[sqlite] In the case of ZIPVFS

[Michael Stephenson]

Having just glanced at the documentation for ZIPVFS (didn't even know it
existed)...

1) Perhaps using a real-time compression algorithm, something like lz4.
It's not clear to me which algorithm ZIPVFS uses by default.

2) Perhaps increasing the cache settings to cache more pages in memory.

3) Perhaps increasing the page size.

4) Perhaps ensure that WAL mode is used.

-Original Message-
From: sqlite-users-boun...@mailinglists.sqlite.org
[mailto:sqlite-users-bounces at mailinglists.sqlite.org] On Behalf Of ???
Sent: Wednesday, December 23, 2015 4:05 AM
To: sqlite-users at mailinglists.sqlite.org
Subject: [sqlite] In the case of ZIPVFS

HI,all
SQLite retrieves the compressed records is slower than the uncompressed
records about 30%.
How can improve the problem?  and anyone any suggustion?

best regards
wqg
___
sqlite-users mailing list
sqlite-users at mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users

[sqlite] In the case of ZIPVFS

[王庆刚]

HI,all
SQLite retrieves the compressed records is slower than the uncompressed 
records about 30%.
How can improve the problem?  and anyone any suggustion?

best regards
wqg

[sqlite] about compile configure

[王庆刚]

I know the reason why  "PRAGMA mmap_size" could not improve the speed of 
retrieving records from ZIPVFS DB.
However,  I find sqlite3_soft_heap_limit64() , cache_szie and so on also which 
could not help improve the speed.
Is all because of the ZIPVFS?








At 2015-12-23 12:34:33, "Richard Hipp"  wrote:
>On 12/22/15, ??? <2004wqg2008 at 163.com> wrote:
>>What do you mean of "render the mmap_size mote "?
>
>The "PRAGMA mmap_size" command sets the operating-system interface
>into a mode so that at calls mmap() to read content from disk rather
>than calling read().  It is often faster to use mmap() because that
>avoids having to copy content from kernel space into user space.
>
>However, mmap() mode only works if the database is reading exactly the
>same content as is present on disk.  In the case of ZIPVFS, the
>content on disk is compressed and encryption.  The content on disk is
>different from the content used by the database engine.  The content
>has to be converted when moving from disk into the application and
>when moving from the application to the disk.  Because the content in
>the application is different from the content on disk, mmap() won't
>work.  And so when using ZIPVFS, the "PRAGMA mmap_size=NNN" command is
>a no-op.
>
>-- 
>D. Richard Hipp
>drh at sqlite.org
>___
>sqlite-users mailing list
>sqlite-users at mailinglists.sqlite.org
>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users

[sqlite] about compile configure

[王庆刚]

  Thank D. Richard Hipp very much.
   I can understand what you said. That is very helpful for me.
   Best regards
At 2015-12-23 12:34:33, "Richard Hipp"  wrote:
>On 12/22/15, ??? <2004wqg2008 at 163.com> wrote:
>>What do you mean of "render the mmap_size mote "?
>
>The "PRAGMA mmap_size" command sets the operating-system interface
>into a mode so that at calls mmap() to read content from disk rather
>than calling read().  It is often faster to use mmap() because that
>avoids having to copy content from kernel space into user space.
>
>However, mmap() mode only works if the database is reading exactly the
>same content as is present on disk.  In the case of ZIPVFS, the
>content on disk is compressed and encryption.  The content on disk is
>different from the content used by the database engine.  The content
>has to be converted when moving from disk into the application and
>when moving from the application to the disk.  Because the content in
>the application is different from the content on disk, mmap() won't
>work.  And so when using ZIPVFS, the "PRAGMA mmap_size=NNN" command is
>a no-op.
>
>-- 
>D. Richard Hipp
>drh at sqlite.org
>___
>sqlite-users mailing list
>sqlite-users at mailinglists.sqlite.org
>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users

[sqlite] whish list for 2016

[lchis...@paradise.net.nz]

Hi all,

What I meant to ask was:
a) Either an ORDER BY clause/equivalent for group_concat() [not GROUP BY as
originally posted], or an assurance that the kludge of sorting a sub-query first
and then grouping the result does and will continue to work - I need this
functionality.

This is what happens when you post when tired! My thanks to Darren Duncan who
questioned what I was asking for. Sorry I can't reply directly to Darren's
message as I get the list via digest.

