FINDINGS SECTION (1 finding)
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1- Index Finding (see explain plans section below)
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通过创建一个或多个索引可以改进此语句的执行计划。
Recommendation (estimated benefit: 98.73%)
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- 考虑运行可以改进物理方案设计的访问指导或者创建推荐的索引。
create index GDSHEC.IDX$$_02290001 on GDSHEC.MY_OBJECTS("OBJECT_NAME");
Rationale
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创建推荐的索引可以显著地改进此语句的执行计划。但是, 使用典型的 SQL 工作量运行 "访问指导"
可能比单个语句更可取。通过这种方法可以获得全面的索引建议案, 包括计算索引维护的开销和附加的空间消耗。
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EXPLAIN PLANS SECTION
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1- Original
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Plan hash value: 880823944
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| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
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| 0 | SELECT STATEMENT | | 2 | 194 | 317 (1)| 00:00:04 |
|* 1 | TABLE ACCESS FULL| MY_OBJECTS | 2 | 194 | 317 (1)| 00:00:04 |
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Predicate Information (identified by operation id):
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1 - filter("O"."OBJECT_NAME"=:BIN)
2- Using New Indices
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Plan hash value: 394593291
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| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
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| 0 | SELECT STATEMENT | | 2 | 194 | 4 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| MY_OBJECTS | 2 | 194 | 4 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | IDX$$_02290001 | 2 | | 3 (0)| 00:00:01 |
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Predicate Information (identified by operation id):
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2 - access("O"."OBJECT_NAME"=:BIN)
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总结：SQL优化顾问发现一个问题，建议在OBJECT_NAME表的MY_OBJECTS字段上创建索引。并对照创建索引前后的执行计划进行对比。
2.6删除SQL优化任务
begin
dbms_sqltune.drop_tuning_task(task_name => 'my_sql_tuning_task');
end;