Category: DBA

May 31st, 2007 by mathias

I'll give myself a quota for no more than one rant a month. However, one of my pet peeves is how Oracle licenses the database. I'l probably return to why I dislike the general model in a future rant, but this on e will be specific to partitioning.

To use partitioning, you have to pay for the Enterprise Edition of the database at $40,000 per CPU and then pay an additional $10,000 for the partitioning option. That is a lot of money if all I really need is SE One (at $5,000 per CPU) with Partitioning. Unfortunately, that is not an option.

I know partitioning used to be a fairly exotic feature. That was however over 10 years ago, when few datbases were really large and few SQL statements would benefit from parallel execution. As the average database has grown to be really large and most database servers now are multi CPU (and core) servers, this should now be treated as core database functionality.

In many cases it doesn't matter as large companies has site wide use of Oracle DB technology. It does, however, matter for smaller companies and startup companies. If you were to build a new solution today and market it initially to small companies or even run it as your own ASP, you would not be able to design with partitioning. Later on, your solution will be created and the cost of rearchitecting for partitioning is unacceptable.

Even worse is when you're taking an existing application and trying to move it downstream where SE One has to be used to meet the budgets those implementations have. Why spend a lot of time of a lot of good resources to implement "manual" partitioning?

I think Oracle would benefit from making partitioning included in all licenses. One thing it would do would tie customers closer to Oracle as the cost of converting partitioning from one DB to another is high due to the lack of standard even for the DDL used. I think it would also remove another reason for customers to consider other databases. I think licensing should be such that customers can scale with the database and get started on what they need. The situation today is such that building small and needing partitioning always requires a discussion of "can we replace Oracle in our technology stack".

By having partitioning as an included feature, companies could design for it when they begin designing new applications and get the use of it as they grow. That helps Oracle attract small companies that hopefully grow into large customers over time. It also helps in not getting people convinced that Oracle doesn't scale as using partitioning was too expensive when they started and now it's too costly (or politically impossible) to change it.

Designing manual partitioning schemes is really a waste of my and other Oracle professionals time. So… Please Oracle, it is time to revisit how licensing partitioning is done. It is a feature we need to put in the core toolbox and get people to make better use of the database with it. I hope 11G comes with a new licensing strategy for this. I believe Oracle would make a lot of money on making this an included feature in all editions of the database.

That's the partitioning rant. I know others have similar ideas on this as I've read some recent blogs on partitioning. I love Oracle's partitioning, but I hate having to use it only for the largest customers. I really dislike having to think of and implement manual partitioning, I know it will n ot scale as well as database driven partitioning and I still have to waste my time on it for financial reasons. Even worse is having to discuss if we should avoid Oracle altogether as we cannot use partitioning and then maybe a cheaper database will work just as well for us. I don't want to have to avoid the best database over financial details.

If one database is the best for the job, then I want a licensing model that allows me to start small and pay more as my need grows (meaning using SE One to start with and grow to EE while I design for and with partitioning the whole time).

Posted in DBA, Licensing, Oracle, Partitioning

May 7th, 2007 by mathias

I'm going to discuss how to get SQL access to your alert log in this entry. I will then build on that to make it even more useful in future posts.

Browsing the alert log can be convenient if you're already on the server. However, it is often not possible or at least not overly convenient. You may find that as the developer DBA you do not have access to the production server, or you have to log in to many different servers to check all your alert logs. Since SQL is the main tool for DBAs and one of the most critical for developers of database driven applications, it would make sense to access the key log for database operations and issues via the same interface and be able to use your SQL tool of choice.

The way to be able to access the alert log with SQL is to define an external table for it. So I'll use this need to write a little about how to create an external table for text file. It's pretty easy and can often be very useful.

create directory bdump as '/path/to/bdump';
create user alertlog identified by alertlog;
alter user alertlog quota unlimited on users;
grant create session, resource to alertlog;
grant read,write on directory bdump to alertlog;

The directory path needs to be what you have "background_dump_dest" set to. You can look the current value up in v$parameter. To be able to do this with one script across databases, you'll want to make this more dynamic with pl*sql such that the directory is retrieved from the database and used to build a dynamic DDL statement.

Now that we have a user with access to our bdump directory, we'll create our alert_log table.

create table alert_log
(text_line varchar2(255))
organization external
(type oracle_loader
default directory bdump
location ('alert_ORCL.log'));

This is a minimal create external table statement. There are many more options to use, but we'll leave those alone in this blog post.

The create table statement is pretty straight forward, here's what it will do:

  • Creates a table with data that is located external to the database
  • Take all data in each line into the column text_line
  • Use the normal oracle_loader (SQL*Loader) driver to access the data
  • It uses the bdump directory object to specify where the alert log file is located.
  • Get data from the file alert_ORCL.log.

That is all it takes. We can now access this table with SQL and use our normal techniques for filtering and aggregating information.

To look at the snapshot too old messages we generated in a previous blog post, we'd use this statement:

select text_line
from alert_log
where text_line like '%ORA-01555%';

TEXT_LINE

Posted in Alert Log, DBA, Oracle, SQL