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Can DELETE statements be rolled back?
DROP and TRUNCATE are DDL commands, whereas DELETE is a DML command. DELETE operations can be rolled back (undone), while DROP and TRUNCATE operations cannot be rolled back.
What is the difference between delete and TRUNCATE statements?
The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row. TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log. DELETE command is slower than TRUNCATE command.
How to begin a delete transaction in SQL?
Now, let’s begin a delete transaction using the begin transaction statement: Since we did not specify the WHERE clause in the delete statement, it removes all ten rows from the test table: Do not commit the transaction as of now. We use the undocumented function fn_dblog to read transaction logs.
How is the transaction log implemented in SQL Server?
The transaction log is implemented as a separate file or set of files in the database. The log cache is managed separately from the buffer cache for data pages, which results in simple, fast, and robust code within the SQL Server Database Engine.
How does the SQL DELETE statement work in SQL?
SQL delete statement removes individual row and logs entry for each row in the transaction log. We removed 10 rows from the test table, and output also reflects LOB_DELETE_ROWS entry for an individual row. This LOP_DELETE_ROWS operation occurs for the delete statement.
How to find the user who ran a DELETE statement?
We can read the above output as “A DELETE statement began at 2013/10/14 12:55:17:630 under transaction ID 0000:000004ce by user transaction SID 0x0105000000000005150000009F11BA296C79F97398D0CF19E8030000. Now our next step is to convert the transaction SID hexadecimal value into text to find the real name of the user.