Import dump using pipe

Background:

Export dump compression using pipe

Same as export using pipe, import can be done by following below steps

Import using Pipe

Step1

Create nods equal to dump files & point it to a pipe

mknod /u01/orabak/export/imp_pipe1 p

mknod /u01/orabak/export/imp_pipe2 p

mknod /u01/orabak/export/imp_pipe3 p

Export dump compression using pipe

This post will help you to run traditional export import backup utility with compression

Background:

Although compression is supported by imp/exp but it is limited to segment extents only & does not solve the purpose.

It will be very much difficult to perform export import operations where db servers holding less space on local file system to keep dump files

Performing export import over network could be a workaround to this issue but due to network delay it could become more tedious

Export/ Import using mknod or pipe will help to zip/unzip the dump files during export or import operation respectively without specifying it explicitly

New 10g (onwards) feature Data Pump COMPRESSION is replaceable with the mknod export/ import method

Export Import Pipe should be used in pre-10g environments to reduce actual export import time, OS space usage & to minimize delay in transport of dump files across the db servers due to less size of the dump

Let us see how it works in export import operation with single & multiple dump files

Truncating table in DB2

Surprised!! How come DB2 blog in Oracle Arena?

Well just a command I want to introduce which has helped a lot to my DB2 DBA’s

How to truncate a table in DB2?

This was the question on everyone’s mind in crisis time

Table was sizing almost over 10GB growing continuously; generating transaction logs (same as our archive-log in our oracle) 

Rows Deletion in turn added fire in the storm, causing huge number of transaction logs with mount point nearing to panic level threshold

Just a thought came in the mind to ask DB2 DBA to truncate the table, being core DBA support no table level operations were known

Connectivity Jdbc & oracle database Troubleshooting java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver

This blog will allow DBA’s to troubleshoot connectivity between Jdbc & oracle database

It will also help to tackle common Java connectivity errors like below in windows environment where tracing/debugging is very difficult  

java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver

at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at bpos.Db.Conectar(Db.java:20)
at bpos.Process.main(Process.java:19)

SQL*Net message to dblink , SQL*Net message from dblink

This blog is written based on the issue faced due to huge response time of sql query waiting on dblink.

Issue:

Query responding in almost 5 min with session wait event of SQL*Net message to dblink / SQL*Net message from dblink

Analysis:

T3157 was a view calling one more view XXECMS_SM_DTLS_VL_ATS

Observing the DDL of XXECMS_SM_DTLS_VL_ATS it has been identified that it is formed with a complex query having remote references via db link.

Each table being referred over db link was holding more than 50 lac records & sizing over 4 GB each.