What is DBCC PAGE?

DBCC PAGE command is used to display contents of data pages where table rows data are stored in SQL Server database tables. Database administrators and SQL developers can use DBCC PAGE statement for displaying data in certain data page.

What is page index in SQL Server?

SQL Server provides us with two main types of indexes, the Clustered index that stores the actual data rows of the table at the leaf level of the index, in addition to controlling the sorting criteria of the data within the data pages and the order of the pages itself, based on the clustered index key.

How do you use DBCC Traceon?

Remarks

  1. Using the DBCC TRACEON and DBCC TRACEOFF commands. For example, to enable the 2528 trace flag globally, use DBCC TRACEON with the -1 argument: DBCC TRACEON (2528, -1) .
  2. Using the -T startup option to specify that the trace flag be set on during startup.
  3. At the query level, by using the QUERYTRACEON query hint.

What is DCM page in SQL Server?

The Differential Changed Map (DCM) is a bitmap pointer referenced by SQL Server to trace the modified pages since the last full backup. It is stored in DCM pages, one per GAM interval. A differential backup process will identify those pages with CHANGED status in the DCM.

What is DBCC in SQL?

Microsoft SQL Server Database Console Commands (DBCC) are used for checking database integrity; performing maintenance operations on databases, tables, indexes, and filegroups; and collecting and displaying information during troubleshooting issues.

How do I run a DBCC Checktable?

To perform DBCC CHECKTABLE on every table in the database, use DBCC CHECKDB. For the specified table, DBCC CHECKTABLE checks for the following: Index, in-row, LOB, and row-overflow data pages are correctly linked. Indexes are in their correct sort order.

What are pages and extents in SQL Server?

The page is the fundamental unit of data storage in SQL Server. An extent is a collection of eight physically contiguous pages. Extents help efficiently manage pages. This guide describes the data structures that are used to manage pages and extents in all versions of SQL Server.

What are DBCC commands?

What is SQL Server Traceon?

Trace flags are used in SQL Server to change the behavior of certain areas. For example, 1222 trace flag is used to enable logging of deadlocks in SQL Server ERRORLOG file. You can imagine this like an if condition in SQL Server. If trace flag is ON. {Do this also}

How many types of pages are there in SQL Server?

As far as I know, there are about 14 types of pages in SQL Server data file. Type 1 – Data page. Small LOB value(s), multiple types and rows.

Is DBCC Checkdb necessary?

Microsoft runs corruption checks in the background with your backups (This doesn’t mean CHECKDB isn’t needed. You should still be doing your DBA 101 tasks.)