Apache Solr Reference Guide Covering Apache Solr 6.0

stats(collection1,
q=*:*,
sum(a_i),
sum(a_f),
min(a_i),
min(a_f),
max(a_i),
max(a_f),
avg(a_i),
avg(a_f),
count(*))
topic
The topic function provides publish/subscribe messaging capabilities built on top of SolrCloud. The topic
function allows users to subscribe to a query. The function then provides one-time delivery of new or updated
documents that match the topic query. The initial call to the topic function establishes the checkpoints for the
specific topic ID. Subsequent calls to the same topic ID will return new or updated documents that match the
topic query.
The topic function should be considered in beta until SOLR-8709 is committed and released.
Parameters
Syntax
checkpointCollection: (Mandatory) The collection where the topic checkpoints are stored.
collection: (Mandatory) The collection that the topic query will be run on.
id: (Mandatory) The unique ID for the topic. The checkpoints will be saved under this id.
q: (Mandatory) The topic query.
fl: (Mandatory) The field list returned by the topic function.
topic(checkpointCollection,
collection,
id="uniqueId",
q="topic query",
fl="id, name, country")
Stream Decorators
Stream decorators wrap other stream functions or perform operations on the stream. The are currently many
stream decorators available: complement, daemon, innerJoin, intersect, hashJoin, merge, leftOuterJoin,
ou
terHashJoin , parallel, reduce, rollup, select, top, unique, and update.
complement
The complement function wraps two streams (A and B) and emits tuples from A which do not exist in B. The
tuples are emitted in the order in which they appear in stream A. Both streams must be sorted by the fields being
used to determine equality (using the on parameter).
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