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#Apache lucene query syntax upgrade

Cost CalculationĮach query index is expected to estimate the worst-case cost to query with the given filter. Of nodes in a loop, you could end up with a too-low cost, see OAK-4065. There is an known issue with this, if you add and remove a lot With Oak 1.2 and newer, the “counter” index is used The expected cost for traversal is, with Oak 1.0.x, really just a guess looking at

The query engine will then pick the index with the lowest expected cost, It doesn't say traversal is actually used, it just lists the expected costs. The cost for the property index would be about 2,Īnd the cost for traversal would be about 3451100.0.Īn index that can't deal with a certain condition will return the cost “Infinity”. This means the cost for the nodetype index would be about 1638354.0, If you enable debug logging for the module .query, you may see this: This is the case when using or conditions such that two indexes are used In order to not return duplicate results. There are other cases where paths of the results read so far are kept in memory, The index can not provide a sorted result. The most common case is when using an order by clause and There are exceptions however, where all data is read in memory when the query Usually, data is read from the index and repository while traversing over the query If no index can efficiently process the filter condition, the nodes in the repository are

A traversal index that iterates over a subtree.

A node type index (which is based on an property index for the properties.

A full-text index which is based on Apache Lucene / Solr.

A property index for each indexed property.

It then uses the index with theīy default, the following indexes are available: Query indexes for the estimated cost to process the query. Internally, the query engine uses a cost based query optimizer that asks all the available Query Indices are defined under the oak:index node. Specific query, then the repository will be traversed. Indexes when necessary, much like in traditional RDBMSs. Oak does not index as much content by default as does Jackrabbit 2. GetIndex ( "sitecore_web_index" ) using ( var context = index. The following example shows how a typical Lucene query may be executed in Sitecore 7+ using LINQ. This makes it easy for us to swap the logic in the helper methods with the new Sitecore 7+ support. The details of how the query was executed and how the results were returned was contained within the helper methods. In some cases we want to continue to use the string based queries so we don’t have to rework them into the new LINQ syntax, simply to save time.įor Sitecore 6.6, we abstracted the logic of executing the queries into helper methods.

#Apache lucene query syntax upgrade

It is now time to upgrade those sites to newer versions of Sitecore to take advantage of the new features and improvements. We built several sites on Sitecore 6.6 using the string-based queries. A second way was to form a string-based representation of a query using the Lucene Query Parser to interpret the string. This provided an object model to create complex queries. The first way was to build up a query using the Field Query Object Model. Prior to Sitecore 7, developers generally had 2 ways to build the query. Developers can now use LINQ-based queries to retrieve data from the Lucene indexes. Among those improvements was the added LINQ support for Lucene queries. Sitecore 7 introduced many improvements to Lucene Search.