Hi, I try to add the following instance to my MongoDB: self database addCollection: '{ "personnelNumber" : "002", "bankAccountNumber" : "45215460", "lastName" : "Tester", "plz" : "79214", "nextTripNumber" : 1, "displayBubbleTip" : "some", "fax" : "+49-762-34834-99", "isEmployer" : false, "street" : "Haslacher Strasse 2", "blz" : "68050101", "tableOfAccounts" : "SKR03", "place" : "Freiburg", "bankName" : "Comdirekt Bank", "subtractPaymentInKind" : true, "email" : "sabine.knfffel@fmail.com", "creationTimestamp" : "22.02.2013-15:08-72889452", "phone" : "+49-762-34834", "mobile" : "+49-151-38374637", "firstName" : "Theo" }' I get this error back from the database: a Dictionary('code'->10080 'errmsg'->'exception: ns name too long, max size is 128' 'ok'->0.0 ) It seems that MongoDB is trying to add an index (with a field "ns") which is a composition of all my fields: { "v": NumberInt(1), "key": { "_id": NumberInt(1) }, "ns": "RKA24B.{\r\t \t\"personnelNumber\" : \"002\",\r\t\"bankAccountNumber\" : \"45215460\",\r\t \r........this is longer than 128 sings and causes the error..........}", "name": "_id_" } Writing above instance to the database DIRECTLY from shell (or with RockMongo) works fine. What is wrong within Mongotalk? (the testcases work fine because the test objects are small enough) how can I write my instance to the database, how can I avoid that MongoTalk tries to create the index thing? Adding a line with id "_id": "512fff76e79dc751e180c000001", does not work either. Sabine -- View this message in context: http://forum.world.st/MongoTalk-ns-name-too-long-error-tp4671488.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.