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Allow CREATE/ALTER DATABASE to manipulate datistemplate and datallowconn.
Historically these database properties could be manipulated only by manually updating pg_database, which is error-prone and only possible for superusers. But there seems no good reason not to allow database owners to set them for their databases, so invent CREATE/ALTER DATABASE options to do that. Adjust a couple of places that were doing it the hard way to use the commands instead. Vik Fearing, reviewed by Pavel Stehule
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+135
-30
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7 files changed

+135
-30
lines changed

‎contrib/pg_upgrade/pg_upgrade.c‎

Lines changed: 4 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -540,9 +540,8 @@ set_frozenxids(void)
540540
*/
541541
if (strcmp(datallowconn, "f") == 0)
542542
PQclear(executeQueryOrDie(conn_template1,
543-
"UPDATE pg_catalog.pg_database "
544-
"SET datallowconn = true "
545-
"WHERE datname = '%s'", datname));
543+
"ALTER DATABASE %s ALLOW_CONNECTIONS = true",
544+
quote_identifier(datname)));
546545

547546
conn = connectToServer(&new_cluster, datname);
548547

@@ -558,9 +557,8 @@ set_frozenxids(void)
558557
/* Reset datallowconn flag */
559558
if (strcmp(datallowconn, "f") == 0)
560559
PQclear(executeQueryOrDie(conn_template1,
561-
"UPDATE pg_catalog.pg_database "
562-
"SET datallowconn = false "
563-
"WHERE datname = '%s'", datname));
560+
"ALTER DATABASE %s ALLOW_CONNECTIONS = false",
561+
quote_identifier(datname)));
564562
}
565563

566564
PQclear(dbres);

‎doc/src/sgml/ref/alter_database.sgml‎

Lines changed: 22 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -25,6 +25,8 @@ ALTER DATABASE <replaceable class="PARAMETER">name</replaceable> [ [ WITH ] <rep
2525

2626
<phrase>where <replaceable class="PARAMETER">option</replaceable> can be:</phrase>
2727

28+
IS_TEMPLATE <replaceable class="PARAMETER">istemplate</replaceable>
29+
ALLOW_CONNECTIONS <replaceable class="PARAMETER">allowconn</replaceable>
2830
CONNECTION LIMIT <replaceable class="PARAMETER">connlimit</replaceable>
2931

3032
ALTER DATABASE <replaceable class="PARAMETER">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
@@ -107,6 +109,26 @@ ALTER DATABASE <replaceable class="PARAMETER">name</replaceable> RESET ALL
107109
</varlistentry>
108110

109111
<varlistentry>
112+
<term><replaceable class="parameter">istemplate</replaceable></term>
113+
<listitem>
114+
<para>
115+
If true, then this database can be cloned by any user with CREATEDB
116+
privileges; if false, then only superusers or the owner of the
117+
database can clone it.
118+
</para>
119+
</listitem>
120+
</varlistentry>
121+
122+
<varlistentry>
123+
<term><replaceable class="parameter">allowconn</replaceable></term>
124+
<listitem>
125+
<para>
126+
If false then no one can connect to this database.
127+
</para>
128+
</listitem>
129+
</varlistentry>
130+
131+
<varlistentry>
110132
<term><replaceable class="parameter">connlimit</replaceable></term>
111133
<listitem>
112134
<para>

‎doc/src/sgml/ref/create_database.sgml‎

Lines changed: 24 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -28,6 +28,8 @@ CREATE DATABASE <replaceable class="PARAMETER">name</replaceable>
2828
[ LC_COLLATE [=] <replaceable class="parameter">lc_collate</replaceable> ]
2929
[ LC_CTYPE [=] <replaceable class="parameter">lc_ctype</replaceable> ]
3030
[ TABLESPACE [=] <replaceable class="parameter">tablespace_name</replaceable> ]
31+
[ IS_TEMPLATE [=] <replaceable class="parameter">istemplate</replaceable> ]
32+
[ ALLOW_CONNECTIONS [=] <replaceable class="parameter">allowconn</replaceable> ]
3133
[ CONNECTION LIMIT [=] <replaceable class="parameter">connlimit</replaceable> ] ]
3234
</synopsis>
3335
</refsynopsisdiv>
@@ -148,6 +150,28 @@ CREATE DATABASE <replaceable class="PARAMETER">name</replaceable>
148150
</varlistentry>
149151

