SQL: forced, hidden versioning [closes #32]

include/mysql_com.h

@@ -185,10 +185,10 @@ enum enum_indicator_type
 #define FIELD_IS_DROPPED (1U << 26)     /* Intern: Field is being dropped */
 
 #define VERS_SYS_START_FLAG (1 << 27)   /* autogenerated column declared with
-                                             `generated always at row start`
+                                             `generated always as row start`
                                               (see II.a SQL Standard) */
 #define VERS_SYS_END_FLAG (1 << 28)     /* autogenerated column declared with
-                                           `generated always at row end`
+                                           `generated always as row end`
                                             (see II.a SQL Standard).*/
 #define VERS_OPTIMIZED_UPDATE_FLAG (1 << 29) /* column that doesn't support
                                                 system versioning when table

plugin/versioning/CMakeLists.txt

+# Copyright (c) 2016, MariaDB corporation. All rights reserved.
+# 
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+
+MYSQL_ADD_PLUGIN(versioning versioning.cc
+  MODULE_ONLY MODULE_OUTPUT_NAME "versioning" COMPONENT Test)

plugin/versioning/versioning.cc

+/* Copyright (c) 2016, MariaDB corporation. All rights
+   reserved.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */
+
+#include <mysql_version.h>
+#include <mysqld.h>
+#include "sql_plugin.h"                         // st_plugin_int
+
+/*
+  Disable __attribute__() on non-gcc compilers.
+*/
+#if !defined(__attribute__) && !defined(__GNUC__)
+#define __attribute__(A)
+#endif
+
+static int forced_versioning_init(void *p __attribute__ ((unused)))
+{
+
+  DBUG_ENTER("forced_versioning_init");
+  vers_force= true;
+  vers_hide= true;
+  DBUG_RETURN(0);
+}
+
+static int forced_versioning_deinit(void *p __attribute__ ((unused)))
+{
+  DBUG_ENTER("forced_versioning_deinit");
+  vers_force= false;
+  vers_hide= false;
+  DBUG_RETURN(0);
+}
+
+
+struct st_mysql_daemon forced_versioning_plugin=
+{ MYSQL_DAEMON_INTERFACE_VERSION  };
+
+/*
+  Plugin library descriptor
+*/
+
+maria_declare_plugin(forced_versioning)
+{
+  MYSQL_DAEMON_PLUGIN,
+  &forced_versioning_plugin,
+  "forced_versioning",
+  "Natsys Lab",
+  "Enable System Vesioning for all newly created tables",
+  PLUGIN_LICENSE_GPL,
+  forced_versioning_init, /* Plugin Init */
+  forced_versioning_deinit, /* Plugin Deinit */
+  0x0100 /* 1.0 */,
+  NULL,                       /* status variables                */
+  NULL,                       /* system variables                */
+  "1.0",                      /* string version */
+  MariaDB_PLUGIN_MATURITY_EXPERIMENTAL /* maturity */
+}
+maria_declare_plugin_end;

sql/handler.cc

@@ -6669,9 +6669,17 @@ bool Vers_parse_info::fix_implicit(THD *thd, Alter_info *alter_info,
 bool Vers_parse_info::check_and_fix_implicit(
   THD *thd,
   Alter_info *alter_info,
-  bool integer_fields,
+  HA_CREATE_INFO *create_info,
   const char* table_name)
 {
+  bool integer_fields=
+      create_info->db_type->flags & HTON_SUPPORTS_SYS_VERSIONING;
+
+  if (vers_force) {
+    declared_with_system_versioning= true;
+    create_info->options|= HA_VERSIONED_TABLE;
+  }
+
   if (!need_to_check())
     return false;
 

sql/handler.h

@@ -1720,7 +1720,8 @@ struct Vers_parse_info
 
 public:
   bool check_and_fix_implicit(THD *thd, Alter_info *alter_info,
-                              bool integer_fields, const char *table_name);
+                              HA_CREATE_INFO *create_info,
+                              const char *table_name);
   bool check_and_fix_alter(THD *thd, Alter_info *alter_info,
                            HA_CREATE_INFO *create_info, TABLE_SHARE *share);
   bool fix_create_like(THD *thd, Alter_info *alter_info,

sql/mysqld.cc

@@ -783,6 +783,8 @@ char *opt_logname, *opt_slow_logname, *opt_bin_logname;
 
