Making Oracle simple for you!

Simplifying Oracle learning by sharing knowledge with professionals across the globe

How to check database size in Oracle

A DBA works on many aspects of database like cloning, backup, performance tuning etc. In every aspect of database administration, most of the times resolution depends upon the size of database. For example, DBA can implement DB FULL backup strategy on a very small database when compared to DB...

READ MORE

How to configure yum server in linux

In this article, we will learn how to configure yum server in different Oracle Linux versions. YUM repository is a software package manager which allows you to easily install, update or delete RPMs. Most of the required RPM packages come along with the Linux installer CD. But! if you have...

READ MORE

How to check query plan change in oracle

If you would like to find out change in SQL plan of a query, below script will help you find the SQL plan ID for previous executions and check if there is any change in SQL plan ID. set pagesize 1000 set linesize 200 column begin_interval_time format a20 column milliseconds_per_execution format...

READ MORE

How to force users change password on first login Linux

How to force users change their passwords upon first login in Linux? How to make sure user changes password at next login time in Linux? You can force a user to change their password upon first time login to Linux server. You can even force existing users to change their passwords on next login....

READ MORE

How to check datafile utilization in Oracle

When you want to shrink a datafile, you must always check the single datafile utilization. In case if you shrink datafile more than the used size, it will fail. Below query gives the datafile utilization and depending upon the datafile free space, you can shrink it Query to check datafile...

READ MORE

How to estimate flashback destination space

Sometimes application team will ask DBA to enable flashback for x number of days. In such case, a DBA needs to estimate the flashback space required for x number of days in order to store the flashback logs. The flashback log size is same as archive log size generated in a database. Method to...

READ MORE

How to check temp tablespace utilization

set lines 200 select TABLESPACE_NAME, sum(BYTES_USED/1024/1024),sum(BYTES_FREE/1024/1024) from V$TEMP_SPACE_HEADER group by TABLESPACE_NAME; SELECT A.tablespace_name tablespace, D.GB_total, SUM (A.used_blocks * D.block_size) / 1024 / 1024 /1024 GB_used, D.mb_total - SUM (A.used_blocks *...

READ MORE

How to count distinct values in a column

Counting values from a single column is easy but at times you need to count single column distinct values. For example, Let us assume we need to count the number of employees whose salary is less than 2000, between 2000 & 4000 and above 4000. Below query helps counting such distinct values...

READ MORE