Re: is date_part immutable or not?

My mistake.

Schema | pg_catalog
Name | date_part
Result data type | double precision
Argument data types | text, timestamp with time zone
Type | func
Volatility | stable
Parallel | safe
Owner | postgres
Security | invoker
Access privileges |
Language | internal
Source code | timestamptz_part
Description | extract field from timestamp with time zone

is stable, but

Schema | pg_catalog
Name | date_part
Result data type | double precision
Argument data types | text, date
Type | func
Volatility | immutable
Parallel | safe
Owner | postgres
Security | invoker
Access privileges |
Language | sql
Source code | select pg_catalog.date_part($1, cast($2 as timestamp without tim
e zone))
Description | extract field from date

is immutable and
Schema | pg_catalog
Name | date_part
Result data type | double precision
Argument data types | text, timestamp without time zone
Type | func
Volatility | immutable
Parallel | safe
Owner | postgres
Security | invoker
Access privileges |
Language | internal
Source code | timestamp_part
Description | extract field from timestamp

immutable too. But date_part('isodow', log_time::date) and date_part('isodow', log_time::timestamp) don't work too.

How to workaround this?

> 21 авг. 2020 г., в 14:57, Олег Самойлов <splarv(at)ya(dot)ru> написал(а):
>
> PostgreSQL 12.4
> Just create partitioned table for PostgreSQL logs
>
> CREATE TABLE pglog.pglog (
> log_time timestamp(3) with time zone,
> user_name text,
> database_name text,
> process_id integer,
> connection_from text,
> session_id text,
> session_line_num bigint,
> command_tag text,
> session_start_time timestamp with time zone,
> virtual_transaction_id text,
> transaction_id bigint,
> error_severity text,
> sql_state_code text,
> message text,
> detail text,
> hint text,
> internal_query text,
> internal_query_pos integer,
> context text,
> query text,
> query_pos integer,
> location text,
> application_name text
> ) PARTITION BY LIST (date_part('isodow', log_time));
>
> ERROR: functions in partition key expression must be marked IMMUTABLE
>
> But, date_part is immutable
>
> Schema | pg_catalog
> Name | date_part
> Result data type | double precision
> Argument data types | text, time with time zone
> Type | func
> Volatility | immutable
> Parallel | safe
> Owner | postgres
> Security | invoker
> Access privileges |
> Language | internal
> Source code | timetz_part
> Description | extract field from time with time zone
>
> What is wrong here?
>
>