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Query Optimization - Coggle Diagram
Query Optimization
Optimizing Specific Types of Queries
Optimizing COUNT() Queries
Optimizing JOIN Queries
Optimizing Subqueries
Optimizing GROUP BY and DISTINCT
Optimizing LIMIT and OFFSET
Optimizing UNION
Query Execution Basics
The client sends the SQL statement to the server
The server checks the query cache
The server optimizes the SQL
The query execution engine executes the plan
The server sends the result to the client
Query Optimization Using EXPLAIN
used to obtain a query execution plan
returns a row of information for each table used in the SELECT
Each output row from EXPLAIN provides information about one table
Slow Query Basics
Optimize Data Access
more data than you need
more rows than it needs.
You Don't Need?
Fetching more rows than needed.
Fetching all columns from a multitable join
Fetching all columns
Fetching the same data repeatedly