sql server index tuning wizard

Label:first, the basic concept of indexed views An indexed view is actually a view that "materialized" a set of unique values into a clustered index, which is materialized almost as a table, and its data is stored in one copy (it consumes hard disk space, but the query is fast, for example, you can set count (), sum () in the indexed view) . The advantage is that it provides a very quick way to find the information behind the view. After the first

Like what: SELECT * FROM table1 where name= ' Zhangsan ' and TID > 10000 and implementation: SELECT * FROM table1 where TID > 10000 and name= ' Zhangsan ' Some people do not know the execution efficiency of the above two statements is the same, because if it is simple to read from the statement, the two statements are indeed different, if the TID is an aggregation index, then the following sentence only from the table after 10,000 records to find the

Index reconstruction aims to reduce data fragmentation. Data fragmentation can cause SQL Server to read unnecessary data and reduce SQL Server performance. Re-indexing also updates column statistics. If the Column Used for the query lacks or misses statistical information, t

1. Check the database space usage to see which tables are consuming larger disk spaceExecute the following statement:SelectO.name, SUM (p.reserved_page_count) asReserved_page_count, SUM (p.used_page_count) asUsed_page_count, SUM ( CaseWhen (p.index_id2) Then (p.in_row_data_page_count+P.lob_used_page_count+p.row_overflow_used_page_count)Elsep.lob_used_page_count+P.row_overflow_used_page_count End) asDataPages, SUM ( CaseWhen (p.index_id2) then Row_countElse 0end) asrowcounts fromsys.dm_db_partiti

to large according to the selected key values,SQL Server 2000Later versions can specify that the data is sorted from large to small. The entire data table is sorted from small to large by key value fields, and then combined with the upper-layer index structure of the key value field plus the pointer, that is, the root node and non-slave layer, forming the enti

An understanding of the index structureIn fact, you can interpret the index as a special kind of directory. Microsoft's SQL Server provides two indexes: a clustered index (clustered index, also known as a clustered, clustered

Original: SQL Server index and table Architecture (nonclustered index)Nonclustered indexesOverviewfor nonclustered indexes, the information involved is a bit more than the clustered index, because the entire length of the page is much more involved in the next "

After setting the SET statistics profile, you will return to the Execution plan table, through which you can understand the process of statement execution and understand if SQL Server chooses the correct execution plan to determine the tuning direction!1. Returns the table field description:Rows: The actual number of rows returned in each step of the execution pl

. CREATEINDEXNCLIX_OrderDetails_ProductIDONdbo.OrderDetails(ProductID) You can also create an index on the required columns on the SQL Server console. Step 2: Create a correct Composite Index Have you created all the appropriate indexes in the database? Assume that you have created an

The basic unit of data storage in SQL Server is the page. The disk space allocated by the data file (. mdf or. ndf) in the database can be logically divided into pages (numbered from 0 to n consecutively). Disk I/O operations are performed at the page level. That is, the smallest unit of data that SQL Server reads or w

I. Overview of Indexes 1. Concept: a database index is a structure that sorts the values of one or more columns in a data table, just like a directory in a book, indexes provide the ability to quickly query specific rows in rows. 2. Advantages and Disadvantages: 2.1 Advantages: 1. It greatly accelerates data search, which is the main reason for the introduction of indexes. 2. Create a unique index to ens

Tags: naming bin Sch clustered User Web page binding modeling altfirst, the basic concept of indexed views An indexed view is actually a view that "materialized" a set of unique values into a clustered index, which is materialized almost as a table, and its data is stored in one copy (it consumes hard disk space, but the query is fast, for example, you can set count (), sum () in an indexed view). The advantage is that it provides a very quick way to

Reproduced:SQL Server index structure and its use (i)FreedkFirst, understand the index structure in a comprehensible senseIn fact, you can interpret an index as a special kind of directory. Microsoft's SQL Server provides two type

Label:The leaf page of a clustered index stores the table's data. As a result, table rows are physically sorted by clustered index columns, because table data can only have one physical order, so a table can have only a single clustered index. When we create a PRIMARY key constraint, if there is no clustered index and

Tags: style using file data ar problem time line　　SQL Server index structure and its use (i)FreedkFirst, understand the index structure in a comprehensible senseIn fact, you can interpret an index as a special kind of directory. Microsoft's

Is null and is not null in SQL SERVER cause index failure ?, Sqlnull In fact, there is nothing to say about this problem. I encountered an SQL statement during optimization today. Because it is interesting, I have cut and simplified the SQL statement and demonstrated it for

SQL Server INDEX OPTIMIZATION Clustered Index , The data stored in the table is stored in the order of indexes. , Higher retrieval efficiency than normal indexes , However, data is added / Modify / The deletion has a large impact. Non-clustered Index , The data storage

Label:first, the concept of bookmark search Bookmarks can help SQL Server quickly direct from the nonclustered index entry to the corresponding line, but I can actually say a few words about it. 　　If the table has a clustered index (the section structure), then the bookmark is the clustered

Tags: DDL transparent full logical read product tree structure row Modify efficient entryfirst, the concept of bookmark search Bookmarks can help SQL Server quickly direct from the nonclustered index entry to the corresponding line, but I can actually say a few words about it. 　　If the table has a clustered index (the

Ind_attribute.is_ Disabled as [is disabled] 4 from (5 select Tab_name,index_name, [Co_names]=stuff ((SELECT ', ' +[co_name ') from 6 (select Tab. Name as Tab_name,ind. Name as index_name,col.name as Co_name from sys.indexes IND 7 INNER JOIN Sys.tables tab on Ind. object_id = tab.object_id and Ind.type in (8) inner join sys.index_columns index_columns on tab.object_id = Index_colu mns.object_id and ind.index_id = index_columns.index_id 9 inner join sys.columns Col on tab.object_id = col.object_i