Pasha Golub's Blog

Joomla! 2.5 with PostgreSQL support officially released

pashagolub — Wed, 25 Jan 2012 12:49:49 +0000

Joomla, one of the world’s most popular open source content management systems (CMS) used for everything from websites to blogs to Intranets, today announces the immediate availability of Joomla 2.5. Along with new features such as advanced search and automatic notification of Joomla core and extension updates, the Joomla CMS for the first time includes multi-database support with the addition of Microsoft SQL Server. Previous versions of Joomla were compatible exclusively with MySQL databases.

Way to go Joomla! But why don’t you guys mention PostgreSQL database in the main release story? Do you really think that MSSQL is more common choice for the database layer for any CMS? Seriously?

UPD Apparently I was a little rushed. PostgreSQL and Oracle support must be added in the shortest time. Waiting for explanations from Joomla!

Filed under: Announces, PostgreSQL Tagged: CMS, Joomla!, microsoft sql server, PostgreSQL, release

Why you cannot create table and PK constraint with the same name

pashagolub — Thu, 12 Jan 2012 12:37:03 +0000

Very interesting message appeared on the pgsql-bugs@postgresql.org list today:

When I do this

CREATE TABLE "T1" ( "T1_ID" bigint NOT NULL, CONSTRAINT "T1" PRIMARY KEY ("T1_ID" ) );

I get the following message:
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "T1" for table "T1" ERROR: relation "T1" already exists ********** Error ********** ERROR: relation "T1" already exists SQL state: 42P07

It does NOT create either the table or the constraint, and the message is confusing because there is no relation by that name.

The SQLSTATE 42P07 is described in the manual as only as “table undefined”, and it is not clear if the intent is to allow or
disallow the creation of a constraint called the same as the table in Postgresql. Oracle 11g allows this, but my feeling is that
doing this should not be allowed, just as Postgresql handles it.

I am complaining about the confusing error message which IMO is off-topic, not about how the DB handles this.

The quick answer is PRIMARY KEY constraint always has underlying system index with the same name. Thus to implement CREATE statement above PostgreSQL should create table with the name “T1″ and the index with the same name. This is impossible, because tables and indexes are stored in the same system catalog pg_class (they share the same namespace). That is where ambiguity appears. The same is true for UNIQUE constraint.

On the other hand you may freely create CHECK constraint under such conditions:
CREATE TABLE "T1" ( "T1_ID" bigint NOT NULL, CONSTRAINT "T1" CHECK ("T1_ID" > 0 ) );

Filed under: PostgreSQL Tagged: bug, development, PostgreSQL, SQL, trick

Determination of a leap year in PostgreSQL

pashagolub — Wed, 28 Dec 2011 11:28:39 +0000

From Wikipedia:

A leap year (or intercalary or bissextile year) is a year containing one extra day (or, in the case of lunisolar calendars, a month) in order to keep the calendar year synchronized with the astronomical or seasonal year. Because seasons and astronomical events do not repeat in a whole number of days, a calendar that had the same number of days in each year would, over time, drift with respect to the event it was supposed to track. By occasionally inserting (or intercalating) an additional day or month into the year, the drift can be corrected. A year that is not a leap year is called a common year.

So to determine whether a year is a leap year or not in either the Gregorian calendar we need to check such condition:

(Year mod 4 = 0) AND ((Year mod 100 != 0) or (Year mod 400 = 0)),

where mod is modulo operation

This dirty query does the trick then:

SELECT c.y, (c.y % 4 = 0) AND ((c.y % 100 <> 0) OR (c.y % 400 = 0)) 
 FROM generate_series(1582, 2020) AS c(y)

I prefer to have function for this task. First I thought it must be written in plpgsql to be fast enough. Yeah, I’m to lazy for C functions. However after tests I saw that SQL function has the same productivity. Don’t know why. Here the sources for both of them:

CREATE OR REPLACE FUNCTION isleapyear(year integer)
 RETURNS boolean AS
'SELECT ($1 % 4 = 0) AND (($1 % 100 <> 0) or ($1 % 400 = 0))'
 LANGUAGE sql IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION isleapyear(year integer) RETURNS boolean AS 'BEGIN RETURN (Year % 4 = 0) AND ((Year % 100 0) or (Year % 400 = 0)); END' LANGUAGE plpgsql IMMUTABLE STRICT;

P.S. Some funny traditions:

On the British isles, it is a tradition that women may propose marriage only on leap years.
In Denmark, the tradition is that women may propose on the bissextile leap day, February 24, and that refusal must be compensated with 12 pairs of gloves.
In Finland, the tradition is that if a man refuses a woman’s proposal on leap day, he should buy her the fabrics for a skirt.

Filed under: Coding Tagged: leap year, plpgsql, PostgreSQL, SQL, trick

Holiday discounts on pgmdd & postgresdac

pashagolub — Wed, 28 Dec 2011 08:01:48 +0000

Holidays came suddenly. I know we’re little bit late with Christmas presents, but who cares anyway!

