{"id":901,"date":"2005-11-19T12:00:00","date_gmt":"2005-11-19T12:00:00","guid":{"rendered":"http:\/\/orcldoug.com\/blog\/?p=901"},"modified":"2005-11-19T12:00:00","modified_gmt":"2005-11-19T12:00:00","slug":"another-interesting-lewis-tip","status":"publish","type":"post","link":"http:\/\/orcldoug.com\/blog\/2005\/11\/19\/another-interesting-lewis-tip\/","title":{"rendered":"Another Interesting Lewis Tip"},"content":{"rendered":"

Updated 24th November 2005<\/strong>
<\/strong>
I wouldn’t normally update an existing entry but there are some very interesting and important comments on this entry, particularly from Jonathan Lewis and Howard Rogers, that I’d recommend you take the time to read. Jonathan also mentions it on his website<\/a>. There’s much more in the book of course 😉 My thanks to Howard and Jonathan.<\/strong>
<\/strong>
I certainly wouldn’t want to reproduce the whole of Jonathan Lewis’ new book<\/a> in a blog but I think it’s worth one last posting for a couple of reasons.<\/p>\n

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  1. I think it’s a good way to highlight the existence of a free sample chapter<\/a> online as pointed out by Radoslav Rusinov<\/a>. If you haven’t ordered the book, have a read of that for free and decide if you’re interested in 13 more chapters of the same quality.<\/li>\n
  2. As someone who is predominantly a DBA I’m very keen on Jonathan pointing out how what might seem<\/span> a simple DBA action could unwittingly impact an application in unusual ways. However (and this is important) as I’ve re-read bits of the book I can also think of dozens of ways that a developer could cause problems for the DBA 😉 In fact, I’ve started to get a teensy bit worried that I’m going to have more and more developers rolling up at my desk with ‘bright ideas’ because they’ve read the bits of this book that they want to, conveniently missing the numerous caveats that Jonathan is always careful to include. As long as people take the book as a whole and use some common sense …<\/li>\n<\/ol>\n

    Anyway, here’s the excerpt, which I’ll consider worth posting if it stops one poor DBA doing this by accident!<\/p>\n

    “Oracle 10g has introduced a mechanism to compact a table online. This
    only works for a table with row movement enabled that is stored in a tablespace using ASSM.<\/p>\n

    You might use a sequence of commands like the following to compact a table:<\/p>\n