Will large datasets impact the instance performance ?

[hacktd]

In my current instance, there are many custom tables of mine which have a lot of records, more than 300k records, I wonder if this number keeps expanding will there be any problem to the instance performance or just the table query it's self ?

[Tanushree Maiti]

Hi @hacktd 

As a Platform Architect , I have seen when table records having large data set ( including custom table), ServiceNow instances can experience both database degradation and platform-wide performance issues.

Key Potential impact:

• Queries without indexed fields will trigger full table scans. In a massive table, this takes significantly longer and exhausts database resources.
• If long-running queries lock the database, it can deplete available semaphores. This causes system-wide sluggishness, where other users experience extreme delays or "system is busy" errors.
• Larger tables increase the time required for platform upgrades, clones, and instance backups. 
• Opening a list view with many rows or a form with related lists pointing to these large tables will slow down UI rendering. 

Actionable Optimization Recommendation

• Ensure you create ServiceNow Database Indexes for any fields frequently used in queries
• Implement Data Archiving to automatically move older, inactive records out of the primary table into an archive table. This keeps the primary active table lean. 
• Regularly delete obsolete or temporary records using scripts or Scheduled Jobs.   ETC.