150152
<varlistentry>
153+
<term><replaceable class="parameter">istemplate</replaceable></term>
154+
<listitem>
155+
<para>
156+
If true, then this database can be cloned by any user with CREATEDB
157+
privileges; if false (the default), then only superusers or the owner
158+
of the database can clone it.
159+
</para>
160+
</listitem>
161+
</varlistentry>
162+
163+
<varlistentry>
164+
<term><replaceable class="parameter">allowconn</replaceable></term>
165+
<listitem>
166+
<para>
167+
If false then no one can connect to this database. The default is
168+
true, allowing connections (except as restricted by other mechanisms,
169+
such as <literal>GRANT</>/<literal>REVOKE CONNECT</>).
170+
</para>
171+
</listitem>
172+
</varlistentry>
173+
174+
<varlistentry>
151175
<term><replaceable class="parameter">connlimit</replaceable></term>
152176
<listitem>
153177
<para>

‎src/backend/commands/dbcommands.c‎

Lines changed: 77 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -123,6 +123,8 @@ createdb(const CreatedbStmt *stmt)
123123
DefElem *dencoding = NULL;
124124
DefElem *dcollate = NULL;
125125
DefElem *dctype = NULL;
126+
DefElem *distemplate = NULL;
127+
DefElem *dallowconnections = NULL;
126128
DefElem *dconnlimit = NULL;
127129
char *dbname = stmt->dbname;
128130
char *dbowner = NULL;
@@ -131,6 +133,8 @@ createdb(const CreatedbStmt *stmt)
131133
char *dbctype = NULL;
132134
char *canonname;
133135
int encoding = -1;
136+
bool dbistemplate = false;
137+
bool dballowconnections = true;
134138
int dbconnlimit = -1;
135139
int notherbackends;
136140
int npreparedxacts;
@@ -189,6 +193,22 @@ createdb(const CreatedbStmt *stmt)
189193
errmsg("conflicting or redundant options")));
190194
dctype = defel;
191195
}
196+
else if (strcmp(defel->defname, "is_template") == 0)
197+
{
198+
if (distemplate)
199+
ereport(ERROR,
200+
(errcode(ERRCODE_SYNTAX_ERROR),
201+
errmsg("conflicting or redundant options")));
202+
distemplate = defel;
203+
}
204+
else if (strcmp(defel->defname, "allow_connections") == 0)
205+
{
206+
if (dallowconnections)
207+
ereport(ERROR,
208+
(errcode(ERRCODE_SYNTAX_ERROR),
209+
errmsg("conflicting or redundant options")));
210+
dallowconnections = defel;
211+
}
192212
else if (strcmp(defel->defname, "connection_limit") == 0)
193213
{
194214
if (dconnlimit)
@@ -244,7 +264,10 @@ createdb(const CreatedbStmt *stmt)
244264
dbcollate = defGetString(dcollate);
245265
if (dctype && dctype->arg)
246266
dbctype = defGetString(dctype);
247-
267+
if (distemplate && distemplate->arg)
268+
dbistemplate = defGetBoolean(distemplate);
269+
if (dallowconnections && dallowconnections->arg)
270+
dballowconnections = defGetBoolean(dallowconnections);
248271
if (dconnlimit && dconnlimit->arg)
249272
{
250273
dbconnlimit = defGetInt32(dconnlimit);
@@ -487,8 +510,8 @@ createdb(const CreatedbStmt *stmt)
487510
DirectFunctionCall1(namein, CStringGetDatum(dbcollate));
488511
new_record[Anum_pg_database_datctype - 1] =
489512
DirectFunctionCall1(namein, CStringGetDatum(dbctype));
490-
new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(false);
491-
new_record[Anum_pg_database_datallowconn - 1] = BoolGetDatum(true);
513+
new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(dbistemplate);
514+
new_record[Anum_pg_database_datallowconn - 1] = BoolGetDatum(dballowconnections);
492515
new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
493516
new_record[Anum_pg_database_datlastsysoid - 1] = ObjectIdGetDatum(src_lastsysoid);
494517
new_record[Anum_pg_database_datfrozenxid - 1] = TransactionIdGetDatum(src_frozenxid);
@@ -1328,7 +1351,11 @@ AlterDatabase(AlterDatabaseStmt *stmt, bool isTopLevel)
13281351
ScanKeyData scankey;
13291352
SysScanDesc scan;
13301353
ListCell *option;
1331-
int connlimit = -1;
1354+
bool dbistemplate = false;
1355+
bool dballowconnections = true;
1356+
int dbconnlimit = -1;
1357+
DefElem *distemplate = NULL;
1358+
DefElem *dallowconnections = NULL;
13321359
DefElem *dconnlimit = NULL;
13331360
DefElem *dtablespace = NULL;
13341361
Datum new_record[Natts_pg_database];
@@ -1340,7 +1367,23 @@ AlterDatabase(AlterDatabaseStmt *stmt, bool isTopLevel)
13401367
{
13411368
DefElem *defel = (DefElem *) lfirst(option);
13421369

