我得到以下错误(转储MongoDB 3.2)(恢复MongoDB 3.4):
Failed: ngivr-dev.ledgerhelpers: error creating indexes for ngivr-dev.ledgerhelpers: **createIndex error:** **The field 'safe' is not valid for an index specification.** Specification: **{ unique: true, name: "ledgerId_1", safe: null, ns: "ngivr-dev.ledgerhelpers", background: true, key: { ledgerId: 1 } }**
看起来安全索引为空.但我如何将其用于MongoDB 3.4?3.2没问题.