I am using group_concat() to form lists of team members in a single report
field, and wish to control the order of the items concatenated. The
documentation explicitly states that "The order of the concatenated elements is
arbitrary", but searching the internet finds a number of answers along the 
lines of:
select a, group_concat(b) from (select a, b from db order by a, b desc) order 
by a;
where the ordering of the sub-select "b desc" is preserved in the group_concat()
result. This seems to work in practice, but I would really like to have surety
on a way to achieve this other than doing it in my application; other SQL
implementations have this feature.

Thanks, Len Chisholm.

[sqlite] about compile configure

[王庆刚]

>Setting the mmap_size will normally help read performance a lot.
>However, if you are reading from a ZIPVFS database, the extra layer of
>decryption and decompression that sits in between the disk and your
>application will render the mmap_size mote - it won't matter.

   Thanks very much. What you said is very improtant for me.
   Because I am  reading from a ZIPVFS database.
   What do you mean of "render the mmap_size mote "?

   best regards
   wqg


At 2015-12-23 12:05:19, "Richard Hipp"  wrote:
>On 12/22/15, ??? <2004wqg2008 at 163.com> wrote:
 >pragma mmap_size= 51200;
 >Pragma page_size = 8192;
 >Vacuum;
 >Pragma cache_size = N;
>>  The above code has nothing to do with the speed of retrieving records,
>> especially the beginning retrieve records from database.
>>  Is this the right?
>>
>
>Setting the mmap_size will normally help read performance a lot.
>However, if you are reading from a ZIPVFS database, the extra layer of
>decryption and decompression that sits in between the disk and your
>application will render the mmap_size mote - it won't matter.
>-- 
>D. Richard Hipp
>drh at sqlite.org
>___
>sqlite-users mailing list
>sqlite-users at mailinglists.sqlite.org
>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users

[sqlite] about compile configure

[王庆刚]

>> >pragma mmap_size= 51200;
>> >Pragma page_size = 8192;
>> >Vacuum;
>> >Pragma cache_size = N;
 The above code has nothing to do with the speed of retrieving records, 
especially the beginning retrieve records from database.
 Is this the right?


