RDBMS Server

Oracle RDBMS Server Articles

Hints on OCA/OCP exam technique

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David Lozano Lucas's picture

Use of the SQL Tuning Advisor

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David Lozano Lucas's picture

Saluting. Start - Stop script

It is an English word that sounds very funny in Spanish, almost unreal.
Well, just wanted to brand the blog with a first entry to introduce myself.
I work as an Oracle and SQL Server DBA (mixed profile, they call it -
concerns twice for the same pay, on me).
Here I will write "how to" articles as they emerge in my day to day.
If you can read Spanish, check out the blog I maintain for a little more time http://blog.davidlozanolucas.com/.

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The ever expanding UNDO tablespace.

During a quite evening of my last on-call bout I was alerted from our monitors that the UNDO tablespace was running out of free space. Thought of adding of a new data file and be done with it; When I checked the current allocation for this tablespace it was already at 40G - couldn't believe what I was seeing. The undo_retention was set to 7200 and max query length in v$undostat was not that high. One column that did caught my eye was the tuned_undoretention, its value was way very high.

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Performing a quick and efficient Performance Tuning audit

Checks to be performed at the machine level (note the example is Red Hat Linux)

run queue should be ideally not more than the number of CPU’s on the machine

At the maximum it should never be more than twice the number of CPU’s.

This is denoted by the column ‘r’ in the vmstat output shown below

vmstat – 5

face:/opt/oracle>vmstat 5
procs memory swap io system cpu
r b swpd free buff cache si so bi bo in cs us sy id wa
4 1 488700 245704 178276 12513572 0 1 10 17 48 1365 40 12 43 5

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How to import table with custom type

When importing table that contained custom type, you will encounter an oracle error as shown below:
Import of table containing object type(s) fails with IMP-00061 IMP-00063

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