PostgreSQL DDL操作是否会重写表

//二进制兼容的类型 
select castsource::regtype,casttarget::regtype,castfunc::regproc,castcontext,castmethod from pg_cast where castmethod='b';

+-------------------+-------------------+----------+-------------+------------+
|    castsource     |    casttarget     | castfunc | castcontext | castmethod |
+-------------------+-------------------+----------+-------------+------------+
| integer           | oid               | -        | i           | b          |
| oid               | integer           | -        | a           | b          |
| oid               | regproc           | -        | i           | b          |
| regproc           | oid               | -        | i           | b          |
| integer           | regproc           | -        | i           | b          |
| regproc           | integer           | -        | a           | b          |
| regproc           | regprocedure      | -        | i           | b          |
| regprocedure      | regproc           | -        | i           | b          |
| oid               | regprocedure      | -        | i           | b          |
| regprocedure      | oid               | -        | i           | b          |
| integer           | regprocedure      | -        | i           | b          |
| regprocedure      | integer           | -        | a           | b          |
| oid               | regoper           | -        | i           | b          |
| regoper           | oid               | -        | i           | b          |
| integer           | regoper           | -        | i           | b          |
| regoper           | integer           | -        | a           | b          |
| regoper           | regoperator       | -        | i           | b          |
| regoperator       | regoper           | -        | i           | b          |
| oid               | regoperator       | -        | i           | b          |
| regoperator       | oid               | -        | i           | b          |
| integer           | regoperator       | -        | i           | b          |
| regoperator       | integer           | -        | a           | b          |
| oid               | regclass          | -        | i           | b          |
| regclass          | oid               | -        | i           | b          |
| integer           | regclass          | -        | i           | b          |
| regclass          | integer           | -        | a           | b          |
| oid               | regcollation      | -        | i           | b          |
| regcollation      | oid               | -        | i           | b          |
| integer           | regcollation      | -        | i           | b          |
| regcollation      | integer           | -        | a           | b          |
| oid               | regtype           | -        | i           | b          |
| regtype           | oid               | -        | i           | b          |
| integer           | regtype           | -        | i           | b          |
| regtype           | integer           | -        | a           | b          |
| oid               | regconfig         | -        | i           | b          |
| regconfig         | oid               | -        | i           | b          |
| integer           | regconfig         | -        | i           | b          |
| regconfig         | integer           | -        | a           | b          |
| oid               | regdictionary     | -        | i           | b          |
| regdictionary     | oid               | -        | i           | b          |
| integer           | regdictionary     | -        | i           | b          |
| regdictionary     | integer           | -        | a           | b          |
| oid               | regrole           | -        | i           | b          |
| regrole           | oid               | -        | i           | b          |
| integer           | regrole           | -        | i           | b          |
| regrole           | integer           | -        | a           | b          |
| oid               | regnamespace      | -        | i           | b          |
| regnamespace      | oid               | -        | i           | b          |
| integer           | regnamespace      | -        | i           | b          |
| regnamespace      | integer           | -        | a           | b          |
| text              | character         | -        | i           | b          |
| text              | character varying | -        | i           | b          |
| character varying | text              | -        | i           | b          |
| character varying | character         | -        | i           | b          |
| pg_node_tree      | text              | -        | i           | b          |
| pg_ndistinct      | bytea             | -        | i           | b          |
| pg_dependencies   | bytea             | -        | i           | b          |
| pg_mcv_list       | bytea             | -        | i           | b          |
| cidr              | inet              | -        | i           | b          |
| bit               | bit varying       | -        | i           | b          |
| bit varying       | bit               | -        | i           | b          |
| xml               | text              | -        | a           | b          |
| xml               | character varying | -        | a           | b          |
| xml               | character         | -        | a           | b          |
+-------------------+-------------------+----------+-------------+------------+
(64 rows)
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