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-rw-r--r--src/backend/commands/dbcommands.c34
-rw-r--r--src/backend/nodes/copyfuncs.c1
-rw-r--r--src/backend/nodes/equalfuncs.c1
-rw-r--r--src/backend/parser/gram.y43
-rw-r--r--src/backend/storage/ipc/procarray.c114
-rw-r--r--src/backend/tcop/utility.c10
-rw-r--r--src/bin/psql/tab-complete.c4
-rw-r--r--src/include/commands/dbcommands.h3
-rw-r--r--src/include/nodes/parsenodes.h1
-rw-r--r--src/include/storage/procarray.h1
-rw-r--r--src/test/regress/expected/drop_if_exists.out10
-rw-r--r--src/test/regress/sql/drop_if_exists.sql7
12 files changed, 219 insertions, 10 deletions
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 6f28859f730..446813f0f0b 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -810,7 +810,7 @@ createdb_failure_callback(int code, Datum arg)
* DROP DATABASE
*/
void
-dropdb(const char *dbname, bool missing_ok)
+dropdb(const char *dbname, bool missing_ok, bool force)
{
Oid db_id;
bool db_istemplate;
@@ -910,6 +910,14 @@ dropdb(const char *dbname, bool missing_ok)
"There are %d subscriptions.",
nsubscriptions, nsubscriptions)));
+
+ /*
+ * Attempt to terminate all existing connections to the target database if
+ * the user has requested to do so.
+ */
+ if (force)
+ TerminateOtherDBBackends(db_id);
+
/*
* Check for other backends in the target database. (Because we hold the
* database lock, no new ones can start after this.)
@@ -1430,6 +1438,30 @@ movedb_failure_callback(int code, Datum arg)
(void) rmtree(dstpath, true);
}
+/*
+ * Process options and call dropdb function.
+ */
+void
+DropDatabase(ParseState *pstate, DropdbStmt *stmt)
+{
+ bool force = false;
+ ListCell *lc;
+
+ foreach(lc, stmt->options)
+ {
+ DefElem *opt = (DefElem *) lfirst(lc);
+
+ if (strcmp(opt->defname, "force") == 0)
+ force = true;
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("unrecognized DROP DATABASE option \"%s\"", opt->defname),
+ parser_errposition(pstate, opt->location)));
+ }
+
+ dropdb(stmt->dbname, stmt->missing_ok, force);
+}
/*
* ALTER DATABASE name ...
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 3432bb921dd..2f267e4bb65 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -3868,6 +3868,7 @@ _copyDropdbStmt(const DropdbStmt *from)
COPY_STRING_FIELD(dbname);
COPY_SCALAR_FIELD(missing_ok);
+ COPY_NODE_FIELD(options);
return newnode;
}
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 18cb0143733..da0e1d139ac 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1676,6 +1676,7 @@ _equalDropdbStmt(const DropdbStmt *a, const DropdbStmt *b)
{
COMPARE_STRING_FIELD(dbname);
COMPARE_SCALAR_FIELD(missing_ok);
+ COMPARE_NODE_FIELD(options);
return true;
}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 3f67aaf30ea..2f7bd662e8a 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -310,6 +310,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <defelt> vac_analyze_option_elem
%type <list> vac_analyze_option_list
%type <node> vac_analyze_option_arg
+%type <defelt> drop_option
%type <boolean> opt_or_replace
opt_grant_grant_option opt_grant_admin_option
opt_nowait opt_if_exists opt_with_data
@@ -406,6 +407,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
TriggerTransitions TriggerReferencing
publication_name_list
vacuum_relation_list opt_vacuum_relation_list
+ drop_option_list
%type <list> group_by_list
%type <node> group_by_item empty_grouping_set rollup_clause cube_clause
@@ -10213,7 +10215,7 @@ AlterDatabaseSetStmt:
/*****************************************************************************
*
- * DROP DATABASE [ IF EXISTS ]
+ * DROP DATABASE [ IF EXISTS ] dbname [ [ WITH ] ( options ) ]
*
* This is implicitly CASCADE, no need for drop behavior
*****************************************************************************/
@@ -10223,6 +10225,7 @@ DropdbStmt: DROP DATABASE database_name
DropdbStmt *n = makeNode(DropdbStmt);
n->dbname = $3;
n->missing_ok = false;
+ n->options = NULL;
$$ = (Node *)n;
}
| DROP DATABASE IF_P EXISTS database_name
@@ -10230,10 +10233,48 @@ DropdbStmt: DROP DATABASE database_name
DropdbStmt *n = makeNode(DropdbStmt);
n->dbname = $5;
n->missing_ok = true;
+ n->options = NULL;
$$ = (Node *)n;
}
+ | DROP DATABASE database_name opt_with '(' drop_option_list ')'
+ {
+ DropdbStmt *n = makeNode(DropdbStmt);
+ n->dbname = $3;
+ n->missing_ok = false;
+ n->options = $6;
+ $$ = (Node *)n;
+ }
+ | DROP DATABASE IF_P EXISTS database_name opt_with '(' drop_option_list ')'
+ {
+ DropdbStmt *n = makeNode(DropdbStmt);
+ n->dbname = $5;
+ n->missing_ok = true;
+ n->options = $8;
+ $$ = (Node *)n;
+ }
+ ;
+
+drop_option_list:
+ drop_option
+ {
+ $$ = list_make1((Node *) $1);
+ }
+ | drop_option_list ',' drop_option
+ {
+ $$ = lappend($1, (Node *) $3);
+ }
;
+/*
+ * Currently only the FORCE option is supported, but the syntax is designed
+ * to be extensible so that we can add more options in the future if required.
