LFC 2b064265bf feat: UDAF made generically (#91) ...

* feat: UDAF implementation backed by DataFusion.

Directly Transplant DataFusion's UDAF related structs, traits and functions, like `AggregateUDF`, `Accumulator` or `create_udaf` etc.

Implement median UDAF on top of it and used in unit testing.

Refs: #61

* feat: UDAF made generically

Refs: #61

* fix: cargo fmt

* fix: use prelude

* fix: uniform the name

* fix: move maybe commonly used functions together

* fix: make comments more clear

* fix: resolve conversations in CR

* fix: store input types in AccumulatorCreator, and use ScalarVector's iterator

* feat: introducing List value and List datatype

* refactor: use ArcSwap instead of Mutext

* refactor: shorten some namings

* refactor: move median UDAF out of tests

* refactor: rename

* feat: aggregate function registry

* fix: make `Value` satisfy ordering again

* fix: clippy warnings

* doc: add "how to write aggregate function"

* fix: address PR comments

* fix: trying to get rid of unwraps

Co-authored-by: luofucong <luofucong@greptime.com>

2022-07-25 10:35:36 +08:00

..

how-to-write-aggregate-function.md

feat: UDAF made generically (#91)

2022-07-25 10:35:36 +08:00