Hello.

Created a poll where there are several dozen groups, each with several questions. When you reach a certain number of such groups, when I try to activate a poll, I get a message:

The poll response table can not be created. This is usually caused by too many (sub-) questions in the survey. Try to reduce the number of questions.

Tell me please what is the maximum number of questions in the survey can be and why such restrictions are caused (a restriction on the number of columns in the table mysql, restrictions in the limesurvey itself or something else)?

Hi,

Read the manual here:
www.limesurvey.org/manual/General_FAQ#Wh...does_LimeSurvey_have ...
regarding survey size and max number of columns.

So, you should try to split your survey.

Regards
Joffm

I read the documentation for your link.

Judging from the documentation: the maximum line size can not be more than 65535 bytes. The size of 1 character is 3 bytes. Therefore, 21 844 characters are maximum for the string.

Now we look at my table, with which the question arose.

The first 8 standard fields of the lime_survey_XXXXXX table are approximately 119 characters + the TEXT - ip field of the respondent. Further at me in the table 1617 fields varchar (5). If 1617 * 5 = 8085 characters.

As a result, 8085 + 119 = 8204 characters, which is much less than 21 844 characters. Where did I misunderstand?

What type of table?
MyISAM or InnoDB?
InnoDB has only about 1000 columns.

But nevertheless you have to restructure your survey.

Split it and use end-url.

Joffm

shiva522 wrote: Now we look at my table, with which the question arose.

How do you inspect a table, which LimeSurvey hasn't created?

Since it all depends on your survey structure and your database configuration, a feedback will depend on knowing both. What version of LimeSurvey is used?

I would recommend to copy the survey and remove some parts. Just to find out, where your installation of LimeSurvey is hitting the limit. It might be impossible to create the survey design in LimeSurvey at the moment.

The roadmap acknowledges the limit issue and developers plan to change the database handling in the future.

Refactor answer database to get rid of column limitations.

www.limesurvey.org/manual/LimeSurvey_roa...eased_.28Feb_2018.29

I know that InnoDB allows no more than 1000 columns. MyISAM table type

I use Toad for MySQL 7.3 for inspecting MySql tables.
2.72.2 version of limesurvey which i use.

about the decrease in the number of questions in the survey, I did it when I encountered this problem. if we reduce the number of columns to 8 service + 1554 varchar (5) columns - the table is created

The decision to split the survey into two parts as a way out of this situation I took yesterday. However, I would like to know where I exceeded the limits? Is this related to the limitations in the limesurvey or are these the limitations of Mysql? This is the initial question .. I was asked by my boss and he waiting for an answer from me

It's MySQL

dev.mysql.com/doc/mysql-reslimits-excerp...umn-count-limit.html

Joffm

I've already read all this. As I understand there is no definite answer. if I did not make a mistake with the calculations, I did not reach the maximum line size of 65535. As a result of the calculation, I get less than 24000+ bytes the size of the string. from which it can be concluded that limesurvey itself limits the number of acceptable questions in polls.

shiva522 wrote: from which it can be concluded that limesurvey itself limits the number of acceptable questions in polls.

The activation error message states that the response table cannot be created correctly. So I would conclude that you cannot inspect a table inside the database which hits the limits.

To learn how the error is triggered, you will need to hope for a core developer to show up.
Or dig inside the code, which is available on GITHUB.
You might start from here: github.com/LimeSurvey/LimeSurvey/blob/ma.../activate_helper.php .

Hi, and what did ddrmoscow tell you in your crosspost in the Russian section?

Please, avoid crossposting at the same time.

I just tried to create your table which you described in the Russian section.
Outside LS, just by running the SQL in phpMyAdmin. If you use TOAD, well, that's the same.
And I failed.


So maybe the best you ask in a MySQL-Forum.

Joffm

"ddrmoscow" asked clarifying questions about my topic but he has no answer.

About what to do if Limesurvey reports that the maximum allowed number of questions in the survey is exceeded, this is understandable. Divide the survey into several surveys.

It is not clear why my calculations are the maximum row size and less than what MYSQL allows and the limesurvey table does not allow creating. I assume that the restrictions are from limesurvey and not from MYSQL. But these are only assumptions based on conjectures. But I would like to know for sure.

I think this discussion should be completed, since no one knows the answer and does not waste your time guessing.

Nevertheless, thanks for the help.