Historical data: history_uint correlation table, from which the maximum, minimum and average values of equipment monitoring items can be found, that is, the original data for storing monitoring data.
Trend data: trend correlation table. Trend data is the data calculated by Zabbix, and the data is summarized from history_uint. From trends_uint, you can view the maximum value, minimum value and average value of monitoring data per hour, that is, the summary data of monitoring data is stored.
Zabbix can obtain historical data in two ways:
1. Get historical data through Zabbix front desk.
It is very simple to view historical data through the Zabbix foreground, and you can use monitoring->; The way to view lasttestdata. You can also click the As plain test button in the upper right corner to save it as a text file.
2. There are many restrictions on the processing and secondary query of data obtained through the foreground, so you can query data directly from the background DB through SQL statements.
First of all, you should be familiar with the common usage of SQL statement Select:
SELECT[ALL | DISTINCT]SELECT _ List[INTO[New _ Table _ name]
From {Table_name | View_name} [[,{table2_name | view2_name}
[,…] ]
[search criteria]
[group by Group_by_list]
[with search criteria]
[Sort by Order List [ASC| DEsC]]
Description:
1)SELECT clause specifies the columns in a specific table to query, which can be *, expression, list, etc.
2) 2) The into clause specifies that a new table is to be generated.
3) 3) The from clause specifies the table or view to be queried.
4)WHERE clause is used to limit the scope and conditions of the query.
5) 5) The group by clause specifies the grouping query clause.
6)HAVING clause is used to specify the conditions of grouping clause.
7)ORDER BY can sort the query results according to one or more columns. In this clause, you can use column names and relative column numbers, ASC for ascending order and DESC for descending order.
8)mysql aggregate functions: sum (), count (), avg (), max (), avg (), etc. Are aggregate functions. When we use aggregate functions, we usually use GROUP BY first, and then operate the aggregate functions. After the operation, it is necessary to use the Having clause to judge, such as whether the value of the aggregate function is greater than a certain value, and so on.