Product Object vs Collection method to sync data:
Out of the box, Klevu uses product objects to collect product data. This works okay when there are up to 5000 SKUs (across all the store views). Anything above, we recommend that you use the "Collection" method to sync data. The difference here is that we will be relying on Magento indices to fetch the data and thus keeping the memory footprint low. This method is much faster as well. But when using the collection method, you must ensure that your Magento indices are all up-to-date.
- Login into Magento admin
- Go to System → Configuration → Klevu → Search Configuration
- Go to Developer Settings (the option is visible at "default config" level)
- Select "Enable Product Sync using the Collections method" to "Yes"
- Save Config