Skip to Main Content
  • Questions

  • SELECT queries and even LATCH FREE 39 object stats modification

Breadcrumb

Question and Answer

Chris Saxon

Thanks for the question, Vu.

Asked: March 15, 2023 - 4:28 pm UTC

Last updated: March 29, 2023 - 1:14 pm UTC

Version: 19.15.0.0.0

Viewed 1000+ times

You Asked

Hi Tom,

While checking ASH, I found some SELECT queries blocked other transactions with LATCH FREE with latch# = 39, which is "object stats modification". Can you explain what that particular latch is for and in which area it stays ?

Thanks,
Vu

and Chris said...

The wait is to do with populating segment statistics in AWR. While you can disable this (see MOS note 2778826.1), it's better to figure out which statements are causing this and get a fix for these.

If this is a significant issue - i.e. it's notably slowing down your transactions - please take this up with support.

Thanks to Mike Hallas for helping with this

Rating

  (2 ratings)

Is this answer out of date? If it is, please let us know via a Comment

Comments

That explains a lot for me.

Vu Pham, March 28, 2023 - 9:07 pm UTC

Thank you. It is really helpful.
Chris Saxon
March 29, 2023 - 1:14 pm UTC

Great
more

Connor and Chris don't just spend all day on AskTOM. You can also catch regular content via Connor's blog and Chris's blog. Or if video is more your thing, check out Connor's latest video and Chris's latest video from their Youtube channels. And of course, keep up to date with AskTOM via the official twitter account.

More to Explore

SQL

The Oracle documentation contains a complete SQL reference.