DAILYDBADIARIES

 Oracle Database Software Installation Methods for Linux • Image-based - DBA downloads the database software and runs the setup wizard - DBA has more control on the options • RPM-based - DBA downloads the database software rpm and installs it - Quick installation with less options - Available from 18c onwards Oracle Database Installation Procedure 1. Make sure the server machine meets the requirements 2. Prepare the installation target machine 3. Download the required software - Download Oracle database software - In some configurations: download the Grid Infrastructure software 4. (optional) Download the lates available Release Update (RU), Release Update Revision (RUR), or Patchset from Oracle Support 5. Install Oracle Database software (and Grid if needed) 6. (optional) Apply the patches 7. Create the database Oracle Database Release/Version • For production systems, if possible, always use the most recent Long Term Release (19c). • Do not use the latest Innovation Release (2...

 Tablespace consists of one or more data files.  A data file belongs to only one tablespace. Segments, Extents, and Blocks • Segments exist within a tablespace • Segments are made up of a collection of extents • An extents is a collection of logically contiguous data blocks - Cannot span multiple data files • Data blocks are mapped to disk blocks SYSTEM and SYSAUX Tablespaces • The SYSTEM and SYSAUX tablespaces are mandatory tablespaces. • They are created at the time of database creation. • They must be online. • The SYSTEM tablespace is used for core functionality (for example, data dictionary tables). • The auxiliary SYSAUX tablespace is used for additional database components.

 Data files Control files: control files are used to save the database physical structure this includes the database file names and their locations the backup files and the database basic information like creation time and last check  Oracle database instance needs only a single control file to operate. However in most production data bases more than one control files are configured no Oracle database can operate without control files   Control files must be there otherwise the instance goes down. Parameter file: the parameter file is a small file to save the parameter value pairs. The parameter is saved in the file are called installization parameters.  Installization parameters are configuration parameters that controls the instance behaviour. Online redolog files: online redo log files are two or more pre allocated files that store changes to the database as they occur.  The files are used for instance recovery, generating archive redolog files, replicat...

 • An Oracle database server consists of at least one database instance and a database. - A database is a set of files, located on disk, that store data. - An instance is a set of memory structures and processes that manage the database files. • An instance consists of a shared memory area, called the system global area (SGA), and a set of background processes. • For each user connection to the instance, there is a client process. Each client process is associated with its own server process. The server process has its own private session memory, known as the program global area (PGA). System Global Area (SGA) Components • Shared Pool - Library Cache: stores executable SQL and PL/SQL code. - Data Dictionary Cache: holds info about accessed database objects - Server Result Cache: holds result sets (not data blocks). It contains the SQL query result cache and PL/SQL function result cache. • Database buffer cache: the memory area that stores copies of data blocks read from dat...

 • Plan the Database Design • Install Oracle database and Grid Infrastructure Software • Create Oracle Databases • Backup the database • Control database security • Tune Oracle database performance • Implement Database Disaster Recovery (DR) plan • Migrate the on-prem databases to the Cloud • Patching database and grid infrastructure • Upgrade Oracle databases • Create and Manage Oracle clusters (RAC) • Clone databases • Monitor database resources growth and determine future demands • Perform database health check • Oracle database options and licenses • Diagnosing and troubleshooting Oracle databases