What caused SQLServer huge transaction log

One sharepoint database transaction log file and backup is getting huge, sharepoint admin turned off the auditing and other features and still having big tran log generated every day. I dig into it and found what is responsible:

Thanks to this:

https://blog.coeo.com/inside-the-transaction-log-file

SELECT

[Operation],

count(*) AS [No of Records],

SUM([Log Record Length]/1024.00/1024.00) AS [RecordSize (MB)]

FROM fn_dblog(NULL,NULL)

GROUP BY Operation

ORDER BY [RecordSize (MB)] DESC

so it's the LOP_shrink_noop that generated 7GB transaction log today since last backup, that's because the database auto shrink is set to true.

select name,is_auto_shrink_on, * FROM    sys.databases

Turn off the autoShrink fixed the problem.

If the cause is DML, you can find what table is it.

SELECT

       [Operation]

       ,SUM([Log Record Length]/1024.00/1024.00) AS [RecordSize (MB)]

        ,count(*) OperationCount

       ,[AllocUnitName]

       --,[Begin Time]

       --,[End Time]

       ,[Transaction Name]

       --,[Transaction SID]

       --,[Transaction Begin]

       --,[Number of Locks]

       --,[Lock Information]

       --,[Description]

       --,[Log Record]

FROM sys.fn_dblog(null,null)

--WHERE [Transaction ID] = '0000:00011043'

group by [Operation],[AllocUnitName],[Transaction Name]

order by SUM([Log Record Length]/1024.00/1024.00) desc