*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***************
*** 16576,16581 **** SELECT collation for ('foo' COLLATE "de_DE");
--- 16576,16594 ----
         <entry><type>text</type></entry>
         <entry>set parameter and return new value</entry>
        </row>
+ 	  <row>
+        <entry>
+         <indexterm>
+          <primary>pg_hba_lookup</primary>
+         </indexterm>
+         <literal><function>pg_hba_lookup(<parameter>database</> <type>text</>,
+ 							<parameter>user</> <type>text</>
+ 							[, <parameter>address</> <type>text</>]
+ 							[, <parameter>hostname</> <type>text</>)</function></literal>
+        </entry>
+        <entry><type>record</type></entry>
+        <entry>Returns all matching row entries of pg_hba.conf</entry>
+       </row>
       </tbody>
      </tgroup>
     </table>
***************
*** 16633,16638 **** SELECT set_config('log_statement_stats', 'off', false);
--- 16646,16667 ----
  </programlisting>
     </para>
  
+    <para>
+     <function>pg_hba_lookup</function> returns a set of records
+ 	containing the line number, type, database, user, address,
+ 	hostname, method and options that are satisfied with the given
+ 	input values. Typical usages include:
+ <programlisting>
+ SELECT pg_hba_lookup('test_database', 'test_user');
+ 
+ 					pg_hba_lookup
+ --------------------------------------------------------------
+  (84,local,"[""all""]","[""all""]",,,trust,{})
+  (86,local,"[""test_database""]","[""test_user""]",,,trust,{})
+ (1 row)
+ </programlisting>
+    </para>
+    
    </sect2>
  
    <sect2 id="functions-admin-signal">
*** a/src/backend/libpq/hba.c
--- b/src/backend/libpq/hba.c
***************
*** 25,39 ****
--- 25,45 ----
  #include <arpa/inet.h>
  #include <unistd.h>
  
+ #include "access/htup_details.h"
  #include "catalog/pg_collation.h"
+ #include "catalog/pg_type.h"
+ #include "funcapi.h"
  #include "libpq/ip.h"
  #include "libpq/libpq.h"
+ #include "miscadmin.h"
  #include "postmaster/postmaster.h"
  #include "regex/regex.h"
  #include "replication/walsender.h"
  #include "storage/fd.h"
  #include "utils/acl.h"
+ #include "utils/builtins.h"
  #include "utils/guc.h"
+ #include "utils/jsonb.h"
  #include "utils/lsyscache.h"
  #include "utils/memutils.h"
  
***************
*** 74,79 **** typedef struct HbaToken
--- 80,95 ----
  	bool		quoted;
  } HbaToken;
  
+ typedef enum hba_lookup_args_mode
+ {
+ 	TWO_ARGS_MODE=0,
+ 	THREE_ARGS_MODE,
+ 	FOUR_ARGS_MODE
+ }hba_lookup_args_mode;
+ 
+ /* Flag to indicate the failure of reloading pg_hba.conf file */
+ bool		load_hba_failure = false;
+ 
  /*
   * pre-parsed content of HBA config file: list of HbaLine structs.
   * parsed_hba_context is the memory context where it lives.
***************
*** 100,105 **** static List *tokenize_inc_file(List *tokens, const char *outer_filename,
--- 116,125 ----
  static bool parse_hba_auth_opt(char *name, char *val, HbaLine *hbaline,
  				   int line_num);
  