+ */
+drop_option:
+ FORCE
+ {
+ $$ = makeDefElem("force", NULL, @1);
+ }
+ ;
/*****************************************************************************
*
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 3da53074b18..13bcbe77de7 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -52,6 +52,8 @@
#include "access/xact.h"
#include "access/xlog.h"
#include "catalog/catalog.h"
+#include "catalog/pg_authid.h"
+#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "storage/proc.h"
@@ -2971,6 +2973,118 @@ CountOtherDBBackends(Oid databaseId, int *nbackends, int *nprepared)
}
/*
+ * Terminate existing connections to the specified database. This routine
+ * is used by the DROP DATABASE command when user has asked to forcefully
+ * drop the database.
+ *
+ * The current backend is always ignored; it is caller's responsibility to
+ * check whether the current backend uses the given DB, if it's important.
+ *
+ * It doesn't allow to terminate the connections even if there is a one
+ * backend with the prepared transaction in the target database.
+ */
+void
+TerminateOtherDBBackends(Oid databaseId)
+{
+ ProcArrayStruct *arrayP = procArray;
+ List *pids = NIL;
+ int nprepared = 0;
+ int i;
+
+ LWLockAcquire(ProcArrayLock, LW_SHARED);
+
+ for (i = 0; i < procArray->numProcs; i++)
+ {
+ int pgprocno = arrayP->pgprocnos[i];
+ PGPROC *proc = &allProcs[pgprocno];
+
+ if (proc->databaseId != databaseId)
+ continue;
+ if (proc == MyProc)
+ continue;
+
+ if (proc->pid != 0)
+ pids = lappend_int(pids, proc->pid);
+ else
+ nprepared++;
+ }
+
+ LWLockRelease(ProcArrayLock);
+
+ if (nprepared > 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_OBJECT_IN_USE),
+ errmsg("database \"%s\" is being used by prepared transaction",
+ get_database_name(databaseId)),
+ errdetail_plural("There is %d prepared transaction using the database.",
+ "There are %d prepared transactions using the database.",
+ nprepared,
+ nprepared)));
+
+ if (pids)
+ {
+ ListCell *lc;
+
+ /*
+ * Check whether we have the necessary rights to terminate other
+ * sessions. We don't terminate any session untill we ensure that we
+ * have rights on all the sessions to be terminated. These checks are
+ * the same as we do in pg_terminate_backend.
+ *
+ * In this case we don't raise some warnings - like "PID %d is not a
+ * PostgreSQL server process", because for us already finished session
+ * is not a problem.
+ */
+ foreach(lc, pids)
+ {
+ int pid = lfirst_int(lc);
+ PGPROC *proc = BackendPidGetProc(pid);
+
+ if (proc != NULL)
+ {
+ /* Only allow superusers to signal superuser-owned backends. */
+ if (superuser_arg(proc->roleId) && !superuser())
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ (errmsg("must be a superuser to terminate superuser process"))));
+
+ /* Users can signal backends they have role membership in. */
+ if (!has_privs_of_role(GetUserId(), proc->roleId) &&
+ !has_privs_of_role(GetUserId(), DEFAULT_ROLE_SIGNAL_BACKENDID))
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ (errmsg("must be a member of the role whose process is being terminated or member of pg_signal_backend"))));
+ }
+ }
+
+ /*
+ * There's a race condition here: once we release the ProcArrayLock,
+ * it's possible for the session to exit before we issue kill. That
+ * race condition possibility seems too unlikely to worry about. See
+ * pg_signal_backend.
