perf scripts python: export-to-postgresql.py: Fix DROP VIEW power_events_view

PostgreSQL can error if power_events_view is not dropped before its
dependent tables e.g.

  Exception: Query failed: ERROR:  cannot drop table mwait because other
  objects depend on it
  DETAIL:  view power_events_view depends on table mwait

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Fixes: aba44287a224 ("perf scripts python: export-to-postgresql.py: Export Intel PT power and ptwrite events")
Link: http://lkml.kernel.org/r/20190708055232.5032-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/scripts/python/export-to-postgresql.py b/tools/perf/scripts/python/export-to-postgresql.py
index 4447f0d..92713d9 100644 (file)
--- a/tools/perf/scripts/python/export-to-postgresql.py
+++ b/tools/perf/scripts/python/export-to-postgresql.py
@@ -898,11 +898,11 @@ def trace_end():
        if is_table_empty("ptwrite"):
                drop("ptwrite")
        if is_table_empty("mwait") and is_table_empty("pwre") and is_table_empty("exstop") and is_table_empty("pwrx"):
+               do_query(query, 'DROP VIEW power_events_view');
                drop("mwait")
                drop("pwre")
                drop("exstop")
                drop("pwrx")
-               do_query(query, 'DROP VIEW power_events_view');
                if is_table_empty("cbr"):
                        drop("cbr")