History

The History page allows you to display system metrics and queries executed during a specified time period. Queries may also be filtered by database and/or user.

Note: By default, the history data displayed on this view are collected and saved in the gpperfmon database by the gpmmon and gpsmon agents. That data is not derived from the real-time metrics displayed on the Query Monitor and Query Detail view. Variations should be expected due to the different data collection methods.

On the Admin> Settings page you can enable saving the real-time metrics to history in the gpmetrics schema of the gpperfmon database. When you enable collecting this history, the Command Center History, Query Monitor, and Query Detail views all use data derived from the same data collection method. When you select a query that ran for at least 10 seconds in the History view, you can see the visual query plan.

Set the time period to display by entering dates and times in the From and To date and time fields. You can enter dates by typing them into the date field or by choosing from the pop-up calendar. Enter 24-hour times in HH:MM format.

To restrict queries that display in the query table at the bottom of the page, enter a Greenplum database name in the Database field, a user name in the User field, or both. Filtering by database and user only affects the queries displayed in the table. The metrics displayed in charts include all activity during the selected time period.

Click Search to display results that match your criteria.

You can click and drag on a chart to zoom in on a time range. Click Search to update the query list and charts to the selected range.

Scroll charts left or right by hovering over the edge of the chart and clicking an arrow. Click ‹ or › to move in half steps. Click « or » to move in full steps.

In the query list, select or hover over a query to highlight its queued and run time in the charts.

Charts of the following metrics are available. Show or hide them at any time with the checklist at the upper right of the view.

Queries

The number of queries running and the number of queries queued to run.

CPU

The percentage of CPU used by system processes and the percentage of CPU used by user processes.

Memory

Percentage of memory in use.

Disk I/O

Disk read and write rates in megabytes per second.

Network

Network I/O read and write rates in megabytes per second. Network metrics include traffic over all NICs (network interface cards), including internal interconnect and administrative traffic.

Load

System load average for 1-minute, 5-minute, and 15-minute periods.

Swap

Percentage of swap space used.

Query Metrics

The Query table displays queries that were active during the specified time period, including queries that started before or finished after the specified time. However, queries that are still active are not included in the table; these queries can be viewed on the Query Monitor page.

The query table has the following columns:

Query ID

An identification string for the query. In the Console, this looks like “1295397846-56415-2”.

Status

The final status of the query. This can be one of the following:

Done
Cancelled

User

The Greenplum Database user who submitted the query.

Database

The name of the database that was queried.

Submit Time

The time the query was submitted to the query planner.

Queued Time

The amount of time a query spent in the queue before it was executed.

Run Time

The amount of time the query required to produce a result.

End Time

The time the query completed or was cancelled.

CPU Skew

The amount of CPU skew. CPU skew occurs when query executor processes for one segment use a disproportionate amount of CPU compared to processes for other segments executing the query. This value is the coefficient of variation for the CPU used by processes running this query on each segment, multiplied by 100. For example, a value of .95 is shown as 95.

Row Skew

A measure of row skew in the system. Row skew occurs when one segment produces a disproportionate number of rows for a query. This value is the coefficient of variation for the Rows Out metric of all iterators across all segments for this query, multiplied by 100. For example, a value of .95 is shown as 95.

Queue

The name of the resource queue for the query.

Priority

Each query inherits the priority assigned to its resource queue.

For more information about Resource Queues and Query Plans, refer to the Greenplum Database Administrator Guide.