At 2015-12-23 11:00:44, "???" <2004wqg2008 at 163.com> wrote:
>>How long does it take to retrieve one record from the database?
>>How long do you want it to take?
> 
>  The faster,the better.
>
>
>
>At 2015-12-23 10:58:13, "Keith Medcalf"  wrote:
>>
>>How long does it take to retrieve one record from the database?
>>How long do you want it to take?
>>
>>> -Original Message-
>>> From: sqlite-users-bounces at mailinglists.sqlite.org [mailto:sqlite-users-
>>> bounces at mailinglists.sqlite.org] On Behalf Of ???
>>> Sent: Tuesday, 22 December, 2015 19:49
>>> To: SQLite mailing list
>>> Subject: Re: [sqlite] about compile configure
>>> 
>>> >pragma mmap_size= 51200;
>>> >Pragma page_size = 8192;
>>> >Vacuum;
>>> >Pragma cache_size = N;
>>> 
>>>   The testing result shows that the above pragma statements could not
>>> improve the speed of retrieving records from data base.
>>> 
>>>   Best regards
>>>   wqg
>>> 
>>> At 2015-12-21 18:29:37, "Quan Yong Zhai"  wrote:
>>> >pragma mmap_size= 51200;
>>> >Pragma page_size = 8192;
>>> >Vacuum;
>>> >Pragma cache_size = N;
>>> >
>>> >???: ???
>>> >: ?2015/?12/?21 18:08
>>> >???: SQLite mailing list
>>> >??: Re: [sqlite] about compile configure
>>> >
>>> >The SQL statement is so easy.
>>> >the table create statement as following:
>>> >CREATE TABLE poiTable (poiId INTEGER NOT NULL, versionId INTEGER NOT
>>> NULL, regionId INTEGER , postalCode TEXT , phone TEXT , attrBitMask
>>> INTEGER , attributeBlob BLOB , primary key (poiId));
>>> >So the poiId is equal to the rowid.
>>> >
>>> >such as : select * from poiTable where poiId = ... ;
>>> >And execute the sql by sqlite3_prepare_v2?sqlite3_step?
>>> >how could I improve the performance?
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >At 2015-12-21 17:15:56, "???" <2004wqg2008 at 163.com> wrote:
>>> >>What Simon said is very helpful for me. Thank you very much.
>>> >>I only want to improve the speed of reading data from data base. Do not
>>> do insert?update and so on.
>>> >>
>>> >>I will try the following suggustion.
>>> >>PRAGMA synchronous = OFF
>>> >>
>>> >>Best regards
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>
>>> >>At 2015-12-21 17:03:13, "Simon Slavin"  wrote:
>>> >>>
>>> >>>On 21 Dec 2015, at 6:19am, ??? <2004wqg2008 at 163.com> wrote:
>>> >>>
>>>   The meaning of "how to use sqlite_table" is that I guess the
>>> sqlite_table may have contained some information which could help to
>>> improve speed.
>>>    I  am not meaning to  modify the data structure of  sqlite_master.
>>> >>>
>>> >>>There is nothing you can do with sqlite_table to improve speed.  Unless
>>> you have a very unusual setup there is nothing you can do with compilation
>>> options to improve speed.
>>> >>>
>>> >>>Since you say you are not using multi-threading or multi-process, you
>>> might like to read the documentation for
>>> >>>
>>> >>>PRAGMA synchronous = OFF
>>> >>>
>>> >>>This might increase speed for you.  However it also means that if your
>>> computer loses power or crashes while the database is open, you will lose
>>> more new data.
>>> >>>
>>> >>>
>>> >>>
>>> >>>However a big increase in speed comes from correct use of indexes.  If
>>> you have any SQL commands which include WHERE or ORDER BY, then these will
>>> execute faster if you have an ideal index on the table they use.  This can
>>> affect INSERT and UPDATE and DELETE FROM commands.  If you want help with
>>> this you must post your SQL commands here.
>>> >>>
>>> >>>Another big increase in speed can come from correctly using
>>> transactions.  When you are making changes to your database it is
>>> finishing the transaction with END or COMMIT which takes most of the time.
>>> So if you have many INSERT commands then
>>> >>>
>>> >>>INSERT ...
>>> >>>INSERT ...
>>> >>>INSERT ...
>>> >>>
>>> >>>is slow but
>>> >>>
>>> >>>BEGIN
>>> >>>INSERT ...
>>> >>>INSERT ...
>>> >>>INSERT ...
>>> >>>COMMIT
>>> >>>
>>> >>>can be much faster.  This can affect INSERT and UPDATE and DELETE
>>> commands.
>>> >>>
>>> >>>Simon.
>>> >>>___
>>> >>>sqlite-users mailing list
>>> >>>sqlite-users at mailinglists.sqlite.org
>>> >>>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>>> >>___
>>> >>sqlite-users mailing list
>>> >>sqlite-users at mailinglists.sqlite.org
>>> >>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>>> >___
>>> >sqlite-users 

[sqlite] Query Regarding Shared Cache

[Zeeshan Hussain]

Hi All,

We are using SQLite - Shared Cache for this we want to open two connection 
one from .Net and Another from C++ lib, both running in the same .Net 
process. 

Problem:
It seems both the connections are using their own cache. even though we 
have opened them using same URI.

Below is the URI
In .Net Code : "FullUri=file::memory:?cache=shared"
In C++ Code: "file::memory:?cache=shared"

Additional Information:
SQLite Version - 3.9.2.0
We have created lib for C++ using following command >lib /def:sqlite3.def 
/out:sqlite3.lib 

Please suggest how to get this working.

Thanks and regards
Zeeshan Hussain
Tata Consultancy Services
Cell:- +86 18721878170
Mailto: zeeshan.hussain at tcs.com
Website: http://www.tcs.com

Experience certainty.   IT Services
Business Solutions
Consulting

=-=-=
Notice: The information contained in this e-mail
message and/or attachments to it may contain 
confidential or privileged information. If you are 
not the intended recipient, any dissemination, use, 
review, distribution, printing or copying of the 
information contained in this e-mail message 
and/or attachments to it are strictly prohibited. If 
you have received this communication in error, 
please notify us by reply e-mail or telephone and 
immediately and permanently delete the message 
and any attachments. Thank you

[sqlite] about compile configure

[王庆刚]

>How long does it take to retrieve one record from the database?
>How long do you want it to take?

  The faster,the better.



