Databases
StackOverflow2013
Postsdbo
PODeciding on when to use XmlDocument vs XmlReader
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PODeciding on when to use XmlDocument vs XmlReader
    primarykey
    data
    text
    <p>I'm optimizing a custom object -> XML serialization utility, and it's all done and working and that's not the issue.</p> <p>It worked by loading a file into an <code>XmlDocument</code> object, then recursively going through all the child nodes.</p> <p>I figured that perhaps using <code>XmlReader</code> instead of having <code>XmlDocument</code> loading/parsing the entire thing would be faster, so I implemented that version as well.</p> <p>The algorithms are exactly the same, I use a wrapper class to abstract the functionality of dealing with an <code>XmlNode</code> vs. an <code>XmlReader</code>. For instance, the <code>GetChildren</code> methods yield returns either a child <code>XmlNode</code> or a SubTree <code>XmlReader</code>.</p> <p>So I wrote a test driver to test both versions, and using a non-trivial data set (a 900kb XML file with around 1,350 elements).</p> <p>However, using JetBrains dotTRACE, I see that the <code>XmlReader</code> version is actually slower than the <code>XmlDocument</code> version! It seems that there is some significant processing involved in <code>XmlReader</code> read calls when I'm iterating over child nodes.</p> <p>So I say all that to ask this:</p> <p><strong>What are the advantages/disadvantages of <code>XmlDocument</code> and <code>XmlReader</code>, and in what circumstances should you use either?</strong></p> <p>My guess is that there is a file size threshold at which <code>XmlReader</code> becomes more economical in performance, as well as less memory-intensive. However, that threshold seems to be above 1MB.</p> <p>I'm calling <code>ReadSubTree</code> every time to process child nodes:</p> <pre><code>public override IEnumerable&lt;IXmlSourceProvider&gt; GetChildren () { XmlReader xr = myXmlSource.ReadSubtree (); // skip past the current element xr.Read (); while (xr.Read ()) { if (xr.NodeType != XmlNodeType.Element) continue; yield return new XmlReaderXmlSourceProvider (xr); } } </code></pre> <p>That test applies to a lot of objects at a single level (i.e. wide &amp; shallow) - but I wonder how well <code>XmlReader</code> fares when the XML is deep &amp; wide? I.e. the XML I'm dealing with is much like a data object model, 1 parent object to many child objects, etc: <code>1..M..M..M</code></p> <p>I also don't know beforehand the structure of the XML I'm parsing, so I can't optimize for it.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USDanny Beckett
    1. USPhilChuang
    plurals
    1. This table or related slice is empty.
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. PODeciding on when to use XmlDocument vs XmlReader
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PODeciding on when to use XmlDocument vs XmlReader
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PODeciding on when to use XmlDocument vs XmlReader
      1. This table or related slice is empty.
      1. VTUpMod
    1. COI've always wondered why there was both an XmlDocument and an XmlReader...
      singulars
      1. PODeciding on when to use XmlDocument vs XmlReader
      1. USJames Jones
    2. COActually there is another option to XMLDocument and XMLReader. You can now use LINQ to XML but actually XMLReader is more efficient in most ways.
      singulars
      1. PODeciding on when to use XmlDocument vs XmlReader
      1. USTarik
    3. COWait. Your `GetChildren` method returns an `XmlReader`? You mean, you're calling `XmlReader.Create()` every time you process a child node?
      singulars
      1. PODeciding on when to use XmlDocument vs XmlReader
      1. USRobert Rossney
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload