What is Apache Cassandra? ▪ NoSQL database ▪ Schema-free ▪ Very fast ‘write’ ▪ Cassandra is designed to handle big data workloads across multiple nodes with no single point of failure ▪ Cassandra addresses the problem of failures by employing a peer-to-peer distributed system across homogeneous nodes where data is distributed among all nodes in … Read more
Cassandra.csv file data: Create keyspace and create tables and then importing the data form local system to Cassandra: $./bin/nodetool status $./cqlsh 192.168.0.104 Below are copied csv data from local system: Now we will export data from Cassandra to local file system:
A Linux distribution is a collection of (usually open source) software on top of a Linux kernel. A distribution (or short, distro) can bundle server software, system management tools, documentation and many desktop applications in a central secure software repository. A distro aims to provide a common look and feel, secure and easy software management … Read more
/etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.56.10 mysql-prim.localdomain mysql-prim 192.168.56.11 mysql-dr.localdomain mysql-dr User to install and configure mysql: avs Install MySQL Configure MySQL master node mysql.conf Change binlog and data dir Startup with default setup and then we will proceed to change data and bin logdirectory: 1. Start mysql (both … Read more
As a DBA, you are responsible for the performance of your Oracle database. Typically, performance problems result from unacceptable response time, which is the time to complete a specified workload, or throughput, which is the amount of work that can be completed in a specified time. Typical problems include: • CPU bottlenecks • Undersized memory … Read more
Staging Streams: Streams may store or stage changes in a database buffered queue. The benefit is that changes are stored in memory which has a fast access time. GoldenGate: When processing a one-time activity : an initial load or a batch run, GoldenGate stages extracted changes in an extract file. During normal operation , GoldenGate … Read more
Transparent Data Encryption (TDE) enables you to encrypt sensitive data that you store in tables and tablespaces. After the data is encrypted, this data is transparently decrypted for authorized users or applications when they access this data. TDE helps protect data stored on media (also called data at rest) in the event that the storage … Read more
CAUSE ALTER TABLESPACE TB1 add datafile ‘+WHALE_DG1’ size 10g autoextend on next 500M * ERROR at line 1: ORA-00059: maximum number of DB_FILES exceeded We do not have to recreate the CONTROL FILE from 10g onwards to change/modify MAXLOGFILE, MAXLOGMEMBERS,MAXLOGHISTORY, MAXDATAFILES, and MAXINSTANCES For MAXDATAFILES, follow the steps below:
There are two types of Undo Modes in 12.2 1) Shared Undo – The Undo tablespace is common, it is shared among the entire CDB. The Management of undo tablespace is similar to Non-CDB database. 2) Local Undo – The Local undo is local particular PDB or a container The benefits having local undo enables … Read more