At 2015-12-23 10:58:13, "Keith Medcalf"  wrote:
>
>How long does it take to retrieve one record from the database?
>How long do you want it to take?
>
>> -Original Message-
>> From: sqlite-users-bounces at mailinglists.sqlite.org [mailto:sqlite-users-
>> bounces at mailinglists.sqlite.org] On Behalf Of ???
>> Sent: Tuesday, 22 December, 2015 19:49
>> To: SQLite mailing list
>> Subject: Re: [sqlite] about compile configure
>> 
>> >pragma mmap_size= 51200;
>> >Pragma page_size = 8192;
>> >Vacuum;
>> >Pragma cache_size = N;
>> 
>>   The testing result shows that the above pragma statements could not
>> improve the speed of retrieving records from data base.
>> 
>>   Best regards
>>   wqg
>> 
>> At 2015-12-21 18:29:37, "Quan Yong Zhai"  wrote:
>> >pragma mmap_size= 51200;
>> >Pragma page_size = 8192;
>> >Vacuum;
>> >Pragma cache_size = N;
>> >
>> >???: ???
>> >: ?2015/?12/?21 18:08
>> >???: SQLite mailing list
>> >??: Re: [sqlite] about compile configure
>> >
>> >The SQL statement is so easy.
>> >the table create statement as following:
>> >CREATE TABLE poiTable (poiId INTEGER NOT NULL, versionId INTEGER NOT
>> NULL, regionId INTEGER , postalCode TEXT , phone TEXT , attrBitMask
>> INTEGER , attributeBlob BLOB , primary key (poiId));
>> >So the poiId is equal to the rowid.
>> >
>> >such as : select * from poiTable where poiId = ... ;
>> >And execute the sql by sqlite3_prepare_v2?sqlite3_step?
>> >how could I improve the performance?
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >At 2015-12-21 17:15:56, "???" <2004wqg2008 at 163.com> wrote:
>> >>What Simon said is very helpful for me. Thank you very much.
>> >>I only want to improve the speed of reading data from data base. Do not
>> do insert?update and so on.
>> >>
>> >>I will try the following suggustion.
>> >>PRAGMA synchronous = OFF
>> >>
>> >>Best regards
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>At 2015-12-21 17:03:13, "Simon Slavin"  wrote:
>> >>>
>> >>>On 21 Dec 2015, at 6:19am, ??? <2004wqg2008 at 163.com> wrote:
>> >>>
>>   The meaning of "how to use sqlite_table" is that I guess the
>> sqlite_table may have contained some information which could help to
>> improve speed.
>>    I  am not meaning to  modify the data structure of  sqlite_master.
>> >>>
>> >>>There is nothing you can do with sqlite_table to improve speed.  Unless
>> you have a very unusual setup there is nothing you can do with compilation
>> options to improve speed.
>> >>>
>> >>>Since you say you are not using multi-threading or multi-process, you
>> might like to read the documentation for
>> >>>
>> >>>PRAGMA synchronous = OFF
>> >>>
>> >>>This might increase speed for you.  However it also means that if your
>> computer loses power or crashes while the database is open, you will lose
>> more new data.
>> >>>
>> >>>
>> >>>
>> >>>However a big increase in speed comes from correct use of indexes.  If
>> you have any SQL commands which include WHERE or ORDER BY, then these will
>> execute faster if you have an ideal index on the table they use.  This can
>> affect INSERT and UPDATE and DELETE FROM commands.  If you want help with
>> this you must post your SQL commands here.
>> >>>
>> >>>Another big increase in speed can come from correctly using
>> transactions.  When you are making changes to your database it is
>> finishing the transaction with END or COMMIT which takes most of the time.
>> So if you have many INSERT commands then
>> >>>
>> >>>INSERT ...
>> >>>INSERT ...
>> >>>INSERT ...
>> >>>
>> >>>is slow but
>> >>>
>> >>>BEGIN
>> >>>INSERT ...
>> >>>INSERT ...
>> >>>INSERT ...
>> >>>COMMIT
>> >>>
>> >>>can be much faster.  This can affect INSERT and UPDATE and DELETE
>> commands.
>> >>>
>> >>>Simon.
>> >>>___
>> >>>sqlite-users mailing list
>> >>>sqlite-users at mailinglists.sqlite.org
>> >>>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>> >>___
>> >>sqlite-users mailing list
>> >>sqlite-users at mailinglists.sqlite.org
>> >>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>> >___
>> >sqlite-users mailing list
>> >sqlite-users at mailinglists.sqlite.org
>> >http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>> >___
>> >sqlite-users mailing list
>> >sqlite-users at mailinglists.sqlite.org
>> >http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>> ___
>> sqlite-users mailing list
>> sqlite-users at mailinglists.sqlite.org
>> 

[sqlite] about compile configure

[王庆刚]

>pragma mmap_size= 51200;
>Pragma page_size = 8192;
>Vacuum;
>Pragma cache_size = N;

  The testing result shows that the above pragma statements could not improve 
the speed of retrieving records from data base.

