The default max memory size for the Windows Internal Database (used by WSUS) is unlimited, so all memory available to the operating system. You may wish to change this to relinquish some memory to other processes if sqlservr.exe is using too much memory.
1. Open a SQL command prompt.
sqlcmd -S \\.\pipe\mssql$microsoft##ssee\sql\query -E
2. Execute the following SQL modifying the memory to your needs.
sp_configure ’show advanced options’, 1;
reconfigure;
go
sp_configure ‘max server memory’, 512;
reconfigure;
go
exit