Bug #1747 Tables with several thousand columns
Submitted: 4 Nov 2003 7:44 Modified: 17 Nov 2003 7:46
Reporter: Dietrich Feist Email Updates:
Status: Closed Impact on me:
Category:MySQL Server Severity:S4 (Feature request)
Version:4.1.0 OS:Solaris (Solaris 8)
Assigned to: CPU Architecture:Any

[4 Nov 2003 7:44] Dietrich Feist
For the processing of scientific data, I often need tables with a very large number of columns. So far, we were happy with roughly 2050 columns and had no problems with MySQL handling these tables. However, the limit of MySQL seems to be somewhere around 2100 and we have a new application coming up that will need about 4300 columns. I would be very happy if MySQL could handle that as well.

How to repeat:
Create a table with more than 2110 columns.

Suggested fix:
Increase the maximum number of columns if that is not too much trouble.
[17 Nov 2003 7:46] Sergei Golubchik
it's not easy.

There are several limits, e.g. max row size (excluding blobs), max_packet_size (as your CREATE TABLE statement must fit in one packet).

But the most hard limit lies in the format or frm files :(

Thus the limit will be raised, true, but not until we'll have new frm format (which cannot happen before 5.1)