Re: [GENERAL] Incorrect information about GIN-index in RUM's docs

[Oleg Bartunov]

On Tue, Nov 15, 2016 at 10:37 AM, Andreas Joseph Krogh 
wrote:

> This item isn't valid, is it?
>
>
>- There isn't phrase search with GIN index. This problem relates with
>previous problem. It is need position information to perform phrase search.
>
> RUM being an extention, and having index-access-methods as extentions is
> new in 9.6, where phrase-search was introduced, this isn't really true, or
> am I missing something?
>

RUM is very good for phrase search, since it has access to coordinates in
index, check slides from PGconf.eu (
http://www.sai.msu.su/~megera/postgres/talks/pgconfeu-fts-2016.pdf).  Where
did you find the citation ?



>
> --
> *Andreas Joseph Krogh*
> CTO / Partner - Visena AS
> Mobile: +47 909 56 963
> andr...@visena.com
> www.visena.com
> 
>

[GENERAL] Incorrect information about GIN-index in RUM's docs

[Andreas Joseph Krogh]

This item isn't valid, is it?
 

 * There isn't phrase search with GIN index. This problem relates with 
previous problem. It is need position information to perform phrase search. 
RUM being an extention, and having index-access-methods as extentions is new 
in 9.6, where phrase-search was introduced, this isn't really true, or am I 
missing something?
 
-- Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
andr...@visena.com 
www.visena.com 
 

[GENERAL] Question about RUM's TODO-list

[Andreas Joseph Krogh]

Hi.
 
The following TODO-items are on RUM's TODO-list:
 

 * Allow multiple additional information (lexemes positions + timestamp). 
 * Add support for arrays. 
 
Will any of these items support storing BIGINT as part of a tsvector+timestamp?
so one an have an index like this:
create index rum_idx on message using rum (fts_all some_opclass, folder_id, 
received_timestamp)WITH (attach=received_timestamp, "to"=fts_all, 
order_by_attach=t);
 
Making it possible for a query like this to use one index:
WHERE fts_all @@ to_tsquery('simple', 'andre:*:*') AND folder_id = ANY(
ARRAY[2,3]::BIGINT[]) ORDER BY received_timestamp DESC LIMIT 10;
 
Thanks.
 
-- Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
andr...@visena.com 
www.visena.com 
 

Re: [GENERAL] How the Planner in PGStrom differs from PostgreSQL?

[Mark Anns]

Thank you so much for your references.

How the planning factors of PGStrom differs from planning factos of
PostgreSQL?



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Re: [GENERAL] How the Planner in PGStrom differs from PostgreSQL?

[John R Pierce]

On 11/14/2016 9:25 PM, Mark Anns wrote:

I am just curious about this planning factors in GPU.

There can be more than one appropriate paths in query plan tree. How the
decision for particular path has been made considering those planning
factors?



the postgresql planner considers a number of alternate execution plans, 
assigns each step of each plan a estimated cost and for each plan sums 
up those costs, the plan with the lowest cost wins.


the documentation on EXPLAIN [1] [2] goes into the basics of planning.   
Chapter 67 [3] goes into some more detail.


[1] https://www.postgresql.org/docs/current/static/using-explain.html
[2] https://www.postgresql.org/docs/current/static/planner-stats.html
[3] 
https://www.postgresql.org/docs/current/static/row-estimation-examples.html



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Re: [GENERAL] Fwd: Creating multiple instances of postresql on Windows environment

[kaustubh kelkar]

Hi,

The issue is not with server , it is running fine .
Issue is not with port either , for local machine,  I guess firewall won't
affect.


On Tue, Nov 8, 2016 at 8:14 PM, Adrian Klaver 
wrote:

> On 11/07/2016 07:27 PM, kaustubh kelkar wrote:
>
>>
>> Hi ,
>>
>> I am a PostgreSQL user who wants to create multiple instances of
>> PostgreSQL database server. I am using PostgreSQL 9.4 and above. 
>>
>> I tried to create more than 2 instances on Linux environment in which I
>> was successful. But, for windows environment, I tried with the help of
>> pgAdmin4 and with the help of commands (initdb and some more commands.)
>> In both cases , there is some issue related to the ports. Please find
>> the attached screenshot for the reference.
>>
>
> To run more then one instance of Postgres on one machine each needs its
> own port. Have you done that?
>
> The screenshot indicates a different problem, namely pgAdmin(?) cannot
> find a running server on port 5434 on the localhost. There can be several
> reasons for this:
>
> 1) The server is not running, eg the start up script failed.
> Solution: Verify the server has actually started
>
> 2) The server is not running on localhost.
> Solution: Verify where it is hosted.
>
> 3) It is running on localhost but not on port 5434.
> Solution: Verify that the port variable in postgresql.conf for
> that instance is set to 5434 and that the server was restarted to see the
> change.
>
> 3) It is running and is using port 5434, but a firewall rule is blocking
> access.
> Solution: Check whether you have a firewall running and whether it
> is blocking port 5434.
>
>
>> __ __
>>
>> Please help me to resolve the issue.
>> 
>>
>> __ __
>>
>>
>>
>>
>>
>>
>
> --
> Adrian Klaver
> adrian.kla...@aklaver.com
>



