[ZODB-Dev] Space used by IOBTrees

[Andreas Jung]

A XML document with about 26.000 nodes (1.3 MB data) is represented
in an application by a nested structure of nodes where the childs
are stored in IOBTrees (17.000 nodes out of the 26.000 nodes are leafs).
The complete object allocates about 20MB inside the ZODB. analyze.py
shows that there are about 9600 IOBTree objects inside the ZODB with an
average size of 1850 bytes. The amount of data stored as attributes
of a single treenode instance is very small (not more than 100-200 bytes).
So why is the pickle of an IOBTree nearly 2KB large instead of several
hundred bytes?

-aj


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   -    Andreas Jung                     http://www.andreas-jung.com   -
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