  Best regards
  wqg

At 2015-12-21 18:29:37, "Quan Yong Zhai"  wrote:
>pragma mmap_size= 51200;
>Pragma page_size = 8192;
>Vacuum;
>Pragma cache_size = N;
>
>???: ???
>: ?2015/?12/?21 18:08
>???: SQLite mailing list
>??: Re: [sqlite] about compile configure
>
>The SQL statement is so easy.
>the table create statement as following:
>CREATE TABLE poiTable (poiId INTEGER NOT NULL, versionId INTEGER NOT NULL, 
> regionId INTEGER , postalCode TEXT , phone TEXT , attrBitMask INTEGER , 
> attributeBlob BLOB , primary key (poiId));
>So the poiId is equal to the rowid.
>
>such as : select * from poiTable where poiId = ... ;
>And execute the sql by sqlite3_prepare_v2?sqlite3_step?
>how could I improve the performance?
>
>
>
>
>
>
>
>
>
>At 2015-12-21 17:15:56, "???" <2004wqg2008 at 163.com> wrote:
>>What Simon said is very helpful for me. Thank you very much.
>>I only want to improve the speed of reading data from data base. Do not do 
>>insert?update and so on.
>>
>>I will try the following suggustion.
>>PRAGMA synchronous = OFF
>>
>>Best regards
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>At 2015-12-21 17:03:13, "Simon Slavin"  wrote:
>>>
>>>On 21 Dec 2015, at 6:19am, ??? <2004wqg2008 at 163.com> wrote:
>>>
  The meaning of "how to use sqlite_table" is that I guess the sqlite_table 
 may have contained some information which could help to improve speed.
   I  am not meaning to  modify the data structure of  sqlite_master.
>>>
>>>There is nothing you can do with sqlite_table to improve speed.  Unless you 
>>>have a very unusual setup there is nothing you can do with compilation 
>>>options to improve speed.
>>>
>>>Since you say you are not using multi-threading or multi-process, you might 
>>>like to read the documentation for
>>>
>>>PRAGMA synchronous = OFF
>>>
>>>This might increase speed for you.  However it also means that if your 
>>>computer loses power or crashes while the database is open, you will lose 
>>>more new data.
>>>
>>>
>>>
>>>However a big increase in speed comes from correct use of indexes.  If you 
>>>have any SQL commands which include WHERE or ORDER BY, then these will 
>>>execute faster if you have an ideal index on the table they use.  This can 
>>>affect INSERT and UPDATE and DELETE FROM commands.  If you want help with 
>>>this you must post your SQL commands here.
>>>
>>>Another big increase in speed can come from correctly using transactions.  
>>>When you are making changes to your database it is finishing the transaction 
>>>with END or COMMIT which takes most of the time.  So if you have many INSERT 
>>>commands then
>>>
>>>INSERT ...
>>>INSERT ...
>>>INSERT ...
>>>
>>>is slow but
>>>
>>>BEGIN
>>>INSERT ...
>>>INSERT ...
>>>INSERT ...
>>>COMMIT
>>>
>>>can be much faster.  This can affect INSERT and UPDATE and DELETE commands.
>>>
>>>Simon.
>>>___
>>>sqlite-users mailing list
>>>sqlite-users at mailinglists.sqlite.org
>>>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>>___
>>sqlite-users mailing list
>>sqlite-users at mailinglists.sqlite.org
>>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>___
>sqlite-users mailing list
>sqlite-users at mailinglists.sqlite.org
>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>___
>sqlite-users mailing list
>sqlite-users at mailinglists.sqlite.org
>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users

[sqlite] In the case of ZIPVFS

[Dominique Pellé]

??? <2004wqg2008 at 163.com> wrote:

> HI,all
> SQLite retrieves the compressed records is slower than the uncompressed 
> records about 30%.
> How can improve the problem?  and anyone any suggustion?
>
> best regards
> wqg


What is your SQLite page size?  If you access small
records, you're better off with a small page size (fewer
bytes to read and decompress).  If you have large BLOBs
you can afford large page sizes (better compression, which
can result in less I/Os).

