Native Text Index
This page talks about native text indices and corresponding search functionality in Pinot
Pinot supports text indexing and search by building Lucene indices as "sidecars" to the main Pinot segments. While this is a great technique, it essentially limits the avenues of optimizations that can be done for Pinot specific use cases of text search.
Pinot, or any other database/OLAP engine, do not need to conform to the entire full text search DSL that is traditionally used by FTS engines like ElasticSearch and Solr. Looking at traditional SQL like text search use cases, majority of text searches comprise of three patterns -- prefix wildcard queries, postfix wildcard queries and term queries.
Native text indices are built from the ground up. They use a custom text indexing engine, coupled with Pinot's powerful inverted indices, to provide a super fast text search experience.
Native text indices are 80-120% faster than Lucene based indices for the text search use cases mentioned above. They are also 40% smaller on disk.
A new feature that native text indices support are real time text search. For REALTIME tables, native text indices allow data to be indexed in memory in the text index, while concurrently supporting text searches on the same index.
Historically, most text indices depend on the in memory text index being written to first and then sealed, before searches are possible. This limits the freshness of the search, being near real time at best.
Native text indices come with a custom in memory text index, which allows for real time indexing and search.
A new function, TEXT_CONTAINS, is introduced for supporting text search on native text indices.
SELECT COUNT(*) FROM Foo WHERE TEXT_CONTAINS (<column_name>, <search_expression>)
Examples:
SELECT COUNT(*) FROM Foo WHERE TEXT_CONTAINS (<column_name>, "foo.*")
SELECT COUNT(*) FROM Foo WHERE TEXT_CONTAINS (<column_name>, ".*bar")
SELECT COUNT(*) FROM Foo WHERE TEXT_CONTAINS (<column_name>, "foo")
TEXT_CONTAINS can be combined using standard boolean operators
SELECT COUNT(*) FROM Foo WHERE TEXT_CONTAINS ("col1", "foo") AND TEXT_CONTAINS ("col2", "bar")
Note that TEXT_CONTAINS supports regex and term queries for now. Also, TEXT_CONTAINS will work only on native indices.
Note that TEXT_CONTAINS supports standard regex patterns (as used by LIKE in SQL Standard). So there might be some syntatical changes from Lucene queries
Native text indices are a type of text search index that Pinot supports, hence are created through the regular way of using field configs to configure a text index on a given field. To indicate that the index type is native, an additional property in the field config has to be specified:
"fieldConfigList":[
{
"name":"text_col_1",
"encodingType":"RAW",
"indexTypes": ["TEXT"],
"properties":{"fstType":"native"}
}
]
Last modified 1d ago