The index of MongoDB learning notes

Index:

#查看执行计划

Db.stu.find (). explain ();

#创建索引 (records without this column also create an index)

Db.bar.ensureIndex ({content:1})

#查看索引

Db.bar.getIndexes ()

#删除索引

Db.bar.dropIndex ({content:1})

#创建多列索引

Db.bar.ensureIndex ({content:1, title:-1})

#查询子文档

Db.shop.find ({' Spc.area ': ' Taiwan '});

#子文档加索引

Db.shop.ensureIndex ({' Spc.area ': 1})

#创建唯一索引

Db.bar.ensureIndex ({content:1},{unique:true})

#创建稀疏索引 (with column creation, no column ignored)

Db.bar.ensureIndex ({content:1},{sparse:true})

Note: At query time, the normal index can be found by {content:null}, and the sparse index cannot be found.

#创建hash索引

Db.bar.ensureIndex ({content: ' hashed '})

#重建索引

Db.bar.reIndex ()

The index of MongoDB learning notes