scan table

基本解释

For example if we want to know the gender ration in employee or customer pool, the bitmap index will help a lot without a full-table scan.
比如在雇员表的“性别”列上只有“男”与“女”两个不同值，因此就无必要建立索引。
For multiple index push-downs, multi-index scan is used to combine RIDs from different index scans, then skip-scan on the fact table is performed.
对于多索引下推，多索引扫描用于组合来自不同索引扫描的 RID，然后就可以执行对事实表的跳跃式扫描了。
Actually, a table scan of an in-memory table is much faster than searching the same table through an index, especially with the Informix light scan mechanism.
实际上，对内存中的表进行表扫描要比通过索引搜索同一表快得多，尤其是在使用 Informix 轻型扫描机制时。