Oracle index (function index, time-based daily)

 

No, too many builds will affect performance, and the maintenance cost will be high.

Generally, it is created on the keyword field.

For example, there are many fields after where, including the logtime field. You can create an index on this field,
The query filters out most records based on the specified time condition of the logtime field, and the rest will not be too many even if the full table is scanned, thus affecting the query speed.

Our services are basically created in the time type.Function IndexOf

For example
Create index emp_ind on EMP (to_char (hiredate, 'yyyy-mm-dd '))

Query time
Select * from EMP
Where (to_char (hiredate, 'yyyy-mm-dd') = '2017-01-25'

In this way, the remaining record is just a day's record, and other fields are used for filtering, which is fast.

Here is a time example.
P_o_w_cellsamplepoints 66.9 GB

Select * From p_o_w_cellsamplepoints
Where to_char ("starttime", 'yyyy-MM-DD ') = '2017-06-08'

Result less than 1 second