Recent incremental to get data from the system of others, because someone is after the integration of data, so is unlikely to be in the CDC's way to extract, had each other Updatetime on index, asked me to do incremental gain from the Timestamp field, the key is this field is also no index, the extraction of part of the large amount of data table, extraction is slow, part of the table once every six hours to perform need to more than 20 minutes, I'm not sure whether can build indexes in the Timestamp field, to speed up the extraction efficiency,
Create rules according to the index, like this will be updated frequently field is less should be indexed, I baidu + Google for quite a while, also have no specific case should said,

CodePudding user response:

Can be added, but the index is only useful in screening of a small number of records,
If you want to take all the data, add index is meaningless,