我无法从 PSQL 中的身份验证挂钩读取 pg_auth_members table

Question

在身份验证阶段，我试图获取与登录用户属于同一组的角色列表。为此，我使用了系统缓存搜索功能，但由于某种原因，使用 AUTHMEMROLEMEM syscache id 我得到了错误 " can't read pg_class without selecting the database (relcache.c:320)"。如果我使用AUTHMEMMEMROLE，搜索是正常执行的。根据代码，两个 ID 必须引用相同的表，为此设置了 relisshare 标志，并且它们必须在身份验证之前可用。

例如hook中会报错的代码：

HeapTuple       role_tup;
role_tup =  SearchSysCache2(AUTHMEMROLEMEM, ObjectIdGetDatum(user_oid), ObjectIdGetDatum(search_oid));

并且不会导致：

HeapTuple       role_tup;
role_tup =  SearchSysCache2(AUTHMEMMEMROLE,ObjectIdGetDatum(user_oid), ObjectIdGetDatum(search_oid));

我是不是遗漏了什么或者是错误？

Answer 1

该索引被认为对身份验证不重要。参见RelationCacheInitializePhase3中的以下代码：

    /*
     * Process critical shared indexes too.
     *
     * DatabaseNameIndexId isn't critical for relcache loading, but rather for
     * initial lookup of MyDatabaseId, without which we'll never find any
     * non-shared catalogs at all.  Autovacuum calls InitPostgres with a
     * database OID, so it instead depends on DatabaseOidIndexId.  We also
     * need to nail up some indexes on pg_authid and pg_auth_members for use
     * during client authentication.  SharedSecLabelObjectIndexId isn't
     * critical for the core system, but authentication hooks might be
     * interested in it.
     */
    if (!criticalSharedRelcachesBuilt)
    {
        load_critical_index(DatabaseNameIndexId,
                            DatabaseRelationId);
        load_critical_index(DatabaseOidIndexId,
                            DatabaseRelationId);
        load_critical_index(AuthIdRolnameIndexId,
                            AuthIdRelationId);
        load_critical_index(AuthIdOidIndexId,
                            AuthIdRelationId);
        load_critical_index(AuthMemMemRoleIndexId,
                            AuthMemRelationId);
        load_critical_index(SharedSecLabelObjectIndexId,
                            SharedSecLabelRelationId);

我无法从 PSQL 中的身份验证挂钩读取 pg_auth_members table

I can't read the pg_auth_members table from the authentication hook in PSQL

c

postgresql

psql