However, tables with deleted data can still be queried using vectorization.
The following example demonstrates the correct usage of this statement: Use the MERGE statement to efficiently perform record-level INSERT, UPDATE, and DELETE operations within Hive tables.
Pinal is also a Cross Fit Level 1 Trainer (CF-L1) and Cross Fit Level 2 Trainer (CF-L2).
In most cases, when using Transact-SQL to modify data in a SQL Server database, you issue an UPDATE statement that changes specific values.
I created the examples in the Adventure Works2008 database on a local instance of SQL Server 2008.
However, most of the examples will work in the original Adventure Works database, on SQL Server 2005 or 2008.
Can I 100% believe on results return by sys.dm_db_index_usage_stats for Last)user_update? Hi Pinal, This shows last user update, do you know of any way to find out when the last table update was made in general, like through an application?
A lot of the tables in my environment get updated through applications, and we are in the process of doing an inventory on old junk tables/records. SELECT DB_NAME(index Stats.database_id) as database Name , OBJECT_NAME(index Stats.”object_id”, index Stats.database_id) as object Name , sum(index Stats.user_seeks ) as user_seeks , sum(index Stats.user_scans ) as user_scans , sum(index Stats.user_lookups ) as user_lookups , sum(index Stats.user_updates ) as user_updates , max(index Stats.last_user_seek ) as last_user_seek , max(index Stats.last_user_scan ) as last_user_scan , max(index Stats.last_user_lookup) as last_user_lookup , max(index Stats.last_user_update) as last_user_update , sum(index Stats.system_seeks ) as system_seeks , sum(index Stats.system_scans ) as system_scans , sum(index Stats.system_lookups ) as system_lookups , sum(index Stats.system_updates ) as system_updates , max(index Stats.last_system_seek ) as last_system_seek , max(index Stats.last_system_scan ) as last_system_scan , max(index Stats.last_system_lookup) as last_system_lookup , max(index Stats.last_system_update) as last_system_update FROM sys.dm_db_index_usage_stats as index Stats group by index Stats.database_id , index Stats.”object_id” order by index Stats.database_id , index Stats.”object_id” ; Dear Sir, I am developing a web application , and need to write a sql query demo satisfy 3nf any change in master table should reflect in all other table where ever that common id shares integrated with PHP and mysql.
The UPDATE and DELETE statements enable users to modify and delete values already written to Hive.
An UPDATE statement must always include a SET clause, which identifies the columns to be updated.
In addition, the statement can include a WHERE clause, which determines what rows to modify, or a FROM clause, which identifies tables or views that provide values for the expressions defined in the SET clause.
On close observation the table is not required to keep history when any row is inserted.
However, the sole prerequisite is to be aware of when any table has been updated. If a user wants to finds out when was the last table updated he can query dynamic management view (dmv) – sys.dm_db_index_usage_stats and easily figure out when was the table updated last.