 /* System Versioning */
 char *temporal_current_timestamp;
+my_bool vers_force= false;
+my_bool vers_hide= false;
 
 /* Static variables */
 

sql/mysqld.h

@@ -176,6 +176,8 @@ extern char *opt_backup_history_logname, *opt_backup_progress_logname,
 extern const char *log_output_str;
 extern const char *log_backup_output_str;
 extern char *temporal_current_timestamp;
+extern my_bool vers_force;
+extern my_bool vers_hide;
 extern char *mysql_home_ptr, *pidfile_name_ptr;
 extern MYSQL_PLUGIN_IMPORT char glob_hostname[FN_REFLEN];
 extern char mysql_home[FN_REFLEN];

sql/sql_parse.cc

@@ -3876,12 +3876,9 @@ mysql_execute_command(THD *thd)
     if (!(create_info.used_fields & HA_CREATE_USED_ENGINE))
       create_info.use_default_db_type(thd);
 
-    DBUG_ASSERT(create_info.db_type);
     if (!create_info.like() &&
         create_info.vers_info.check_and_fix_implicit(
-            thd, &alter_info,
-            create_info.db_type->flags & HTON_SUPPORTS_SYS_VERSIONING,
-            create_table->table_name))
+            thd, &alter_info, &create_info, create_table->table_name))
     {
       goto end_with_restore_list;
     }

sql/sql_show.cc

@@ -2064,6 +2064,10 @@ int show_create_table(THD *thd, TABLE_LIST *table_list, String *packet,
   {
     uint flags = field->flags;
 
+    if (vers_hide &&
+        (flags & (VERS_SYS_START_FLAG | VERS_SYS_END_FLAG)))
+      continue;
+
     if (ptr != table->field)
       packet->append(STRING_WITH_LEN(",\n"));
 
@@ -2229,7 +2233,7 @@ int show_create_table(THD *thd, TABLE_LIST *table_list, String *packet,
                           hton->index_options);
   }
 
-  if (table->versioned())
+  if (table->versioned() && !vers_hide)
   {
     const Field *fs = table->vers_start_field();
     const Field *fe = table->vers_end_field();
@@ -2278,7 +2282,7 @@ int show_create_table(THD *thd, TABLE_LIST *table_list, String *packet,
     add_table_options(thd, table, create_info_arg,
                       table_list->schema_table != 0, 0, packet);
 
-  if (table->versioned())
+  if (table->versioned() && !vers_hide)
   {
     packet->append(STRING_WITH_LEN(" WITH SYSTEM VERSIONING"));
   }

sql/sys_vars.cc

@@ -387,6 +387,14 @@ static Sys_var_charptr sys_temporal_current_timestamp(
        GLOBAL_VAR(temporal_current_timestamp), CMD_LINE(REQUIRED_ARG, 'b'),
        IN_FS_CHARSET, DEFAULT("now"));
 
+static Sys_var_mybool Sys_vers_force(
+       "vers_force", "Force system versioning for all created tables",
+       GLOBAL_VAR(vers_force), CMD_LINE(OPT_ARG), DEFAULT(FALSE));
+
+static Sys_var_mybool Sys_vers_hide(
+       "vers_hide", "Hide system versioning from being displayed in table info",
+       GLOBAL_VAR(vers_hide), CMD_LINE(OPT_ARG), DEFAULT(FALSE));
+
 static Sys_var_ulonglong Sys_binlog_cache_size(
        "binlog_cache_size", "The size of the transactional cache for "
        "updates to transactional engines for the binary log. "