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From "Carl Steinbach (JIRA)" <>
Subject [jira] Commented: (HIVE-1364) Increase the maximum length of SERDEPROPERTIES values (currently 767 characters)
Date Thu, 17 Jun 2010 02:58:24 GMT


Carl Steinbach commented on HIVE-1364:

@Prasad: It's possible that people who ran into problems were before were using a version
of MySQL older than 5.0.3. These versions supported a 255 byte max length for VARCHARs. It's
also possible that older versions of the package.jdo mapping contained more indexes, in which
case the 767 byte limit holds. Also, UTF encoding should not make a difference since these
are byte lengths, not character lengths.

@John: I think using LOBs is the right approach, but perhaps we should handle that problem
in a different ticket? I don't think we can just change the mapping to use LOB instead of
VARCHAR, and will instead have to add a new LOB column, deprecate the old VARCHAR column,
and create an accessor that is capable of using either column.

> Increase the maximum length of SERDEPROPERTIES values (currently 767 characters)
> --------------------------------------------------------------------------------
>                 Key: HIVE-1364
>                 URL:
>             Project: Hadoop Hive
>          Issue Type: Bug
>          Components: Metastore
>    Affects Versions: 0.5.0
>            Reporter: Carl Steinbach
>            Assignee: Carl Steinbach
>             Fix For: 0.6.0
>         Attachments: HIVE-1364.2.patch.txt, HIVE-1364.patch
> The value component of a SERDEPROPERTIES key/value pair is currently limited
> to a maximum length of 767 characters. I believe that the motivation for limiting the
length to 
> 767 characters is that this value is the maximum allowed length of an index in
> a MySQL database running on the InnoDB engine:
> * The Metastore OR mapping currently limits many fields (including SERDEPROPERTIES.PARAM_VALUE)
to a maximum length of 767 characters despite the fact that these fields are not indexed.
> * The maximum length of a VARCHAR value in MySQL 5.0.3 and later is 65,535.
> * We can expect many users to hit the 767 character limit on SERDEPROPERTIES.PARAM_VALUE
when using the hbase.columns.mapping serdeproperty to map a table that has many columns.
> I propose increasing the maximum allowed length of SERDEPROPERTIES.PARAM_VALUE to 8192.

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