+ */
+ foreach(lc, pids)
+ {
+ int pid = lfirst_int(lc);
+ PGPROC *proc = BackendPidGetProc(pid);
+
+ if (proc != NULL)
+ {
+ /*
+ * If we have setsid(), signal the backend's whole process
+ * group
+ */
+#ifdef HAVE_SETSID
+ (void) kill(-pid, SIGTERM);
+#else
+ (void) kill(pid, SIGTERM);
+#endif
+ }
+ }
+ }
+}
+
+/*
* ProcArraySetReplicationSlotXmin
*
* Install limits to future computations of the xmin horizon to prevent vacuum
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 6787d8e66d3..3a03ca7e2f0 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -595,13 +595,9 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
case T_DropdbStmt:
- {
- DropdbStmt *stmt = (DropdbStmt *) parsetree;
-
- /* no event triggers for global objects */
- PreventInTransactionBlock(isTopLevel, "DROP DATABASE");
- dropdb(stmt->dbname, stmt->missing_ok);
- }
+ /* no event triggers for global objects */
+ PreventInTransactionBlock(isTopLevel, "DROP DATABASE");
+ DropDatabase(pstate, (DropdbStmt *) parsetree);
break;
/* Query-level asynchronous notification */
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 2b1e3cda4a4..98c917bf7ae 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -2844,6 +2844,10 @@ psql_completion(const char *text, int start, int end)
COMPLETE_WITH_FUNCTION_ARG(prev2_wd);
else if (Matches("DROP", "FOREIGN"))
COMPLETE_WITH("DATA WRAPPER", "TABLE");
+ else if (Matches("DROP", "DATABASE", MatchAny))
+ COMPLETE_WITH("WITH (");
+ else if (HeadMatches("DROP", "DATABASE") && (ends_with(prev_wd, '(')))
+ COMPLETE_WITH("FORCE");
/* DROP INDEX */
else if (Matches("DROP", "INDEX"))
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index 154c8157ee2..d1e91a24559 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -20,7 +20,8 @@
#include "nodes/parsenodes.h"
extern Oid createdb(ParseState *pstate, const CreatedbStmt *stmt);
-extern void dropdb(const char *dbname, bool missing_ok);
+extern void dropdb(const char *dbname, bool missing_ok, bool force);
+extern void DropDatabase(ParseState *pstate, DropdbStmt *stmt);
extern ObjectAddress RenameDatabase(const char *oldname, const char *newname);
extern Oid AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel);
extern Oid AlterDatabaseSet(AlterDatabaseSetStmt *stmt);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index d93a79a5547..ff626cbe61e 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3145,6 +3145,7 @@ typedef struct DropdbStmt
NodeTag type;
char *dbname; /* database to drop */
bool missing_ok; /* skip error if db is missing? */
+ List *options; /* currently only FORCE is supported */
} DropdbStmt;
/* ----------------------
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index da8b672096f..8f67b860e72 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -113,6 +113,7 @@ extern void CancelDBBackends(Oid databaseid, ProcSignalReason sigmode, bool conf
extern int CountUserBackends(Oid roleid);
extern bool CountOtherDBBackends(Oid databaseId,
int *nbackends, int *nprepared);
+extern void TerminateOtherDBBackends(Oid databaseId);
extern void XidCacheRemoveRunningXids(TransactionId xid,
int nxids, const TransactionId *xids,
diff --git a/src/test/regress/expected/drop_if_exists.out b/src/test/regress/expected/drop_if_exists.out
index 6a174677177..5e44c2c3cea 100644
--- a/src/test/regress/expected/drop_if_exists.out
+++ b/src/test/regress/expected/drop_if_exists.out
@@ -330,3 +330,13 @@ HINT: Specify the argument list to select the routine unambiguously.
-- cleanup
DROP PROCEDURE test_ambiguous_procname(int);
DROP PROCEDURE test_ambiguous_procname(text);
+-- This test checks both the functionality of 'if exists' and the syntax
+-- of the drop database command.
+drop database test_database_exists (force);
+ERROR: database "test_database_exists" does not exist
+drop database test_database_exists with (force);
+ERROR: database "test_database_exists" does not exist
+drop database if exists test_database_exists (force);
+NOTICE: database "test_database_exists" does not exist, skipping
+drop database if exists test_database_exists with (force);
+NOTICE: database "test_database_exists" does not exist, skipping
diff --git a/src/test/regress/sql/drop_if_exists.sql b/src/test/regress/sql/drop_if_exists.sql
index 8a791b1ef2d..ac6168b91f8 100644
--- a/src/test/regress/sql/drop_if_exists.sql
+++ b/src/test/regress/sql/drop_if_exists.sql
@@ -295,3 +295,10 @@ DROP ROUTINE IF EXISTS test_ambiguous_procname;
-- cleanup
DROP PROCEDURE test_ambiguous_procname(int);
DROP PROCEDURE test_ambiguous_procname(text);
+
+-- This test checks both the functionality of 'if exists' and the syntax
+-- of the drop database command.
+drop database test_database_exists (force);
+drop database test_database_exists with (force);
+drop database if exists test_database_exists (force);
+drop database if exists test_database_exists with (force);
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-28 18:32:08 +0000