Support the tables with column GENERATED AS IDENTITY (new with PG 10)…

…. In regression tests, add to a tables group a sequence associated to a GENERATED AS IDENTITY column.

CHANGES

@@ -5,6 +5,7 @@ E-Maj - Release notes
 Enhancements:
   - Let E-Maj work with PostgreSQL 10.
   - Support elementary partitions of partitionned tables (PostgreSQL 10+).
+  - Support tables with GENERATED AS IDENTITY columns (PostgreSQL 10+)
   - The emaj_alter_group() function can process any attribute change 
     registered in the emaj_group_def table, among priority level, log schema 
     suffix, emaj names prefix, log data or index tablespace, for relations 

docs/en/mainFunctions.rst

@@ -119,7 +119,7 @@ On the contrary, if specific tablespaces are referenced for any log table or log
 
 The *emaj_create_group()* function also checks the existence of application triggers on any tables of the group. If a trigger exists on a table of the group, a message is returned, suggesting the user to verify that this trigger does not update any tables that would not belong to the group. 
 
-If a sequence of the group is associated to a *SERIAL* or *BIGSERIAL* column and the table that owns this column does not belong to the same tables group, the function also issues a *WARNING* message.
+If a sequence of the group is associated either to a *SERIAL* or *BIGSERIAL* column or to a column created with a *GENERATED AS IDENTITY* clause, and the table that owns this column does not belong to the same tables group, the function also issues a *WARNING* message.
 
 A specific version of the function allows to create an empty tables group, i.e. without any table or sequence at creation time::
 

docs/fr/mainFunctions.rst

@@ -119,7 +119,7 @@ En revanche, si des tablespaces spécifiques pour les tables de log ou pour leur
 
 La fonction *emaj_create_group()* contrôle également l'existence de « triggers applicatifs » impliquant les tables du groupe. Si un trigger existe sur une table du groupe, un message d'avertissement est retourné incitant l'utilisateur à vérifier que ce trigger ne fait pas de mises à jour sur des tables n'appartenant pas au groupe.
 
-Si une séquence du groupe est associée à une colonne de type *SERIAL* ou *BIGSERIAL* et que sa table d'appartenance ne fait pas partie du groupe, la fonction génère également un message de type *WARNING*.
+Si une séquence du groupe est associée à une colonne soit de type *SERIAL* ou *BIGSERIAL* soit définie avec une clause *GENERATED AS IDENTITY*, et que sa table d'appartenance ne fait pas partie du groupe, la fonction génère également un message de type *WARNING*. 
 
 Une forme particulière de la fonction permet de créer un groupe de table vide, c’est à dire ne contenant à sa création aucune table ni séquence ::
 

sql/emaj--2.0.1--next_version.sql

@@ -841,6 +841,72 @@ $_create_seq$
   END;
 $_create_seq$;
 
+CREATE OR REPLACE FUNCTION emaj._rlbk_tbl(r_rel emaj.emaj_relation, v_minGlobalSeq BIGINT, v_maxGlobalSeq BIGINT, v_nbSession INT, v_isLoggedRlbk BOOLEAN)
+RETURNS BIGINT LANGUAGE plpgsql SECURITY DEFINER AS
+$_rlbk_tbl$
+-- This function rollbacks one table to a given point in time represented by the value of the global sequence
+-- The function is called by emaj._rlbk_session_exec()
+-- Input: row from emaj_relation corresponding to the appplication table to proccess
+--        global sequence (non inclusive) lower and (inclusive) upper limits covering the rollback time frame
+-- Output: number of rolled back primary keys
+-- For unlogged rollback, the log triggers have been disabled previously and will be enabled later.
+-- The function is defined as SECURITY DEFINER so that emaj_adm role can use it even if he is not the owner of the application table.
+  DECLARE
+    v_fullTableName          TEXT;
+    v_logTableName           TEXT;
+    v_tmpTable               TEXT;
+    v_tableType              TEXT;
+    v_insertClause           TEXT = '';
+    v_nbPk                   BIGINT;
+  BEGIN
+    v_fullTableName  = quote_ident(r_rel.rel_schema) || '.' || quote_ident(r_rel.rel_tblseq);
+    v_logTableName   = quote_ident(r_rel.rel_log_schema) || '.' || quote_ident(r_rel.rel_log_table);
+-- insert begin event in history
+    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
+      VALUES ('ROLLBACK_TABLE', 'BEGIN', v_fullTableName, 'All log rows with emaj_gid > ' || v_minGlobalSeq || ' and <= ' || v_maxGlobalSeq);
+-- create the temporary table containing all primary key values with their earliest emaj_gid
+    IF v_nbSession = 1 THEN
+      v_tableType = 'TEMP';
+      v_tmpTable = 'emaj_tmp_' || pg_backend_pid();
+    ELSE
+--   with multi session parallel rollbacks, the table cannot be a TEMP table because it would not be usable in 2PC
+--   but it may be an UNLOGGED table
+      v_tableType = 'UNLOGGED';
+      v_tmpTable = 'emaj.emaj_tmp_' || pg_backend_pid();
+    END IF;
+    EXECUTE 'CREATE ' || v_tableType || ' TABLE ' || v_tmpTable || ' AS '
+         || '  SELECT ' || r_rel.rel_sql_pk_columns || ', min(emaj_gid) as emaj_gid'
+         || '    FROM ' || v_logTableName
+         || '    WHERE emaj_gid > ' || v_minGlobalSeq || 'AND emaj_gid <= ' || v_maxGlobalSeq
+         || '    GROUP BY ' || r_rel.rel_sql_pk_columns;
+    GET DIAGNOSTICS v_nbPk = ROW_COUNT;
+-- delete all rows from the application table corresponding to each touched primary key
+--   this deletes rows inserted or updated during the rolled back period
+    EXECUTE 'DELETE FROM ONLY ' || v_fullTableName || ' tbl USING ' || v_tmpTable || ' keys '
+         || '  WHERE ' || r_rel.rel_sql_pk_eq_conditions;
+-- for logged rollbacks, if the number of pkey to process is greater than 1.000, ANALYZE the log table to take into account
+--   the impact of just inserted rows, avoiding a potentialy bad plan for the next INSERT statement
+    IF v_isLoggedRlbk AND v_nbPk > 1000 THEN
+      EXECUTE 'ANALYZE ' || v_logTableName;
+    END IF;
+-- insert into the application table rows that were deleted or updated during the rolled back period
+    IF emaj._pg_version_num() >= 100000 THEN
+      v_insertClause = ' OVERRIDING SYSTEM VALUE';
+    END IF;
+    EXECUTE 'INSERT INTO ' || v_fullTableName || v_insertClause
+         || '  SELECT ' || r_rel.rel_sql_columns
+         || '    FROM ' || v_logTableName || ' tbl, ' || v_tmpTable || ' keys '
+         || '    WHERE ' || r_rel.rel_sql_pk_eq_conditions || ' AND tbl.emaj_gid = keys.emaj_gid AND tbl.emaj_tuple = ''OLD'''
+         || '      AND tbl.emaj_gid > ' || v_minGlobalSeq || 'AND tbl.emaj_gid <= ' || v_maxGlobalSeq;
+-- drop the now useless temporary table
+    EXECUTE 'DROP TABLE ' || v_tmpTable;
+-- insert end event in history
+    INSERT INTO emaj.emaj_hist (hist_function, hist_event, hist_object, hist_wording)
+      VALUES ('ROLLBACK_TABLE', 'END', v_fullTableName, v_nbPk || ' rolled back primary keys');
+    RETURN v_nbPk;
+  END;
+$_rlbk_tbl$;
+
 CREATE OR REPLACE FUNCTION emaj._delete_log_tbl(r_rel emaj.emaj_relation, v_beginTimeId BIGINT, v_endTimeId BIGINT, v_lastGlobalSeq BIGINT)
 RETURNS BIGINT LANGUAGE plpgsql AS
 $_delete_log_tbl$

sql/emaj--next_version.sql

@@ -1422,7 +1422,7 @@ $_create_seq$
     v_tableGroup             TEXT;
   BEGIN
 -- the checks on the sequence properties are performed by the calling functions
--- get the schema and the name of the table that contains a serial column this sequence is linked to, if one exists
+-- get the schema and the name of the table that contains a serial or a "generated as identity" column this sequence is linked to, if one exists
     SELECT nt.nspname, ct.relname INTO v_tableSchema, v_tableName
       FROM pg_catalog.pg_class cs, pg_catalog.pg_namespace ns, pg_depend,
            pg_catalog.pg_class ct, pg_catalog.pg_namespace nt
@@ -1480,6 +1480,7 @@ $_rlbk_tbl$
     v_logTableName           TEXT;
     v_tmpTable               TEXT;
     v_tableType              TEXT;
+    v_insertClause           TEXT = '';
     v_nbPk                   BIGINT;
   BEGIN
     v_fullTableName  = quote_ident(r_rel.rel_schema) || '.' || quote_ident(r_rel.rel_tblseq);
@@ -1513,7 +1514,10 @@ $_rlbk_tbl$
       EXECUTE 'ANALYZE ' || v_logTableName;
     END IF;
 -- insert into the application table rows that were deleted or updated during the rolled back period
-    EXECUTE 'INSERT INTO ' || v_fullTableName
+    IF emaj._pg_version_num() >= 100000 THEN
+      v_insertClause = ' OVERRIDING SYSTEM VALUE';
+    END IF;
+    EXECUTE 'INSERT INTO ' || v_fullTableName || v_insertClause
          || '  SELECT ' || r_rel.rel_sql_columns
          || '    FROM ' || v_logTableName || ' tbl, ' || v_tmpTable || ' keys '
          || '    WHERE ' || r_rel.rel_sql_pk_eq_conditions || ' AND tbl.emaj_gid = keys.emaj_gid AND tbl.emaj_tuple = ''OLD'''