What is the key word "Snowball" mean in Elastic search?

Question

When i'm using elastic search , i've to indecies it first. In this process i blindly using "SNOWBALL" , "KEYWORD" n analyzer coloumn. What is the main use of Analyzer (I know it is a booster) but it helps me in elastic search n What is the key word "Snowball" mean?

'data.description': {'analyzer': 'snowball', 'type': 'string'},
'data.title': {'analyzer': 'snowball', 'type': 'string'}

Answer 1

Analyzers are process which extracts indexable terms from text given for indexing.

For example

In the text "i am a dinosaur from modern age" When this is analyzed against "stop word" analyzer only dinosaur, modern and age keywords are stored in the index. Which means if you search for "am", though the word is present in the text you indexed, it wont point to that indexed document.

Similarly snowball is a combination of stopword , lowercase and standard analyzer - https://www.elastic.co/guide/en/elasticsearch/reference/2.4/analysis-snowball-analyzer.html

Answer 2

The snowball filter is used to stem words based on a specific stemmer. A stemmer uses some rules to determine the proper stem of a word. That means different stemmers may return different results.

For example, the words “indexing”, “indexable”, “indexes”, “indexation”, etc will be stemmed as “index”. It’s particularly interesting to retrieve a document with the title “Make my string indexable” when you search “Indexing a string”. (c)

To configure this filter see https://www.elastic.co/guide/en/elasticsearch/reference/current/analysis-snowball-tokenfilter.html

P.S. http://snowball.tartarus.org/ | http://snowballstem.org/