paulwong

MONGODB删除/新增/更改大量记录的方法

MONGODB中,由于删除大量记录会十分耗时,一般推荐由MONGODB自己在后台处理,只需在某个字段设一个索引的标签即可。

@Indexed(expireAfterSeconds=180)
private Date deletedAt;

以上代码,如果字段deletedAt有值,那么将在180秒后被MONGODB删除,如果没值不会被删除。

批量新增,小批量更新,防止读取超时
private <T> void insertAll(List<T> list) {
        if (null != list) {
            int total = list.size();
            int count = (total + 50000 -1) / 50000;
            for (int i = 0; i < count; i++) {
                int toIndex = ((i +1) * 50000 > total) ? total : ((i +1) * 50000);
                log.info("toIndex = " + toIndex);
                mongoTemplate1.insertAll(list.subList(i * 50000, toIndex));
            }
        }
    }

批量更改
import java.util.Date;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.core.query.Update;

import com.tcl.project7.boss.gameapplication.yearendactivities.bigwheelgame.valueobject.SingleUseRedeemCode;

public class SingleUseRedeemCodeRepositoryImpl implements SingleUseRedeemCodeRepositoryCustom{
    
    @Autowired
    private MongoTemplate mongoTemplate1;
    
    public void batchUpdateSingleUseRedeemCodeList(String bigWheelGameAwardId) {
        
        Query query = new Query();
        query.addCriteria(Criteria.where("bigwheelgameawardid").is(bigWheelGameAwardId));
        mongoTemplate1.updateMulti(
                                    query, 
                                    new Update().set("bigwheelgameawardid", "-1")
                                        .set("deletedat", new Date()), 
                                    SingleUseRedeemCode.class);
    }

}


Expire Data from Collections by Setting TTL

New in version 2.2.

This document provides an introduction to MongoDB’s “time to live” or TTL collection feature. TTL collections make it possible to store data in MongoDB and have the mongod automatically remove data after a specified number of seconds or at a specific clock time.

Data expiration is useful for some classes of information, including machine generated event data, logs, and session information that only need to persist for a limited period of time.

A special TTL index property supports the implementation of TTL collections. The TTL feature relies on a background thread in mongod that reads the date-typed values in the index and removes expired documentsfrom the collection.

Procedures

To create a TTL index, use the db.collection.createIndex() method with theexpireAfterSeconds option on a field whose value is either a date or an array that contains date values.

NOTE

The TTL index is a single field index. Compound indexes do not support the TTL property. For more information on TTL indexes, see TTL Indexes.

Expire Documents after a Specified Number of Seconds

To expire data after a specified number of seconds has passed since the indexed field, create a TTL index on a field that holds values of BSON date type or an array of BSON date-typed objects and specify a positive non-zero value in the expireAfterSeconds field. A document will expire when the number of seconds in the expireAfterSeconds field has passed since the time specified in its indexed field. [1]

For example, the following operation creates an index on the log_events collection’s createdAt field and specifies the expireAfterSeconds value of 3600 to set the expiration time to be one hour after the time specified by createdAt.

db.log_events.createIndex( { "createdAt": 1 }, { expireAfterSeconds: 3600 } ) 

When adding documents to the log_events collection, set the createdAt field to the current time:

db.log_events.insert( {    "createdAt": new Date(),    "logEvent": 2,    "logMessage": "Success!" } ) 

MongoDB will automatically delete documents from the log_events collection when the document’screatedAt value [1] is older than the number of seconds specified in expireAfterSeconds.

[1](12) If the field contains an array of BSON date-typed objects, data expires if at least one of BSON date-typed object is older than the number of seconds specified in expireAfterSeconds.

SEE ALSO

$currentDate operator

Expire Documents at a Specific Clock Time

To expire documents at a specific clock time, begin by creating a TTL index on a field that holds values of BSON date type or an array of BSON date-typed objects and specify an expireAfterSeconds value of0. For each document in the collection, set the indexed date field to a value corresponding to the time the document should expire. If the indexed date field contains a date in the past, MongoDB considers the document expired.

For example, the following operation creates an index on the log_events collection’s expireAt field and specifies the expireAfterSeconds value of 0:

db.log_events.createIndex( { "expireAt": 1 }, { expireAfterSeconds: 0 } ) 

For each document, set the value of expireAt to correspond to the time the document should expire. For instance, the following insert() operation adds a document that should expire at July 22, 201314:00:00.

db.log_events.insert( {    "expireAt": new Date('July 22, 2013 14:00:00'),    "logEvent": 2,    "logMessage": "Success!" } ) 

MongoDB will automatically delete documents from the log_events collection when the documents’expireAt value is older than the number of seconds specified in expireAfterSeconds, i.e. 0 seconds older in this case. As such, the data expires at the specified expireAt value.

posted on 2015-12-11 15:03 paulwong 阅读(736) 评论(0)  编辑  收藏 所属分类: MONGODB


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