Materialize Documentation
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jsonb_agg Function

The jsonb_agg(expression) function aggregates all values indicated by its expression, returning the values (including nulls) as a jsonb array. The input values to the aggregate can be filtered.

Syntax

jsonb_agg ( expression ORDER BY col_ref ASC DESC , ) FILTER ( WHERE filter_clause )

Signatures

Parameter Type Description
expression jsonb The values you want aggregated.

Return value

jsonb_agg returns the aggregated values as a jsonb array.

This function always executes on the data from value as if it were sorted in ascending order before the function call. Any specified ordering is ignored. If you need to perform aggregation in a specific order, you must specify ORDER BY within the aggregate function call itself. Otherwise incoming rows are not guaranteed any order.

Details

Usage in dataflows

While jsonb_agg is available in Materialize, materializing jsonb_agg(expression) is considered an incremental view maintenance anti-pattern. Any change to the data underlying the function call will require the function to be recomputed entirely, discarding the benefits of maintaining incremental updates.

Instead, we recommend that you materialize all components required for the jsonb_agg function call and create a non-materialized view using jsonb_agg on top of that. That pattern is illustrated in the following statements:

CREATE MATERIALIZED VIEW foo_view AS SELECT * FROM foo;
CREATE VIEW bar AS SELECT jsonb_agg(foo_view.bar) FROM foo_view;

Examples

SELECT jsonb_agg(1);
 jsonb_agg
-----------
 [1]

SELECT jsonb_agg('example'::text);
  jsonb_agg
-------------
 ["example"]

See also

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