A case of MongoDB error

Development Program error Message:

caused By:com.mongodb.MongoException:Executor error:

Operationfailed:sort operation used more than the maximum 33554432 bytes of RAM. Add an index, or specify a smaller limit.

From the program error, you can see that the sort of memory is low.

Workaround: Version 3.x

Use admin

Db.admincommand ({getparameter: "*"}) #查看参数的配置

Db.admincommand ({setparameter:1, internalqueryexecmaxblockingsortbytes:335544320}) #修改内存为排序为320M

Other solutions: (by creating an index)

Db. Your Collection.createindex ({"Your field":-1}), here-1 for reverse, 1 for positive sequence;

Db. Your collecton.getindexes ();

　　

Refer to the official documentation:

https://docs.mongodb.com/manual/reference/method/cursor.sort/#cursor. Sort

https://docs.mongodb.com/manual/tutorial/optimize-query-performance-with-indexes-and-projections/

Recommended solutions for these issues:

1. Optimize queries and indexes.
2. Reduce the output column (limit the number of output columns) or rows (such as the limit function, or limit the number of input query _id).
3. The query is divided into 2 steps, the 1th step only output _id, the 2nd step through _id to find thin.
Can solve the in-memory sort overflow problem.

A case of MongoDB error