LouisGac wrote: ok, could you please attach the survey so we can do some testing here?

Unfortunately, I can't make it public because it's a corporate survey...

But you know what, I'm having a different issue right now, which might be related to the size of the survey (my guess)..
Right now I have 72 question groups in which there are more than 150 questions. I've been going through them editing their settings to suit the needs. But when I reached the 51st question group (which is question 110), this happens to be the last question I can see in the preview. When I run the preview, I can see only the question group's title, but no question.
If I create a new test group at the end and create a question (simple text box), it doesn't show up. Dang...
I know.. it's a bit off-topic here (perhaps I should start a new topic)..
But is there a limit for question groups in a survey and/or number of questions?

indeed: you should update to 2.73

LouisGac wrote: indeed: you should update to 2.73

I'm on the latest 3.6.2

sorry, I get confused by the first post.

I should add that actually, according to LimeSurvey's numbering, the last question that I can preview is 188, not 110. Sorry about that. Because I have a bunch of hidden workaround questions for the main 110.
So, overall it would be total 230+ questions in the survey ( when taking into account hidden workarounds so far)...
I need to understand whether it's a limitation of LimeSurvey or some technical glitch

for what I've seen until now, most of the time, when a survey become huge, it's because of logical imbrication.

Ex: 1 survey of 20 questions for people of type X, 1 survey of 20 questions for people of type Y, 1 survey of 20 questions for people of type Z. Then a first question "are you X or Y or Z?" ==> 61 questions.

There are different way to avoid those situations, one of them being to create 4 surveys, the first one being the first question + redirection to the correct survey at the end of it.

Thank for the hint!

So do you know that such a thing can happen - when questions aren't shown in the preview because of the survey size?
I haven't had this before, so I can't compare...

you should read this:
goo.gl/eZBvcV

Note: 'Survey size' refers to the maximum number of questions (and answers) in your survey - don't confuse this with the number of replies on your survey (there is no limitation on that). Theoretically there would also be no limit on the maximum number of questions/answers in LimeSurvey. But the database engine you are using has several limits. The most important one is the limit on the number of fields(columns) in the result table.

MySQL ISAM: The sum of the lengths of the VARCHAR and CHAR columns in a table may be up to 64KB.
MySQL InnoDB: Maximum number of 1000 columns
MS SQL Server 2000: Maximum number of 1024 columns
Postgres: Maximum number of 250-1600 columns depending on column types. The maximum number of columns can be quadrupled by increasing the default block size to 32k.

Take care here: please think about what you do before you do it: an array of 10 x 10 items already costs you 100 columns. Rule of thumb: every item on the screen that can be filled in or selected costs one column!

The mySQL ISAM engine is the most tricky one (see mysql documentation for more information). As it allows only up to 65,535 bytes per row and utf8 characters can require up to three bytes per character the maximum may be only 21,844 characters (but this depends on your DB encoding).

You can roughly calculate the size of your survey like this:

Every multiple numerical question: 20 chars for each answer
Every multiple choice & array question answers: 5 chars for each answer
Every other question type: 5 chars
Add 10% for the usual overhead

Yeah, I've found that bit too... But actually this note doesn't provide more than just giving a bunch of numbers in columns for different SQLs. It says in theory there's no limit but then again there are limits... Still, there is no way to estimate where the limit lies in, when you first design your survey on paper. If one uses LimeSurvey on their servers, what is the limit then?
There should be some kind of system calculator in LimeSurvey that gives you estimation of how many questions of this and that kind you still have.

Hi, krosser,

There should be some kind of system calculator in LimeSurvey

You could read this thread:
www.limesurvey.org/forum/design-issues/1...in-the-survey#166230

And shiva's conclusion:

Limitations, as far as I understand, come from MySql itself.

In "Toad for mysql" I tried manually creating a table based on the script of the created table and adding fields of the same type and dimension (varchar (5)) to the number where I encountered the problem. Experimentally (reducing the number of fields) reached the 1575 field, when the table allows creating.

After, I tried varchar (5) instead of varchar (1). The result is the same. 1575 fields - the number at which I was able to create the table.
So Limesurvey has nothing to do with it.

So the estimation is: about 1500 columns. That's the always mentioned MySQL limitation.

And single punch is one column, multi punch and array one column per subquestion. array (numbers) or (text) one column per row and column.

In probably most cases the design of the questionnaire can be revised and adapted; or you just split the survey and use end-url.

Joffm

Hi Joffm,

Thanks for this extra info and referring to the end-url use. That could be a workaround...