历史版本。 PostgreSQL 9.2 已结束支持。 2017-11-09. 请参阅 当前版本手册.
56.5. The Initialization Fork #
Each unlogged table, and each index on an unlogged table, has an initialization fork. The initialization fork is an empty table or index of the appropriate type. When an unlogged table must be reset to empty due to a crash, the initialization fork is copied over the main fork, and any other forks are erased (they will be recreated automatically as needed).