1343-
if (strcmp(defel->defname, "connection_limit") == 0)
1370+
if (strcmp(defel->defname, "is_template") == 0)
1371+
{
1372+
if (distemplate)
1373+
ereport(ERROR,
1374+
(errcode(ERRCODE_SYNTAX_ERROR),
1375+
errmsg("conflicting or redundant options")));
1376+
distemplate = defel;
1377+
}
1378+
else if (strcmp(defel->defname, "allow_connections") == 0)
1379+
{
1380+
if (dallowconnections)
1381+
ereport(ERROR,
1382+
(errcode(ERRCODE_SYNTAX_ERROR),
1383+
errmsg("conflicting or redundant options")));
1384+
dallowconnections = defel;
1385+
}
1386+
else if (strcmp(defel->defname, "connection_limit") == 0)
13441387
{
13451388
if (dconnlimit)
13461389
ereport(ERROR,
@@ -1380,13 +1423,17 @@ AlterDatabase(AlterDatabaseStmt *stmt, bool isTopLevel)
13801423
return InvalidOid;
13811424
}
13821425

1426+
if (distemplate && distemplate->arg)
1427+
dbistemplate = defGetBoolean(distemplate);
1428+
if (dallowconnections && dallowconnections->arg)
1429+
dballowconnections = defGetBoolean(dallowconnections);
13831430
if (dconnlimit && dconnlimit->arg)
13841431
{
1385-
connlimit = defGetInt32(dconnlimit);
1386-
if (connlimit < -1)
1432+
dbconnlimit = defGetInt32(dconnlimit);
1433+
if (dbconnlimit < -1)
13871434
ereport(ERROR,
13881435
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1389-
errmsg("invalid connection limit: %d", connlimit)));
1436+
errmsg("invalid connection limit: %d", dbconnlimit)));
13901437
}
13911438

13921439
/*
@@ -1413,16 +1460,37 @@ AlterDatabase(AlterDatabaseStmt *stmt, bool isTopLevel)
14131460
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
14141461
stmt->dbname);
14151462

1463+
/*
1464+
* In order to avoid getting locked out and having to go through
1465+
* standalone mode, we refuse to disallow connections to the database
1466+
* we're currently connected to. Lockout can still happen with concurrent
1467+
* sessions but the likeliness of that is not high enough to worry about.
1468+
*/
1469+
if (!dballowconnections && dboid == MyDatabaseId)
1470+
ereport(ERROR,
1471+
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
1472+
errmsg("cannot disallow connections for current database")));
1473+
14161474
/*
14171475
* Build an updated tuple, perusing the information just obtained
14181476
*/
14191477
MemSet(new_record, 0, sizeof(new_record));
14201478
MemSet(new_record_nulls, false, sizeof(new_record_nulls));
14211479
MemSet(new_record_repl, false, sizeof(new_record_repl));
14221480

