Custom Statistics Block Column Alteration DDL

Max Vernon demonstrates that custom statistics and prevent you for modifying a column:

Interestingly, if SQL Server has auto-created a stats object on a column, and you subsequently modify that column, you receive no such error. SQL Server silently drops the statistics object, and modifies the column. The auto-created stats object is *not* automatically recreated until a query is executed that needs the stats object. This difference in how auto-created stats and manually created stats are treated by the engine can make for some confusion.

Just one more thing to think about if you manually create statistics on tables.  But at least the error message is clear.

Related Posts

Errors Updating Stats on Columnstore Indexes

Max Vernon walks us through some problems trying to update statistics on columnstore indexes: The first error above would be seen if you have a SQL Server Agent job that updates statistics. The second error is how it looks in an SSMS Query window. The error message claims that UPDATE STATISTICS can only be used on a […]

Read More

SET STATISTICS IO And Automated Statistics Updates

Niko Neugebauer shows us something new in SQL Server 2019: There has never been such information before!We are just writing into it!Why do we have those wonderful 1351498 logical reads ?Are they actually writes ? And if they would be, would not it be correct to display them as physical accesses ? The answer is […]

Read More

Categories

July 2018
MTWTFSS
« Jun Aug »
 1
2345678
9101112131415
16171819202122
23242526272829
3031