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Kaus2bh Kelkar

Re: [GENERAL] How the Planner in PGStrom differs from PostgreSQL?

[Mark Anns]

Thank you so much for your kind reply.

I am just curious about this planning factors in GPU.

There can be more than one appropriate paths in query plan tree. How the
decision for particular path has been made considering those planning
factors?





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[GENERAL] Fwd: Mail to be posted in PostgreSQL community

[kaustubh kelkar]

Hi,



Trying to create multiple database instances of PostgreSQL 9.6
In this case , trying to create 2nd instance with port 5434/5435.



*1st attempt:*




*Create new database cluster : *

C:\Program Files\PostgreSQL\9.6\installer\server>initcluster.vbs postgres
postgr

es 12345 "C:\Program Files\PostgreSQL\9.6" "C:\Program
Files\PostgreSQL\9.6\data

5434" 5433 DEFAULT



*Register as Windows Service: *

C:\Program Files\PostgreSQL\9.6\installer\server>startupcfg.vbs 9.6
postgres 123

45 "C:\Program Files\PostgreSQL\9.6" "C:\Program
Files\PostgreSQL\9.6\data5434"

postgresql-x64-9.6-5434



But after this step, new service is supposed to be found in services.msc
which is not successful.

(Reference http://stackoverflow.com/questions/6241793/are-
independent-instances-of-postgresql-possible )



*2nd attempt :*



*Create new database cluster : *

C:\Program Files\PostgreSQL\9.6\bin>initdb C:\PostgreSQL\9.6\data5435

The files belonging to this database system will be owned by user
"Administrator

".

This user must also own the server process.



The database cluster will be initialized with locale "English_United
States.1252

".

The default database encoding has accordingly been set to "WIN1252".

The default text search configuration will be set to "english".



Data page checksums are disabled.



creating directory C:/PostgreSQL/9.6/data5435 ... ok

creating subdirectories ... ok

selecting default max_connections ... 100

selecting default shared_buffers ... 128MB

selecting dynamic shared memory implementation ... windows

creating configuration files ... ok

running bootstrap script ... ok

performing post-bootstrap initialization ... ok

syncing data to disk ... ok



WARNING: enabling "trust" authentication for local connections

You can change this by editing pg_hba.conf or using the option -A, or

--auth-local and --auth-host, the next time you run initdb.



Success. You can now start the database server using:



"pg_ctl" -D "C:\PostgreSQL\9.6\data5435" -l logfile start


*Register as Windows Service: *


C:\Program Files\PostgreSQL\9.6\bin>pg_ctl register -N pgsql-9.6-5435 -U
administrator -P test@123 -D "C:\PostgreSQL\9.6\data5435" -o "-p 5435"



C:\Program Files\PostgreSQL\9.6\bin>net start pgsql-9.6-5435

The pgsql-9.6-5435 service is starting.

The pgsql-9.6-5435 service was started successfully.



(Reference: http://www.dbforums.com/showthread.php?1669767-How-to-
create-two-different-postgresql-services-for-configure-database  )



*After trying to login through SQL shell*

Server [localhost]:

Database [postgres]:

Port [5433]: 5435

Username [postgres]:

psql: FATAL:  role "postgres" does not exist

Press any key to continue . . .

 * *

Kaus2bh Kelkar

Re: [GENERAL] How the Planner in PGStrom differs from PostgreSQL?

[Kouhei Kaigai]

Sorry, I got the question a week before from the sender but couldn't respond 
timely.

