The Young DBA

RMAN (Recovery Manager) is a backup and recovery manager supplied for Oracle databases (from version 8) created by the Oracle Corporation. It provides database backup, restore, and recovery capabilities addressing high availability and disaster recovery concerns. How to start recovery manager in and connect to database? just go to bin folder of oracle and then execute C:\oraclexe\app\oracle\product\11.2.0\server\ rman target / <enter> or start-run-rman <enter> connect target / <enter> After connecting how to check configurations ? SHOW ALL; How to perform backup operation. BACKUP AS BACKUPSET DATABASE PLUS ARCHIVELOG; BACKUP AS BACKUPSET DATABASE How to check backup history? LIST BACKUP SUMMARY;

After being SQL DBA 4+ years now since 2 years I am trying to be a DBA mean cross platform database administrator. So trying multiple technologies. MySQL, mongodb and Oracle too. My today's post is on oracle, true fiction working on large data-set. Actually I was testing CRUD and aggregations on oracle 11g over 21 millions records (21326826). I had a table employee having huge amount of data and there is a column city which have null values on 21 millions records. The story begins when I was trying to update these null value with some information. Column have already secondary index we have created on city column because result of group by was slow on city so for better response time we have created index on city column. Physical architecture of database and tables space are default . Table is present in user tablespace. We have not changed any configuration of oracle before, I am totally new on oracle.

Avro schema generally used to define the data schema for a record's value. This schema describes the fields allowed in the value, along with their data types. We can apply a schema to the value portion of an Oracle NoSQL Database record using Avro bindings. These bindings are used to serialize values before writing them, and to deserialize values after reading them. The usage of these bindings requires our applications to use the Avro data format, which means that each stored value is associated with a schema. The use of Avro schemas allows serialized values to be stored in a very space-efficient binary format. Each value is stored without any metadata other than a small internal schema identifier, between 1 and 4 bytes in size. One such reference is stored per key-value pair. In this way, the serialized Avro data format is always associated with the schema used to serialize it, with minimal overhead. This association is made transparently to the application, and the internal sche