I'm trying to update a row in a table but it comes back with:
Row size too large. The maximum row size for the used table type, not counting BLOBs, is 8126. You have to change some columns to TEXT or BLOBs
All of my fields apart from the ID are BLOBs so I have no idea what the error is meaning.
Can anybody help?
Just change your columns type to TEXT as mysql said.
Related
I've searched for this subject on the site, and found some tips, but non of them is working for me.
In VB net I am making a table in MySQL (InnoDB), first I will make all the columns and then I fill them with data. But when I am trying to make a table with many columns, I get this error:
Row size to large. The maximum row size for the used table type, not counting BLOBs, is 8126. This includes storage overhead, check the manual. You have to change some columns to TEXT or BLOBs.
It is crashing when I want more then 196 columns.
I already tried the row format at compressed, but then my maximum is 186 columns (?!). The maximum amount of columns is 300 for my project. I've searched n the config of mySQL workbench 6.3, but can't find the solution. So currently my settings are standard by wizard creation. All the data in the table is TEXT.
When I try to modify size of varchar:
alter table foo modify column content varchar(20000);
I got this error:
ERROR 1118 (42000): Row size too large. The maximum row size for the used table type,
not counting BLOBs, is 65535. This includes storage overhead, check the manual.
You have to change some columns to TEXT or BLOBs
How to use varchar with large data ?
Youssef, I think you're getting confused between varchar size and row size. A varchar can be up to 65533 in length (2 bytes are reserved to define the length) so your varchar is within the accepted size, however the other columns in your table must add up to more than 45535 bytes - thus giving you a "row" size error.
If you post your existing create table script we can confirm that this is the case.
The pertinent section in the manual is C.10.4 Limits on Table Column Count and Row Size
What is the MySQL VARCHAR max size?
I have searched on stackoverflow about varchar vs text and studied the documentation.
Iam not sure if i understood it the right way but let me ask you this. I have got Mysql version 5.5.34 and yes the maximum varchar size is 65535 bytes and the text content on my website cannot exceed more than 600 characters, I would prefer using varchar(600) rather than Text.
Since varchar is stored inline with table and faster and when I read all the answers of the question.
rajukoyilandy answer
varchar has 64K row limit
paxdiablo answer
if your row size is approaching 64K, you may want to examine the schema of your database. It's a rare table that needs to be that wide in a properly set up (3NF) database - it's possible, just not very common.
If you want to use more than that, you can use the BLOB or TEXT types. These do not count against the 64K limit of the row
So I have decided to use Text
http://dev.mysql.com/doc/refman/5.0/en/column-count-limit.html
When I have seen this documentation on the very top it says
Every table (regardless of storage engine) has maximum row size of 65,535 bytes.
Storage engines may place additional constraints on this limit,
reducing the effective maximum row size
My question is, So no matter what you use Text or Varchar, the row limit is 65kb? or if you use Text there is no row limit? Any help is greatly appreciated.
http://dev.mysql.com/doc/refman/5.0/en/column-count-limit.html
BLOB and TEXT columns count from one to four plus eight bytes each
toward the row-size limit because their contents are stored separately
from the rest of the row.
So yes no matter what you use the row limit is 65KB, but since BLOB and TEXT types are stored separately the length of the contents do not count towards the row size, just the initial one to four plus eight bytes do.
This is why you can use LONGBLOB LONGTEXT to store huge files and still be able to have more than just a single LONGBLOB/LONGTEXT column in a table.
As for which is better VARCHAR(600) vs TEXT, with VARCHAR you would be taking up 1802 bytes per column so you still have lots of room to work with when it comes to the row limit. But for performance you would have to do benchmarks as this comment points out inline storage is faster if it frequently used in your queries.
The row size limit applies to the amount of space required to store the row itself, which is not the same as the amount of space required to store the data in the row. From the page you linked to:
BLOB and TEXT columns count from one to four plus eight bytes each toward the row-size limit because their contents are stored separately from the rest of the row.
This is why you can store huge amounts of data in a BLOB or TEXT field without exceeding the row-size limit.
I have 22 database fields of type longtext. If I try saving 12 of the fields with the following data I get the following error:
#1118 - Row size too large. The maximum row size for the used table type, not
counting BLOBs, is 8126. You have to change some columns to TEXT or BLOBs
It saves fine if I only save 11 fields. Here's the data:
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
How can I fix the issue? How can I increase the bytes of the row size so it is more than 8126?
The problem is the row size limit for InnoDB tables, in this links you can find some approaches to solve this:
http://www.mysqlperformanceblog.com/2011/04/07/innodb-row-size-limitation/
https://dba.stackexchange.com/questions/6598/innodb-create-table-error-row-size-too-large
Columns of type Varchar's, text, and blob arent included in the innodb row size limit.. so if you have a lot of columns that aren't you can get that error.
I had a load of char(1)'s that I changed to varchar and it fixed the problem nicely
I've heard that if you have a table with a TEXT column that will hold a large chunk of text data, it's better for performance to move that column into a separate table and get it via JOINs to the base record.
Is this true, and if so why?
Not with PostgreSQL, from the manual:
Very long values are also stored in background tables so that they do not interfere with rapid access to shorter column values.
So a large character column (such as TEXT or VARCHAR without a specified size limit) is stored away from the main table data. So, PostgreSQL has your "put it in a separate table" optimization built in. If you're using PostgreSQL, arrange your table sensibly and leave the data layout to PostgreSQL.
I don't know how MySQL or other RDBMs arrange their data.
The reason behind this optimization is that the database will usually keep the data for each row in contiguous blocks on disk to cut down on seeking when the row needs to be read or updated. If you have a TEXT (or other variable length type) column in a row then the size of the row is variable so more work is needed to go from row to row. An analogy would be the difference between accessing something in a linked list versus accessing an array; with a linked list, you have to read three elements one at a time to get to the fourth one, with an array you just offset 3 * element_size bytes from the beginning and you're there in one step.
From the MySQL Manual:
For a table with several columns, to
reduce memory requirements for queries
that do not use the BLOB column,
consider splitting the BLOB column
into a separate table and referencing
it with a join query when needed.
In some scenarios, this might be true. The reason is that let's say your table is:
create table foo (
id serial primary key,
title varchar(200) not null,
pub_date datetime not null,
text_content text
);
Then you do a query like this:
select id, title, pub_date
from foo;
You will have to load much more pages from disk that you would have if you didn't have the text_content field in that table. And query optimization is most about reducing disk I/O to the minimum possible.