sql update statistics

needs to be displayed in the result setStatisticsInformation, The optimizer will select the best execution method, because the optimizer willStatisticsInformation. InCreateWhen indexing, SQLServer will be on the index ColumnCreateStatisticsInformation. To put it simply,StatisticsInformationThat is, the data that can describe the data distribution in the index or column. Query selectivity: Formula: Total number of non-duplicated data in a column/total number of data in a column The higher the s

Tags: SP data bs SQL Information Server nbsp First 500Pre-Preparation:Normal table, temporary table: It has statistical information on the two sessions.Table variable: There is no statistical information.--------------------------------------------------------------------------------------------------------------- -----------------------------------Create a scenario for statistics:1. When you create an inde

The basic algorithm for automatically updating statistics is: · If the table is in the tempdb database table the cardinality is less than 6, automatically updated to the table for each of the six modifications. · If the base of the table is greater than 6, but less than or equal to 500, update the status every 500 of the modifications. · If the cardinality is greater than 500, the table changes when the

Summary: Statistical information for the query:So far, the selection index and maintenance index have been introduced. If you have an appropriate index and update statistics in real time, the optimizer chooses a useful index for querying, because the SQL Server optimizer is cost-based optimization. When the data on the where and on columns needs to be displayed i

Statistics of SQL Server research-discover and process expired statistics, and analyze SQL statisticsPreface: Statistical information is the main source of information about data distribution in predicates. If you do not know the specific data distribution, the optimizer cannot obtain the estimated data set and therefo

. Update Time: SELECT name AS index_name, STATS_DATE (object_id, index_id) AS update_dateFROM sys. indexes WHERE object_id = OBJECT_ID ('[Sales]. [SalesOrderDetail] '); -- view all statistics. Update Time: select s. name, STATS_DATE (s. object_id, stats_id) AS update_datefrom sys. stats s WHERE s. object_id = OBJECT_ID ('[Sales]. [SalesOrderDetail] '); -- view al

Original: Performance optimization-Statistics--sqlserver Automatic Update and auto-create statistics optionsOriginal translation from: Http://www.mssqltips.com/sqlservertip/2766/sql-server-auto-update-and-auto-create-statistics-op

Label:Original: Chapter 12th--sqlserver Statistics (1)--Create and update statisticsSummary: Statistical information for the query:So far, the selection index and maintenance index have been introduced. If you have an appropriate index and update statistics in real time, the optimizer chooses a useful index for queryin

Original translation from: Http://www.mssqltips.com/sqlservertip/2766/sql-server-auto-update-and-auto-create-statistics-options/?utm _source=dailynewsletterutm_medium=emailutm_content=headlineutm_campaign=2012913How does statistical information improve SQL Server query performance? The statistical histogram is used as

Statistical information is used by the query optimizer to create query plans that improve query performance by using statistics.Statistics are the object of the database, and the statistics provided are information about the table or indexed view.Statistics for query optimization is objects that contain statistical information on the distribution of values in one or more columns of a table or indexed view.View sta