案例八

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--执行drop_customers_indexes.sql, 删除除主键索引外的所有索引.
sh@TESTDB11>@drop_customers_indexes.sql
--创建复合索引
CREATE INDEX idx_cust_last_first_name ON customers(cust_last_name, cust_first_name) NOLOGGING COMPUTE STATISTICS;
--query09.sql
--优化程序仅使用索引,而不访问表本身,最终成本非常理想.
SET ECHO ON
SET TIMING ON
SET AUTOTRACE TRACEONLY
SET PAGESIZE 1000
@flush.sql
SELECT c.cust_last_name, c.cust_first_name FROM customers c;
SET TIMING OFF
SET AUTOTRACE OFF
--执行query09.sql
sh@TESTDB11>@query09.sql

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