advisor.Rule{Item:"ARG.001", Severity:"L4", Summary:"不建议使用前项通配符查找", Content:"例如“%foo”,查询参数有一个前项通配符的情况无法使用已有索引。", Case:"select c1,c2,c3 from tbl where name like '%foo'", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.001", Severity:"L4", Summary:"不建议使用前项通配符查找", Content:"例如“%foo”,查询参数有一个前项通配符的情况无法使用已有索引。", Case:"select c1,c2,c3 from tbl where name like '%foo'", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.002", Severity:"L1", Summary:"没有通配符的LIKE查询", Content:"不包含通配符的LIKE查询可能存在逻辑错误,因为逻辑上它与等值查询相同。", Case:"select c1,c2,c3 from tbl where name like 'foo'", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.002", Severity:"L1", Summary:"没有通配符的LIKE查询", Content:"不包含通配符的LIKE查询可能存在逻辑错误,因为逻辑上它与等值查询相同。", Case:"select c1,c2,c3 from tbl where name like 'foo'", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.003", Severity:"L4", Summary:"参数比较包含隐式转换,无法使用索引", Content:"隐式类型转换有无法命中索引的风险,在高并发、大数据量的情况下,命不中索引带来的后果非常严重。", Case:"SELECT * FROM sakila.film WHERE length >= '60';", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.003", Severity:"L4", Summary:"参数比较包含隐式转换,无法使用索引", Content:"隐式类型转换有无法命中索引的风险,在高并发、大数据量的情况下,命不中索引带来的后果非常严重。", Case:"SELECT * FROM sakila.film WHERE length >= '60';", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.004", Severity:"L4", Summary:"IN (NULL)/NOT IN (NULL)永远非真", Content:"正确的作法是col IN ('val1', 'val2', 'val3') OR col IS NULL", Case:"SELECT * FROM sakila.film WHERE length >= '60';", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.004", Severity:"L4", Summary:"IN (NULL)/NOT IN (NULL)永远非真", Content:"正确的作法是col IN ('val1', 'val2', 'val3') OR col IS NULL", Case:"SELECT * FROM tb WHERE col IN (NULL);", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.006", Severity:"L1", Summary:"应尽量避免在WHERE子句中对字段进行NULL值判断", Content:"使用IS NULL或IS NOT NULL将可能导致引擎放弃使用索引而进行全表扫描,如:select id from t where num is null;可以在num上设置默认值0,确保表中num列没有null值,然后这样查询: select id from t where num=0;", Case:"select id from t where num is null", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.006", Severity:"L1", Summary:"应尽量避免在WHERE子句中对字段进行NULL值判断", Content:"使用IS NULL或IS NOT NULL将可能导致引擎放弃使用索引而进行全表扫描,如:select id from t where num is null;可以在num上设置默认值0,确保表中num列没有null值,然后这样查询: select id from t where num=0;", Case:"select id from t where num is null", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.007", Severity:"L3", Summary:"避免使用模式匹配", Content:"性能问题是使用模式匹配操作符的最大缺点。使用LIKE或正则表达式进行模式匹配进行查询的另一个问题,是可能会返回意料之外的结果。最好的方案就是使用特殊的搜索引擎技术来替代SQL,比如Apache Lucene。另一个可选方案是将结果保存起来从而减少重复的搜索开销。如果一定要使用SQL,请考虑在MySQL中使用像FULLTEXT索引这样的第三方扩展。但更广泛地说,您不一定要使用SQL来解决所有问题。", Case:"select c_id,c2,c3 from tbl where c2 like 'test%'", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.007", Severity:"L3", Summary:"避免使用模式匹配", Content:"性能问题是使用模式匹配操作符的最大缺点。使用LIKE或正则表达式进行模式匹配进行查询的另一个问题,是可能会返回意料之外的结果。最好的方案就是使用特殊的搜索引擎技术来替代SQL,比如Apache Lucene。另一个可选方案是将结果保存起来从而减少重复的搜索开销。如果一定要使用SQL,请考虑在MySQL中使用像FULLTEXT索引这样的第三方扩展。但更广泛地说,您不一定要使用SQL来解决所有问题。", Case:"select c_id,c2,c3 from tbl where c2 like 'test%'", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.008", Severity:"L1", Summary:"OR查询索引列时请尽量使用IN谓词", Content:"IN-list谓词可以用于索引检索,并且优化器可以对IN-list进行排序,以匹配索引的排序序列,从而获得更有效的检索。请注意,IN-list必须只包含常量,或在查询块执行期间保持常量的值,例如外引用。", Case:"SELECT c1,c2,c3 FROM tbl WHERE c1 = 14 OR c1 = 17", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}
advisor.Rule{Item:"ARG.008", Severity:"L1", Summary:"OR查询索引列时请尽量使用IN谓词", Content:"IN-list谓词可以用于索引检索,并且优化器可以对IN-list进行排序,以匹配索引的排序序列,从而获得更有效的检索。请注意,IN-list必须只包含常量,或在查询块执行期间保持常量的值,例如外引用。", Case:"SELECT c1,c2,c3 FROM tbl WHERE c1 = 14 OR c1 = 17", Position:0, Func:func(*advisor.Query4Audit) advisor.Rule {...}}