NewIndex returns a new initialized Index.

NewShardIndex returns a new index for a shard.

IndexName is the name of this index.

Index is the in memory index of a collection of measurements, time series, and their tags.

ShardIndex represents a shim between the TSDB index interface and the shared in-memory index.

TagFilter represents a tag filter when looking up other tags or measurements.

FilterExprs represents a map of series IDs to filter expressions.