Skip to main content

Welcome to DBA Master – Database Tips, Tricks, and Tutorials

Welcome to DBA Master ! This blog is dedicated to all things related to database administration , SQL optimization , and performance tuning . Whether you're a beginner or a seasoned DBA, you'll find practical guides, troubleshooting tips, and real-world tutorials to help you work smarter with data. What to Expect: SQL performance tuning tips Indexing strategies Backup and recovery best practices High availability and replication techniques Database creation, configuration, and setup Monitoring queries and scripts for proactive performance management Migration guides across different database platforms Security essentials and best practices Recommended tools for DBAs Real-world error fixes and how to solve them Stay tuned — exciting content is coming soon. Feel free to bookmark and share: www.dbamaster.com ! Thanks for visiting!
Post a Comment

Oracle Operators and Functions

Operators:

Manipulates data items and returns a result

Arithmetic Operators:

+ (Addition)
– (Subtraction)
* (Multiplication)
/ (Division)
% (Modulus)

Comparison Operators:

= (Equal to)
!= or <> (Not equal to)
< (Less than)
> (Greater than)
<= (Less than or equal to)
>= (Greater than or equal to)

Logical Operators:

AND (Logical AND)
OR (Logical OR)
NOT (Logical NOT)

Others:

Concatenation Operator (Concat or ||)
In
Between
Null
Like (%,_)

Functions:

Functions take one or more parameters as input, perform a computation or operation, and then return a result.

Predefined Functions and (User Defined Functions):

Scalar functions

  1. Character or string Functions
  2. Numeric Functions
  3. Date Functions
  4. Conversion Function
  5. Miscellaneous Function

Aggregate Functions

  1. Count
  2. Sum
  3. Avg
  4. Max
  5. Min
  6. Group by
  7. Having
  8. Order by

Character or string Functions:

Concat
Length
Substr
Instr
Lpad
Rpad
Trim
Lower
Upper
Initcap

Numeric Functions:

Ascii
Abs
Ceil
Floor
Round
Power
Sqr
Greatest
least
Mod
Sign

Date functions:

Sysdate
Systimestamp
Months_between
Add_months
Last_date
Next_day
Round
Trunc

Conversion functions:

To_char
To_date
To_number

Miscellaneous Functions:

Nvl
Nvl2
Nullif
Coalesce
Decode
Case
Vsize

Labels:

Comments

Post a Comment

Popular posts from this blog

Oracle Database 19C Performance Tunning - PART 1

Advantages: 1. Improved Query Performance •    Optimized SQL execution plans lead to faster query response times. •    Reduces unnecessary full table scans and improves indexing strategies. •    Parallel execution tuning speeds up large data processing tasks. 2. Better Resource Utilization •    Efficient use of CPU, memory, disk I/O, and network resources. •    Reduces contention on Redo Logs, Undo Tablespaces, and Buffer Cache. •    Helps in load balancing across multiple instances in RAC (Real Application Clusters). 3. Increased System Scalability •    Ensures that the database can handle a growing number of users and transactions. •    Proper tuning allows scaling without degrading performance. •    Optimized parallel processing ensures better performance on multi-core servers. 4. Lower Infrastructure Costs •    Reduces the need for add...
Post a Comment
Read more

Oracle RMAN Backup And Restore

RMAN: (Oracle 8) RMAN (Recovery Manager) is a utility provided by Oracle Database to perform backup, restore, and recovery operations. It is a command line tool. Features of RMAN in Oracle 19c Comprehensive Backup Capabilities: Full and incremental backups. Block-level backups for efficient data storage. Archived redo log backups. Fast Recovery Area (FRA) integration for centralized backup storage. Efficient Recovery Options: Point-in-time recovery (PITR). Complete and incomplete recovery. Flashback database capabilities for quick undo of changes. Multitenant Database Support: RMAN fully supports container databases (CDBs) and pluggable databases (PDBs). Provides flexibility to back up and recover individual PDBs or entire CDBs. Automatic Space Management: Manages disk space in the FRA. Automatically deletes obsolete backups and archived logs. Data Deduplication and Compression: Backup optimization through block-level deduplication. Built-in compression algorithms to reduce storage req...
Post a Comment
Read more

Oracle 19c Database Software Installation in OEL8

 Pre-requisites for OS level:            Set the static IP Address     Disable the Firewall (systemctl stop firewalld & systemctl disable firewalld)     set SELINUX=permissive on /etc/selinux/config  ##Need to restart the server use init 6 Oracle Installation Pre-requisites Methods     Automatic Setup     Manual Setup      Automatic requisites Setup: (avoid step 1 to step 5): dnf install -y oracle-database-preinstall-19c Install the dependencies: curl -o oracle-database-preinstall-19c-1.0-2.el8.x86_64.rpm https://yum.oracle.com/repo/OracleLinux/OL8/appstream/x86_64/getPackage/oracle-database-preinstall-19c-1.0-2.el8.x86_64.rpm dnf -y localinstall oracle-database-preinstall-19c-1.0-2.el8.x86_64.rpm Manual Setup: step 1: Add the karenl parameters and values vi /etc/sysctl.conf     fs.file-max = 6815744 kernel.sem = 250 32000 100 128 kernel....
Post a Comment
Read more