scan table
常見(jiàn)例句
- 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.
比如在雇員表的“性別”列上只有“男”與“女”兩個(gè)不同值,因此就無(wú)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.
對(duì)于多索引下推,多索引掃描用于組合來(lái)自不同索引掃描的 RID,然后就可以執(zhí)行對(duì)事實(shí)表的跳躍式掃描了。 - 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.
實(shí)際上,對(duì)內(nèi)存中的表進(jìn)行表掃描要比通過(guò)索引搜索同一表快得多,尤其是在使用 Informix 輕型掃描機(jī)制時(shí)。 返回 scan table