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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
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
Last updated on February 16th, 2019 at 12:37 pmWe need to connect system for monitoring,administration.We need to have ssh passwordless login setup to remote server for monitoring and administration. In this article ,I will post steps on How to Setup ssh passwordless login using SSH keygen between two servers System 1 : serv1 System 2 : serv2 Username : orac Lets us first describe from system … Continue reading How to Setup ssh passwordless login using SSH keygen between two servers
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
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
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
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
Last updated on March 22nd, 2019 at 03:56 amSometimes we need to drop the datafile or tempfile from the tablespace in Oracle. We have different procedure as per Oracle release Procedure to drop the datafile till 10gR2 There is no direct SQL statement to drop datafiles from a tablespace . In that case we need to drop the tablespace after all data has been moved … Continue reading How to Drop a datafile from Tablespace in Oracle
Last updated on March 22nd, 2019 at 04:10 amOracle tablespace stores the data in the Oracle database and as the data grows, we often need to add space to the tablespace. We can add space in two ways. we can either resize the existing datafile or add the new datafile to the tablespace. We will check out adding datafile to tablespace in this post. First … Continue reading How to add datafile to tablespace in Oracle
Last updated on March 21st, 2019 at 02:48 pmWe often need to find out how big is that particular oracle table. Suppose you did huge data load and want to know the oracle table size. We can use below Query to check table size in Oracle For oracle table size in MB select owner as “Schema” , segment_name as “Object Name” , segment_type as “Object … Continue reading Query to check table size in Oracle
Last updated on March 22nd, 2019 at 04:05 amWe often need to find the definition of the table ,index ,views etc to replicate the structure in another oracle database .Oracle has a very useful command to find the metadata definition of the various structure .This command is very useful in extracting the metadata of any objects like table, index, views, Materialized views select dbms_metadata.get_ddl (‘<OBJECT_TYPE>’,'<OBJECT_NAME>’,'<OBJECT_OWNER>’) … Continue reading how to find the metadata of any object in Oracle
I was working on certain project last week where i need to insert line after match in 100 of files in Linux or Unix operating system. I found that insert line after match using sed is easy. It was quite successful for me ,so i thought i will share this on my blog. Let’s take an example to understand it We have a html file like below … Continue reading How to insert line after match using sed