Documentation
Installation instructions
You can install extension using Extension Installer or manually. In the latter case unpack and upload all folders from "upload" directory to the root of your store. If there's install.xml file in the package, rename it to extension_name.ocmod.xml, replacing "extension_name" with extension's name (or any other name), and upload it to "system" folder. When upgrading from previous version simply rewrite all existing files. Refresh modifications cache from Extensions -> Modifications page (not needed if install.xml file is not included in the package).
Note for OpenCart 3 users
If you see "The directory is not allowed to be written to" error message, download OpenCart 3.0 Extension Installer Fix from this page and install it. Then install the main extension.
Note for OpenCart 2.0.X users
Sometimes OCMod inserts modification in multiple files, which are separated by "|" character in XML-file. On earlier OpenCart 2 versions a comma was used instead. To quickly fix this, open XML file (usually, install.xml) and replace all occurrences of "|" character with "," for "path" attribute in every applicable <file> element. Search for "<file path=" to quickly find and highlight all elements.
If after installation you have "Permission denied" issue when accessing Modules, Shipping, Payments, Order Totals (or any other) section of Extensions menu, remove "module", "shipping", "payment", "total" (or any other) folder from "admin/controller/extension" directory. Same for "admin/language/en-gb/extension" directory. For example ("module" should be removed from both paths):
admin/controller/extension/module
admin/language/en-gb/extension/module
Permissions
In some cases it is required to manually set permissions for installed extension. To do this go to System -> User Groups, find your group and select access/modify permissions for desired extension. You can find extension in permissions list by folder/filename pair (for example, marketing/acoupon).
Extension Setup
Go to Extensions -> Modules, find Database Cache, click Install and then setup accordingly.
How to Use
You don't need to do anything specific, extension will create cache of queries in time. To clean the cache manually just click Clean Database Cache button at the top right corner of any page of back-end.
Be careful with Cached Tables option! Some queries contain multiple tables and if you exclude one of them such queries will not be cached.
Also note, that Cache Search option is not very good, if you have AJAX-based search. It sends the query every time a keyword character is typed, so for 10-character word 10 queries will be sent and 10 cache files created. Only enable this option for the old-school search.