Add a pg_dump option --lock-wait-timeout to allow failing the dump if unable

to acquire shared table locks within a specified amount of time.

David Gould

diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index e7889f04625eac63234fe0ae071040e90277728c..c8aae47b6f043dd495f65112030a2300d1bab518 100644 (file)
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -1,5 +1,5 @@
 
 
@@ -415,23 +415,6 @@ PostgreSQL documentation
       
      
 
-     
-      --no-tablespaces
-      
-       
-        Do not output commands to select tablespaces.
-        With this option, all objects will be created in whichever
-        tablespace is the default during restore.
-       
-
-       
-        This option is only meaningful for the plain-text format.  For
-        the archive formats, you can specify the option when you
-        call pg_restore.
-       
-      
-     
-
      
       -s
       --schema-only
@@ -550,6 +533,18 @@ PostgreSQL documentation
       
      
 
+     
+      -Z 0..9
+      --compress=0..9
+      
+       
+        Specify the compression level to use in archive formats that
+        support compression.  (Currently only the custom archive
+        format supports compression.)
+       
+      
+     
+
      
       --disable-dollar-quoting
       
@@ -557,8 +552,8 @@ PostgreSQL documentation
         This option disables the use of dollar quoting for function bodies,
         and forces them to be quoted using SQL standard string syntax.
        
-     
-    
+      
+     
 
      
       --disable-triggers
@@ -587,6 +582,39 @@ PostgreSQL documentation
       
      
 
+     
+      --lock-wait-timeout=timeout
+      
+       
+        Do not wait forever to acquire shared table locks at the beginning of
+        the dump. Instead fail if unable to lock a table within the specified
+        timeout. The timeout may be
+        specified in any of the formats accepted by SET
+        statement_timeout.  (Allowed values vary depending on the server
+        version you are dumping from, but an integer number of milliseconds
+        is accepted by all versions since 7.3.  This option is ignored when
+        dumping from a pre-7.3 server.)
+       
+      
+     
+
+     
+      --no-tablespaces
+      
+       
+        Do not output commands to select tablespaces.
+        With this option, all objects will be created in whichever
+        tablespace is the default during restore.
+       
+
+       
+        This option is only meaningful for the plain-text format.  For
+        the archive formats, you can specify the option when you
+        call pg_restore.
+       
+      
+     
+
      
       --use-set-session-authorization
       
@@ -601,18 +629,6 @@ PostgreSQL documentation
        
       
      
-
-     
-      -Z 0..9
-      --compress=0..9
-      
-       
-        Specify the compression level to use in archive formats that
-        support compression.  (Currently only the custom archive
-        format supports compression.)
-       
-      
-     
     
    
 
@@ -663,7 +679,7 @@ PostgreSQL documentation
       
        
         Force pg_dump to prompt for a
-        password before connecting to a database.  
+        password before connecting to a database.
        
 
        

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 1f09df210996681610ef2c43899a7a32875bfad2..c4a01c55af914cf040d4b324d3f5d62297fef568 100644 (file)
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -12,7 +12,7 @@
  * by PostgreSQL
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.496 2008/07/18 03:32:52 tgl Exp $
+ *   $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.497 2008/07/20 18:43:30 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -71,6 +71,7 @@ bool      attrNames;          /* put attr names into insert strings */
 bool       schemaOnly;
 bool       dataOnly;
 bool       aclsSkip;
+const char *lockWaitTimeout;
 
 /* subquery used to convert user ID (eg, datdba) to user name */
 static const char *username_subquery;
@@ -264,6 +265,7 @@ main(int argc, char **argv)
         */
        {"disable-dollar-quoting", no_argument, &disable_dollar_quoting, 1},
        {"disable-triggers", no_argument, &disable_triggers, 1},
+       {"lock-wait-timeout", required_argument, NULL, 2},
        {"no-tablespaces", no_argument, &outputNoTablespaces, 1},
        {"use-set-session-authorization", no_argument, &use_setsessauth, 1},
 
@@ -279,6 +281,7 @@ main(int argc, char **argv)
    strcpy(g_opaque_type, "opaque");
 
    dataOnly = schemaOnly = dumpInserts = attrNames = false;
+   lockWaitTimeout = NULL;
 
    progname = get_progname(argv[0]);
 
