Mongoose创建不在方案中的索引

Question

猫鼬有一种奇怪的行为。

在方案中我有几个索引，但有时它会索引所有字段，有时它只会索引_id。它永远不会像在计划中那样制作索引。其他方案工作得很好，但这个方案特别给我带来了麻烦。也许是因为它有80个领域？

我的环境是mongodb v2.4.12，节点v0.10.40，mongoose npm包v4.0.0

这是架构（为了清楚起见，我拿出了一些字段）：

'use strict';

var log = require('../../../../lib/logging')(module.id),
    config = require('../../../../production.config'),

    me = module.exports = {

        name: 'natstransactions',

        model: {
            originType: { // postback or import
                type: String,
                index: true,
                unique: false,
                required: true
            },
            type: {
                type: String,
                index: true,
                unique: false,
                required: true
            },
            memberid: {
                type: Number,
                index: false,
                unique: false,
                required: false
            },
            //transaction: {
            transaction_id: {
                type: Number,
                index: true,
                unique: true,
                required: false,
                trim: false,
                sparse: true // This makes the transaction to be unique only if not null, so there can be more than one document with null as transaction_id
            },
            post_time: {
                type: Date,
                index: false,
                unique: false,
                required: false
            },
            post_type: {
                type: String,
                index: false,
                unique: false,
                required: false
            }
        },

        virtual: function(schema) {

        },

        postInit: function(schema) {
            // schema.plugin(random, {path: 'r'});
            schema.set('toObject', {getters: true, virtuals: true});
            schema.set('toJSON', {getters: true, virtuals: true});
        }
    };

if (config.debug) {
    inspect(me.name + ' Schema', me);
}