutionService : IScheduledProfileExecutionServic
             // Crea lista indicizzata per mantenere il record number
             var indexedRecords = sourceRecords.Select((record, index) => new { Record = record, RecordNumber = index + 1 }).ToList();
 
-            _logger.LogInformation("COMPOSITE SCHEDULED: Inizio analisi parallela di {RecordCount} record", indexedRecords.Count);
+            _logger.LogInformation("COMPOSITE SCHEDULED: Inizio analisi di {RecordCount} record", indexedRecords.Count);
             var analysisStartTime = DateTime.UtcNow;
 
-            // Processa tutti i record in parallelo
+            // === STEP A: Bulk Pre-Discovery (1 query SQLite + poche SOQL IN invece di 2N+N) ===
+            // Pre-calcolo locale: source key per ogni record (operazione thread-safe)
+            var sourceKeyByRecordIndex = new Dictionary<int, string>(indexedRecords.Count);
+            foreach (var idx in indexedRecords)
+            {
+                var key = GenerateSourceKey(idx.Record, profile.SourceKeyField);
+                if (!string.IsNullOrEmpty(key))
+                    sourceKeyByRecordIndex[idx.RecordNumber] = key;
+            }
+
+            Dictionary<string, KeyAssociation> associationsByKey = new(StringComparer.Ordinal);
+            if (currentUseRecordAssociations && !string.IsNullOrEmpty(profile.SourceKeyField) && sourceKeyByRecordIndex.Count > 0)
+            {
+                var commonRequest = new PreDiscoveryRequest
+                {
+                    SourceKeyField = profile.SourceKeyField,
+                    DestinationEntity = currentEntityName,
+                    CredentialName = currentCredentialName,
+                    DestinationKeyField = "Id",
+                    FieldMappings = fieldMappings,
+                    RestClient = restClient,
+                    EnablePreDiscovery = true,
+                    UseParallelMethod = true,
+                    IsScheduledTransfer = true,
+                    SourceType = profile.SourceType
+                };
+
+                associationsByKey = await _associationService.BatchFindOrCreateAssociationsAsync(
+                    sourceKeyByRecordIndex.Values, commonRequest);
+
+                _logger.LogInformation("COMPOSITE SCHEDULED: Bulk Pre-Discovery completata - {Found}/{Total} associazioni risolte",
+                    associationsByKey.Count, sourceKeyByRecordIndex.Count);
+            }
+
+            // === STEP B: Analisi locale parallela per decidere create/update/skip ===
+            // Nessuna chiamata DB o REST in questo loop — solo memoria.
             var processingTasks = indexedRecords.Select(async indexedRecord =>
             {
                 try
@@ -916,49 +951,7 @@ public class ScheduledProfileExecutionService : IScheduledProfileExecutionServic
                     // Analizza le associazioni per capire se aggiornare, creare o saltare
                     if (currentUseRecordAssociations && !string.IsNullOrEmpty(sourceKey))
                     {
-                        _logger.LogDebug("COMPOSITE SCHEDULED: Cerco associazione per KeyValue: '{KeyValue}', Entity: '{Entity}', Credential: '{Credential}'",
+                        associationsByKey.TryGetValue(sourceKey, out var existingAssociation);
-                            sourceKey, currentEntityName, currentCredentialName);
-
-                        // Cerca associazione esistente usando il metodo parallelo
-                        var existingAssociation = await _dataConnectionCredentialService.FindKeyAssociationByValueParallelAsync(
-                            sourceKey, currentEntityName, currentCredentialName);
-
-                        // FALLBACK: Se non troviamo l'associazione con tutti i parametri, proviamo solo con il KeyValue
-                        if (existingAssociation == null)
-                        {
-                            existingAssociation = await _dataConnectionCredentialService.FindKeyAssociationByValueParallelAsync(sourceKey);
-                            if (existingAssociation != null)
-                            {
-                                // Verifica compatibilità
-                                if (existingAssociation.DestinationEntity != currentEntityName ||
-                                    existingAssociation.RestCredentialName != currentCredentialName)
-                                {
-                                    existingAssociation = null;
-                                }
-                            }
-                        }
-
-                        // 🔍 PRE-DISCOVERY: Usa il servizio centralizzato
-                        if (existingAssociation == null && !string.IsNullOrEmpty(profile.SourceKeyField))
-                        {
-                            var preDiscoveryRequest = new PreDiscoveryRequest
-                            {
-                                SourceKey = sourceKey,
-                                SourceKeyField = profile.SourceKeyField,
-                                DestinationEntity = currentEntityName,
-                                CredentialName = currentCredentialName,
-                                DestinationKeyField = "Id",
-                                FieldMappings = fieldMappings,
-                                RestClient = restClient,
-                                CurrentDataHash = currentDataHash,
-                                EnablePreDiscovery = true,
-                                UseParallelMethod = true, // Usa metodi paralleli thread-safe
-                                IsScheduledTransfer = true,
-                                SourceType = profile.SourceType
-                            };
-
-                            existingAssociation = await _associationService.FindOrCreateAssociationAsync(preDiscoveryRequest);
-                        }
 
                         if (existingAssociation != null && existingAssociation.IsActive)
                         {