Please note that the upgrade process to the Deep Castle Gen 2 Update 2 (13.0.2) can take longer than usual because IceWarp has added a new index for the WebClient database item table.
To avoid this complication in bigger instances, adding the index before starting the upgrade is recommended by using a script for the MySQL hosted on the Linux server attached below.
Based on checking the number of rows in the item table, the script will select the best method for adding the index.
It will create a new table without items based on the original table for a smaller number of rows, add the index, select-insert on all items, and finally rename the tables.
For the bigger number of the rows, it will transfer to the different databases which are processed by mysqldump. In the end, it will transfer the growth created after the start of the script and rename the database again.
How to run the script (example):
./addwebcindex.sh 127.0.0.1 root password1 3306 webclientdb
For 100 million rows in the item table, the script takes roughly 4 hours by the second method.
For 35 million rows, it takes circa 1 hour, and for 44,5 million, it takes roughly 1,5 hours.
Despite the fact maintenance is not necessary for this action, it is recommended to run it outside of business hours.