On Tue, 23 May 2000, Thomas Weholt wrote:
Is it possible to store lots of huge objects, like 2-3 MB in size each, in ZODB and catalog them for easy searching? Can I catalog special properties of custom objects and skip others? Are there any limitations to ZCatalog and the amount of stuff to index, before the speed is affected?
Yes, Yes, and not really. ZCatalog uses BTrees to store the index data, so it would take a *huge* amount of data to slow it down on searches. If your objects and their properties are static you shouldn't have any problem. If either are dynamic, you are going to have a file size growth problem with the ZODB as those large objects get written to disk on every update. You can get around the latter by structuring your site so that the content is in one object and the properties are in another helper object, or by using ZPatterns if you are willing to work with developing code and either wait for the indexing support or roll your own. Storing many large objects, though, you need to be aware of any limits your OS puts on maximum file size. The ZODB uses 64 bit pointers, but, eg, Linux currently has a maximum file size of 2GB. FreeBSD, for the reverse example, supports files up to the maximum ZODB will handle. Or you could work out a way to store the object content in the file system by using external methods or LocalFS. As for the indexing of properties, you tell ZCatalog the property names to index (could be custom methods, too), and any cataloged object that has the property will be indexed, and any cataloged object that doesn't have that property will be ignored in that index.
If somebody has pointers on how to store custom python-objects in ZODB and make them ZCatalog-aware or somehow work with the ZCatalog, I`d be most grateful.
There are a couple of How-Tos on using the catalog. If you are implementing your objects in Python (as opposed to ZClasses), you just need to include CatalogAware in the base clases, and make sure you put a self.reindex_object() call in any methods that handle property changes. It's very simple to do: from Products.ZCatalog.CatalogAwareness import CatalogAware class MyClass(CatalogAware): .... def instance_Edit(self,REQUEST): .... self.reindex_object() .... --RDM