Create a _sum_log_stat_group() function to directly compute the sum o…

…f log rows. This avoids calls to the emaj_log_stat_group() function by the _set_mark_groups(), _delete_intermediate_mark_group() and emaj_get_consolidable_rollbacks() functions. Adjust the 3 functions accordingly. Also improve the coding of the emaj_log_stat_group() function.

sql/emaj--2.1.0--next_version.sql

@@ -951,8 +951,8 @@ $_delete_log_tbl$
     EXECUTE 'DELETE FROM ' || quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_table) || ' WHERE emaj_gid > ' || v_lastGlobalSeq;
     GET DIAGNOSTICS v_nbRows = ROW_COUNT;
 -- record the sequence holes generated by the delete operation
--- this is due to the fact that log sequences are not rolled back, this information will be used by the emaj_log_stat_group
---   function (and indirectly by emaj_estimate_rollback_group() and emaj_estimate_rollback_groups())
+-- this is due to the fact that log sequences are not rolled back, this information will be used by the emaj_log_stat_group() function
+--   (and indirectly by emaj_estimate_rollback_group() and emaj_estimate_rollback_groups())
 -- first delete, if exist, sequence holes that have disappeared with the rollback
     DELETE FROM emaj.emaj_seq_hole
       WHERE sqhl_schema = r_rel.rel_schema AND sqhl_table = r_rel.rel_tblseq
@@ -2287,9 +2287,9 @@ $_set_mark_groups$
       v_nbTb = v_nbTb + 1;
     END LOOP;
 -- record the number of log rows for the old last mark of each group
---   the statement returns no row in case of emaj_start_group(s)
+--   the statement updates no row in case of emaj_start_group(s)
     UPDATE emaj.emaj_mark m SET mark_log_rows_before_next =
-      coalesce( (SELECT sum(stat_rows) FROM emaj.emaj_log_stat_group(m.mark_group,'EMAJ_LAST_MARK',NULL)) ,0)
+      coalesce(emaj._sum_log_stat_group(m.mark_group,emaj._get_mark_time_id(m.mark_group,'EMAJ_LAST_MARK'),NULL),0)
       WHERE mark_group = ANY (v_groupNames)
         AND (mark_group, mark_id) IN                   -- select only the last non deleted mark of each concerned group
             (SELECT mark_group, MAX(mark_id) FROM emaj.emaj_mark
@@ -2546,6 +2546,8 @@ $_delete_intermediate_mark_group$
   DECLARE
     v_previousMark           TEXT;
     v_nextMark               TEXT;
+    v_previousMarkTimeId     BIGINT;
+    v_nextMarkTimeId         BIGINT;
   BEGIN
 -- delete the sequences related to the mark to delete
 --   delete first data related to the application sequences currently belonging to the group
@@ -2564,19 +2566,18 @@ $_delete_intermediate_mark_group$
     DELETE FROM emaj.emaj_mark WHERE mark_group = v_groupName AND mark_name = v_markName;
 -- adjust the mark_log_rows_before_next column of the previous mark
 -- get the name of the mark immediately preceeding the mark to delete
-    SELECT mark_name INTO v_previousMark FROM emaj.emaj_mark
+    SELECT mark_name, mark_time_id INTO v_previousMark, v_previousMarkTimeId FROM emaj.emaj_mark
       WHERE mark_group = v_groupName AND mark_id < v_markId ORDER BY mark_id DESC LIMIT 1;
 -- get the name of the first mark succeeding the mark to delete
-    SELECT mark_name INTO v_nextMark FROM emaj.emaj_mark
+    SELECT mark_name, mark_time_id INTO v_nextMark, v_nextMarkTimeId FROM emaj.emaj_mark
       WHERE mark_group = v_groupName AND mark_id > v_markId ORDER BY mark_id LIMIT 1;
     IF NOT FOUND THEN
 -- no next mark, so update the previous mark with NULL
       UPDATE emaj.emaj_mark SET mark_log_rows_before_next = NULL
         WHERE mark_group = v_groupName AND mark_name = v_previousMark;
     ELSE
--- update the previous mark with the emaj_log_stat_group() call's result
-      UPDATE emaj.emaj_mark SET mark_log_rows_before_next =
-          (SELECT sum(stat_rows) FROM emaj.emaj_log_stat_group(v_groupName, v_previousMark, v_nextMark))
+-- update the previous mark with the _sum_log_stat_group() call's result
+      UPDATE emaj.emaj_mark SET mark_log_rows_before_next = emaj._sum_log_stat_group(v_groupName, v_previousMarkTimeId, v_nextMarkTimeId)
         WHERE mark_group = v_groupName AND mark_name = v_previousMark;
     END IF;
 -- reset the mark_logged_rlbk_target_mark column to null for other marks of the group
@@ -3653,6 +3654,31 @@ $_delete_between_marks_group$
   END;
 $_delete_between_marks_group$;
 
+CREATE OR REPLACE FUNCTION emaj.emaj_get_consolidable_rollbacks()
+RETURNS SETOF emaj.emaj_consolidable_rollback_type LANGUAGE plpgsql AS
+$emaj_get_consolidable_rollbacks$
+-- This function returns the list of logged rollback operations that can be consolidated, defined as a marks range for a group.
+-- It doesn't need input parameter.
+-- It returns a set of emaj_consolidable_rollback_type records, sorted by ascending rollback time.
+-- The cons_group and cons_end_rlbk_mark_name returned columns can be used as input parameters for the emaj_consolidate_rollback_group() function.
+  BEGIN
+-- search and return all marks range corresponding to any logged rollback operation
+    RETURN QUERY
+      SELECT m1.mark_group AS cons_group,
+             m2.mark_name AS cons_target_rlbk_mark_name, m2.mark_id AS cons_target_rlbk_mark_id,
+             m1.mark_name AS cons_end_rlbk_mark_name, m1.mark_id AS cons_end_rlbk_mark_id,
+             cast(coalesce(emaj._sum_log_stat_group(m1.mark_group, m2.mark_time_id, m1.mark_time_id),0) AS BIGINT) AS cons_rows,
+             cast((SELECT count(*) FROM emaj.emaj_mark m3
+                   WHERE m3.mark_group = m1.mark_group AND m3.mark_id > m2.mark_id AND m3.mark_id < m1.mark_id) AS INT) AS cons_marks
+        FROM emaj.emaj_mark m1
+          JOIN emaj.emaj_mark m2 ON (m2.mark_name = m1.mark_logged_rlbk_target_mark AND m2.mark_group = m1.mark_group)
+          WHERE m1.mark_logged_rlbk_target_mark IS NOT NULL
+          ORDER BY m1.mark_id;
+  END;
+$emaj_get_consolidable_rollbacks$;
+COMMENT ON FUNCTION emaj.emaj_get_consolidable_rollbacks() IS
+$$Returns the list of logged rollback operations that can be consolidated.$$;
+
 CREATE OR REPLACE FUNCTION emaj._reset_groups(v_groupNames TEXT[])
 RETURNS INT LANGUAGE plpgsql SECURITY DEFINER AS
 $_reset_groups$
@@ -3716,19 +3742,16 @@ RETURNS SETOF emaj.emaj_log_stat_type LANGUAGE plpgsql AS
 $emaj_log_stat_group$
 -- This function returns statistics on row updates executed between 2 marks or between a mark and the current situation.
 -- It is used to quickly get simple statistics of updates logged between 2 marks (i.e. for one or several processing)
--- It is also used to estimate the cost of a rollback to a specified mark
 -- These statistics are computed using the serial id of log tables and holes is sequences recorded into emaj_seq_hole at rollback time
 -- Input: group name, the 2 mark names defining a range
 --   a NULL value or an empty string as first_mark indicates the first recorded mark
 --   a NULL value or an empty string as last_mark indicates the current situation
 --   Use a NULL or an empty string as last_mark to know the number of rows to rollback to reach the mark specified by the first_mark parameter.
 --   The keyword 'EMAJ_LAST_MARK' can be used as first or last mark to specify the last set mark.
--- Output: table of log rows by table (including tables with 0 rows to rollback)
+-- Output: set of log rows by table (including tables with 0 rows to rollback)
   DECLARE
     v_realFirstMark          TEXT;
     v_realLastMark           TEXT;
-    v_firstMarkId            BIGINT;
-    v_lastMarkId             BIGINT;
     v_firstMarkTimeId        BIGINT;
     v_lastMarkTimeId         BIGINT;
     v_firstMarkTs            TIMESTAMPTZ;
@@ -3743,30 +3766,30 @@ $emaj_log_stat_group$
     IF v_firstMark IS NULL OR v_firstMark = '' THEN
 --   if no mark exists for the group (just after emaj_create_group() or emaj_reset_group() functions call),
 --     v_realFirstMark remains NULL
-      SELECT mark_name, mark_id, mark_time_id, time_clock_timestamp INTO v_realFirstMark, v_firstMarkId, v_firstMarkTimeId, v_firstMarkTs
+      SELECT mark_name, mark_time_id, time_clock_timestamp INTO v_realFirstMark, v_firstMarkTimeId, v_firstMarkTs
         FROM emaj.emaj_mark, emaj.emaj_time_stamp
         WHERE time_id = mark_time_id AND mark_group = v_groupName
         ORDER BY mark_id LIMIT 1;
     ELSE
--- else, check and retrieve the name, timestamp and last sequ_hole id of the supplied first mark for the group
+-- else, check and retrieve the name and the timestamp id of the supplied first mark for the group
       SELECT emaj._get_mark_name(v_groupName,v_firstMark) INTO v_realFirstMark;
       IF v_realFirstMark IS NULL THEN
         RAISE EXCEPTION 'emaj_log_stat_group: The start mark "%" is unknown for the group "%".', v_firstMark, v_groupName;
       END IF;
-      SELECT mark_id, mark_time_id, time_clock_timestamp INTO v_firstMarkId, v_firstMarkTimeId, v_firstMarkTs
+      SELECT mark_time_id, time_clock_timestamp INTO v_firstMarkTimeId, v_firstMarkTs
         FROM emaj.emaj_mark, emaj.emaj_time_stamp
         WHERE time_id = mark_time_id AND mark_group = v_groupName AND mark_name = v_realFirstMark;
     END IF;
--- if a last mark name is supplied, check and retrieve the name, timestamp and last sequ_hole id of the supplied end mark for the group
+-- if a last mark name is supplied, check and retrieve the name, and the timestamp id of the supplied end mark for the group
     IF v_lastMark IS NOT NULL AND v_lastMark <> '' THEN
       SELECT emaj._get_mark_name(v_groupName,v_lastMark) INTO v_realLastMark;
       IF v_realLastMark IS NULL THEN
         RAISE EXCEPTION 'emaj_log_stat_group: The end mark "%" is unknown for the group "%".', v_lastMark, v_groupName;
       END IF;
-      SELECT mark_id, mark_time_id, time_clock_timestamp INTO v_lastMarkId, v_lastMarkTimeId, v_lastMarkTs
+      SELECT mark_time_id, time_clock_timestamp INTO v_lastMarkTimeId, v_lastMarkTs
         FROM emaj.emaj_mark, emaj.emaj_time_stamp
         WHERE time_id = mark_time_id AND mark_group = v_groupName AND mark_name = v_realLastMark;
--- if last mark is null or empty, v_realLastMark, v_lastMarkTimeId, v_lastMarkTs and v_lastLastSeqHoleId remain NULL
+-- if last mark is null or empty, v_realLastMark, v_lastMarkTimeId and v_lastMarkTs remain NULL
     END IF;
 -- check that the first_mark < end_mark
     IF v_lastMarkTimeId IS NOT NULL AND v_firstMarkTimeId > v_lastMarkTimeId THEN
@@ -3781,11 +3804,34 @@ $emaj_log_stat_group$
         FROM emaj.emaj_relation
         WHERE rel_group = v_groupName AND rel_kind = 'r' AND upper_inf(rel_time_range)
         ORDER BY rel_priority, rel_schema, rel_tblseq;
-  END;
+ END;
 $emaj_log_stat_group$;
 COMMENT ON FUNCTION emaj.emaj_log_stat_group(TEXT,TEXT,TEXT) IS
 $$Returns global statistics about logged events for an E-Maj group between 2 marks.$$;
 
+CREATE OR REPLACE FUNCTION emaj._sum_log_stat_group(v_groupName TEXT, v_firstMarkTimeId BIGINT, v_lastMarkTimeId BIGINT)
+RETURNS BIGINT LANGUAGE plpgsql AS
+$_sum_log_stat_group$
+-- This function the sum of row updates executed between 2 marks or between a mark and the current situation for a tables group.
+-- It is used by several functions to set the mark_log_rows_before_next column of the emaj_mark table.
+-- The sum is computed for each table of the group by calling the _log_stat_tbl() function.
+-- Input: group name, the time id of both marks defining a time range
+--   a NULL value as last_mark_time_id indicates the current situation
+--   Checks on input values are performed in calling functions.
+-- Output: sum of log rows for the group between both marks
+  BEGIN
+-- Directly return 0 if the firstMarkTimeId is set to NULL (ie no mark exists for the group - just after emaj_create_group() or emaj_reset_group() functions call)
+    IF v_firstMarkTimeId IS NULL THEN
+      RETURN 0;
+    END IF;
+-- for each table currently belonging to the group, add the number of log rows and return the sum
+--TODO ok ?
+    RETURN sum(emaj._log_stat_tbl(emaj_relation, v_firstMarkTimeId, v_lastMarkTimeId))
+      FROM emaj.emaj_relation
+      WHERE rel_group = v_groupName AND rel_kind = 'r' AND upper_inf(rel_time_range);
+  END;
+$_sum_log_stat_group$;
+
 CREATE OR REPLACE FUNCTION emaj.emaj_detailed_log_stat_group(v_groupName TEXT, v_firstMark TEXT, v_lastMark TEXT)
 RETURNS SETOF emaj.emaj_detailed_log_stat_type LANGUAGE plpgsql AS
 $emaj_detailed_log_stat_group$
@@ -4766,6 +4812,7 @@ REVOKE SELECT ON TABLE emaj.emaj_param FROM emaj_viewer;
 GRANT EXECUTE ON FUNCTION emaj._get_mark_name(v_groupName TEXT, v_mark TEXT) TO emaj_viewer;
 GRANT EXECUTE ON FUNCTION emaj._get_mark_time_id(v_groupName TEXT, v_mark TEXT) TO emaj_viewer;
 GRANT EXECUTE ON FUNCTION emaj._log_stat_tbl(r_rel emaj.emaj_relation, v_firstMarkTimeId BIGINT, v_lastMarkTimeId BIGINT) TO emaj_viewer;
+GRANT EXECUTE ON FUNCTION emaj._sum_log_stat_group(v_groupName TEXT, v_firstMarkTimeId BIGINT, v_lastMarkTimeId BIGINT) TO emaj_viewer;
 
 ------------------------------------
 --                                --