1481+
if (distemplate)
1482+
{
1483+
new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(dbistemplate);
1484+
new_record_repl[Anum_pg_database_datistemplate - 1] = true;
1485+
}
1486+
if (dallowconnections)
1487+
{
1488+
new_record[Anum_pg_database_datallowconn - 1] = BoolGetDatum(dballowconnections);
1489+
new_record_repl[Anum_pg_database_datallowconn - 1] = true;
1490+
}
14231491
if (dconnlimit)
14241492
{
1425-
new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(connlimit);
1493+
new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
14261494
new_record_repl[Anum_pg_database_datconnlimit - 1] = true;
14271495
}
14281496

‎src/bin/initdb/initdb.c‎

Lines changed: 1 addition & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -2288,11 +2288,7 @@ make_template0(void)
22882288
PG_CMD_DECL;
22892289
const char **line;
22902290
static const char *template0_setup[] = {
2291-
"CREATE DATABASE template0;\n",
2292-
"UPDATE pg_database SET "
2293-
" datistemplate = 't', "
2294-
" datallowconn = 'f' "
2295-
" WHERE datname = 'template0';\n",
2291+
"CREATE DATABASE template0 IS_TEMPLATE = true ALLOW_CONNECTIONS = false;\n",
22962292

22972293
/*
22982294
* We use the OID of template0 to determine lastsysoid

‎src/bin/pg_dump/pg_dumpall.c‎

Lines changed: 3 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -1374,19 +1374,15 @@ dumpCreateDB(PGconn *conn)
13741374
appendPQExpBuffer(buf, " TABLESPACE = %s",
13751375
fmtId(dbtablespace));
13761376

1377+
if (strcmp(dbistemplate, "t") == 0)
1378+
appendPQExpBuffer(buf, " IS_TEMPLATE = true");
1379+
13771380
if (strcmp(dbconnlimit, "-1") != 0)
13781381
appendPQExpBuffer(buf, " CONNECTION LIMIT = %s",
13791382
dbconnlimit);
13801383

13811384
appendPQExpBufferStr(buf, ";\n");
13821385

1383-
if (strcmp(dbistemplate, "t") == 0)
1384-
{
1385-
appendPQExpBufferStr(buf, "UPDATE pg_catalog.pg_database SET datistemplate = 't' WHERE datname = ");
1386-
appendStringLiteralConn(buf, dbname, conn);
1387-
appendPQExpBufferStr(buf, ";\n");
1388-
}
1389-
13901386
if (binary_upgrade)
13911387
{
13921388
appendPQExpBufferStr(buf, "-- For binary upgrade, set datfrozenxid.\n");

‎src/bin/psql/tab-complete.c‎

Lines changed: 4 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -1021,7 +1021,8 @@ psql_completion(const char *text, int start, int end)
10211021
pg_strcasecmp(prev2_wd, "DATABASE") == 0)
10221022
{
10231023
static const char *const list_ALTERDATABASE[] =
1024-
{"RESET", "SET", "OWNER TO", "RENAME TO", "CONNECTION LIMIT", NULL};
1024+
{"RESET", "SET", "OWNER TO", "RENAME TO", "IS_TEMPLATE",
1025+
"ALLOW_CONNECTIONS", "CONNECTION LIMIT", NULL};
10251026

10261027
COMPLETE_WITH_LIST(list_ALTERDATABASE);
10271028
}
@@ -2111,8 +2112,8 @@ psql_completion(const char *text, int start, int end)
21112112
pg_strcasecmp(prev2_wd, "DATABASE") == 0)
21122113
{
21132114
static const char *const list_DATABASE[] =
2114-
{"OWNER", "TEMPLATE", "ENCODING", "TABLESPACE", "CONNECTION LIMIT",
2115-
NULL};
2115+
{"OWNER", "TEMPLATE", "ENCODING", "TABLESPACE", "IS_TEMPLATE",
2116+
"ALLOW_CONNECTIONS", "CONNECTION LIMIT", NULL};
21162117

21172118
COMPLETE_WITH_LIST(list_DATABASE);
21182119
}

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