KUDU_READ_MODE Query Option (Impala 3.1 or higher only)

The KUDU_READ_MODE query option allows you to set a desired consistency level for scans of Kudu tables.

Type: String

Default: "DEFAULT"

Added in: Impala 3.1

Usage notes:

The following values are supported for the query option:
  • "DEFAULT": The value of the startup flag, ‑‑kudu_read_mode, is used.
  • "READ_LATEST": Commonly known as the Read Committed isolation mode, in this mode, Kudu provides no consistency guarantees for this mode, except that all returned rows were committed at some point.
  • "READ_AT_SNAPSHOT": Kudu will take a snapshot of the current state of the data and perform the scan over the snapshot, possibly after briefly waiting for ongoing writes to complete. This provides "Read Your Writes" consistency within a single Impala session, except in the case of a Kudu leader change. See the Kudu documentation for more details.