+ static void hba_getvalues_for_line(HbaLine *hba, Datum *values, bool *nulls);
+ static bool pg_hba_match(HbaLine *hba, char *database, char *user,  struct sockaddr_storage *addr,
+ 				char *hostname, bool ssl_inuse, hba_lookup_args_mode args_mode);
+ 
  /*
   * isblank() exists in the ISO C99 spec, but it's not very portable yet,
   * so provide our own version.
***************
*** 2233,2235 **** hba_getauthmethod(hbaPort *port)
--- 2253,2826 ----
  {
  	check_hba(port);
  }
+ 
+ 
+ /* LDAP supports 10 currently, keep this well above the most any method needs */
+ #define MAX_OPTIONS 12
+ 
+ /*
+  * Fill in suitable values to build a tuple representing the
+  * HbaLine provided
+  */
+ static void
+ hba_getvalues_for_line(HbaLine *hba, Datum *values, bool *nulls)
+ {
+ 	int			index = 0;
+ 	JsonbInState result;
+ 	JsonbValue	v;
+ 	char	   *str;
+ 	int			len;
+ 
+ 	/* line_number */
+ 	values[index] = Int32GetDatum(hba->linenumber);
+ 
+ 	/* method */
+  	index++;
+  	switch (hba->auth_method)
+  	{
+  		case uaReject:
+  			values[index] = CStringGetTextDatum("reject");
+  			break;
+  		case uaTrust:
+  			values[index] = CStringGetTextDatum("trust");
+  			break;
+  		case uaIdent:
+  			values[index] = CStringGetTextDatum("ident");
+  			break;
+  		case uaPassword:
+  			values[index] = CStringGetTextDatum("password");
+  			break;
+  		case uaMD5:
+  			values[index] = CStringGetTextDatum("md5");
+  			break;
+  		case uaGSS:
+  			values[index] = CStringGetTextDatum("gss");
+  			break;
+  		case uaSSPI:
+  			values[index] = CStringGetTextDatum("sspi");
+  			break;
+  		case uaPAM:
+  			values[index] = CStringGetTextDatum("pam");
+  			break;
+  		case uaLDAP:
+  			values[index] = CStringGetTextDatum("ldap");
+  			break;
+  		case uaCert:
+  			values[index] = CStringGetTextDatum("cert");
+  			break;
+  		case uaRADIUS:
+  			values[index] = CStringGetTextDatum("radius");
+  			break;
+  		case uaPeer:
+  			values[index] = CStringGetTextDatum("peer");
+  			break;
+  		default:
+  			elog(ERROR, "unexpected authentication method in parsed HBA entry");
+  			break;
+  	}
+ 
+ 	/* options */
+ 	index++;
+ 	memset(&result, 0, sizeof(JsonbInState));
+ 	result.res = pushJsonbValue(&result.parseState, WJB_BEGIN_OBJECT, NULL);
+ 
+ 	if (hba->auth_method == uaGSS || hba->auth_method == uaSSPI)
+ 	{
+ 		if (hba->include_realm)
+ 		{
+ 			str = pstrdup("include_realm");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(BoolGetDatum(true), false, &result, BOOLOID, false);
+ 		}
+ 
+ 		if (hba->krb_realm)
+ 		{
+ 			str = pstrdup("krb_realm");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->krb_realm), false, &result, TEXTOID, false);
+ 		}
+ 	}
+ 
+ 	if (hba->usermap)
+ 	{
+ 		str = pstrdup("map");
+ 		len = strlen(str);
+ 
+ 		v.type = jbvString;
+ 
+ 		v.val.string.len = len;
+ 		v.val.string.val = str;
+ 
+ 		result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 		add_jsonb(CStringGetTextDatum(hba->usermap), false, &result, TEXTOID, false);
+ 	}
+ 
+ 	if (hba->auth_method == uaLDAP)
+ 	{
+ 		if (hba->ldapserver)
+ 		{
+ 			str = pstrdup("ldapserver");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->ldapserver), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->ldapport)
+ 		{
+ 			str = pstrdup("ldapport");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(Int32GetDatum(hba->ldapport), false, &result, INT4OID, false);
+ 		}
+ 
+ 		if (hba->ldaptls)
+ 		{
+ 			str = pstrdup("ldaptls");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(BoolGetDatum(true), false, &result, BOOLOID, false);
+ 		}
+ 
+ 		if (hba->ldapprefix)
+ 		{
+ 			str = pstrdup("ldapprefix");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->ldapprefix), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->ldapsuffix)
+ 		{
+ 			str = pstrdup("ldapsuffix");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->ldapsuffix), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->ldapbasedn)
+ 		{
+ 			str = pstrdup("ldapbasedn");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->ldapbasedn), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->ldapbinddn)
+ 		{
+ 			str = pstrdup("ldapbinddn");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->ldapbinddn), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->ldapbindpasswd)
+ 		{
