Test the size and number of mysql blob fields.

Test conclusion
Mysql 5.1
Table type: innodb, row_format = compact (this is the default row format)


Insert more than 10 blobs. The blob data volume is small (<768 bytes) and is successfully inserted.
Insert more than 10 blobs, The blob data volume is large (> 768 bytes), insertion failed: Got error 139 from storage engine is reported.


Note: If the mysql server version is 5.1 and the innodb_file_format option does not exist, you cannot talk about the Barracuda format. Setting row_format = dynamic is meaningless.


Mysql 5.5
Table type: innodb, row_format = compact (this is the default row format)
Insert more than 10 blobs, blob data size is large (> 768 bytes), insertion failed: Row size too large (> 8126 ). changing some columns to TEXT or BLOB or using ROW_FORMAT = DYNAMIC or ROW_FORMAT = COMPRESSED may help. in current row format, BLOB prefix of 768 bytes is stored inline.


Table type: innodb, row_format = dynamic (this is the row format supported by the new file storage format Barracuda of innodb)
Insert more than 10 blobs. The blob data volume is large (> 768 bytes) and is successfully inserted.


Note:
1) In actual testing, the length of each field I use is 100 K +
2) For mysql5.5, although Barracuda is supported. However, the old format is Antelope by default.
Unless I. cnf is modified in the mysql Configuration:
Innodb_file_per_table = 1
Innodb_file_format = Barracuda
Or modify the set global command dynamically:
Set global innodb_file_format = barracuda;
Set global innodb_file_per_table = 1;


Note:
1) The modified innodb_file_format only affects the tables created later. That is, the table created later. You can set row_format to dynamic.
2) set global is only valid during mysql server running. After restart, innodb_file_format is restored to the original format.
3) A simple method to determine whether a table supports more than 10 blob fields:
Show table status like 't1' \ G
View Row_format. Compact is not supported. dynamic is supported.