> I am reading through Postgres and PGStrom. Regarding the planning factors,
> I need some clarifications. Can u help me with that?
> 
> Planner in Postgres checks for different scan and join methods, and then
> find the cheapest one and creates a query plan tree. While going for same
> thing in GPU, the checks should also be made for, whether it is device
> executable or not and the query plan tree from Postgres has been updated.
> 
> How this planning in GPU actually works for? How to determine device
> executables? What are the factors considered for the planner in GPU?
>
PostgreSQL v9.5 newly adds custom-scan interface that allows extensions
to add its own path prior to selection of the cheapest path.
What PG-Strom generally does is (1) check whether the scan qualifier can
be executable on GPU device, (2) if yes, construct a CustomScanPath with
estimated cost value, (3) then, add_path() to register the CustomScanPath
node.
If cost of CustomScanPath is cheaper than others, it shall be chosen.
Its logic is same with a case when planner choose either of SeqScan or
IndexScan.

> For example, in gpujoin.c, the function responsible for this plan is
> pgstrom_post_planner_gpujoin. What is the work of this function? What is
> this actually doing?  It is updating some target list. What are they? It
> is checking for pgstrom_device_expression(tle->expr) i.e., for device
> executables. What are the tasks covered under this?
>
That is an ad-hoc surgical operation on the plan-tree once constructed.
It shall be removed in the v9.6 based implementation because of planner
infrastructure improvement.

In v9.5, we cannot attach general expression node on the target-list
of the plan-node under the create_plan_recurse(), thus, PG-Strom cannot
determine how device-side projection works. So, it hooks planner_hook
to adjust the plan tree. For example, if final target list contains
something like (x * y - z), it is more reasonable to reference the result
of calculated result in GPU rather than returning 3 attributed from GPU
and calculating on CPU.

Unlike your expectation, pgstrom_post_planner_gpujoin() does not perform
primary role on GPU path construction. I'd like to follow the code path
from the gpujoin_add_join_path().

Best regards,

> -Original Message-
> From: pgsql-general-ow...@postgresql.org
> [mailto:pgsql-general-ow...@postgresql.org] On Behalf Of Mark Anns
> Sent: Thursday, November 10, 2016 4:12 PM
> To: pgsql-general@postgresql.org
> Subject: [GENERAL] How the Planner in PGStrom differs from PostgreSQL?
> 
> I am reading through Postgres and PGStrom. Regarding the planning factors,
> I need some clarifications. Can u help me with that?
> 
> Planner in Postgres checks for different scan and join methods, and then
> find the cheapest one and creates a query plan tree. While going for same
> thing in GPU, the checks should also be made for, whether it is device
> executable or not and the query plan tree from Postgres has been updated.
> 
> How this planning in GPU actually works for? How to determine device
> executables? What are the factors considered for the planner in GPU?
> 
> For example, in gpujoin.c, the function responsible for this plan is
> pgstrom_post_planner_gpujoin. What is the work of this function? What is
> this actually doing?  It is updating some target list. What are they? It
> is checking for pgstrom_device_expression(tle->expr) i.e., for device
> executables. What are the tasks covered under this?
> 
> Best regards
> 
> 
> 
> --
> View this message in context:
> http://postgresql.nabble.com/How-the-Planner-in-PGStrom-differs-from-P
> ostgreSQL-tp5929724.html
> Sent from the PostgreSQL - general mailing list archive at Nabble.com.
> 
> 
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Re: [GENERAL] C code with embedded SQL

[John R Pierce]

On 11/14/2016 10:21 AM, Poul Kristensen wrote:

Can't the gcc compiler be used for the subject


oops, left out the documentation link re ECPG,

https://www.postgresql.org/docs/current/static/ecpg.html



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Re: [GENERAL] C code with embedded SQL

[John R Pierce]

On 11/14/2016 10:21 AM, Poul Kristensen wrote:

Can't the gcc compiler be used for the subject

I have ordered the book "Postgresql for develophers" and hope to see
some examples there
covering C(Gnu) with embedded SQL.


are you talking about ECPG ?


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[GENERAL] C code with embedded SQL

[Poul Kristensen]

Can't the gcc compiler be used for the subject

I have ordered the book "Postgresql for develophers" and hope to see
some examples there
covering C(Gnu) with embedded SQL.

Thanks

Poul

Re: [GENERAL] C code with embedded SQL

[Joshua D. Drake]

On 11/14/2016 10:21 AM, Poul Kristensen wrote:

Can't the gcc compiler be used for the subject


Without sample code and an error message there isn't much we can do here.

jD



I have ordered the book "Postgresql for develophers" and hope to see
some examples there
covering C(Gnu) with embedded SQL.