+ 			str = pstrdup("ldapbindpasswd");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->ldapbindpasswd), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->ldapsearchattribute)
+ 		{
+ 			str = pstrdup("ldapsearchattribute");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->ldapsearchattribute), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->ldapscope)
+ 		{
+ 			str = pstrdup("ldapscope");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(Int32GetDatum(hba->ldapscope), false, &result, INT4OID, false);
+ 		}
+ 	}
+ 
+ 	if (hba->auth_method == uaRADIUS)
+ 	{
+ 		if (hba->radiusserver)
+ 		{
+ 			str = pstrdup("radiusserver");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->radiusserver), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->radiussecret)
+ 		{
+ 			str = pstrdup("radiussecret");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->radiussecret), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->radiusidentifier)
+ 		{
+ 			str = pstrdup("radiusidentifier");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(CStringGetTextDatum(hba->radiusidentifier), false, &result, TEXTOID, false);
+ 		}
+ 
+ 		if (hba->radiusport)
+ 		{
+ 			str = pstrdup("radiusport");
+ 			len = strlen(str);
+ 
+ 			v.type = jbvString;
+ 
+ 			v.val.string.len = len;
+ 			v.val.string.val = str;
+ 
+ 			result.res = pushJsonbValue(&result.parseState, WJB_KEY, &v);
+ 			add_jsonb(Int32GetDatum(hba->radiusport), false, &result, INT4OID, false);
+ 		}
+ 	}
+ 
+ 	result.res = pushJsonbValue(&result.parseState, WJB_END_OBJECT, NULL);
+ 	values[index] = PointerGetDatum(JsonbValueToJsonb(result.res));
+ }
+ 
+ static bool
+ pg_hba_match(HbaLine *hba, char *database, char *user, struct sockaddr_storage *addr,
+ 			char *hostname, bool ssl_inuse, hba_lookup_args_mode args_mode)
+ {
+ 	Oid			roleid;
+ 
+ 	if (ssl_inuse)
+ 	{
+ #ifdef USE_SSL
+ 		if (EnableSSL && hba->conntype != ctHostSSL)
+ 		{
+ 			ereport(NOTICE, (errmsg("Skipped %d Hba line, because of non SSL connection type.",
+ 					hba->linenumber)));
+ 			return false;
+ 		}
+ 		else
+ 		{
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_CONFIG_FILE_ERROR),
+ 					 errmsg("hostssl requires SSL to be turned on"),
+ 					 errhint("Set ssl = on in postgresql.conf.")));
+ 			return false;
+ 		}
+ #else
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_CONFIG_FILE_ERROR),
+ 				 errmsg("hostssl is not supported by this build"),
+ 		  errhint("Compile with --with-openssl to use SSL connections.")));
+ 		return false;
+ #endif
+ 	}
+ 
+ 	/* Get the target role's OID.  Note we do not error out for bad role. */
+ 	roleid = get_role_oid(user, true);
+ 
+ 	if (!check_db(database, user, roleid, hba->databases))
+ 	{
+ 		ereport(NOTICE, (errmsg("Skipped %d Hba line, because of non matching database.",
+ 				hba->linenumber)));
+ 		return false;
+ 	}
+ 
+ 	if (!check_role(user, roleid, hba->roles))
+ 	{
+ 		ereport(NOTICE, (errmsg("Skipped %d Hba line, because of non matching role.",
+ 				hba->linenumber)));
+ 		return false;
+ 	}
+ 
+ 	if (args_mode != TWO_ARGS_MODE)
+ 	{
+ 		/* Check IP address */
+ 		switch (hba->ip_cmp_method)
+ 		{
+ 			case ipCmpMask:
+ 				if (hostname && hba->hostname)
+ 				{
+ 					if (!hostname_match(hostname, hba->hostname))
+ 					{
+ 						ereport(NOTICE, (errmsg("Skipped %d Hba line, because of non matching hostname.",
+ 								hba->linenumber)));
+ 						return false;
+ 					}
+ 				}
+ 				else
+ 				{
+ 					if (!check_ip((SockAddr *)addr,
+ 								  (struct sockaddr *) & hba->addr,
+ 								  (struct sockaddr *) & hba->mask))
+ 					{
+ 						ereport(NOTICE, (errmsg("Skipped %d Hba line, because of non matching IP.",
+ 								hba->linenumber)));
+ 						return false;
+ 					}
+ 				}
+ 				break;
+ 			case ipCmpAll:
+ 				break;
+ 			case ipCmpSameHost:
+ 			case ipCmpSameNet:
+ 				if (!check_same_host_or_net((SockAddr *)addr,
+ 											hba->ip_cmp_method))
+ 				{
+ 					ereport(NOTICE, (errmsg("Skipped %d Hba line, because of non matching SameHost/SameNet.",
+ 							hba->linenumber)));
+ 					return false;
+ 				}
+ 				break;
+ 			default: /* Not reachable case*/
+ 				break;
+ 		}
+ 	}
+ 
+ 	return true;
+ }
+ 
+ /*
+  * SQL-accessible SRF to return all the settings from the pg_hba.conf
+  * file.
+  */
+ Datum
+ pg_hba_lookup_2args(PG_FUNCTION_ARGS)
+ {
+ 	return pg_hba_lookup(fcinfo);
+ }
+ 
+ /*
