Comments on: Image Caching in PL/SQL Applications

By: Tyler Muth

Tyler Muth — Sat, 11 Apr 2009 21:34:30 +0000

Stew,

Expires headers in APEX will have no impact on images served by Apache from the file system, as is the case with anything under /i/… You need to enable this in Apache. Here’s the doc:
http://httpd.apache.org/docs/1.3/mod/mod_expires.html

Tyler

By: stewstryker

stewstryker — Sat, 11 Apr 2009 21:26:00 +0000

John,

Expires really got implemented in Apex 3.1? Because we’re running 3.1.1 and I just ran the YSlow plugin on my new app’s page with an Interactive Report and it complained about no caching.

Here’s the log from YSlow as I thought you’d like to see all the IR images not w/o expires. If the .png filenames look familiar it’s because I copied the tabs from the development environment.

Finally, I noticed that they include Etags (which YSlow recommends) but it says they’re not being used?

I’ve trimmed the body after the first one, for brevity.

These components do not have a far future Expires or cache-control: max-age header:

* [HTTP headers] (no expires) https://oracle-www.ourserver.edu/i/themes/theme_13/theme_3_1.css * ParamsHeadersPost Response Headers Date:Sat, 11 Apr 2009 20:15:01 GMT Server:Oracle-Application-Server-10g Last-Modified:Thu, 21 Aug 2008 20:57:24 GMT Etag:"104572-71f3-48add6b4" Accept-Ranges:bytes Content-Length:29171 Connection:close Content-Type:text/css X-Pad:avoid browser bug Loading... ... * [HTTP headers] (no expires) .../i/css/apex_3_1.css * [HTTP headers] (no expires) .../htmldb/harpo/wwv_flow_file_mgr.get_file?p_security_group_id=65488007[snip] * [HTTP headers] (no expires) .../i/javascript/apex_ns_3_1.js * [HTTP headers] (no expires) .../i/javascript/apex_3_1.js * [HTTP headers] (no expires) .../i/javascript/apex_get_3_1.js * [HTTP headers] (no expires) .../i/javascript/apex_builder.js * [HTTP headers] (no expires) .../images/Volt-logo.gif * [HTTP headers] (no expires) .../images/tabOffL.gif * [HTTP headers] (no expires) .../images/tabOffR.gif * [HTTP headers] (no expires) .../images/tabOnL.gif * [HTTP headers] (no expires) .../images/tabOnR.gif * [HTTP headers] (no expires) .../i/htmldb/builder/finder_w_dropdown.gif * [HTTP headers] (no expires) .../i/ws/action_dropdown.gif * [HTTP headers] (no expires) .../i/ws/edit_col_32.gif * [HTTP headers] (no expires) .../i/ws/filter_32.gif * [HTTP headers] (no expires) .../i/ws/sort_32.gif * [HTTP headers] (no expires) .../i/ws/break_col_32x24.gif * [HTTP headers] (no expires) .../i/ws/highlight_32x24.gif * [HTTP headers] (no expires) .../i/ws/calc_32x24.gif * [HTTP headers] (no expires) .../i/ws/sum_32x24.gif * [HTTP headers] (no expires) .../i/ws/chart_32x24.gif * [HTTP headers] (no expires) .../i/ws/disk_32.gif * [HTTP headers] (no expires) .../i/ws/reset_32x24.gif * [HTTP headers] (no expires) .../i/ws/help_32x24.gif * [HTTP headers] (no expires) .../i/ws/download_32x24.gif * [HTTP headers] (no expires) .../i/jtfunexe.gif * [HTTP headers] (no expires) .../i/ws/dup.gif * [HTTP headers] (no expires) .../i/ws/ddown.gif * [HTTP headers] (no expires) .../i/ws/trash.gif * [HTTP headers] (no expires) .../i/ws/break_col.gif * [HTTP headers] (no expires) .../i/ws/info_20x18.gif * [HTTP headers] (no expires) .../i/ws/calc.gif * [HTTP headers] (no expires) .../i/ws/ajax-loader.gif * [HTTP headers] (no expires) https://www.dartmouth.edu/~alfund/assets/jpg/banner-dcf.jpg * [HTTP headers] (no expires) .../images/tabOnM.gif * [HTTP headers] (no expires) .../i/htmldb/misc/tabOnM.png * [HTTP headers] (no expires) .../i/htmldb/builder/builder_find_bg.png * [HTTP headers] (no expires) .../i/htmldb/builder/builder_find_top.png * [HTTP headers] (no expires) .../i/htmldb/builder/builder_find_bottom.png * [HTTP headers] (no expires) .../i/ws/report_bg.gif

By: naineumNaice

naineumNaice — Mon, 29 Dec 2008 16:10:55 +0000

kxgkwzzqxsxuglsgwell, hi admin adn people nice forum indeed. how’s life? hope it’s introduce branch

By: Tyler Muth

Tyler Muth — Mon, 28 Apr 2008 12:40:46 +0000

Renu,

I was doing this research for an APEX application. You could call the “image_test” procedure from an APEX report, or when someone clicks on a link, or using htp.p in a PL/SQL region. On a related note, APEX 3.1 actually implements this technique, so the images you upload through the APEX UI use this technique to handle downloads. One more reason to upgrade to 3.1.

By: renu

renu — Mon, 28 Apr 2008 09:44:27 +0000

Could any one reply how to implement into oracle apex

By: Loga

Loga — Mon, 28 Apr 2008 09:38:45 +0000

Excellent valuable solution for my searched query
Loga.

By: Greg Jarmiolowski

Greg Jarmiolowski — Fri, 14 Mar 2008 16:15:44 +0000

This addresses per user/browser cache. What about caching on the webserver file system with owa_cache? Is that already in the APEX plumbing?

By: Tyler Muth

Tyler Muth — Sat, 23 Feb 2008 15:13:49 +0000

Phil, I would need more details to comment, but this situation would apply to Oracle Application Server when you are serving images out of the database using mod_plsql with your own custom code.

By: Phil Winfield

Phil Winfield — Sat, 23 Feb 2008 12:41:54 +0000

Tyler, I spent a bit of time looking into improving performance for a client but it seems that if Oracle Application server is serving up the pages, images and other page components can be cached already. Is it correct to say this is specific to the HTTP server that ships with 10g or does OAS not really do this?

Phil

By: Tyler Muth

Tyler Muth — Fri, 22 Feb 2008 04:40:14 +0000

Jan,

Yes, this will still hit the database. Do you have a suggestion for how it could be solved in the middle tier?

Tyler