DATA_COLLECTOR_HELP
返回有关数据收集器、
DATA_COLLECTOR 系统表和数据收集器控制函数的在线使用说明。
这是元函数。您必须在顶级 SELECT 语句中调用元函数。
行为类型
易变语法
DATA_COLLECTOR_HELP()
特权
无
返回
DATA_COLLECTOR_HELP() 函数将返回以下信息：
=> SELECT DATA_COLLECTOR_HELP();
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Usage Data Collector
The data collector retains history of important system activities.
This data can be used as a reference of what actions have been taken
by users, but it can also be used to locate performance bottlenecks,
or identify potential improvements to the Vertica configuration.
This data is queryable via Vertica system tables.
Acccess a list of data collector components, and some statistics, by running:
SELECT * FROM v_monitor.data_collector;
The amount of data retained by size and time can be controlled with several
functions.
To just set the size amount:
set_data_collector_policy(<component>,
<memory retention (KB)>,
<disk retention (KB)>);
To set both the size and time amounts (the smaller one will dominate):
set_data_collector_policy(<component>,
<memory retention (KB)>,
<disk retention (KB)>,
<interval>);
To set just the time amount:
set_data_collector_time_policy(<component>,
<interval>);
To set the time amount for all tables:
set_data_collector_time_policy(<interval>);
The current retention policy for a component can be queried with:
get_data_collector_policy(<component>);
Data on disk is kept in the "DataCollector" directory under the Vertica
\catalog path. This directory also contains instructions on how to load
the monitoring data into another Vertica database.
To move the data collector logs and instructions to other storage locations,
create labeled storage locations using add_location and then use:
set_data_collector_storage_location(<storage_label>);
Additional commands can be used to configure the data collection logs.
The log can be cleared with:
clear_data_collector([<optional component>]);
The log can be synchronized with the disk storage using:
flush_data_collector([<optional component>]);