Using derived values in the bot—such as counts—reduces performance dramatically; however, it would be nice to still be able to display them somehow. In my opinion, the best solution would be to add a new column to both the "tags" and "series" tables that stores the value of the number of posts for each character or series. Since the tables never change between full updates, the counts should always be accurate—additionally, accessing them should have no negative consequences on performance.
Only when the tables are filled completely as part of a regular update or a backup, should the process of counting the posts for each character and series begin.
Using derived values in the bot—such as counts—reduces performance dramatically; however, it would be nice to still be able to display them somehow. In my opinion, the best solution would be to add a new column to both the "tags" and "series" tables that stores the value of the number of posts for each character or series. Since the tables never change between full updates, the counts should always be accurate—additionally, accessing them should have no negative consequences on performance.
Only when the tables are filled completely as part of a regular update or a backup, should the process of counting the posts for each character and series begin.
Tips: Use batch SELECTs and UPDATEs.