is elasticsearch nosql database

1.NOSQL IntroductionNOSQL (not only Sql) refers to a non-relational database. The next generation of databases mainly solves several key points: non-relational, distributed, open-source, horizontally extensible. The original goal was for large-scale Web applications, which began in the early 2009 with features such as freedom of mode, support for simple replication, simple APIs, eventual consistency (non-ac

Recently in the know to see this problem, oneself also engaged half semester of Elasticsearch, so want to use oneself know shallow knowledge to answer this question.Cluster contains multiple node,indices that should not be understood as a verb index , indices can be understood as databases,indices in a relational database can contain multiple indexes, The index corresponds to the

table, usually according to the user to the table, will be the same user all the data are placed on the same machine, but if we create time to query, want to query all the users in the journal published today, then this will be invalidated. At this point you need to go to each of the sub-table query and then the query results are assembled. And the native SQL is not complete. When an index is unavailable,

Article Source: http://article.yeeyan.org/view/271351/239915Although SQL database is a very useful tool, the monopoly is about to be broken after 15 years of a single show. This is only a matter of time: forced to use relational databases, but eventually found to be unable to adapt to the needs of the numerous.But the

NoSQL series: Why use NoSQL databases when appropriate databases are selected? The impedance imbalance relationship model does not match the data structure in the memory. More convenient data interaction methods are used to improve development efficiency. The amount of data to be processed is large. The amount of data exceeds the capacity of the relational

Tags: daily capacity large number of scene mode shopping cart economic bidding copy Dynamodb is a fully managed NoSQL database service. Customers can easily use Dynamodb's services. Enjoy high performance, massive scalability and persistent data protection at the same time. The Dynamodb database was published by Amazo

transactions in the database (transaction) have ACID4 basic features that can be compared to trading:1,A (atomicity) atomicityEverything in the transaction is either completed or failed during execution and is rolled back.2,C (consistency) ConsistencyThe database should be in a consistent state.For example: Existing in

With the development of Internet technology, the traditional relational database can not be satisfied with the storage and analysis of massive data, thus deriving a database NoSQL (not only SQL) which is different from the relational database.The more mature nosql in foreign

Using Https://github.com/taowen/es-monitor, you can use SQL to make Elasticsearch queries. Sometimes buckets are aggregated to produce a lot of buckets, and we only care about some of them. The simplest way is to sort and then take the first few results.ORDER by _termSql$ catEof|./es_query.py http://127.0.0.1:9200SELECTIpo_year,COUNT(*) fromSymbolGROUP byIpo_yearORDER byIpo_year LIMIT2eof{"COUNT(*)":4, "I

Tags: style java using OS io strong file dataAn example of a simple NoSQL memory database-berkeley DB Basic operationRecently, due to the development of cloud computing, database technology has evolved from a structured database to a NoSQL

Cassandra may not be interested in being a nosql, but it's fascinating to do certain jobs, as Netflix and Instagram two companies must know.Over the years, NoSQL participants, such as MongoDB, have gotten a lot of attention, but the halo of Apache Cassandra has faded, and Facebook, which created Cassandra, has given up on it, The community of Cassandra seems to be out of date soon. But Cassandra's fortunes

Label:Recently, the well-known independent benchmark evaluation agency Bankmark, for the current mainstream NoSQL database sequoiadb, MongoDB and Cassandra three NoSQL database products to do performance comparison testing and release test reports. in all of the tests, the three No