mysql建表问题

 

11

When I run a program which does something with MySQL, I got this error message:

2015-06-10 15:41:12,250 ERROR app.wsutils 419 INCRON: Error: ('HY000', '[HY000] [MySQL][ODBC 5.2(w) Driver][mysqld-5.7.7-rc-log]Index column size too large. The maximum column size is 767 bytes. (1709) (SQLExecDirectW)')

I Googled a little bit, and found this error might be relating to the innodb_large_prefix option. However, I am using MySQL 5.7.7 rc, which has already set innodb_large_prefix to be "ON" (checked in MySQL Workbench), allowing up to 3072 bytes. I am not sure if that is the problem with innodb_large_prefix or not.

Anyway, does anyone have an idea how to fix this problem?

8 Answers

15

Your column that you are trying to index is too large and your settings must not be correct for innodb_large_prefix. There are a couple prerequisites parameters that also have to be set in order for innodb_large_prefix to work correctly.

You can check to make sure that innodb_large_prefix is set by running:

show global variables like 'innodb_lar%';

Here are a couple prerequisites for using innodb_large_prefix:

You need to set your global variable innodb_file_format=BARRACUDA

to check settings run: show global variables like 'innodb_fil%';

At the table level you have to use ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED

for Innodb, rows are stored in COMPACT format (ROW_FORMAT=COMPACT) by default.

  •  
    How do you do that "At the database level"? Perhaps you mean SET GLOBAL? – Rick James Jun 11 '15 at 0:55
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    You better configure these settings in my.cnf or else they are stored in memory and hence lost when restarting MySQL/MariaDB. – Braek Aug 18 '15 at 8:40
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    @RickJames - Yes doing this at a database level is enough. Infact, doing it at the particular table level also will solve the problem. – Sasank Mukkamala Feb 4 '16 at 14:17
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    @Sasank, Rick was just being picky about the word usage... – BK435 Feb 5 '16 at 0:43 
  • 3
    In some cases where I was trying to CONVERT TO CHARACTER SET, I was using MySQL 5.5 where the default ROW_FORMAT for InnoDB was COMPACT. Using ALTER TABLE foo ROW_FORMAT=DYNAMIC, CONVERT TO CHARACTER SET charset did the trick. – Christopher Schultz Jun 29 '17 at 13:24 
14

With the help of the answer given by BK435, I did the following and solved the problem.

set global innodb_file_format = BARRACUDA;
set global innodb_large_prefix = ON;
create table test (........) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC;

posted on 2019-06-04 21:11  与非朋仔  阅读(390)  评论(0编辑  收藏  举报

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