- From: Per Bothner <per@bothner.com>
- Date: Thu, 29 Aug 2002 13:31:45 -0700
- To: Adam Bosworth <adam.bosworth@bea.com>
- CC: "'noah_mendelsohn@us.ibm.com'" <noah_mendelsohn@us.ibm.com>, www-ql@w3.org
Adam Bosworth wrote: >>From a performance point of view, one can imagine a factory object that > given xml queries, generates optimal code for executing them. Well, that dort of what Qexo does: It compiles Java bytecodes from an XQuery "program", and can do so on-the-fly. > -----Original Message----- > From: noah_mendelsohn@us.ibm.com [mailto:noah_mendelsohn@us.ibm.com] > > DOM is already somewhat slow/heavyweight for certain purposes. Qexo uses it's own lightweight DOM, where each document (or document fragment) is encoded in a flat array of chars. This is a binary, not textual, encoding, using relative offsets to point from a begin element "chunk" to the corresponding end, and vice versa. A Node is represented an an int offset into this array. An entire document is one TreeList object plus this char array plus an array of Object nodes. (For example an element's QName is an offset in this Object array.) In contrast, standard DOM uses one object per node, and each object has lots of fields. -- --Per Bothner per@bothner.com http://www.bothner.com/per/
Received on Thursday, 29 August 2002 16:30:55 UTC