sql-execution-plan

How can a table scan return more rows than are in the table?

I have a complex query on a database with bad statistics and fragmented indices.What I\'m puzzled by is that when I examine an actual query plan I get 54 M rows from a table scan on a table that has 2[详细]

2023-03-08 20:21 分类：问答

Why does the Execution Plan include a user-defined function call for a computed column that is persisted?

I have a table with 2 computed columns, both of which has \"Is Persisted\" set to true. However, when using them in a query the Execution Plan shows the UDF used to compute the columns as part of the[详细]

2023-03-06 01:01 分类：问答

What influences a query plan's performance besides what is shown in Mgt Studio's graphical output?

(Note: This was formerly titled \"How do a query plan\'s estimated executions/IO/CPU/Executions, etc, influence performance, all other things being equal?\", but I renamed it now that I know the answe[详细]

2023-03-05 12:40 分类：问答

How to get the execution plan using LINQ to SQL/ADO.NET

Is it possible to get the execution plan of a LINQ to SQL or ADO.NET Query programatically for displaying in debug information?If so, ho开发者_如何学Cw?Sure, there are 2 things you will need.[详细]

2023-03-05 04:39 分类：问答

Erlang: qlc:info throws an error while qlc:eval does not - why?

Works root@test # erl Erlang R14B02 (erts-5.8.3) [source] [64-bit] [smp:4:4] [rq:4] [async-threads:0] [kernel-poll:false][详细]

2023-02-25 17:53 分类：问答

SQL Server: what will trigger execution plan?

If I have statement DECLARE @i INT; DECLARE @d NUMERIC(9,3); SET @i = 123; SET @d = @i; SEL开发者_StackOverflow社区ECT @d;[详细]

2023-02-23 02:50 分类：问答

Parse phase of sql statement Oracle and TOAD

Is it only the explain plan to look in when tuning a large sql string? Because when I push Ctrl+E in TOAD for Oracle (which generates explain plan), this takes several seconds. D开发者_Go百科oes TOAD[详细]

2023-02-22 16:55 分类：问答

Why would the exact same SQL query result with a different execution plan when executed via the sp_executeSQL procedure?

As the title states, I don\'t understand why the sp_executeSQL would generate a completely different execution plan than running the query from Sql Management Studio.[详细]

2023-02-21 00:11 分类：问答

Comparision between A select statement and Multiple select statment that act as batch

I have a stored procedure that contains some Select statements that return union result of them. I think and write one select instead of several Select and want to compa开发者_运维知识库re EXECUTION[详细]

2023-02-20 13:41 分类：问答

How to inline a variable in PL/SQL?

The Situation I have some trouble with my query execution pl开发者_运维知识库an for a medium-sized query over a large amount of data in Oracle 11.2.0.2.0. In order to speed things up, I introduced a[详细]

2023-02-18 04:42 分类：问答