I started looking for notes on MOS when I could not see the list of named credentials I had added to EM. This is a fresh install of EM 188.8.131.52, with an 184.108.40.206.11 repository database. All the EM components and monitored targets are on rhel 5 x86-64. There is one MOS note (Missing Named Credentials in the Jobs Drop Down List in Cloud Control 12c (Doc ID 1493690.1) from December 2012. The note says to increase the number that may be stored as named credentials, because table sysman.em_nc_creds has more records than 50, which is the default number of credentials.
However, table sysman.em_nc_creds has hundreds of records, and I only set one named credential so far through the EM API. Table sysman.em_nc_creds is populated with all the targets that were added when 12c agents were deployed to new hosts. It does not matter if the 12c agents were deployed using Setup > Add Targets > Add Targets Manually > Add Host Targets, or if server-side scripts were executed from the new nodes to EM. The table has a named credential for every target discovered by EM.
My questions are: is it expected for EM to add named credentials on its own? If so, is it reasonable for me to set the number of named credentials to (say) 2000, which should* cover every current and future target I may register with EM? Last: should every named credential stored in sysman.em_nc_creds be visible to its owner using the EM API?