"The minimum across all databases, in turn, is recorded in checkpoint records, and CHECKPOINT removes pg_multixact/ segments older than that value once the checkpoint record has been flushed."
The above part of the paragraph in README.tuplock seems to be outdated. I think now we truncate the multixact files only during vacuum. This file has been last updated by commit cdbdc4382743fcfabb3437ea7c4d103adaa01324 and it seems that there are substantial changes happened since then in this area, so it might be a good idea to update this file. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
