在做维护项目的时，我们经常会遇到索引维护的问题;接下来介绍分析表的索引建立情况/重建索引前后对比等等，感兴趣的朋友可以了解下
在做维护项目的时，我们经常会遇到索引维护的问题，通过语句，我们就可以判断某个表的索引是否需要重建。执行一下语句：先分析表的索引
分析表的索引建立情况：DBCC showcontig('Table')
DBCC SHOWCONTIG 正在扫描 'Table'' 表...
表: 'Table'' (53575229)；索引 ID: 1，数据库 ID: 14
已执行 TABLE 级别的扫描。
- 扫描页数................................: 228
- 扫描区数..............................: 52
- 区切换次数..............................: 225
- 每个区的平均页数........................: 4.4
- 扫描密度 [最佳计数:实际计数].......: 12.83% [29:226]
- 逻辑扫描碎片 ..................: 97.37%
- 区扫描碎片 ..................: 98.08%
- 每页的平均可用字节数........................: 2686.3
- 平均页密度(满).....................: 66.81%
当你发现，扫描密度行，最佳计数和实际计数的比例已经严重失调，逻辑扫描碎片占了非常大的百分比，每页平均可用字节数非常大时，就说明
你的索引需要重新整理一下了。
执行重建索引命令：
DBCC DBREINDEX('Table'')
后分析的情况
DBCC SHOWCONTIG 正在扫描 'Table'' 表...
表: 'Table'' (53575229)；索引 ID: 1，数据库 ID: 14
已执行 TABLE 级别的扫描。
- 扫描页数................................: 154
- 扫描区数..............................: 20
- 区切换次数..............................: 19
- 每个区的平均页数........................: 7.7
- 扫描密度 [最佳计数:实际计数].......: 100.00% [20:20]
- 逻辑扫描碎片 ..................: 0.00%
- 区扫描碎片 ..................: 55.00%
- 每页的平均可用字节数........................: 86.8
- 平均页密度(满).....................: 98.93%
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