AW: AW: [firebird-support] How to interprete gstat-results

2016-04-14 Thread 'Checkmail' check_m...@satron.de [firebird-support] 
Hi Thomas, I will study this :)

 

Von: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com] 
Gesendet: Donnerstag, 14. April 2016 16:12
An: firebird-support@yahoogroups.com
Betreff: Re: AW: [firebird-support] How to interprete gstat-results

 

  

Hi Olaf,

> Database "D:\INTERBASE\IFLS.GDB"
> 
> Database header page information:
> 
> Flags 0
> 
> Generation 2939162
> 
> System Change Number 0
> 
> Page size 4096

You might consider increasing to 8K, especially when the tree depth of an
index starts to become > 3. To be checked with gstat -i.

> ODS version 12.0

Indeed, the database was created with Firebird 3. ;-)

> Oldest transaction 2893677

The "oldest interesting" transaction (OIT) in a state other than committed,
e.g. also rolled back. There are no record versions for transactions <
2893677 available (cause they have been garbage collected), thus one could
say why the marker is called "interesting".

> Oldest active 2929833

The oldest transaction currently active/running. This is the lowest
transaction ID which should be visible in MON$TRANSACTIONS.

> Oldest snapshot 2878316

This is the oldest transaction started in snapshot mode. Hope I remembered
that correctly.

> Next transaction 2938824

Transaction id for the next new transaction.

> Sequence number 0
> 
> Next attachment ID 87910
> 
> Implementation HW=Intel/i386 little-endian OS=Windows
> CC=MSVC
> 
> Shadow count 0
> 
> Page buffers 0

The default value in firebird.conf is used for the size of the page cache of
the database. Might be too small, depending on your use case.

> Next header page 0
> 
> Database dialect 3
> 
> Creation date Mar 7, 2016 18:33:37
> 
> Attributes force write
> 
> 
> 
> Variable header data:
> 
> Sweep interval: 5000

That's not a good idea. Because if the difference of OIT and OST (oldest
snapshot) reaches that threshold, a sweep will kick in, visits all records
in the database and removes out-dated record versions which are not
interesting for other transactions anymore.

Regarding OIT/OAT movement/gaps etc., commit retaining is one of your #1
enemies. Usually used behind the scene by drivers with auto commit = ON.

--
With regards,
Thomas Steinmaurer
 <http://www.upscene.com> http://www.upscene.com

Professional Tools and Services for Firebird
FB TraceManager, IB LogManager, Database Health Check, Tuning etc.

> 
> *END*
> 
> 
> 
> 
> 
> 
> 
> Von: firebird-support@yahoogroups.com
<mailto:firebird-support@yahoogroups.com> 
> [mailto:firebird-support@yahoogroups.com] 
> Gesendet: Donnerstag, 14. April 2016 14:03
> An:  <mailto:firebird-support@yahoogroups.com>
firebird-support@yahoogroups.com
> Betreff: Re: [firebird-support] How to interprete gstat-results
> 
> 
> 
> 
> 
>> Hello @ll,
>> 
>> 
>> 
>> we are using firebird 3.0 RC2 and have some questions about open
>> transactions. (Clients connect over odbc) The gstat output gives 7
>> transactions between the oldest and the current transaction, if we look
> into
>> the monitoring table, we see only 10 transactions. The "oldest one" we
>> cannot find in this table. What is the oldest transaction and which roll
>> does the garbage collector play? If we have many open transactions, the
>> performance is bad. What role plays the attachments? What is the best way
> to
>> check the performance bottleneck in such cases?
> 
> Please post an entire gstat -h output.
> 
> --
> With regards,
> Thomas Steinmaurer
> < <http://www.upscene.com> http://www.upscene.com>
<http://www.upscene.com> http://www.upscene.com
> 
> Professional Tools and Services for Firebird
> FB TraceManager, IB LogManager, Database Health Check, Tuning etc.
> 
> 
> 
>

Re: AW: [firebird-support] How to interprete gstat-results

2016-04-14 Thread 'Thomas Steinmaurer' t...@iblogmanager.com [firebird-support] 
Hi Olaf,

> Database "D:\INTERBASE\IFLS.GDB"
> 
> Database header page information:
> 
>Flags   0
> 
>Generation  2939162
> 
>System Change Number0
> 
>Page size   4096

You might consider increasing to 8K, especially when the tree depth of an index 
starts to become > 3. To be checked with gstat -i.

>ODS version 12.0

Indeed, the database was created with Firebird 3. ;-)

>Oldest transaction  2893677

The "oldest interesting" transaction (OIT) in a state other than committed, 
e.g. also rolled back. There are no record versions for transactions < 2893677 
available (cause they have been garbage collected), thus one could say why the 
marker is called "interesting".

