I am very new to any type of tuning but have been learning more.. One of my specific databases one of the problems identified with slow queries are a number of Implicit conversions. It is my ...
By saving a plan in a file, I don't mean to view it, but force the optimizer to use the saved plan to execute some query. For example, if the optimizer chooses to do a hash join for a two-table ...
We are using Oracle 11g, 22.214.171.124. We know a record exists in a table but a select is not returning it for some odd reason. The execution plans the general query, not forcing any index, shows that ...
Why are there execution plan differences between OFFSET … FETCH and the old-style ROW_NUMBER scheme?
The new OFFSET ... FETCH model introduces with SQL Server 2012 offers simple and faster paging. Why are there any differences at all considering that the two forms are semantically identical and very ...
Having some trouble identifying why a query's duration would decrease when using OPTION (HASH JOIN) or OPTION (MERGE JOIN), although plan cost increases. Background I have a reporting database using ...
For a moderately complex query I am trying to optimize, I noticed that removing the TOP n clause changes the execution plan. I would have guessed that when a query includes TOP n the database engine ...