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Optimization - Coggle Diagram
Optimization
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Mistakes
Fetching more rows, than you need
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Join
Don`t use subquery, better join!
Be sure, that ON and Using have indexes.
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Explain
EXPLAIN [explain_type] {explainable_stmt | FOR CONNECTION connection_id}
explain_type: {EXTENDED | PARTITIONS | FORMAT = format_name}
explainable_stmt: {SELECT statement | DELETE statement | INSERT statement | REPLACE
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UNION
use WHERE, LIMIT, ORDER BY and other
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it`s better, when all index
have same type and size
ALTER TABLE tt
MODIFY ActualPC VARCHAR (15),
MODIFY AssignedPC VARCHAR (15),
MODIFY ClientID VARCHAR (15);