Enterprise Edition Home | Express Edition Home | Previous Page | Next Page  

Queries and the Query Optimizer

In This Chapter
The Query Plan
Access Plan
Join Plan
Nested-Loop Join
Hash Join
Join Order
Example of Query-Plan Execution
Join with Column Filters
Join with Indexes
Query Plan Evaluation
Query Plan Report
EXPLAIN Output File
EXPLAIN Output Description
Sample Query Plan Reports
Single-Table Query
Multitable Query
Key-First Scan
Query Plans for Subqueries
Query Plans for Collection-Derived Tables
Factors That Affect the Query Plan
Statistics Held for the Table and Index
Filters in the Query
Indexes for Evaluating a Filter
Effect of PDQ on the Query Plan
Effect of OPTCOMPIND on the Query Plan
Single-Table Query
Multitable Query
Effect of Available Memory on the Query Plan
Time Costs of a Query
Memory-Activity Costs
Sort-Time Costs
Row-Reading Costs
Sequential Access Costs
Nonsequential Access Costs
Index Lookup Costs
Reading Duplicate Values From an Index
Searching for NCHAR or NVARCHAR Columns in an Index
In-Place ALTER TABLE Costs
View Costs
Small-Table Costs
Data-Mismatch Costs
Encrypted-Value Costs
GLS Functionality Costs
Network-Access Costs
SQL Within SPL Routines
SQL Optimization
Displaying the Execution Plan
Automatic Reoptimization
Reoptimizing SPL Routines
Optimization Levels for SQL in SPL Routines
Execution of an SPL Routine
UDR Cache
Changing the UDR Cache
Monitoring the UDR Cache
Trigger Execution
Performance Implications for Triggers
SELECT Triggers on Tables in a Table Hierarchy
SELECT Triggers and Row Buffering
Enterprise Edition Home | Express Edition Home | [ Top of Page | Previous Page | Next Page | Contents | Index ]