Re: oracle database-startup time

From: Noons <wizofoz2k_at_yahoo.com.au>
Date: Tue, 23 Nov 2010 21:32:55 +1100
Message-ID: <icg58o$pi9$1_at_news.eternal-september.org>



alex123 wrote,on my timestamp of 23/11/2010 5:36 AM:

>>> I wanted to know what oracle database startup time depends on? Does
>>> size of database matter or it is constant on the same machine?
>>
>> What do you mean by "database startup" time?
>
> Time of executing command 'startup' (when database is shut down)

If you have a very large SGA (tens of Gigabytes) and you are not using hugepages - or its equivalent in your OS - then it will take some time to startup, no matter what. In our Power6 IBm it takes 90 seconds to allocate all page tables for an SGA of 35GB. If I use hugepages, it takes 2 seconds. That's how much difference it makes.

If the startup follows a shutdown abort then it will also be slow, depending on how many redo log files you have and how busy with changes the database was at the time of the shutdown. Other than shutdown abort, the size of redo logs has almost no impact on startup time. We use 1GB redos and it makes no difference whatsoever.

Size of database is mostly immaterial. Other than size of undo and redos in the case above. Received on Tue Nov 23 2010 - 04:32:55 CST

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