cassandra

ScyllaDB 2.1 - Inconsistency with Materialized View

由 夙愿已清 提交于 2021-01-27 13:40:00
问题 While deciding on the technology stack for my own product, I decided to go with scyllaDB for database due to it's impressive performance. For local development, I setup Cassandra on my Macbook. Considering ScyllaDB now supports (experimental) MV (Materialized View), it made the development easy. For dev server, I'm running ScyllaDB on Ubuntu 16.04 hosted on Linod. I am facing following issues : After a few weeks, one day when I deleted an entry from base table (from ScyllaDB running on Ubuntu

How to understand the 'Flexible schema' in Cassandra？

由 别等时光非礼了梦想. 提交于 2021-01-27 11:22:26
问题 I am new to Cassandra, and found below in the wikipedia. A column family (called "table" since CQL 3) resembles a table in an RDBMS (Relational Database Management System). Column families contain rows and columns. Each row is uniquely identified by a row key. Each row has multiple columns, each of which has a name, value, and a timestamp. Unlike a table in an RDBMS, different rows in the same column family do not have to share the same set of columns, and a column may be added to one or

Cassandra Materialized views impact

由 二次信任 提交于 2021-01-27 08:19:15
问题 Would like to know impact of mv on base table. Does it slows down base table? When does it starts writing to mv like does it write to base table and mv same time? If I have CL of local_quorum and RF=3 does the client has to wait till it write to mv to get the ack. what kind of lock involved in base table and mv does it impacts the latencies on base table 回答1: Materialized Views are considered experimental. The next patch releases of 3.0, 3.11, and 4.0 will include CASSANDRA-13959, which will

Cassandra Materialized views impact

由 别等时光非礼了梦想. 提交于 2021-01-27 08:18:12
问题 Would like to know impact of mv on base table. Does it slows down base table? When does it starts writing to mv like does it write to base table and mv same time? If I have CL of local_quorum and RF=3 does the client has to wait till it write to mv to get the ack. what kind of lock involved in base table and mv does it impacts the latencies on base table 回答1: Materialized Views are considered experimental. The next patch releases of 3.0, 3.11, and 4.0 will include CASSANDRA-13959, which will

Cassandra Materialized views impact

由 ≯℡__Kan透↙ 提交于 2021-01-27 08:17:07
问题 Would like to know impact of mv on base table. Does it slows down base table? When does it starts writing to mv like does it write to base table and mv same time? If I have CL of local_quorum and RF=3 does the client has to wait till it write to mv to get the ack. what kind of lock involved in base table and mv does it impacts the latencies on base table 回答1: Materialized Views are considered experimental. The next patch releases of 3.0, 3.11, and 4.0 will include CASSANDRA-13959, which will

Cannot connect to Cassandra on localhost

由 不想你离开。 提交于 2021-01-27 07:32:37
问题 First time using cassandra, I have attempted to configue the yaml file according to other related posts but had no luck so far. Any idea how do so on the localhost? The specified host(s) could not be reached. All host(s) tried for query failed (tried: localhost/0:0:0:0:0:0:0:1:9042 (com.datastax.driver.core.TransportException: [localhost/0:0:0:0:0:0:0:1:9042] Cannot connect), localhost/127.0.0.1:9042 (com.datastax.driver.core.TransportException: [localhost/127.0.0.1:9042] Cannot connect))

Cannot connect to Cassandra on localhost

由 南笙酒味 提交于 2021-01-27 07:32:29
问题 First time using cassandra, I have attempted to configue the yaml file according to other related posts but had no luck so far. Any idea how do so on the localhost? The specified host(s) could not be reached. All host(s) tried for query failed (tried: localhost/0:0:0:0:0:0:0:1:9042 (com.datastax.driver.core.TransportException: [localhost/0:0:0:0:0:0:0:1:9042] Cannot connect), localhost/127.0.0.1:9042 (com.datastax.driver.core.TransportException: [localhost/127.0.0.1:9042] Cannot connect))

NoSQL概述-从Mongo和Cassandra谈谈NoSQL

由 强颜欢笑 提交于 2021-01-27 07:21:33
分两部分介绍NoSQL - NoSQL 概览 1. RDBMS VS NoSQL 2. NoSQL 种类 3. NoSQL 的一些名词 - 结合Mongo,Cassandra谈谈NoSQL的设计和应用 1. 部署架构 2. 分片 3. 数据存储与维护 4. 读写分析 5. 数据模型 关系型数据库 VS NoSQL VS New SQL 关系型数据库：元组关系(ER)，提供了一套标准的接口，SQL NoSQL: non-relational,Not-Only SQL,致力于解决关系型数据库扩展的问题 New SQL: 结合RDBMS 与NoSQL的优势(还没有看到一个清晰的概念定义) NoSQL 种类 数据模型|相关数据库|典型应用|优势|劣势| ----|:----:|----:|----:|----:| key-value|Redis|缓存|快速查询|存储数据缺乏结构化 列族|Cassandra,Hbase|分布式的文件系统，大规模的数据存储|易于分布式扩展|功能受限 document|Mongo,CouchDB||free-schema|可扩展性查 图|Neo4J|社交网络|利用图结构相关算法|不易扩展 key-value 结构 wide-column(两级映射) document mongo应用 NoSQL 主要概念 1. 不支持事务和join 2. BASE VS ACID

Dynamic Table name in Cassandra Pojo Sink Flink

由 混江龙づ霸主 提交于 2021-01-27 07:06:06
问题 I am a newbie to Apache Flink. I am using Pojo Sink to load the data into Cassandra. Right now, I am specifying table and keyspace names with the help of @Table annotation. Now, I want to pass table name and keyspace name dynamically on run time so that I can load data into tables specified by user. Is there any way to achieve this? 回答1: @Table is a CQL annotation that defines which table this class entity maps to. AFAIK, currently there is no way to make it dynamically mapped to any table at

How can I add a new field in a Cassandra table with default value “whatever”?

由 匆匆过客 提交于 2021-01-27 05:32:00
问题 How can I add a new field/column in a Cassandra table with default value "whatever" ? I know how to add a new column, however, need it to be set to a certain value. 回答1: There is no cell default value in cassandra. Best option is to in your application identify null values and change it to the default. 来源： https://stackoverflow.com/questions/48749253/how-can-i-add-a-new-field-in-a-cassandra-table-with-default-value-whatever
订阅 cassandra