create table t
(
id int,
name nvarchar(128),
value sql_variant
)

CREATE TYPE public.sql_variant AS (
  i INTEGER,
  bi BIGINT,
  d NUMERIC,
  b BYTEA,
  t TIMESTAMP WITHOUT TIME ZONE,
  bl BOOLEAN
);
create table t
(
id int,
name varchar(128),
value sql_variant
)

INSERT INTO [PGSQL].[db].[public].[t]([id],[name],[value]) 
SELECT TOP 10 [id],name, value FROM [dbo].[t]


OLE DB provider "PGNP" for linked server "PGSQL" returned message "ERROR:  column "var" is of type sql_variant but expression is of type character varying
LINE 1: ...c"."t"("id","var","name") VALUES ($1,$2,$3)
                                                                     ^
HINT:  You will need to rewrite or cast the expression.