11.125. Release 0.116

Cast between JSON and VARCHAR

Casts of both directions between JSON and VARCHAR have been removed. If youhave such casts in your scripts or views, they will fail with a message whenyou move to release 0.116. To get the semantics of the current casts, use:

  • JSON_PARSE(x) instead of CAST(x as JSON)
  • JSON_FORMAT(x) instead of CAST(x as VARCHAR)In a future release, we intend to reintroduce casts between JSON and VARCHARalong with other casts involving JSON. The semantics of the new JSON andVARCHAR cast will be consistent with the other casts being introduced. But itwill be different from the semantics in 0.115 and before. When that comes,cast between JSON and VARCHAR in old scripts and views will produce unexpectedresult.

Cluster Memory Manager Improvements

The cluster memory manager now has a low memory killer. If the cluster runs lowon memory, the killer will kill queries to improve throughput. It can be enabledwith the query.low-memory-killer.enabled config flag, and the delay betweenwhen the cluster runs low on memory and when the killer will be invoked can beconfigured with the query.low-memory-killer.delay option.

General Changes

  • Add multimap_agg() function.
  • Add checksum() function.
  • Add max() and min() that takes a second argument and producesn largest or n smallest values.
  • Add query_max_run_time session property and query.max-run-timeconfig. Queries are failed after the specified duration.
  • Removed experimental.cluster-memory-manager-enabled config. The clustermemory manager is now always enabled.
  • Removed task.max-memory config.
  • optimizer.optimize-hash-generation and distributed-joins-enabled areboth enabled by default now.
  • Add optimization for IF on a constant condition.