JMSM (1/21/2010)
We've got a client that detect that in one database three tables are without statistics.Q1: My SQL Instance its configured to automatically update statistics so why are not update statistics on those objects?
Auto_update only updates existing statistics, it won't create new ones. For that, auto_create has statistics to be enabled and SQL has to need the statistics. If it doesn't need them, it won't create them.
Q3: What is the best way to configure or not configure statistics in an object?
Let SQL create them (auto create), let SQL automatically update them unless you know that the auto_update is not sufficient.
Q4: Whar is the impact on create statistics during daily working hours?
Table [TableName1] on column [column1]
Table [TableName2] on column [column2]
Table [TableName3] on column [column3]
Minimal, but only create them if you're sure they're needed. If auto_create statistics is on, SQL will automatically create any it needs and you don't have to bother.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability