How do I make indexes faster?
Add the index to the new empty table. copy the data from the old table to the new table in chunks. drop the old table. My theory is that it will be less expensive to index the data as it is added than to dig through the data that is already there and add the index after the fact.
Are clustered or nonclustered indexes faster?
If you want to select only the index value that is used to create and index, non-clustered indexes are faster. On the other hand, with clustered indexes since all the records are already sorted, the SELECT operation is faster if the data is being selected from columns other than the column with clustered index.
When to not use the index filter in SQL Server?
Here are a couple of scenarios when this filter is not very useful: If we have user_updates = 2 and user_scans + user_seeks + user_lookups = 1 for an index then this index will be returned when the filter above is used. But it doesn’t really mean that we have a huge index update overhead.
What happens if you don’t filter out unused indexes?
The query above is missing Unique and Primary Key constraints exclusions and you can break your application if you don’t filter out “unused” indexes that are also Unique and Primary Key constraints. Make sure you always use the filter above when you check unused indexes.
Why are array formulas so slow in Excel?
It is the array formulas that are slowing your worksheet down. It take about 30 seconds on my machine to recalculate as well. If you can figure out a solution without the array formulas, then you won’t run to the slow calculation. If you cannot, the only solution I can think of is to change your spreadsheet to manual calculation.
When to delete or disabling ” unused ” indexes can cause application issues?
Here is another real-life example when deleting or disabling “unused” indexes can cause application issues. If a vendor’s application queries have table/query hints to force a specific index usage you will break the application by dropping this index. Here is an error the application will raise: