pg_upgrade: Parallelize retrieving extension updates.

This commit makes use of the new task framework in pg_upgrade to
parallelize retrieving the set of extensions that should be updated
with the ALTER EXTENSION command after upgrade.  This step will now
process multiple databases concurrently when pg_upgrade's --jobs
option is provided a value greater than 1.

Reviewed-by: Daniel Gustafsson, Ilya Gladyshev
Discussion: https://postgr.es/m/20240516211638.GA1688936%40nathanxps13

diff --git a/src/bin/pg_upgrade/version.c b/src/bin/pg_upgrade/version.c
index 2de6dffccdab4d7ab039b7e3da46c3604e4c6615..5084b088057e9346b52dd7d7c664a6c81e2f9a0d 100644 (file)
--- a/src/bin/pg_upgrade/version.c
+++ b/src/bin/pg_upgrade/version.c
@@ -139,6 +139,41 @@ old_9_6_invalidate_hash_indexes(ClusterInfo *cluster, bool check_mode)
        check_ok();
 }
 
+/*
+ * Callback function for processing results of query for
+ * report_extension_updates()'s UpgradeTask.  If the query returned any rows,
+ * write the details to the report file.
+ */
+static void
+process_extension_updates(DbInfo *dbinfo, PGresult *res, void *arg)
+{
+   bool        db_used = false;
+   int         ntups = PQntuples(res);
+   int         i_name = PQfnumber(res, "name");
+   UpgradeTaskReport *report = (UpgradeTaskReport *) arg;
+
+   AssertVariableIsOfType(&process_extension_updates, UpgradeTaskProcessCB);
+
+   for (int rowno = 0; rowno < ntups; rowno++)
+   {
+       if (report->file == NULL &&
+           (report->file = fopen_priv(report->path, "w")) == NULL)
+           pg_fatal("could not open file \"%s\": %m", report->path);
+       if (!db_used)
+       {
+           PQExpBufferData connectbuf;
+
+           initPQExpBuffer(&connectbuf);
+           appendPsqlMetaConnect(&connectbuf, dbinfo->db_name);
+           fputs(connectbuf.data, report->file);
+           termPQExpBuffer(&connectbuf);
+           db_used = true;
+       }
+       fprintf(report->file, "ALTER EXTENSION %s UPDATE;\n",
+               quote_identifier(PQgetvalue(res, rowno, i_name)));
+   }
+}
+
 /*
  * report_extension_updates()
  * Report extensions that should be updated.
@@ -146,57 +181,26 @@ old_9_6_invalidate_hash_indexes(ClusterInfo *cluster, bool check_mode)
 void
 report_extension_updates(ClusterInfo *cluster)
 {
-   int         dbnum;
-   FILE       *script = NULL;
-   char       *output_path = "update_extensions.sql";
+   UpgradeTaskReport report;
+   UpgradeTask *task = upgrade_task_create();
+   const char *query = "SELECT name "
+       "FROM pg_available_extensions "
+       "WHERE installed_version != default_version";
 
    prep_status("Checking for extension updates");
 
-   for (dbnum = 0; dbnum < cluster->dbarr.ndbs; dbnum++)
-   {
-       PGresult   *res;
-       bool        db_used = false;
-       int         ntups;
-       int         rowno;
-       int         i_name;
-       DbInfo     *active_db = &cluster->dbarr.dbs[dbnum];
-       PGconn     *conn = connectToServer(cluster, active_db->db_name);
-
-       /* find extensions needing updates */
-       res = executeQueryOrDie(conn,
-                               "SELECT name "
-                               "FROM pg_available_extensions "
-                               "WHERE installed_version != default_version"
-           );
+   report.file = NULL;
+   strcpy(report.path, "update_extensions.sql");
 
-       ntups = PQntuples(res);
-       i_name = PQfnumber(res, "name");
-       for (rowno = 0; rowno < ntups; rowno++)
-       {
-           if (script == NULL && (script = fopen_priv(output_path, "w")) == NULL)
-               pg_fatal("could not open file \"%s\": %m", output_path);
-           if (!db_used)
-           {
-               PQExpBufferData connectbuf;
+   upgrade_task_add_step(task, query, process_extension_updates,
+                         true, &report);
 
-               initPQExpBuffer(&connectbuf);
-               appendPsqlMetaConnect(&connectbuf, active_db->db_name);
-               fputs(connectbuf.data, script);
-               termPQExpBuffer(&connectbuf);
-               db_used = true;
-           }
-           fprintf(script, "ALTER EXTENSION %s UPDATE;\n",
-                   quote_identifier(PQgetvalue(res, rowno, i_name)));
-       }
+   upgrade_task_run(task, cluster);
+   upgrade_task_free(task);
 
-       PQclear(res);
-
-       PQfinish(conn);
-   }
-
-   if (script)
+   if (report.file)
    {
-       fclose(script);
+       fclose(report.file);
        report_status(PG_REPORT, "notice");
        pg_log(PG_REPORT, "\n"
               "Your installation contains extensions that should be updated\n"
@@ -204,7 +208,7 @@ report_extension_updates(ClusterInfo *cluster)
               "    %s\n"
               "when executed by psql by the database superuser will update\n"
               "these extensions.",
-              output_path);
+              report.path);
    }
    else
        check_ok();