elstc_sch_session

lucene
ElasticSearch - provides a json based rest api to refer to lucene 
full text search 
techniques--> serial scanning , for large documents --> index and searching
Inverted-index
indexing
stemming

TF - IDF==> term frequency - invertdocument frequency

How it works
Node 
Cluster
exteral http request
node forwarding transport layer

how the data is organised
documents
sharding
routing of documents

replication
filtering - normal filtering as we do in any language

so what makes the ElasticSearch special is
scoring
stemming

Query Contest 
    How well does this document match this query clause?(Score)

Filter Context
    Does this document match this query clause?(true or flalse)









major advantages of ElasticSearch-->
Distributed---> parallel processing, fault taulerence
schemaless