Assume that you are creating or dropping large number of temporary tables in Microsoft SQL Server 2016 or 2017. Certain application workload invalidates the cache of temporary tables. For example, you are creating temporary tables and then creating ALTER TABLE or CREATE INDEX which will invalidate the cache of temporary tables. In this situation, you may experience the following issues:
- Data Definition Language (DDL) contention in the tempdb on system catalog sysobjvalues and large number of sessions that are waiting on the PAGELATCH_EX, PAGELATCH_SH and PAGELATCH_UP wait type occur.
- This situation also affects the workload when the entries count is more than 4,000. However, this may vary, depending on the workload. See the following example:
SELECT [name], [type], [entries_count], [entries_in_use_count]
WHERE [type] = N'CACHESTORE_TEMPTABLES'
Temporary Tables & Table Variables
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.