Postgres XML datatype

Question

What are the benefits of using the "xml" datatype versus storing the xml content inside a "text" datatype?

Am I able to query by some specific xml attribute or element?

What about indexing and query performance?

Besides the postgresql manual what other online sources can you point me to?

Answer 1

Right now the biggest thing you get from XML fields over raw text is XPath. So if you had something similar to

CREATE TABLE pages (id int, html xml);

you could get the title of page 4 by

SELECT xpath('/html/head/title/text()', html) FROM pages WHERE id = 4;

Right now XML support is fairly limited, but got a lot better in 8.3, current docs are at link text