oracle join syntax examples

Comment

There are various joins in Oracle like inner join,left outer join,right outer join,full outer join,cross join. I will be giving oracle join syntax on each of them with example 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 EMP INNER JOIN DEPT on  EMP. DEPTNO= DEPT. DEPTNO; … Continue reading oracle join syntax examples »

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

Comment

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

Comment

Here 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> select CON_ID, NAME, OPEN_MODE, TOTAL_SIZE from v$containers; CON_ID … Continue reading Useful Oracle 12c pluggable database commands »

alter system switch logfile v/s archive log current

Comment

Redo 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 command switch the redo log in the instance … Continue reading alter system switch logfile v/s archive log current »

Query to check table size in Oracle

Comment

We often need to find out how big is that particular table. Suppose you did huge data load and want to know the size of the table. We can use below Query to check table size in Oracle For size in MB select owner as “Schema” , segment_name as “Object Name” , segment_type as “Object Type” , round(bytes/1024/1024,2) as “Object Size (Mb)” , tablespace_name as “Tablespace” … Continue reading Query to check table size in Oracle »

how to find the metadata of any object in Oracle

Comment

We often need to find the definition of the table ,index ,views etc to replicate the structure in another 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>’) from dual; The output of the query is of … Continue reading how to find the metadata of any object in Oracle »

Top Oracle 12c New Features for developers

Comment

Last updated on November 26th, 2018 at 05:13 pmOracle has released 12c with lot of new fetaures. Here in this article,I would presenting the top Oracle 12c New Features for developers I have categorized the features in the broad category to make it easier to understand and use SELECT IMPROVEMENTS 1) Top-N feature A Top-N query allows us to retrieve the top or bottom N rows … Continue reading Top Oracle 12c New Features for developers »

Flashback PDB in Oracle Database 12c Release 2

Comment

Last updated on November 26th, 2018 at 05:12 pmOracle database 12c Release 2 provides flashback capability at the individual PDB level. Lets discuss the new feature. we can learn about Flashback database in general from below links Flashback Database explained and limitation For the oracle database to be flashback, archive log mode and flashback mode should be on How to put database in archive log … Continue reading Flashback PDB in Oracle Database 12c Release 2 »

PDB Relocate in Oracle database 12c Release 2

Comment

Last updated on November 26th, 2018 at 05:14 pmA pluggable database is a self-contained, fully-functional Oracle database. We often need to move the pluggable database from one CDB to another CDB. This will be a unplug/plug operation where outage will depend on the location of source and destination CDB 1) When moving between servers with shared storage, such as is typically the case in Cloud … Continue reading PDB Relocate in Oracle database 12c Release 2 »