Which compression algorithm are you using? You can
see the compression algorithm the first few bytes of
the database file. Some compression algorithms are
faster than others. For example, lz4hc decompression
is much faster than zlib (about 10x faster I think) at
the cost of compressing less than zlib.

Are you reading only or also writing to the DB? Some
algorithms have very different speed for compression
and decompression.

And of course, make sure that your queries minimize
the number of SQLite pages read, which is always good
whether you compress, but especially true with compressed
DB. Watch for queries doing full table scan, etc.

Regards
Dominique

[sqlite] about compile configure

[Simon Slavin]

On 23 Dec 2015, at 4:46am, ??? <2004wqg2008 at 163.com> wrote:

> sqlite3_soft_heap_limit64() , cache_szie and so on also which could not help 
> improve the speed

These commands reduce the amount of memory your application uses.  They will 
not help increase the speed unless you are repeatedly searching for the same 
rows.

Compilation options are the wrong place to look if you are trying to increase 
your speed.  You are at the wrong end of the software.  You should be looking 
at the SQL commands you execute and the schema of your tables.

You seem to be searching using the primary key of your table which is an 
integer, so there's no simple way to increase speed there.  If you really need 
every column in the table in your answer there's no way to increase speed there 
either.

Simon.

[sqlite] In the case of ZIPVFS

[Richard Hipp]

On 12/23/15, ??? <2004wqg2008 at 163.com> wrote:
> HI,all
> SQLite retrieves the compressed records is slower than the uncompressed
> records about 30%.
> How can improve the problem?  and anyone any suggustion?
>

Have you run your system in a profiler to determine where the extra
30% time is being used?  If the extra time is inside of inflate() (or
whatever other decompression algorithm you are using) or within
rijndaelDecrypt() (or whatever other decryption algorithm you are
using) then probably your only solution will be to disable encryption
and/or compression.  There is an engineering trade-off here.

Please run your system in a profiler and send us the results.  Perhaps
we can spot other opportunities to improve performance.

Also please send as many details about your system as possible.  What
kind of hardware are you using?  What operating system?  Which
compression and encryption algorithms are you using?  How large is
your dataset?  What kinds of queries are you running?  Which specific
version of the NDS dev-kit are you running?

Probably you should send us the above information through your secure
NDS support channel, rather than here in this public forum.

-- 
D. Richard Hipp
drh at sqlite.org

[sqlite] Query Regarding Shared Cache

[Richard Hipp]

On 12/22/15, Zeeshan Hussain  wrote:
> Hi All,
>
> We are using SQLite - Shared Cache for this we want to open two connection
> one from .Net and Another from C++ lib, both running in the same .Net
> process.
>
> Problem:
> It seems both the connections are using their own cache. even though we
> have opened them using same URI.

Are you linking two separate versions of the SQLite library - one for
System.Data.SQLite and the other for C++?

>
> Below is the URI
> In .Net Code : "FullUri=file::memory:?cache=shared"
> In C++ Code: "file::memory:?cache=shared"
>
> Additional Information:
> SQLite Version - 3.9.2.0
> We have created lib for C++ using following command >lib /def:sqlite3.def
> /out:sqlite3.lib
>
> Please suggest how to get this working.
>
> Thanks and regards
> Zeeshan Hussain
> Tata Consultancy Services
> Cell:- +86 18721878170
> Mailto: zeeshan.hussain at tcs.com
> Website: http://www.tcs.com
> 
> Experience certainty.   IT Services
> Business Solutions
> Consulting
> 
> =-=-=
> Notice: The information contained in this e-mail
> message and/or attachments to it may contain
> confidential or privileged information. If you are
> not the intended recipient, any dissemination, use,
> review, distribution, printing or copying of the
> information contained in this e-mail message
> and/or attachments to it are strictly prohibited. If
> you have received this communication in error,
> please notify us by reply e-mail or telephone and
> immediately and permanently delete the message
> and any attachments. Thank you
>
>
> ___
> sqlite-users mailing list
> sqlite-users at mailinglists.sqlite.org
> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>


-- 
D. Richard Hipp
drh at sqlite.org