Postgres JSONB and Composite Type property access performance

postgres_jsonb_perf.sql

-------------------------------------------------------
-- create small object and measure time to access a key
-------------------------------------------------------
CREATE TABLE small_object AS (
  SELECT jsonb_object_agg(n, 'abc') AS obj FROM generate_series(1,10) n
);

SELECT small_object.obj->'10' FROM small_object;
-- Time: 0.996 ms


-------------------------------------------------------
-- create large object and measure time to access a key
-------------------------------------------------------
CREATE TABLE large_object AS (
  SELECT jsonb_object_agg(n, 'abc') AS obj FROM generate_series(1,1000000) n
);

SELECT large_object.obj->'1000000' FROM large_object;
-- Time: 20.994 ms


-----------------------------------------------------------------
-- create a large composite type and measure time to access a key
-----------------------------------------------------------------
CREATE TYPE small_composite_type AS (
  a integer,
  b integer,
  c integer,
  d integer,
  e integer,
  f integer,
  g integer,
  h integer,
  i integer,
  j integer
);

CREATE TABLE composite_type AS (
  SELECT (1, 1, 1, 1, 1, 1, 1, 1, 1, 1)::small_composite_type AS composite_type
);

SELECT (composite_type.composite_type).j FROM composite_type;
-- Time: 0.418 ms