+  * SQL-accessible SRF to return all the settings from the pg_hba.conf
+  * file.
+  */
+ Datum
+ pg_hba_lookup_3args(PG_FUNCTION_ARGS)
+ {
+ 	return pg_hba_lookup(fcinfo);
+ }
+ 
+ #define NUM_PG_HBA_CONF_ATTS   3
+ 
+ /*
+  * SQL-accessible SRF to return all the settings from the pg_hba.conf
+  * file. 
+  */
+ Datum
+ pg_hba_lookup(PG_FUNCTION_ARGS)
+ {
+ 	char	*user;
+ 	char	*database;
+ 	char	*address = NULL;
+ 	bool    ssl_inuse = false;
+ 	TupleDesc	tupdesc;
+ 	ListCell   *line;
+ 	Datum		values[NUM_PG_HBA_CONF_ATTS];
+ 	bool		nulls[NUM_PG_HBA_CONF_ATTS];
+ 	HeapTuple	tuple;
+ 	Datum		result;
+ 	struct sockaddr_storage addr;
+ 	char *hostname = NULL;
+ 	hba_lookup_args_mode args_mode = TWO_ARGS_MODE; /* Minimum number of arguments */
+ 
+ 	if (!superuser())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ 				 (errmsg("only superuser can view pg_hba.conf settings"))));
+ 
+ 	if (PG_ARGISNULL(0))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				(errmsg("database name is required to match pg_hba configuration entry"))));
+ 	else
+ 		database = TextDatumGetCString(PG_GETARG_DATUM(0));
+ 
+ 	if (PG_ARGISNULL(1))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				(errmsg("user name is required to match pg_hba configuration entry"))));
+ 	else
+ 		user = TextDatumGetCString(PG_GETARG_DATUM(1));
+ 
+ 	if (PG_NARGS() != 2)
+ 	{
+ 		struct addrinfo *gai_result;
+ 		struct addrinfo hints;
+ 		int ret;
+ 
+ 		args_mode = THREE_ARGS_MODE;
+ 		if (!PG_ARGISNULL(2))
+ 			address = TextDatumGetCString(PG_GETARG_DATUM(2));
+ 
+ 		/* Get the IP address either way */
+ 		hints.ai_flags = AI_NUMERICHOST;
+ 		hints.ai_family = AF_UNSPEC;
+ 		hints.ai_socktype = 0;
+ 		hints.ai_protocol = 0;
+ 		hints.ai_addrlen = 0;
+ 		hints.ai_canonname = NULL;
+ 		hints.ai_addr = NULL;
+ 		hints.ai_next = NULL;
+ 
+ 		ret = pg_getaddrinfo_all(address, NULL, &hints, &gai_result);
+ 		if (ret == 0 && gai_result)
+ 			memcpy(&addr, gai_result->ai_addr, gai_result->ai_addrlen);
+ 		else if (ret == EAI_NONAME)
+ 			hostname = pstrdup(address);
+ 		else
+ 		{
+ 			ereport(ERROR,
+ 					(errmsg("invalid IP address \"%s\": %s",
+ 							 address, gai_strerror(ret))));
+ 			if (gai_result)
+ 				pg_freeaddrinfo_all(hints.ai_family, gai_result);
+ 			return false;
+ 		}
+ 
+ 		pg_freeaddrinfo_all(hints.ai_family, gai_result);
+ 
+ 		if (PG_NARGS() != 3)
+ 		{
+ 			args_mode = FOUR_ARGS_MODE;
+ 			if (!PG_ARGISNULL(3))
+ 				ssl_inuse = DatumGetBool(PG_GETARG_DATUM(3));
+ 		}
+ 	}
+ 
+ 	if (load_hba_failure)
+ 		ereport(WARNING,
+ 				(errmsg("There was some failure in reloading pg_hba.conf file. "
+ 				"The pg_hba.conf settings data may contains stale information")));
+ 
+ 	/* Create the tupledesc	*/
+ 	tupdesc = CreateTemplateTupleDesc(NUM_PG_HBA_CONF_ATTS, false);
+ 	TupleDescInitEntry(tupdesc, (AttrNumber)1, "line_number",
+ 		INT4OID, -1, 0);
+ 	TupleDescInitEntry(tupdesc, (AttrNumber)2, "method",
+ 		TEXTOID, -1, 0);
+ 	TupleDescInitEntry(tupdesc, (AttrNumber)3, "options",
+ 		JSONBOID, -1, 0);
+ 	BlessTupleDesc(tupdesc);
+ 
+ 	MemSet(values, 0, sizeof(values));
+ 	MemSet(nulls, true, sizeof(nulls));
+ 
+ 	/*
+ 	 * Loop through the list and deparse each entry as it comes, and returns
+ 	 * the first matched entry.
+ 	 */
+ 	foreach(line, parsed_hba_lines)
+ 	{
+ 		HbaLine    *hba = (HbaLine *)lfirst(line);
+ 
+ 		CHECK_FOR_INTERRUPTS();
+ 
+ 		if (pg_hba_match(hba, database, user, &addr, hostname, ssl_inuse, args_mode))
+ 		{
+ 			/* Get the next parsed hba line values */
+ 			MemSet(nulls, false, sizeof(nulls));
+ 			hba_getvalues_for_line(hba, values, nulls);
+ 			break;
+ 		}
+ 	}
+ 
+ 	/* build a tuple */
+ 	tuple = heap_form_tuple(tupdesc, values, nulls);
+ 
+ 	/* make the tuple into a datum */
+ 	result = HeapTupleGetDatum(tuple);
+ 	PG_RETURN_DATUM(result);
+ }
+ 
+ 
*** a/src/backend/tcop/postgres.c
--- b/src/backend/tcop/postgres.c
***************
*** 4005,4010 **** PostgresMain(int argc, char *argv[],
--- 4005,4023 ----
  		{
  			got_SIGHUP = false;
  			ProcessConfigFile(PGC_SIGHUP);
+ 			
+ 			/* 
+ 			 * Reload authentication config files too to refresh 
+ 			 * pg_hba_conf view data.
+ 			 */
+ 			if (!load_hba())
+ 			{
+ 				ereport(DEBUG1,
+ 					(errmsg("Falure in reloading pg_hba.conf, pg_hba_conf view may show stale information")));
+ 				load_hba_failure = true;
+ 			}
+ 			
+ 			load_hba_failure = false;
  		}
  
