SharePoint 2013 - PSCONFIG is mandatory after installing July 2015 CU for SharePoint Server 2013.
With July 2015 CU for SharePoint Server 2013, we have an important update w.r.t. the database schema changes for the analytics reporting database. The change was required to support URLs with up to 4000 characters length.
It is important to note here that the crawler now expects the database schema to be updated and will fail to crawl if PSCONFIG (Wizard or Command) did not run to update the database schema.
In other words: unlike other CU's, it is important to run PSCONFIG right after installing the July 2015 CU binaries.
Note: If you do not run PSCONFIG (Wizard or Command), crawling will no longer work.
Another important thing to note here is that if you have a farm where you want to install any CU later than July 2015 CU, but have not installed July 2015 CU, same step of running PSCONFIG (Wizard or Command) is required else Search Crawls will not work.
This information is already updated in below articles.
https://support.microsoft.com/en-us/kb/3054933 July 14, 2015, cumulative update for Project Server 2013 (KB3054933)
https://support.microsoft.com/en-us/kb/3054937 July 14, 2015, cumulative update for SharePoint Server 2013 (KB3054937)