@@ -437,6 +440,11 @@ main(int argc, char **argv)
                /* This covers the long options equivalent to -X xxx. */
                break;
 
+           case 2:
+               /* lock-wait-timeout */
+               lockWaitTimeout = optarg;
+               break;
+
            default:
                fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
                exit(1);
@@ -754,12 +762,13 @@ help(const char *progname)
    printf(_("  %s [OPTION]... [DBNAME]\n"), progname);
 
    printf(_("\nGeneral options:\n"));
-   printf(_("  -f, --file=FILENAME      output file name\n"));
-   printf(_("  -F, --format=c|t|p       output file format (custom, tar, plain text)\n"));
-   printf(_("  -v, --verbose            verbose mode\n"));
-   printf(_("  -Z, --compress=0-9       compression level for compressed formats\n"));
-   printf(_("  --help                   show this help, then exit\n"));
-   printf(_("  --version                output version information, then exit\n"));
+   printf(_("  -f, --file=FILENAME         output file name\n"));
+   printf(_("  -F, --format=c|t|p          output file format (custom, tar, plain text)\n"));
+   printf(_("  -v, --verbose               verbose mode\n"));
+   printf(_("  -Z, --compress=0-9          compression level for compressed formats\n"));
+   printf(_("  --lock-wait-timeout=TIMEOUT fail after waiting TIMEOUT for a table lock\n"));
+   printf(_("  --help                      show this help, then exit\n"));
+   printf(_("  --version                   output version information, then exit\n"));
 
    printf(_("\nOptions controlling the output content:\n"));
    printf(_("  -a, --data-only             dump only the data, not the schema\n"));
@@ -2957,8 +2966,6 @@ getTables(int *numTables)
    int         ntups;
    int         i;
    PQExpBuffer query = createPQExpBuffer();
-   PQExpBuffer delqry = createPQExpBuffer();
-   PQExpBuffer lockquery = createPQExpBuffer();
    TableInfo  *tblinfo;
    int         i_reltableoid;
    int         i_reloid;
@@ -3192,6 +3199,21 @@ getTables(int *numTables)
    i_reltablespace = PQfnumber(res, "reltablespace");
    i_reloptions = PQfnumber(res, "reloptions");
 
+   if (lockWaitTimeout && g_fout->remoteVersion >= 70300)
+   {
+       /*
+        * Arrange to fail instead of waiting forever for a table lock.
+        *
+        * NB: this coding assumes that the only queries issued within
+        * the following loop are LOCK TABLEs; else the timeout may be
+        * undesirably applied to other things too.
+        */
+       resetPQExpBuffer(query);
+       appendPQExpBuffer(query, "SET statement_timeout = ");
+       appendStringLiteralConn(query, lockWaitTimeout, g_conn);
+       do_sql_command(g_conn, query->data);
+   }
+
    for (i = 0; i < ntups; i++)
    {
        tblinfo[i].dobj.objType = DO_TABLE;
@@ -3246,12 +3268,12 @@ getTables(int *numTables)
         */
        if (tblinfo[i].dobj.dump && tblinfo[i].relkind == RELKIND_RELATION)
        {
-           resetPQExpBuffer(lockquery);
-           appendPQExpBuffer(lockquery,
+           resetPQExpBuffer(query);
+           appendPQExpBuffer(query,
                              "LOCK TABLE %s IN ACCESS SHARE MODE",
                         fmtQualifiedId(tblinfo[i].dobj.namespace->dobj.name,
                                        tblinfo[i].dobj.name));
-           do_sql_command(g_conn, lockquery->data);
+           do_sql_command(g_conn, query->data);
        }
 
        /* Emit notice if join for owner failed */
@@ -3260,6 +3282,11 @@ getTables(int *numTables)
                      tblinfo[i].dobj.name);
    }
 
+   if (lockWaitTimeout && g_fout->remoteVersion >= 70300)
+   {
+       do_sql_command(g_conn, "SET statement_timeout = 0");
+   }
+
    PQclear(res);
 
    /*
@@ -3292,8 +3319,6 @@ getTables(int *numTables)
    }
 
    destroyPQExpBuffer(query);
-   destroyPQExpBuffer(delqry);
-   destroyPQExpBuffer(lockquery);
 
    return tblinfo;
 }