Lobs file size

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Lobs file size

Alexander Gerbig
Hallo hsqldb developers,

we use a hsqldb in our application an experience a strange behavior. We have some clob columns in different tables and when we execute an select with an upper on the clob column in a where clause the lobs file increases in size. Is it a very practice to make an upper on an clob column? Is this normal?

Thanks for any help.

Bye
Alex
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Re: Lobs file size

HSQLDB - Dev mailing list
This is normal. An uppercase copy of the CLOB  is created. To avoid it,
cast the CLOB to VARCHAR before converting to uppercase.

Fred Toussi

On Thu, Jul 13, 2017, at 10:52, Alexander Gerbig wrote:

> Hallo hsqldb developers,
>
> we use a hsqldb in our application an experience a strange behavior. We
> have some clob columns in different tables and when we execute an select
> with an upper on the clob column in a where clause the lobs file
> increases in size. Is it a very practice to make an upper on an clob
> column? Is this normal?
>
> Thanks for any help.
>
> Bye
> Alex
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> hsqldb-developers mailing list
> [hidden email]
> https://lists.sourceforge.net/lists/listinfo/hsqldb-developers

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Re: Lobs file size

Alexander Gerbig
Ok, thank you. Is it possible to reduce the size of the file again?

> Am 13.07.2017 um 18:08 schrieb Fred Toussi via hsqldb-developers <[hidden email]>:
>
> This is normal. An uppercase copy of the CLOB  is created. To avoid it,
> cast the CLOB to VARCHAR before converting to uppercase.
>
> Fred Toussi
>
>> On Thu, Jul 13, 2017, at 10:52, Alexander Gerbig wrote:
>> Hallo hsqldb developers,
>>
>> we use a hsqldb in our application an experience a strange behavior. We
>> have some clob columns in different tables and when we execute an select
>> with an upper on the clob column in a where clause the lobs file
>> increases in size. Is it a very practice to make an upper on an clob
>> column? Is this normal?
>>
>> Thanks for any help.
>>
>> Bye
>> Alex
>> ------------------------------------------------------------------------------
>> Check out the vibrant tech community on one of the world's most
>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>> _______________________________________________
>> hsqldb-developers mailing list
>> [hidden email]
>> https://lists.sourceforge.net/lists/listinfo/hsqldb-developers
>
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
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> hsqldb-developers mailing list
> [hidden email]
> https://lists.sourceforge.net/lists/listinfo/hsqldb-developers

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Re: Lobs file size

Alexander Gerbig
Hi Fred,

because of the following reasons we consider this as a bug:
- the upper copy of the clob is not removed afterwards and the already occupied space is not reused
- it is not easily possible to reduce the size of the lobs-file
- this behavior is not documented

Therefore I will open a bug in the Bug Tracker.

Bye, Alex


2017-07-13 19:31 GMT+02:00 Alexander Gerbig <[hidden email]>:
Ok, thank you. Is it possible to reduce the size of the file again?

> Am 13.07.2017 um 18:08 schrieb Fred Toussi via hsqldb-developers <[hidden email]>:
>
> This is normal. An uppercase copy of the CLOB  is created. To avoid it,
> cast the CLOB to VARCHAR before converting to uppercase.
>
> Fred Toussi
>
>> On Thu, Jul 13, 2017, at 10:52, Alexander Gerbig wrote:
>> Hallo hsqldb developers,
>>
>> we use a hsqldb in our application an experience a strange behavior. We
>> have some clob columns in different tables and when we execute an select
>> with an upper on the clob column in a where clause the lobs file
>> increases in size. Is it a very practice to make an upper on an clob
>> column? Is this normal?
>>
>> Thanks for any help.
>>
>> Bye
>> Alex
>> ------------------------------------------------------------------------------
>> Check out the vibrant tech community on one of the world's most
>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>> _______________________________________________
>> hsqldb-developers mailing list
>> [hidden email]
>> https://lists.sourceforge.net/lists/listinfo/hsqldb-developers
>
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> hsqldb-developers mailing list
> [hidden email]
> https://lists.sourceforge.net/lists/listinfo/hsqldb-developers


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Re: Lobs file size

HSQLDB - Dev mailing list
You can open a bug report if you wish.

The space for temporary lobs is reclaimed at each checkpoint and is reused for future lobs.

It is not possible to reduce the size of the lobs file. There is a procedure in HyperXtremeSQL for this, but not in HSQLDB.

Fred


On Tue, Jul 18, 2017, at 16:05, Alexander Gerbig wrote:
Hi Fred,

because of the following reasons we consider this as a bug:
- the upper copy of the clob is not removed afterwards and the already occupied space is not reused
- it is not easily possible to reduce the size of the lobs-file
- this behavior is not documented

Therefore I will open a bug in the Bug Tracker.

Bye, Alex


2017-07-13 19:31 GMT+02:00 Alexander Gerbig <[hidden email]>:
Ok, thank you. Is it possible to reduce the size of the file again?


> Am 13.07.2017 um 18:08 schrieb Fred Toussi via hsqldb-developers <[hidden email]>:
>
> This is normal. An uppercase copy of the CLOB  is created. To avoid it,
> cast the CLOB to VARCHAR before converting to uppercase.
>
> Fred Toussi
>
>> On Thu, Jul 13, 2017, at 10:52, Alexander Gerbig wrote:
>> Hallo hsqldb developers,
>>
>> we use a hsqldb in our application an experience a strange behavior. We
>> have some clob columns in different tables and when we execute an select
>> with an upper on the clob column in a where clause the lobs file
>> increases in size. Is it a very practice to make an upper on an clob
>> column? Is this normal?
>>
>> Thanks for any help.
>>
>> Bye
>> Alex
>> ------------------------------------------------------------------------------
>> Check out the vibrant tech community on one of the world's most
>> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
>> _______________________________________________
>> hsqldb-developers mailing list
>
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> hsqldb-developers mailing list
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