[
https://issues.apache.org/jira/browse/IOTDB-1140?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17275509#comment-17275509
]
Chao Wang commented on IOTDB-1140:
----------------------------------
thanks [~qiaojialin] ,
value is not sort..
sample:
create timeseries root.db_0.tab0.salary with datatype=INT64,encoding=REGULAR ;
(time, salary) == > (1, 1000) ,(2, 1100),(3, 1800)(4, 1400),(5,1500)
only time series will be sorted by time, not salary.
> optimize regular data encoding
> ------------------------------
>
> Key: IOTDB-1140
> URL: https://issues.apache.org/jira/browse/IOTDB-1140
> Project: Apache IoTDB
> Issue Type: Improvement
> Components: Core/Engine
> Reporter: Chao Wang
> Assignee: Chao Wang
> Priority: Critical
>
> current regular data encoding algorithm：
> # Calculate the difference between two adjacent values. The smallest
> difference is used as the equal-frequency frequency.
> # Determine the data range of this batch of data based on the difference
> between the last value and the first value.
> # Traverse this batch of data, use a BitSet, compare the difference between
> two adjacent values with the same frequency, and save the value true by
> default,
> If the value is not equal to the equal frequency, calculate the number of
> equal frequency differences and set the value to false at the corresponding
> position, indicating that the point is a missing point.
>
> this algorithm only can identity missing point, if have error point , it
> will throw exception..
> because BitSet only can do this thing, indicates whether the same frequency
> exists in a segment of data
>
> But there is some optimize point..
> If there is an abnormal value in a column of values, the algorithm is
> deviated if the difference is directly obtained to the minimum value.
> sample: 1000，1100，1800，1400，1500...
> current algorithm be do not use...
> 1800 is a error point, we should identity error point, revise data.
> revise data should be : 1000，1100，1300，1400，1500
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
