Top "Sql-execution-plan" questions

A execution, or query plan, is the breakdown of steps the database engine uses to get a result.

Nested Join vs Merge Join vs Hash Join in PostgreSQL

I know how the Nested Join Merge Join Hash Join works and its functionality. I wanted to know in which …

postgresql sql-execution-plan
Is there a way to make Oracle recalculate a query plan for each query invocation?

I have a parameterized query. Depending on parameter values optimal query plan varies significantly. Here is the trouble: Oracle uses …

oracle sql-execution-plan
SQL Error: ORA-01039: insufficient privileges on underlying objects of the view

I am trying to get explain plan for a view using below query explain plan for select * from SCHEMA1.VIEW1; …

database oracle view grant sql-execution-plan
SQL order of operations

If I run the following SQL query SELECT * FROM A LEFT JOIN B ON A.foo=B.foo WHERE A.…

sql join optimization where sql-execution-plan
Easy way to run "explain" on query sets in django

It seems like it should be easy to run "explain" directly off of a queryset in Django, but I don't …

django sql-execution-plan
How to understand SQLite `EXPLAIN QUERY PLAN` result?

I have read that joins are better than subqueries. But EXPLAIN QUERY PLAN SELECT Queue.Id, NULL FROM Queue INNER …

sql sqlite explain sql-execution-plan
Why does putting a WHERE clause outside view have terrible performance

Let's say you have a view: CREATE VIEW dbo.v_SomeJoinedTables AS SELECT a.date, a.Col1, b.Col2, DENSE_…

sql-server-2005 tsql where-clause sql-execution-plan
Why would MySQL use index intersection instead of combined index?

From time to time I encounter a strange MySQL behavior. Let's assume I have indexes (type, rel, created), (type), (rel). …

mysql query-optimization sql-execution-plan database-indexes
Oracle EXECUTE IMMEDIATE changes explain plan of query

I have a stored procedure that I am calling using EXECUTE IMMEDIATE. The issue that I am facing is that …

oracle performance sql-execution-plan execute-immediate
Tool for comparison of SQL Server query plans?

Does anyone know of a tool that can be used to compare (relatively complex) query plans? I'm not looking for …

sql sql-server sql-execution-plan