Thanks

Poul



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Re: [GENERAL] Converting a TimestampTz into a C# DateTime

[Arjen Nienhuis]

On Nov 14, 2016 12:53, "valeriof"  wrote:
>
> Hi,
> I'm handling a TimestampTz value inside a plugin to stream WAL changes to
a
> .NET client application. What I'm trying to do is to return all possible
> column changes as binary (don't like to have Postgres handle the
conversion
> to string as I may need to have access to the bytes at the client level).
In
> case of a TimestampTz, is it possible to return the 8-bytes long integer
and
> then from the C# application convert the value to Ticks?

Npgsql supports the binary COPY protocol. Their implementation is here:

https://github.com/npgsql/npgsql/blob/dev/src/Npgsql/TypeHandlers/DateTimeHandlers/TimeStampHandler.cs

Re: [GENERAL] Converting a TimestampTz into a C# DateTime

[Tom Lane]

Jerome Wagner  writes:
> seeing you answer I have a question for which I found no answer a few weeks
> ago : is there a way to know at runtime which internal representation
> timestamps have ?

You can inspect the integer_datetimes setting, via SHOW or
current_setting().  In a libpq client it's also directly available
from PQparameterStatus().

regards, tom lane


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Re: [GENERAL] Converting a TimestampTz into a C# DateTime

[Albe Laurenz]

Jerome Wagner wrote:
> seeing you answer I have a question for which I found no answer a few weeks 
> ago : is there a way to
> know at runtime which internal representation timestamps have ?
> I am trying to deal with the COPY binary protocol with only SQL access to the 
> remote server and would
> like to find a way to know the internal representation to read / write the 
> correct timestamps.

I guess you have to use the SPI interface to run the SQL statement

   SHOW integer_datetimes;

and check if the result is 'on'.

Yours,
Laurenz Albe

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Re: [GENERAL] Converting a TimestampTz into a C# DateTime

[Jerome Wagner]

Hello,
seeing you answer I have a question for which I found no answer a few weeks
ago : is there a way to know at runtime which internal representation
timestamps have ?
I am trying to deal with the COPY binary protocol with only SQL access to
the remote server and would like to find a way to know the internal
representation to read / write the correct timestamps.
Thanks for your help  !

On Mon, Nov 14, 2016 at 1:12 PM, Albe Laurenz 
wrote:

> valeriof wrote:
> > I'm handling a TimestampTz value inside a plugin to stream WAL changes
> to a
> > .NET client application. What I'm trying to do is to return all possible
> > column changes as binary (don't like to have Postgres handle the
> conversion
> > to string as I may need to have access to the bytes at the client
> level). In
> > case of a TimestampTz, is it possible to return the 8-bytes long integer
> and
> > then from the C# application convert the value to Ticks?
>
> Sure, if you know how it is stored internally.
>
> One of your problems will be that the format depends on whether PostgreSQL
> was configured with --disable-integer-datetimes or not.
>
> With that switch, a timestamp is a double precision value, otherwise a
> 64-bit integer value. In the former case, it measures seconds after
> midnight 2000-01-01, while in the latter case it measures microseconds
> after that timestamp.
>
> Yours,
> Laurenz Albe
>
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Re: [GENERAL] Syncing Data of data type BLOB into Postgres- Bytea

[Adrian Klaver]

On 11/13/2016 11:40 PM, Cynthia Hombakazi Ngejane wrote:

Please reply to list also.
Ccing list.


9.3
it just says syntax error near (


Can you show the actual complete error?


I have a variable QByteArray that stores the fingerprint data, then:
I am using QString Query = "insert into tableName(colName) values
(:valName)";


What is the actual value of :valName?

In other words is it the raw value or has it been escaped per here:

https://www.postgresql.org/docs/9.3/static/datatype-binary.html


prepare the query;
then query.bindValue;

lastly query.exec();

On 10 November 2016 at 16:31, Adrian Klaver > wrote:

On 11/09/2016 11:35 PM, Cynthia Hombakazi Ngejane wrote:



Hello,

I have two databases SQLlite and Postgres,  SQLite is my local
database
in it I am saving fingerprint templates that get capture onsite (i.e
offline) and my column is of type BLOB. Now I want to sync these
templates into Postgres (to the server), so I created a column
of type
bytea but Postgres is refusing to take BLOB it says there was a
syntax
error. I am using Qt c++ 5.7  application  to do the syncing.


What version of Postgres?

What is the syntax error?

What is the code you are using to insert/update the data into Postgres?


Please Help...

