diff --git a/installer/data/mysql/en/mandatory/sysprefs.sql b/installer/data/mysql/en/mandatory/sysprefs.sql
index a579169bbf..600c20c611 100755
--- a/installer/data/mysql/en/mandatory/sysprefs.sql
+++ b/installer/data/mysql/en/mandatory/sysprefs.sql
@@ -18,7 +18,7 @@ INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES('BorrowerMandatoryField','zipcode|surname|cardnumber','Choose the mandatory fields for a patron\'s account',NULL,'free');
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES('borrowerRelationship','father|mother','Define valid relationships between a guarantor & a guarantee (separated by | or ,)','','free');
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES('BorrowersLog',1,'If ON, log edit/create/delete actions on patron data',NULL,'YesNo');
-INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES('CataloguingLog',1,'If ON, log edit/create/delete actions on bibliographic data',NULL,'YesNo');
+INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES('CataloguingLog',1,'If ON, log edit/create/delete actions on bibliographic data. WARNING: this feature is very resource consuming.',NULL,'YesNo');
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES('checkdigit','none','If ON, enable checks on patron cardnumber: none or \"Katipo\" style checks','none|katipo','Choice');
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES('delimiter',';','Define the default separator character for exporting reports',';|tabulation|,|/|\\|#|\|','Choice');
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES ('EnhancedMessagingPreferences',0,'If ON, allows patrons to select to receive additional messages about items due or nearly due.','','YesNo');
@@ -101,7 +101,7 @@ INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES('z3950NormalizeAuthor',0,'If ON, Personal Name Authorities will replace authors in biblio.author','','YesNo');
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES('ReservesNeedReturns',1,'If ON, a hold placed on an item available in this library must be checked-in, otherwise, a hold on a specific item, that is in the library & available is considered available','','YesNo');
 INSERT INTO `systempreferences` (variable,value,explanation,options,type)  VALUES ('DebugLevel',2,'Define the level of debugging information sent to the browser when errors are encountered (set to 0 in production). 0=none, 1=some, 2=most','0|1|2','Choice');
-INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES ('NoZebra',1,'If ON, Zebra indexing is turned off, simpler setup, but slower searches','','YesNo');
+INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES ('NoZebra',1,'If ON, Zebra indexing is turned off, simpler setup, but slower searches. WARNING: using NoZebra on even modest sized collections is very slow.','','YesNo');
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES ('SessionStorage','mysql','Use database or a temporary file for storing session data','mysql|Pg|tmp','Choice');  
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES ('CircAutocompl',1,'If ON, autocompletion is enabled for the Circulation input',NULL,'YesNo');
 INSERT INTO `systempreferences` (variable,value,explanation,options,type) VALUES ('RoutingSerials',1,'If ON, serials routing is enabled',NULL,'YesNo');
@@ -201,7 +201,7 @@ INSERT INTO `systempreferences` (variable,value,options,explanation,type) VALUES
 	('TagsShowOnDetail','10','','Number of tags to display on detail page.  0 is off.',        'Integer'),
 	('TagsShowOnList',   '6','','Number of tags to display on search results list.  0 is off.','Integer');
 
-INSERT INTO `systempreferences` (variable,value,options,explanation,type) VALUES('OPACShelfBrowser','1','','Enable/disable Shelf Browser on item details page','YesNo');
+INSERT INTO `systempreferences` (variable,value,options,explanation,type) VALUES('OPACShelfBrowser','1','','Enable/disable Shelf Browser on item details page. WARNING: this feature is very resource consuming on collections with large numbers of items.','YesNo');
 INSERT INTO `systempreferences` (variable,value,options,explanation,type) VALUES
 ('XSLTDetailsDisplay','0','','Enable XSL stylesheet control over details page display on OPAC WARNING: MARC21 Only','YesNo'),
 ('XSLTResultsDisplay','0','','Enable XSL stylesheet control over results page display on OPAC WARNING: MARC21 Only','YesNo');
diff --git a/installer/data/mysql/updatedatabase.pl b/installer/data/mysql/updatedatabase.pl
index c2008786c7..4f89478697 100755
--- a/installer/data/mysql/updatedatabase.pl
+++ b/installer/data/mysql/updatedatabase.pl
@@ -1937,6 +1937,30 @@ if (C4::Context->preference("Version") < TransformToNum($DBversion)) {
     SetVersion ($DBversion);
 }
 
+$DBversion = '3.00.00.107';
+if (C4::Context->preference("Version") < TransformToNum($DBversion)) {
+    $dbh->do(<<'END_SQL');
+UPDATE systempreferences
+  SET explanation = CONCAT( explanation, '. WARNING: this feature is very resource consuming on collections with large numbers of items.' )
+  WHERE variable = 'OPACShelfBrowser'
+    AND explanation NOT LIKE '%WARNING%'
+END_SQL
+    $dbh->do(<<'END_SQL');
+UPDATE systempreferences
+  SET explanation = CONCAT( explanation, '. WARNING: this feature is very resource consuming.' )
+  WHERE variable = 'CataloguingLog'
+    AND explanation NOT LIKE '%WARNING%'
+END_SQL
+    $dbh->do(<<'END_SQL');
+UPDATE systempreferences
+  SET explanation = CONCAT( explanation, '. WARNING: using NoZebra on even modest sized collections is very slow.' )
+  WHERE variable = 'NoZebra'
+    AND explanation NOT LIKE '%WARNING%'
+END_SQL
+    print "Upgrade to $DBversion done (warning added to OPACShelfBrowser system preference)\n";
+    SetVersion ($DBversion);
+}
+
 =item DropAllForeignKeys($table)
 
   Drop all foreign keys of the table $table
diff --git a/kohaversion.pl b/kohaversion.pl
index d8cfb9b1d2..582aa2c163 100644
--- a/kohaversion.pl
+++ b/kohaversion.pl
@@ -10,7 +10,7 @@
 use strict;
 
 sub kohaversion {
-    our $VERSION = '3.00.00.106';
+    our $VERSION = '3.00.00.107';
     # version needs to be set this way
     # so that it can be picked up by Makefile.PL
     # during install