Everybody is welcome to use “Christmas” coupon code till January 14 for 20% discount on any product from MicroOLAP Technologies including the most robust Database Designer for PostgreSQL and PostgresDAC component suite.

From all of us at MicroOLAP, we wish you happy holidays and a prosperous new year!

Filed under: Announces, MicroOLAP Database Designer for PostgreSQL, PostgresDAC Tagged: designer, ER, gift, happy holidays, PostgresDAC, PostgreSQL

Database Designer for PostgreSQL 1.8.2 released

pashagolub — Tue, 20 Dec 2011 13:45:16 +0000

Database Designer for PostgreSQL is an easy CASE tool which works natively under Windows OS family and Linux under Wine/WineHQ.

This is mostly bug fixing release. You should update your version of database designer as soon as possible.

You’re welcome to download the Database Designer for PostgreSQL 1.8.2 right now at:
http://microolap.com/products/database/postgresql-designer/download/

Full changelog:

[*] “ALTER TABLE SET WITH OIDS” support added to Modify Database engine
[*] Functions body is now printed as is without leading tabs
[-] “Cannot add WHERE predicate for index in Table Editor” bug fixed
[-] “Evaluation type for stored routine is always VOLATILE after Reverse Engineering” bug fixed
[-] “Find & Replace functionality is broken in SQL Executor” bug fixed
[-] “Model repair doesn’t work until table coloring option is selected” bug fixed
[-] “Modify Database ignores unchecked Grant Privileges option sometimes” bug fixed
[-] “Modify Database using incorrect syntax for ADD CONSTRAINT if tablespace specified” bug fixed
[-] “Object Tree View doesn’t refresh Roles and Tablespaces count after changes” bug fixed
[-] “Privileges are lost for schemes after editing in Schema Manager” bug fixed
[-] “Privileges are lost for schemes after model saving” bug fixed
[-] “Role name must be quoted in CREATE DATABASE statement” bug fixed
[-] “Semicolon needed after REVOKE statement in Modify Database script” bug fixed
[-] “Some functions may have the same ID” bug fixed
[-] Bugs in Privilege Manager fixed

Please don’t hesitate to ask any questions or report bugs with our Support Ticketing system available at
http://www.microolap.com/support/

Filed under: Announces

Popularity of database servers by Jelastic PaaS

pashagolub — Tue, 13 Dec 2011 09:17:19 +0000

Today found an interesting statistics by Jelastic platform on database servers used in November 2011.

As before, MySQL is still the leader. PosgreSQL takes second place of honor, followed by MariaDB. Only one of the NoSQL databases MongoDB showed very good results in November.

If compare current data with the October, we can conclude that the number of fans did not change.

Current numbers:

	Europe	North America	Total
MySQL	45%	44%	44%
PostgreSQL	17%	12%	21%
MariaDB	18%	24%	15%
MongoDB	20%	20%	20%

According to the table we need PgConf.eu twice a year.

Filed under: PostgreSQL Tagged: PostgreSQL, stats

PostgresDAC 2.7.0 is out!

pashagolub — Mon, 14 Nov 2011 10:29:12 +0000

This release introduces support for RAD Studio XE2 (including Win32 & Win64 compilers) and PostgreSQL 9.1. Database engine packages for FastReport added. Migration component improved a lot.

Full changelog:
[!] Support for RAD Studio XE2 added
[!] v9.1.0 client libraries added
[!] v9.1.0 dump & restore libraries (pg_dump.dll, pg_restore.dll)
[!] DB engine for FastReport added
[-] “TPSQLDump ignores TPSQLDatabase.Params on connection” bug fixed
[+] Ability to convert MySQLDAC components by TBDE2PSQLDAC added
[+] ConvertComponents property added to TBDE2PSQL migration component
[+] dfDirectory format added to TPSQLDump
[+] SourceConnection property added to TBDE2PSQL migration component
[+] TPSQLDump doNoSecurityLabels option added to exclude security labels from dump
[+] TPSQLDump doNoUnloggedTableData option added to exclude contents of unlogged tables from the dump
[+] TPSQLDump doQuoteAllIdentifiers option added to force quoting of all identifiers
[+] TPSQLDump doSerializableDeferrable option added to use a serializable transaction for the dump
[+] TPSQLNotify.SendNotify supports Payload parameter
[+] TPSQLNotify.UnlistenAll method added
[+] XE2 SSH packages added

You’re welcome to download the PostgresDAC v2.7.0 right now at:
http://microolap.com/products/connectivity/postgresdac/download/
or login to your private area on our site at
http://microolap.com/my/downloads/

Filed under: Announces Tagged: component, Delphi, PostgresDAC, PostgreSQL, release

PGConf.EU 2011: My schedule

pashagolub — Wed, 12 Oct 2011 08:28:11 +0000

I’m very exciting about upcoming PGConf.EU 2011, which will be held in Amsterdam, The Netherlands this month. And it’s time to choose the most interesting talks to visit. So I prefer these:

Wednesday, October 19

11:10 - 12:00 PostgreSQL 9.1 - what's new Magnus Hagander

Despite the fact I read a lot about new Pg 9.1 features, it’s always interesting to get overview by someone who knows system very well and spent a lot of time developing it.

