Start Updating a row in sql server

Updating a row in sql server

And when I say every operation I really do mean every operation, including the often misunderstood minimally logged and bulk logged operations, and the so called “non-logged” operations, like .

Remember that even non-partitioned tables are still represented in dbcc traceon(3604,-1); dbcc page(5,1,79,3); Slot 0 Offset 0x60 Length 39 Record Type = PRIMARY_RECORD Record Attributes = NULL_BITMAP Record Size = 39 Memory Dump @0x000000000EB0A060 0000000000000000: 10002400 01000000 7374616e 64616c6f 6e652078 ..$.....standalone x 0000000000000014: 61637420 20202020 912ba300 b6a10000 030000 act ‘ £.¶¡.....

Split Page transactions are how SQL Server maintains the structural key order constraints of B-Trees and there is ample literature on this subject, see Tracking page splits using the transaction log or How expensive are page splits in terms of transaction log? Notice that all these Slip Page transactions have the same was started.

Tables are normally created w/o any page and the very first INSERT will trigger the allocation of the first page for the table.

Although all three transactions run ‘simultaneous’ the true order of operation is the one in the log, given by the create table demotable ( id int not null identity(1,1) primary key, data char(20), created_at datetime default getutcdate()); go insert into demotable (data) values ('standalone xact'); go 5 begin transaction go insert into demotable (data) values ('one xact'); go 5 commit; go delete from demotable where id in (2,5,6,9); go operations.

This log record marks the beginning of a transaction and is very important in log analysis because is the only log record that contains the date and time when the transaction started, and also contains the SID of the user that had issued the statement.

It is one of the main forensic tools at your disposal when trying to identify the author of an unwanted change.

Understanding the log and digging through it for information is pretty hard core and definitely not for the faint of heart.

In addition we also see a number of transactions that we cannot correlate directly with a statement from their name.