When testing some queries, I set the recovery model to full on a database and ran two identical 1M row inserts, with and without TABLOCK.
On the one with TABLOCK, I got around 9295 log records on a sql server 2008 instance, and around 8714 log records on a SQL Server 2017 instance.
When running the insert without tablock, I get around 1035659 records for the 2008 instance and around 1068599 records for the 2017 instance.
The reason for testing on sql server 2008 is to match the data loading performance guide's statement on the recovery models for ML operations :
Minimally logged operations are available only if your database is in bulk-logged or simple recovery mode.
So, what am Is seeing here if it is not minimal logging?
Use DatabaseName ALTER DATABASE DatabaseName SET RECOVERY FULL; GO BACKUP DATABASE DatabaseName TO DISK = '\\location\DatabaseName.bak'; BACKUP LOG DatabaseName TO DISK = '\\location\DatabaseName_log.trn'; GO IF OBJECT_ID(N'dbo.Accounts', N'U') IS NOT NULL BEGIN DROP TABLE dbo.Accounts; END; GO CREATE TABLE dbo.Accounts( AccountID INT PRIMARY KEY NOT NULL, AccountName varchar(255), DateCreated DATETIME2); -- Insert 1M Rows into dbo.Account without TABLOCK GO SET STATISTICS IO, TIME ON; INSERT INTO dbo.Accounts (AccountID,AccountName,DateCreated) SELECT TOP(1000000) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)), 'Name N ' + CAST(ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS varchar(255)), DATEADD(MINUTE,-ROW_NUMBER() OVER (ORDER BY (SELECT NULL)),GETDATE()) FROM MASTER..SPT_VALUES SPT1 CROSS APPLY MASTER..SPT_VALUES SPT2; GO -- check the amount of records in the log file SELECT count(*) FROM fn_dbLog(NULL,NULL); --1035659 rows GO -- clear the log BACKUP LOG DatabaseName to disk = '\\location\DatabaseName_log2.trn'; GO --drop the table IF OBJECT_ID(N'dbo.Accounts', N'U') IS NOT NULL BEGIN DROP TABLE dbo.Accounts; END; GO -- create the table CREATE TABLE dbo.Accounts( AccountID INT PRIMARY KEY NOT NULL, AccountName varchar(255), DateCreated DATETIME2); -- Insert 1M Rows into dbo.Account WITH TABLOCK GO SET STATISTICS IO, TIME ON; INSERT INTO dbo.Accounts WITH(TABLOCK) (AccountID,AccountName,DateCreated) SELECT TOP(1000000) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)), 'Name N ' + CAST(ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS varchar(255)), DATEADD(MINUTE,-ROW_NUMBER() OVER (ORDER BY (SELECT NULL)),GETDATE()) FROM MASTER..SPT_VALUES SPT1 CROSS APPLY MASTER..SPT_VALUES SPT2; GO -- check the amount of records in the log file SELECT count(*) FROM fn_dbLog(NULL,NULL); --9295 rows 
