Sometimes, things you are searching for, are already there and wait to be found. Today, I have such an example. The DB2 Information Center features a page that lists both the Oracle concepts and DB2 concepts, the "DB2-Oracle terminology mapping".
If you need to explain the DB2 architecture to someone with Oracle background (or vice versa), this comes handy.
Monday, November 15, 2010
Wednesday, November 10, 2010
How long is long? Maximum size of an XML text node in DB2
I was recently asked about the maximum size of a single text node when stored in DB2 pureXML. Basically, when you create a table
and insert an XML document with several elements, how long can the text between the open and closing tag be, e.g., the value of myText?
The background to this question is that XML values are formatted to data pages. If the XML document is larger than the page size, the document is broken up into subtrees that fit into the page. However, a text node is already a single node. Can a text value be larger than the page size?
My answer: It can be really, really large. Try it out and let me know the biggest value that you could insert (or produce in an update statement).
CREATE TABLE test(id int, doc xml)
and insert an XML document with several elements, how long can the text between the open and closing tag be, e.g., the value of myText?
INSERT INTO test VALUES(1,'<root><myText>all the text that you want </myText></root>')
The background to this question is that XML values are formatted to data pages. If the XML document is larger than the page size, the document is broken up into subtrees that fit into the page. However, a text node is already a single node. Can a text value be larger than the page size?
My answer: It can be really, really large. Try it out and let me know the biggest value that you could insert (or produce in an update statement).
Tuesday, November 9, 2010
Some flights, appliances, and "one size fits all"
As I wrote before, I was traveling within Europe. Similar to the Skymall brochure in North America, some airplanes feature the Worldshop brochure. I used some spare time and read about the new G3Ferrari Pizzamaker. This brought up memories of the Popcorn Maker, the Ice Cream Maker, the Donut Maker, the bread machine, and all the other advertised appliances. How many of them do you own?
One reason I don't own (all of) them is the storage space required when they are not used. Another reason is that they usually can only do what they have been designed for (sometimes not even that!) and it often requires reading additional instructions, getting familiar with the do's and don'ts. Sometimes, some of those "specialty appliances" are something en vogue for few months, then disappear again. I trust my (hightech) oven and my induction stove on helping me out when I need a pizza or some popcorn and they work fine for base regular food. They are my "one size fits all" solution to my culinary requirements.
The same goes for my database system. I trust DB2 to handle all kinds of data: Strings, numbers, dates, timestamps, and - yes - XML documents. DB2 can manage my data for OLTP applications and in BI scenarios. Sometimes, the crust on the pizza is not as crispy as that from a true Pizzamaker, but I can prepare a pizza side by side with a nice plum tart in my convection oven. Hmm, a taste of Fall...
One reason I don't own (all of) them is the storage space required when they are not used. Another reason is that they usually can only do what they have been designed for (sometimes not even that!) and it often requires reading additional instructions, getting familiar with the do's and don'ts. Sometimes, some of those "specialty appliances" are something en vogue for few months, then disappear again. I trust my (hightech) oven and my induction stove on helping me out when I need a pizza or some popcorn and they work fine for base regular food. They are my "one size fits all" solution to my culinary requirements.
The same goes for my database system. I trust DB2 to handle all kinds of data: Strings, numbers, dates, timestamps, and - yes - XML documents. DB2 can manage my data for OLTP applications and in BI scenarios. Sometimes, the crust on the pizza is not as crispy as that from a true Pizzamaker, but I can prepare a pizza side by side with a nice plum tart in my convection oven. Hmm, a taste of Fall...
Thursday, November 4, 2010
DB2 9.7 and changes to DBADM authorities
I was traveling the last 2 weeks and met with business partners and customers. One of the topics that was discussed were the security-related changes that happened in DB2 9.7. Some new roles like DATAACCESS and ACCESSCTRL were introduced and authorities for, e.g., DBADM were reduced.
Everybody agreed that a separation of duties means better access control and higher security. However, less authorities for the DBADM can make the life harder or more complex when there are no changes to development and test processes.
What are the changes that you had to make? What are the best practices that were introduced in your company? And last: What don't you like about the security changes?
Everybody agreed that a separation of duties means better access control and higher security. However, less authorities for the DBADM can make the life harder or more complex when there are no changes to development and test processes.
What are the changes that you had to make? What are the best practices that were introduced in your company? And last: What don't you like about the security changes?
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