  		/*
*** a/src/backend/utils/adt/jsonb.c
--- b/src/backend/utils/adt/jsonb.c
***************
*** 28,39 ****
  #include "utils/syscache.h"
  #include "utils/typcache.h"
  
- typedef struct JsonbInState
- {
- 	JsonbParseState *parseState;
- 	JsonbValue *res;
- } JsonbInState;
- 
  /* unlike with json categories, we need to treat json and jsonb differently */
  typedef enum					/* type categories for datum_to_jsonb */
  {
--- 28,33 ----
***************
*** 83,89 **** static void jsonb_categorize_type(Oid typoid,
  static void datum_to_jsonb(Datum val, bool is_null, JsonbInState *result,
  			   JsonbTypeCategory tcategory, Oid outfuncoid,
  			   bool key_scalar);
! static void add_jsonb(Datum val, bool is_null, JsonbInState *result,
  		  Oid val_type, bool key_scalar);
  static JsonbParseState *clone_parse_state(JsonbParseState *state);
  static char *JsonbToCStringWorker(StringInfo out, JsonbContainer *in, int estimated_len, bool indent);
--- 77,83 ----
  static void datum_to_jsonb(Datum val, bool is_null, JsonbInState *result,
  			   JsonbTypeCategory tcategory, Oid outfuncoid,
  			   bool key_scalar);
! void add_jsonb(Datum val, bool is_null, JsonbInState *result,
  		  Oid val_type, bool key_scalar);
  static JsonbParseState *clone_parse_state(JsonbParseState *state);
  static char *JsonbToCStringWorker(StringInfo out, JsonbContainer *in, int estimated_len, bool indent);
***************
*** 1113,1119 **** composite_to_jsonb(Datum composite, JsonbInState *result)
   * lookups only once.
   */
  
