Cross Join in Oracle

Last updated on March 24th, 2019 at 01:35 pmThis SQL tutorial focuses on cross join in Oracle, and provides explanations, examples A CROSS JOIN  in Oracle is a JOIN operation that produces the Cartesian product of two tables. i,e if one of the table is having 100 rows and another one 8 rows, then cross join will produce 800 rows Here table emp has 14 … Continue reading Cross Join in Oracle »

self join in oracle with examples

Last updated on March 24th, 2019 at 01:37 pmThis SQL tutorial focuses on self join in oracle, and provides syntax, explanations, examples A self join is a join of table to  itself.. We can use the table multiple times .Each occurrence should have an alias name.Oracle database while executing the query join the table with itself and produce the result General  syntax select a.col1 ,b.col2  … Continue reading self join in oracle with examples »

oracle join syntax examples

Last updated on March 24th, 2019 at 01:38 pmThere are various joins in Oracle like inner join,left outer join,right outer join,full outer join,cross join. This SQL tutorial provides oracle join syntax on each of them with examples Inner Join syntax and Example Two tables examples and syntax SELECT EMP.EMPNO,EMP.ENAME, DEPT.DEPTNO,DEPT.DNAME FROM EMP , DEPT where EMP. DEPTNO= DEPT. DEPTNO; or ANSI syntax SELECT EMP.EMPNO,EMP.ENAME, DEPT.DEPTNO,DEPT.DNAME FROM … Continue reading oracle join syntax examples »

How to create ,List and unzip Tar.gz file in Linux

The GNU tar command included with Linux distributions has integrated compression(.gz) .It can create a .tar archive and then compress it with gzip or bzip2 compression in a single command.  The resulting file is a .tar.gz file or .tar.bz2 file. we will learn about how to create ,List and unzip Tar.gz file in Linux How to create the tar.gz file It uses the extra letter z to … Continue reading How to create ,List and unzip Tar.gz file in Linux »

Useful Oracle 12c pluggable database commands

Last updated on March 8th, 2019 at 06:37 pmHere are very useful Oracle 12c pluggable database commands Query to check if the database is CDB or non-CDB SELECT NAME, CDB, CON_ID FROM V$DATABASE; NAME CDB CON_ID ————————— ——— ———- CDB01 YES 0 Query to check containers in the CDB database. Each PDB and root is a container SQL> alter session set container=CDB$ROOT; Session altered. SQL> … Continue reading Useful Oracle 12c pluggable database commands »

alter system switch logfile v/s archive log current

Last updated on March 8th, 2019 at 06:32 pmRedo and archive log files are two important pieces in Oracle database environment. They both are used for recovering the database from failure.I would be explaining two important command alter system switch logfile and alter system archive log current about them ,their difference and what they command actually performs in the oracle database ALTER SYSTEM SWITCH LOGFILE This … Continue reading alter system switch logfile v/s archive log current »