server index

The order of clustered indexes is the physical order in which data is stored, so a table can have at most one clustered index.The order of nonclustered indexes is independent of the physical storage order.The data in SQL Server is indexed by the

Transferred from: HTTP://WWW.CNBLOGS.COM/CHENMHNonclustered 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 "index of

1.1 Clustered IndexThe data for the table is stored in the data page (the pagetype tag of the data page is 1), and the SQL Server page is 8k, and the next page is saved by filling a page. If the table has a clustered index, then a single piece of

1.1 Clustered IndexThe data for the table is stored in the data page (the pagetype tag of the data page is 1), and the SQL Server page is 8k, and the next page is saved by filling a page. If the table has a clustered index, then a single piece of

David Durant,2011/10/05Original link:http://www.sqlservercentral.com/articles/Stairway+Series/72441/the series This article is“StairwaySeries:SQL Serverpart of the ladder of the index indexes are the basis of database design and tell developers to

The main considerations for designing SQL Server indexes are as follows:Check where condition and join condition column;Use narrow index;Check the selectivity of the column;Check the data type of the column;Consider the order of the columns;Consider

The SQL Server version is R2.SQL statement (source) for querying database index fragmentation conditions:SELECT object_name(Ind.)object_id) asTableName, Ind.name asIndexName, Indexstats.index_type_desc asIndextype,

I. Non-clustered index maintenanceThe row locator value for a nonclustered index keeps the same clustered index value, even after the clustered index column is physically relocated.To optimize this maintenance overhead, SQL Server adds a pointer to

first, the basic concept of indexed viewsAn 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,

first, the storage structureIn SQL Server, there are many different options available for arranging rules.Binary: Sort by the numeric representation of the characters (ASCII, with the number 32 for spaces, and 68 for the letter "D"). Because

Index categoryUnique index (unique) clustered index (CLUSTERED) nonclustered index (nonclustered)The difference between a primary key and a unique indexA primary key is a constraint, and a unique index is an index, and the two are essentially

The database has two storage requirements: data pages and index pages. Understanding and viewing actual data in your table is quite simple. Run some query examples to learn which columns are used and what types of data are actually stored. On the

To improve SQL statements, many people do not know how SQL statements are executed in SQL Server. They are worried that SQL statements they write will be misunderstood by SQL Server. For example: select * fromtable1wherenamezhangsanandtID10000 and

With the SQL Server event probe tool, you can use a captured trace to collect important information about the Server. With the Index Tuning Wizard, ITW, Index OPTIMIZATION Wizard, and correct general Index information, this trail can help you debug

Run the following script to view the size of database index fragments:Copy codeThe Code is as follows:Dbcc showcontig with fast, TABLERESULTS, ALL_INDEXES, NO_INFOMSGSThe following scripts are used to process maintenance tasks:Copy codeThe Code is

I took over an optimization project in the previous section, which requires that the company optimize the indexes of more than existing tables to improve the existing ones and eliminate invalid indexes. In view of the serious shortage of manpower

In view of the serious shortage of manpower (the resources of two and a half persons were counted at that time), the idea of Manually changing databases one by one was dispelled. The current program structure does not allow revolutionary practices,

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

Index instructions Digress: Yesterday, we were depressed. When we maintained a customer's database system, we found that the system was processing data and there was a false death. At first, Because of software problems, I was too busy to copy

If we want to optimize the database, we can use the following five methods to optimize the database system: If we want to optimize the database, we can use the following five methods to optimize the database system: 1.1.1 Summary If we want to