! static void
  add_jsonb(Datum val, bool is_null, JsonbInState *result,
  		  Oid val_type, bool key_scalar)
  {
--- 1107,1113 ----
   * lookups only once.
   */
  
! void
  add_jsonb(Datum val, bool is_null, JsonbInState *result,
  		  Oid val_type, bool key_scalar)
  {
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***************
*** 3079,3084 **** DATA(insert OID = 2084 (  pg_show_all_settings	PGNSP PGUID 12 1 1000 0 0 f f f f
--- 3079,3090 ----
  DESCR("SHOW ALL as a function");
  DATA(insert OID = 3329 (  pg_show_all_file_settings PGNSP PGUID 12 1 1000 0 0 f f f f t t v s 0 0 2249 "" "{25,23,23,25,25,16,25}" "{o,o,o,o,o,o,o}" "{sourcefile,sourceline,seqno,name,setting,applied,error}" _null_ _null_ show_all_file_settings _null_ _null_ _null_ ));
  DESCR("show config file settings");
+ DATA(insert OID = 3997 (pg_hba_lookup PGNSP PGUID 12 1 1000 0 0 f f f f t t v u 2 0 2249 "25 25" "{25,25,23,25,3802}" "{i,i,o,o,o}" "{database,user,line_number,method,options}" _null_ _null_ pg_hba_lookup_2args _null_ _null_ _null_));
+ DESCR("view client authentication settings");
+ DATA(insert OID = 3998 (pg_hba_lookup PGNSP PGUID 12 1 1000 0 0 f f f f t t v u 3 0 2249 "25 25 25" "{25,25,25,23,25,3802}" "{i,i,i,o,o,o}" "{database,user,address,line_number,method,options}" _null_ _null_ pg_hba_lookup_3args _null_ _null_ _null_));
+ DESCR("view client authentication settings");
+ DATA(insert OID = 3999 (pg_hba_lookup PGNSP PGUID 12 1 1000 0 0 f f f f t t v u 4 0 2249 "25 25 25 16" "{25,25,25,16,23,25,3802}" "{i,i,i,i,o,o,o}" "{database,user,address,ssl_inuse,line_number,method,options}" _null_ _null_ pg_hba_lookup _null_ _null_ _null_));
+ DESCR("view client authentication settings");
  DATA(insert OID = 1371 (  pg_lock_status   PGNSP PGUID 12 1 1000 0 0 f f f f t t v s 0 0 2249 "" "{25,26,26,23,21,25,28,26,26,21,25,23,25,16,16}" "{o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}" "{locktype,database,relation,page,tuple,virtualxid,transactionid,classid,objid,objsubid,virtualtransaction,pid,mode,granted,fastpath}" _null_ _null_ pg_lock_status _null_ _null_ _null_ ));
  DESCR("view system lock information");
  DATA(insert OID = 1065 (  pg_prepared_xact PGNSP PGUID 12 1 1000 0 0 f f f f t t v s 0 0 2249 "" "{28,25,1184,26,26}" "{o,o,o,o,o}" "{transaction,gid,prepared,ownerid,dbid}" _null_ _null_ pg_prepared_xact _null_ _null_ _null_ ));
*** a/src/include/libpq/hba.h
--- b/src/include/libpq/hba.h
***************
*** 96,101 **** typedef struct IdentLine
--- 96,103 ----
  /* kluge to avoid including libpq/libpq-be.h here */
  typedef struct Port hbaPort;
  
