Form Caches

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Revision as of 12:06, 7 October 2013 by Sturlington (talk | contribs)

The iHRIS software caches data saved in the database (or XML file or LDAP server) for faster access and the ability to create indices. These caches are used, for example, to populate reports and drop-down lists.


The data for a form XXXXX may be cached into a table hippo_XXXXX. This hippo table can be used for:

Hippo Table Structure

If a form XXXXX has a field YYYYY then the hippo_XXXXX table will have a column `XXXXX+YYYYY.` There is also a column `XXXXX+id` containing the id of the form and a column `XXXXX+parent` containing the parent form, if any.

Cache Times and Command Line

The hippo tables are generated by a background process once a form cache is consider stale. See the Configuring Form Cache Generation Timing document for information on timing for form caches and information on manually creating the form caches from the command line.

To see this tutorial for different versions of the software see the following:


Editing, Exporting and Updating Form Caches Using Profiles

In version 4.0.6 we add the ability to create profiles of form caches. A profile is a simply a list of forms that you can use to rapidly:

  • Update the cache for each of the forms in the profile
  • Export the cache, via a mysqldump, for each of the forms in the profile. This is particularly useful for exporting data from a regional or district office to the national level.

This functionality is part of the Cached Forms modules and can be accessed by clicking on the links for Configure System and then Cached Forms

Creating A Profile

The first step is to create a profile of the forms. A profile is a list of forms with a short name that you can use to help you identify the list.


  1. Look under Create/Edit Profile on the Cached Forms page. Here make sure "Create a new profile" is selected in the drop-down, and then click the "Edit" button.
  2. Now type a name for the profile. It is best to keep it short with limited punctuation such as "nightly_update"
  3. Now select each of the forms you wish to include in the profile
  4. Finally, click the "Submit" button at the bottom of the page

Updating the Cache of a Profile

You can update all of the forms in a profile under Cache Forms on the Cached Forms page.

  1. Choose the profile for which you wish to cache forms
  2. Click the "Cache" button

Exporting the Cache of a Profile

There are two main usages of exporting all of the forms in profile, you can either get all the data, or only the modifications to the data since the last date. Both can be accessed under Export Cached Forms on the Cached Forms page.

  1. Choose the profile you wish to export
  2. Choose to enable bzip2 compression or not
  3. Optionally select the modification time.
    1. If you do not set the modification time, you will get all of the data for the forms. The mysqldump will include "DROP TABLE IF EXISTS" and "CREATE" statements for each of the hippo_XXXX tables. Data is populated via "INSERT" statements
    2. If you do not set the modification time, you will get all of the data for the forms. The mysqldump will include neither the "DROP TABLE IF EXISTS" nor the "CREATE" statement for each of the hippo_XXXX tables. Data is populated via "REPLACE" statements.
  4. click the "Export" button

Note: When you export the cache, it does not first update it. You will need to do this manually.

Crontab and Command Line Interaction

For example, you may wish to put an update of the profile "nightly_update" in your crontab:

 30     1     *     *     *         /usr/bin/php /var/www/ihris-manage/index.php --page=/CachedForms/cache --get=profile=nightly_update

will cause all forms in the 'nightly_update' profile to be update at 1:30am. Putting:

 10     *     *     *     *         /usr/bin/php /var/www/ihris-manage/index.php --page=/CachedForms/cache --get=profile=hourly_update

in your profile will update every form in the 'hourly_update' profile at ten minutes past the hour.