Best approach for data migration: moving data from two columns to JSONB

   -- Add new column
   ALTER TABLE "table" ADD COLUMN "new_jsonb_col" JSONB;
   --> statement-breakpoint
   
   -- Transform data
   UPDATE "table" SET "new_jsonb_col" = jsonb_build_object(
       'old_col1_value', "old_col1",
       'old_col2_value', "old_col2"
   );
   --> statement-breakpoint
   
   -- Make NOT NULL
   ALTER TABLE "table" ALTER COLUMN "new_jsonb_col" SET NOT NULL;
   --> statement-breakpoint
   
   -- Drop old columns
   ALTER TABLE "table" DROP COLUMN "old_col1";
   --> statement-breakpoint
   ALTER TABLE "table" DROP COLUMN "old_col2";