Ruby Operation MongoDB (Advanced six)-index indexing

In this blog post, we mainly introduce database indexes. Main include create index, DROP index, list index

The database driver provides a way to create, delete, and view indexes on the collection.

1. Create an index

In an operation that creates an index, you can create one index at a time, or you can create multiple indexes at once. In the 3.0 and later versions of the MONGODB database, multiple indexes are created in parallel. In earlier versions, multiple indexes were created in order.

Creation of a single index, using the Create_one method

Client=mongo::client.new ([' 127.0.0.1:27017 '],:d atabase=> ' film ') Client[:actors].indexes.create_one ({: name= >1},unique:true)

Multiple indexes are created, using the Create_many method. It is important to note that when multiple indexes are created at one time, the key values of the index must be passed by the corresponding specific key-value pair as described. This is because the parameters of each created index may be different.

Client=mongo::client.new ([' 127.0.0.1:27017 '],:d atabase=> ' film ') Client[:actors].indexes.create_many ([{: key= >{name:1},unique:true}, {: Key=>{label:-1}}])

The complete list of parameters available when creating an index is listed in the following table

Parameters	Parameter description
: Background	Evaluates to TRUE or FALSE, explicitly when the index is created in the background or foreground execution
: Expire_after	The number of seconds to expire the document from the current time
: Name	The name of the index
: Sparse	Determines whether the index is sparse, either true or False
: Storage_engine	Name of the storage engine that defines the index
: Version	version of the indexed format used
:d Efault_language	Default language for text indexing
: Language_override	The name of the domain to use when overriding the default language
: text_version	Format version for storing text indexes

: Weights	Documents that specify fields and weights in a text search
: sphere_version	Version of the 2-D index
: Bits	Set the maximum boundary of latitude and longitude in a 2-bit index
: Max	Maximum boundary value for latitude and longitude of a 2-D index
: Min	Minimum boundary value for latitude and longitude of 2-D index
: bucket_size	Grouping Geo Haystack index position values is the number of units adapted
:p artial_filter_expression	Parallel Index Expression Filters

2. Deleting an index

Delete index, use Dropone or Dropall

Client=mongo::client.new ([' 127.0.0.1:27017 '],:d atabase=> ' film ') Client[:bands].index.drop_one (' Name_1 ') Client[:bands],drop_all

3. Listing indexes

Client=mongo::client.new ([' 127.0.0.1:27017 '],:d atabase=> ' film ') Client[:bands].indexes.each do |index| P Index End

This article from "Techfuture" blog, declined reprint!

Ruby Operation MongoDB (Advanced six)-index indexing