12:10 - 13:00 Look Out The Window Functions (and free your SQL) Gianni Ciolli

It’s a shame, but I really know a little about this powerful functionality.

Lunch!

It goes without saying!

14:00 - 14:50 Explaining the Postgres Query Optimizer Bruce Momjian

I hope index-only scans will be presented here also.

15:20 - 16:10 Asynchronous Notifications for Fun and Profit Marc Balmer

I like NOTIFY\LISTEN functionality a lot, but sometimes it’s hard to find really useful use case for demonstration to clients.

16:20 - 17:10 Review of Patch Reviewing Stephen Frost

Development process! What else to say?!

Thursday, October 20

09:30 - 10:20 Improving VACUUM Suction Greg Smith

I liked the title.

10:50 - 11:40 Extensions are good for business logic Dimitri Fontaine

Had no time to give extensions a chance. This time I will.

11:50 - 12:40 Fast GiST index build Alexander Korotkov

Want to know more about techniques used.

13:40 - 14:30 More Mistakes Were Made Selena Deckelmann

Have no idea what all of this is about, but I need to see Selena.

14:40 - 15:30 Port databases from MySQL to PostgreSQL Andreas Scherbaum

Want to know what’s new in this area appeared.

Friday, October 21

09:30 - 10:20 Relational Database Designer for pgAdmin Guillaume Lelarge, Luis Ochoa

Frankly speaking this is the first hard choice for me. I would like to listen Simon’s roadmap for PostgreSQL too. But ER-designer is my proffesional interest. So without a chance.

10:50 - 11:40 Bottom-up Database Benchmarking Greg Smith

Benchmarking is so elusive subject, but exciting at the same time.

11:50 - 12:40 Mission impossible? Can I replace my most important databases with PostgreSQL? Michael Meskes

Holy war detected!

13:40 - 14:30 Managing Terabytes Selena Deckelmann

Never had deal with such huge databases, but need to know how it is.

Meet me at the PGConf.EU soon!

Filed under: PostgreSQL Tagged: pgconf.eu, PostgreSQL

PostgresDAC 2.7.0 Beta is available

pashagolub — Wed, 05 Oct 2011 09:53:48 +0000

Attention should be paid to RAD Studio XE2 Win32 support testing and specific PostgreSQL 9.1 features testing (especially dump and restore functionality). FastReport engine added. TBDE2PSQL migration component improved.

You’re welcome to download the PostgresDAC v2.7.0 Beta right now at:
http://microolap.com/products/connectivity/postgresdac/download/
or login to your private area on our site at
http://microolap.com/my/downloads/

Filed under: Announces Tagged: beta, component, Delphi, PostgresDAC, PostgreSQL

MicrOLAP Database Designer with PostgreSQL 9.1 support is out!

pashagolub — Tue, 20 Sep 2011 10:12:47 +0000

Database Designer for PostgreSQL is an easy CASE tool which works natively under Windows OS family and Linux under Wine/WineHQ.

This release introduces new functionality as well as several bug fixes. Support for PostgreSQL 9.1 added, new Create HTML Report functionality present, unlogged tables support added, Database Generation and
Modification dialogs improved.

You’re welcome to download the Database Designer for PostgreSQL 1.8.1 right now at:
http://microolap.com/products/database/postgresql-designer/download/

Full changelog:

[+] Name patterns for newly created objects supported
[+] Object selection added to Create HTML Report dialog
[+] Support for unlogged tables using the UNLOGGED option added
[*] Additional checks added for dependent composite types during model loading
[*] Improved processing for fields deletion with referenced foreign keys in Modify engine
[*] Syntax highlighting improved for base types
[-] “Access violation on Privilege Manager Add button click” bug fixed
[-] “Cannot cast type text[] to text error during Reverse Engineering on pre-8.2 servers” bug fixed
[-] “EInvalidCast error occurs during deletion of domain in Domain & UDT Manager” bug fixed
[-] “Relation ‘pg_users’ does not exist during Reverse Engineering on pre-8.1 servers” bug fixed
[-] “Some sequences may not be generated using Generate Database dialog” bug fixed
[-] “Stamp colors are not saved” bug fixed
[-] “Stored Routine Editor disallows non-Latin character in routine name” bug fixed

Please don’t hesitate to ask any questions or report bugs with our Support Ticketing system available at
http://www.microolap.com/support/

Filed under: Announces Tagged: designer, ER, pgmdd, PostgreSQL, release