+ extern bool load_hba_failure;
+ 
  extern bool load_hba(void);
  extern bool load_ident(void);
  extern void hba_getauthmethod(hbaPort *port);
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
***************
*** 1123,1128 **** extern Datum set_config_by_name(PG_FUNCTION_ARGS);
--- 1123,1133 ----
  extern Datum show_all_settings(PG_FUNCTION_ARGS);
  extern Datum show_all_file_settings(PG_FUNCTION_ARGS);
  
+ /* hba.c */
+ extern Datum pg_hba_lookup_2args(PG_FUNCTION_ARGS);
+ extern Datum pg_hba_lookup_3args(PG_FUNCTION_ARGS);
+ extern Datum pg_hba_lookup(PG_FUNCTION_ARGS);
+ 
  /* rls.c */
  extern Datum row_security_active(PG_FUNCTION_ARGS);
  extern Datum row_security_active_name(PG_FUNCTION_ARGS);
*** a/src/include/utils/json.h
--- b/src/include/utils/json.h
***************
*** 43,49 **** extern Datum json_object(PG_FUNCTION_ARGS);
  extern Datum json_object_two_arg(PG_FUNCTION_ARGS);
  
  extern void escape_json(StringInfo buf, const char *str);
- 
  extern Datum json_typeof(PG_FUNCTION_ARGS);
  
  /* functions in jsonfuncs.c */
--- 43,48 ----
*** a/src/include/utils/jsonb.h
--- b/src/include/utils/jsonb.h
***************
*** 343,348 **** typedef struct JsonbIterator
--- 343,354 ----
  	struct JsonbIterator *parent;
  } JsonbIterator;
  
+ typedef struct JsonbInState
+ {
+ 	JsonbParseState *parseState;
+ 	JsonbValue *res;
+ } JsonbInState;
+ 
  /* I/O routines */
  extern Datum jsonb_in(PG_FUNCTION_ARGS);
  extern Datum jsonb_out(PG_FUNCTION_ARGS);
***************
*** 428,433 **** extern bool JsonbDeepContains(JsonbIterator **val,
--- 434,441 ----
  extern void JsonbHashScalarValue(const JsonbValue *scalarVal, uint32 *hash);
  
  /* jsonb.c support functions */
+ void add_jsonb(Datum val, bool is_null, JsonbInState *result,
+ 	Oid val_type, bool key_scalar);
  extern char *JsonbToCString(StringInfo out, JsonbContainer *in,
  			   int estimated_len);
  extern char *JsonbToCStringIndent(StringInfo out, JsonbContainer *in,
*** a/src/test/regress/expected/rules.out
--- b/src/test/regress/expected/rules.out
***************
*** 1327,1332 **** pg_group| SELECT pg_authid.rolname AS groname,
--- 1327,1344 ----
            WHERE (pg_auth_members.roleid = pg_authid.oid)) AS grolist
     FROM pg_authid
    WHERE (NOT pg_authid.rolcanlogin);
+ pg_hba_conf| SELECT a.line_number,
+     a.type,
+     a.keyword_databases,
+     a.databases,
+     a.keyword_users,
+     a.users,
+     a.address,
+     a.compare_method,
+     a.hostname,
+     a.method,
+     a.options
+    FROM pg_hba_conf() a(line_number, type, keyword_databases, databases, keyword_users, users, address, compare_method, hostname, method, options);
  pg_indexes| SELECT n.nspname AS schemaname,
      c.relname AS tablename,
      i.relname AS indexname,
