Submit a ticketCall us

AnnouncementsFace your biggest database issues head-on

Our new eCourse helps you navigate SQL Server performance blocks by teaching you how to recognize and deal with the three DBA Disruptors: Performance Hog, Blame Shifter, and Query Blocker. Register today to learn how to defend your environment and fend off menacing disruptions.

Register for your free eCourse.

Home > Success Center > Netflow Traffic Analyzer (NTA) > NTA - Knowledgebase Articles > NTA data retention and compression

NTA data retention and compression

Table of contents


This article details how the Orion NTA data compression works to meet specific reporting requirements, while optimizing database storage requirements.


Customer may see an issue where they select an absolute time period and no matter what the "from" time is set to the time period will be set to 12:00 AM of that same day. The cause is because data is rolled up and averaged out in the entire day and the data points do not have specific time periods.


NTA 3.0 to NTA 3.11, NTA 4.0x86 (32bit server install) to 4.0.3x86  (32bit server install).

This information does not apply to NTA versions 4.0 and higher.


Orion NTA performs compression on flow data by combining older flows by conversation and summing up the total traffic numbers. It is still the same flow data from the previous versions, but summarized to save database space and improve resource and report loading times on historical data.


By default, NTA retains:

  • 1-minute granularity for the last 60 minutes of data. After 60 minutes, it gets collapsed into 15-minute segments (“keep uncompressed data” setting in NTA global settings).
  • 15-minute granularity for 24 hours. After 24 hours, it gets collapsed into hourly data (CollapseTrigger2InHours option in NetFlowGlobalSettings table = 24)
  • Hourly granularity for 3 days. After 3 days, it gets collapsed into daily data (CollapseTrigger3InDays option in NetFlowGlobalSettings table = 3)
  • Daily data for 30 days. After 30 days, the data expires and it is deleted (RetainCompressedDataInDays option in NetFlowGlobalSettings table = 30)

It is important to map your reporting granularity requirements to the appropriate NTA compression settings. For example, if you need 1-min granularity on the last 3 hours worth of data, set “keep uncompressed data” in the NTA global settings to 180 minutes.


  • Consult your System Administrator before performing the following procedure.
  • Before changing any of the default compression settings, make sure the changes are absolutely necessary. Adjusting compression settings to retain granularity for longer periods increases the amount of DB storage required and may impact reporting and website loading performance.


Last modified