eland.Index¶
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class
eland.Index(query_compiler: QueryCompiler, es_index_field: Optional[str] = None)¶ The index for an eland.DataFrame.
TODO - This currently has very different behaviour than pandas.Index
Currently, the index is a field that exists in every document in an Elasticsearch index. For slicing and sorting operations it must be a docvalues field. By default _id is used, which can’t be used for range queries and is inefficient for sorting:
https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-id-field.html (The value of the _id field is also accessible in aggregations or for sorting, but doing so is discouraged as it requires to load a lot of data in memory. In case sorting or aggregating on the _id field is required, it is advised to duplicate the content of the _id field in another field that has doc_values enabled.)