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#12833 closed bug (notabug)

Opened November 02, 2012 09:02AM UTC

Closed November 21, 2012 06:41PM UTC

IE7 class selector much slower after 1.8.0 release

Reported by: morrijr Owned by:
Priority: undecided Milestone: None
Component: unfiled Version: git
Keywords: Cc:
Blocked by: Blocking:
Description

We upgraded our corporate website from 1.7.2 to 1.8.1 and immediately started taking calls on how much slower this release was, unfortunately, despite a major push from us we have been unable to get the majority of our customers off IE7 (something like 71%).

Please note that this is with regards to IE7 only.

Using http://jsperf.com/id-vs-class-vs-tag-selectors/2 as a benchmark I've compared versions 1.7.2, 1.8.0, 1.8.1, 1.8.2 and some git versions going forwards (12, 16, 17, 18, 22 Oct and 2 Nov).

While there has been significant increase in some selectors; ($('blockquote') has nearly doubled and pseudo ($(':hidden')) is up by 50%. Class selectors (which I would argue are used most) have seen a 50% reduction in speed from 168 operations/sec to an average of 70 ops/sec.

We would dearly like to upgrade to the latest jQuery, however our corporate user base requires us to support IE7.

I have been unable to locate any changes between 1.7.2 and 1.8.0 which may be responsible and sincerely hope somebody here can!

Regards,

John.

Attachments (0)
Change History (1)

Changed November 21, 2012 06:41PM UTC by dmethvin comment:1

resolution: → notabug
status: newclosed

As we discussed in IRC, various selectors will get slower and faster from version to version. Without seeing the specific code, which you weren't able to share, we can't tell if this is a pathological case or not. The fact that it was a table with more than a thousand entries including form fields tells me that it might be. Staying with 1.7 may be the best solution here.