CH Ngejane




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Re: [GENERAL] Syncing Data of data type BLOB into Postgres- Bytea

[Adrian Klaver]

On 11/13/2016 11:40 PM, Cynthia Hombakazi Ngejane wrote:

9.3
it just says syntax error near (
I have a variable QByteArray that stores the fingerprint data, then:
I am using QString Query = "insert into tableName(colName) values
(:valName)";
prepare the query;
then query.bindValue;

lastly query.exec();



On my last post I never did get to the point I was trying to make, that 
this this may be a string escaping issue. To help with identifying the 
problem it would be good to know the value of:


standard_conforming_strings

in postgresql.conf and whether it is commented out or not.



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Re: [GENERAL] Converting a TimestampTz into a C# DateTime

[Albe Laurenz]

valeriof wrote:
> I'm handling a TimestampTz value inside a plugin to stream WAL changes to a
> .NET client application. What I'm trying to do is to return all possible
> column changes as binary (don't like to have Postgres handle the conversion
> to string as I may need to have access to the bytes at the client level). In
> case of a TimestampTz, is it possible to return the 8-bytes long integer and
> then from the C# application convert the value to Ticks?

Sure, if you know how it is stored internally.

One of your problems will be that the format depends on whether PostgreSQL
was configured with --disable-integer-datetimes or not.

With that switch, a timestamp is a double precision value, otherwise a
64-bit integer value. In the former case, it measures seconds after
midnight 2000-01-01, while in the latter case it measures microseconds
after that timestamp.

Yours,
Laurenz Albe

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[GENERAL] Converting a TimestampTz into a C# DateTime

[valeriof]

Hi,
I'm handling a TimestampTz value inside a plugin to stream WAL changes to a
.NET client application. What I'm trying to do is to return all possible
column changes as binary (don't like to have Postgres handle the conversion
to string as I may need to have access to the bytes at the client level). In
case of a TimestampTz, is it possible to return the 8-bytes long integer and
then from the C# application convert the value to Ticks? 

Thanks,
Valerio



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Re: [GENERAL] Sequential parallel scan / agg

[Tobias Bussmann]

Hi,

On 2016-11-13 23:04:44 +, James Sewell said:
>   1.  INSERT ... SELECT doesn't work
>   2.  WITH a AS (SELECT ...) INSERT FROM a doesn't work
>   3.  SELECT .. INTO doesn't work
>   4.  SELECT with no insert does work as expected
>> 
>> CREATE TABLE blah AS SELECT ...  ?

Unfortunately, in these cases the current parallelism features cannot be used 
as all of these queries do write data. See in the doc [1] at "When Can Parallel 
Query Be Used?" 

> Even when it is in general possible for parallel query plans to be generated, 
> the planner will not generate them for a given query if any of the following 
> are true:
>   •   The query writes any data or locks any database rows. If a 
> query contains a data-modifying operation either at the top level or within a 
> CTE, no parallel plans for that query will be generated. This is a limitation 
> of the current implementation which could be lifted in a future release.

Best
Tobias

[1]: 
https://www.postgresql.org/docs/current/static/when-can-parallel-query-be-used.html



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Re: [GENERAL] Request to share information regarding deadlock in postgresql-8.1.18

[John R Pierce]

On 11/13/2016 11:52 PM, Yogesh Sharma wrote:

you can look those relation numbers up in the pg_catalog to see what they are.  
 you can see what the processes are in pg_stat_activity.

Currently machine is not available. Please suggest if any other approach  to 
identify the same.



without access to the system thats generating the error, there's nothing 
you can learn.



>THis has nothing to do with the growing WAL logs...something is blocking 
checkpoints if a single WAL file keeps >growing, are you using some form of wal 
archiving, is that working correctly ? could something
>be preventing checkpoints?what are the related checkpoint and WAL settings?

Many WAL files are generated in pg_xlog directory. I don’t know how I can check 
checkpoint and WAL settings?
By default setting of postgresql.conf is used.


I just noticed, you're talking about postgresql 8.1.18?thats an 
unsupported and obsolete version from 2009.


A standalone postgres installation that hasn't been configured for WAL 
archiving will normally only generate up to 2*CHECKPOINT_SEGMENTS + 1 
wal files of 16MB each (assuming all defaults, thats 7 files).The 
obsolete 8.1 documentation on this is here, 
https://www.postgresql.org/docs/8.1/static/wal-configuration.html


If you've configured wal archiving, AND this isn't working correctly, 
WAL files can stack up indefinitely.  See 
https://www.postgresql.org/docs/8.1/static/backup-online.html




--
john r pierce, recycling bits in santa cruz