[
https://issues.apache.org/jira/browse/DERBY-3907?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Kristian Waagan updated DERBY-3907:
-----------------------------------
Attachment: derby-3907-7a3-use_new_header_format.stat
derby-3907-7a3-use_new_header_format.diff
Patch 7a3 is the patch that enables the new header format.
I plan to commit this Tuesday or Wednesday next week.
Patch ready for review.
Remaining work:
o Determine if the database version should be kept in the Database object.
It all depends on how expensive it is to consult the data dictionary about
the version.
o Investigate upgrade further to understand whether long columns can easily be
upgraded with a new header or not.
o (stretch task) Investigate how to add the functionality to update only the
first few bytes of a data value.
NOTE: After this patch has been committed, databases containing CLOBs written
with a Derby revision after the commit cannot be read with a Derby revision
before the commit.
> Save useful length information for Clobs in store
> -------------------------------------------------
>
> Key: DERBY-3907
> URL: https://issues.apache.org/jira/browse/DERBY-3907
> Project: Derby
> Issue Type: Improvement
> Components: JDBC, Store
> Affects Versions: 10.5.0.0
> Reporter: Kristian Waagan
> Assignee: Kristian Waagan
> Fix For: 10.5.0.0
>
> Attachments: derby-3907-1a-alternative_approach.diff,
> derby-3907-2b-header_write_preparation.diff,
> derby-3907-2b-header_write_preparation.diff,
> derby-3907-2b-header_write_preparation.stat,
> derby-3907-2c-header_write_preparation-PREVIEW.diff,
> derby-3907-2c-header_write_preparation-PREVIEW.stat,
> derby-3907-2c-header_write_preparation.diff,
> derby-3907-2c-header_write_preparation.diff,
> derby-3907-2c-header_write_preparation.stat,
> derby-3907-3a-readertoutf8stream_cleanup.diff,
> derby-3907-3a-readertoutf8stream_cleanup.diff,
> derby-3907-3a-readertoutf8stream_cleanup.stat,
> derby-3907-3b-readertoutf8stream_cleanup.diff,
> derby-3907-4a-add_getStreamWithDescriptor.diff,
> derby-3907-4a-add_getStreamWithDescriptor.stat,
> derby-3907-5a-use_getStreamWithDescriptor.diff,
> derby-3907-5a-use_getStreamWithDescriptor.stat,
> derby-3907-6a-SQLClob_stream_descriptor_sync.diff,
> derby-3907-7a-write_new_header_format-PREVIEW.diff,
> derby-3907-7a-write_new_header_format.diff,
> derby-3907-7a-write_new_header_format.diff,
> derby-3907-7a-write_new_header_format.stat,
> derby-3907-7a1-write_new_header_format.diff,
> derby-3907-7a2-use_new_framework.diff, derby-3907-7a2-use_new_framework.stat,
> derby-3907-7a3-use_new_header_format.diff,
> derby-3907-7a3-use_new_header_format.stat
>
>
> The store should save useful length information for Clobs. This allows the
> length to be found without decoding the whole data stream.
> The following thread raised the issue on what information to store, and also
> contains some background information:
> http://www.nabble.com/Storing-length-information-for-CLOB-on-disk-tp19197535p19197535.html
> The information to store, and the exact format of it, is still to be
> discussed/determined.
> Currently two bytes are set aside for length information, which is inadequate.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