>Oldest active   2929833

The oldest transaction currently active/running. This is the lowest transaction 
ID which should be visible in MON$TRANSACTIONS.

>Oldest snapshot 2878316

This is the oldest transaction started in snapshot mode. Hope I remembered that 
correctly.

>Next transaction2938824

Transaction id for the next new transaction.
 
>Sequence number 0
> 
>Next attachment ID  87910
> 
>Implementation  HW=Intel/i386 little-endian OS=Windows
> CC=MSVC
> 
>Shadow count0
> 
>Page buffers0

The default value in firebird.conf is used for the size of the page cache of 
the database. Might be too small, depending on your use case.


>Next header page0
> 
>Database dialect3
> 
>Creation date   Mar 7, 2016 18:33:37
> 
>Attributes  force write
> 
> 
> 
>Variable header data:
> 
>Sweep interval: 5000

That's not a good idea. Because if the difference of OIT and OST (oldest 
snapshot) reaches that threshold, a sweep will kick in, visits all records in 
the database and removes out-dated record versions which are not interesting 
for other transactions anymore.

Regarding OIT/OAT movement/gaps etc., commit retaining is one of your #1 
enemies. Usually used behind the scene by drivers with auto commit = ON.



--
With regards,
Thomas Steinmaurer
http://www.upscene.com

Professional Tools and Services for Firebird
FB TraceManager, IB LogManager, Database Health Check, Tuning etc.


> 
>*END*
> 
> 
> 
> 
> 
> 
> 
> Von: firebird-support@yahoogroups.com
> [mailto:firebird-support@yahoogroups.com] 
> Gesendet: Donnerstag, 14. April 2016 14:03
> An: firebird-support@yahoogroups.com
> Betreff: Re: [firebird-support] How to interprete gstat-results
> 
> 
> 
>  
> 
>> Hello @ll,
>> 
>> 
>> 
>> we are using firebird 3.0 RC2 and have some questions about open
>> transactions. (Clients connect over odbc) The gstat output gives 7
>> transactions between the oldest and the current transaction, if we look
> into
>> the monitoring table, we see only 10 transactions. The "oldest one" we
>> cannot find in this table. What is the oldest transaction and which roll
>> does the garbage collector play? If we have many open transactions, the
>> performance is bad. What role plays the attachments? What is the best way
> to
>> check the performance bottleneck in such cases?
> 
> Please post an entire gstat -h output.
> 
> --
> With regards,
> Thomas Steinmaurer
>  http://www.upscene.com
> 
> Professional Tools and Services for Firebird
> FB TraceManager, IB LogManager, Database Health Check, Tuning etc.
> 
> 
> 
>

AW: [firebird-support] How to interprete gstat-results

2016-04-14 Thread 'Checkmail' check_m...@satron.de [firebird-support] 
Hello Thomas..

 

 

Database "D:\INTERBASE\IFLS.GDB"

Database header page information:

Flags   0

Generation  2939162

System Change Number0

Page size   4096

ODS version 12.0

Oldest transaction  2893677

Oldest active   2929833

Oldest snapshot 2878316

Next transaction2938824

Sequence number 0

Next attachment ID  87910

Implementation  HW=Intel/i386 little-endian OS=Windows
CC=MSVC

Shadow count0

Page buffers0

Next header page0

Database dialect3

Creation date   Mar 7, 2016 18:33:37

Attributes  force write

 

Variable header data:

Sweep interval: 5000

*END*

 

 

 

Von: firebird-support@yahoogroups.com
[mailto:firebird-support@yahoogroups.com] 
Gesendet: Donnerstag, 14. April 2016 14:03
An: firebird-support@yahoogroups.com
Betreff: Re: [firebird-support] How to interprete gstat-results

 

  

> Hello @ll,
> 
> 
> 
> we are using firebird 3.0 RC2 and have some questions about open
> transactions. (Clients connect over odbc) The gstat output gives 7
> transactions between the oldest and the current transaction, if we look
into
> the monitoring table, we see only 10 transactions. The "oldest one" we
> cannot find in this table. What is the oldest transaction and which roll
> does the garbage collector play? If we have many open transactions, the
> performance is bad. What role plays the attachments? What is the best way
to
> check the performance bottleneck in such cases?

Please post an entire gstat -h output.

--
With regards,
Thomas Steinmaurer
  http://www.upscene.com

Professional Tools and Services for Firebird
FB TraceManager, IB LogManager, Database Health Check, Tuning etc.