greenplum

As it developers and small and medium-sized software companies have always benefited from the open source community and open source projects, my first contact with Linux based on the GNU program is that we can use or publish the source code as long as we comply with the GNU GPL. Later, in the work and learning process, we contacted many open source communities (open source, China unix.net, etc.), open source Projects (Hadoop, OpenStack, etc.) and foundations supporting open source projects (such

;/proc/sys/vm/overcommit_memory Resources: Http://serverfault.com/questions/606185/how-does-vm-overcommit-memory-workhttp://linuxperf.com/?p=102 Summarize: Say so much, then why do you want to change the value of kernel parameter vm.overcommit_memory? This is because this server ran over the Greenplum database before, when I got my hand, I did not reload the system, then it is recommended that if you get the machine ran before other business

materials: Http://serverfault.com/questions/606185/how-does-vm-overcommit-memory-workhttp://linuxperf.com/?p=102 Summary: Say so much, then why do you want to change the value of kernel parameter vm.overcommit_memory? This is because this server ran over the Greenplum database before, when I got my hand, I did not reload the system, then it is recommended that if you get the machine ran before other business, then the insurance method or reload th

applications, because compared to OLTP applications, DSS applications are more easily distributed expansion, such as PostgreSQL based on the development of Greenplum, it is very good to solve the problem of usability and scalability, And it provides a powerful parallel computing capability. For OLTP applications, business characteristics determine their requirements: high availability, consistency, short response time, support for transactions and jo

summer of 2011, Oracle published a famous white paper that mentions that the NoSQL database feels like an ice cream flavor, but you shouldn't cling to it too much because it won't last long. But only a few months later, Oracle has demonstrated their plans to integrate Hadoop into large data devices. Even, they set up their own NoSQL database, which is a modification of the berkeleydb. Since then, all vendors have competed in integrating Hadoop. Microsoft, Sybase, IBM,

the *gp_vmem_protect_limit* parameter configuration at the database level. Use the following example to calculate the value in the resource queue, setting a memory quota for each query is using session settings to reduce the *statement_mem* of the query at the database level reduce *statememt_mem* reduce the number of databases on the node in the cluster, But this requires reinstalling the database cluster and reloading the data adds hardware resources to the node, and increasing the number of

Dag (directed acyclic Graph) (see article: Dryad, cascading, and cascading's homepage). (4) MapReduce and database combination of products: hadoopdb and Greenplum. This article mainly explains the current more famous traditional MapReduce open source realization. Now there are a lot of open source MapReduce framework implementations, the most famous is the Java implementation version of Hadoop. In fact, it's a heavyweight implementation version (a la

greenplum, IBM DB2 BLU, and the national NTU Gbase 8a have a significant overlap with the location of Hadoop. In the case of high concurrent online transactions, the distributed database occupies an absolute advantage in Hadoop, except that HBase is barely available. Figure 3 Distributed database and Hadoop application scene limit At present, from the perspective of the development of the Hadoop industry, Cloudera, Hortonworks and other m

Label:MySQL is so widely used that I have to migrate some applications from MySQL to PostgreSQL, many open source software is mysql as a database standard, and MySQL as the basis of the abstract, but the use of the process, found that MySQL has a lot of problems, So all migrated to PostgreSQL and turned to a MySQL vs. PostgreSQL article: PostgreSQL is a multi-process framework similar to Oracle, so it can support high concurrency scenarios, much like the Oracle database, so transfer Oracle DBA

]# free -k Total used free 132096808 1583944 130512864 0 10240 133220 -/+ Buffers/cach E: 1440484 130656324 Swap: 4095992 0 4095992 3306 cat /proc/sys/vm/ overcommit_ratio 3306 Total virtual Memory =132096808 * 50% + 4095992= 70144396 KB The final result is that the buffer pool cannot exceed 70144396 KB- 135196 kb=70009200 kb=66g. In fact, the buffer pool can only be set to 57G after testing. Finally look at the total virtual memory situation: Commitlimit: Maximum available virt

algorithm and placed on HDFS--it's a bit of a headache to change a compressed record.Changed a place, immediately resonate. Look at this person's analysis.##########################################1. Very much agree that big data is a platform view, it is not only related to data storage and access, but also related to data import, export, analysis, application and so on.2. The core problem of big data is distributed, including distributed data storage, distributed computing (including distribu

Greenplum is a distributed database based on PostgreSQL . It uses the shared nothing architecture (MPP), the host, the operating system, the memory, the storage is self-controlled, there is no sharing. That is, each node is a separate database. The information interaction between nodes is realized through the node internetwork. By distributing data across multiple nodes to achieve storage of scale data, the query performance can be improved by paralle