IIUG World 2019

IIUG 2020 Online World Conference Presentations will begin soon!

Monday, June 21, 2021

Informix delivers!

This will be a quicky.

There are two things that I have been asking for in Informix for a while. One is what I consider a bug fix, bout could be considered a feature. The other is a failure to complete a feature that was never released officially and finally release and document it. Both are now in the lastest release of Informix, v14.10.FC6!

A real ROWID for partitioned tables

When table partitioning (aka fragmenting) was introduced partitioned tables did not supply access to the pseudo-column ROWID that has always been a part of Informix (and most other RDBMS) tables. It was the physical address of a row in the table and could be used to quickly access a given row. However, the rows of a partitioned table existed in multiple partitions and the Nth row in each partition would all have the same ROWID it was impractical to support the feature. So you had no built-in unique identifier you could use for tables created without a unique key. Shortly after that the option to create a partitioned table WITH ROWIDS was introduced which added a real but hidden integer column to the table and creates an index on it. However, if you created the table without the WITH ROWIDS clause and the table was very large it was impractical to add that feature to an existing table.

It seems that for a long time there has actually been a physical address of a row in a partitioned table and I have written about it before. This was the undocumented pseudo-column ifx_row_id which is a 45 byte CHAR type value containing the partition number and rowid of the row as a colon separated string. Unfortunately if you used the ifx_row_id to query a row the engine would perform a table scan rather than using the value as a row address and directly accessing the data. A SET EXPLAIN will show this behavior. Well, version 14.10.FC6 has fixed that. If you run such a query now, it is lightening fast even on a massive table and the SET EXPLAIN output will show an index scan query plan for ifx_row_id. YEEHA!

Querying LVARCHAR type columns in an array fetch

This was finally fixed in the CSDK v 4.50.xC5! Since the introduction of LVARCHAR type columns if you used an array fetch to fetch a batch of many rows into your program's memory space in a single FETCH operation you would get a spurious error (-1831 Combination of FetArrSize, Deferred-PREPARE, and OPTOFC is not supported) which have nothing to do with the actual problem which was using FetArrSize > 1 with a query that returned an LVARCHAR. This issue prevented one from using my dbcopy utility to copy any table that has one or more LVARCHAR columns or writing one from writing their own mass data processing applications. This was a large problem because array fetching is several times faster than row-by-row fetching for very large data sets.


Wednesday, June 17, 2020

Stepping into a different realm for a few minutes

This morning I was introduced to a 5 minute video recorded by Rabbi Lord Jonathan Sacks, former Chief Rabbi of the United Kingdom talking about the New Antisemitism. At the end Rabbi Sacks makes a warning that I think is relevant in this time of the incidents of overt racism in the United States and elsewhere. I therefore offer this link, not only because as a proud person of Jewish heritage it speaks of things that have affected my family and myself, but because I think that it speaks to all of us:

https://youtu.be/3UAcYn4uUbs

After that I sought other words of wisdom from Rabbi Sacks and found this TED Talk from 2017 where he asserts that today's focus on the self is a major problem in society and that a simple shift to a focus on "us" and "we" and the "other" may be the cure:

https://www.youtube.com/watch?v=F-QFwhWmC3U

If you have something constructive to offer in comment, whether you agree with Rabbi Sacks or not, I welcome the dialogue. If, on the other hand, you post comments of hatred to any person or group at all I will delete your comment. So just don't bother!


Tuesday, March 10, 2020

IIUG Forums have moved to the IBM Community Site

IIUG Forums
For those who are not aware, the IIUG SIGS or Forums, including the old comp.databases.informix Usenet group, are no longer available. They were using some very old home built software running on the old IIUG server which was quite literally falling apart.
IBM has graciously created a new Community site for IIUG forums and blogs which is accessible through the IBM web pages. Back in the depths of time, shortly after the IBM acquisition, I was opposed to efforts to bring the forums in to IBM's systems. Honestly, we had no reason 18 years ago to trust IBM would continue to support the best database system on the market, ie Informix. Today, the story is different. IBM has been a true partner to the Informix community, so I have joined the rest of the IIUG Board of Directors in making this change. The new forum is linked to the IIUG Site under the Resources menu item. The link is: www.iiug.org/community
You will need an IBM ID if you do not already have one, but that is free for the asking. When you log in to the site for the first time, please go to the Informix group page and make a “Hello world” post so that the group moderator can validate that you are not a spammer or bot. That will take an hour or so after which you will be able to post instantly! You can also create your own Blog there for the community if you want.
It is very important that EVERYONE who cares about Informix database systems join the IBM Informix Community forum and ONLY post there. IBM sees that site and counts both the number of members and the number of posts there and uses that information to determine how much attention they should pay to our favorite database system!

Tuesday, November 5, 2019

I learned something new!

Have you ever needed the functionality of ROWID for use with a partitioned table that you did not create using the WITH ROWID clause? Well, I recently found out that such a facility is available!

It is not compatible with the traditional ROWID, so you cannot just use it in applications that were written for ROWID use on single partition tables, but it works and it does not require any indexing or rebuilding your massive multi-partition table! The undocumented pseudo-column named ifx_row_id. This is a VARCHAR(45) type and it returns a string of the form "ppppppp:rrr" where the p's are the fragment's partnum and the r's are the row's actual rowid within the partition. Also it works exactly the same for single partition (ie non-fragmented) tables as it does for multi-partition tables.

You can select the ifx_row_id for any row in any table:

select ifx_row_id from systables where tabid = 1;

ifx_row_id                                    

5244160:769                                 


You can select data by ifx_rowid:

select * from systables where ifx_row_id = '5244160:769';

tabname          systables
owner            informix
partnum          5244160
tabid            1
rowsize          500
ncols            26
nindexes         2
nrows            307.0000000000
created          01/30/2019
version          65638
tabtype          T
locklevel        R
npused           22.00000000000
fextsize         16
nextsize         16
flags            0
site             
dbname           
type_xid         0
am_id            0
pagesize         2048
ustlowts         2019-11-03 08:44:57.35225
secpolicyid      0
protgranularity  
statchange       
statlevel  
       


If you do need a numeric "rowid" you could convert it to a BIGINT:


CREATE FUNCTION "art".ifx_row_id_to_rowid ( ifx lvarchar ) returning bigint;
define partnm, rw, bigrowid bigint;
define pos int;

let pos=instr( ifx, ':' );

let partnm=left( ifx, pos - 1 )::bigint;
let rw=substr( ifx, pos + 1, 10 )::bigint;
let bigrowid=(partnm * pow(2, 32 )::bigint ) + rw;

return bigrowid;
end function;  



Thursday, August 1, 2019

New RFE I have posted

Please vote for this RFE if you agree with it.

RFE URL:


RFE Description:

When creating a stored procedure or function with the IF NOT EXISTS optional clause included, the option text is currently included in the saved source code for the procedure.

This should be changed such that the optional clause is removed before saving the procedure source code in sysprocbody.

Justification:

This can confuse some software, both IBM and third party, written to analyse and support Informix and is not necessary to be saved as its addition does not change the understanding of the procedure source nor how it was created. The very fact that the source with that text was saved indicates that the procedure did not exist at the time it was last created which would be true and the only valid inference even without that text.

Similarly, when the behavior of CREATE OR REPLACE PROCEDURE/FUNCTION is fixed, that syntax should also not be saved as it also does not add to the understanding of the routine's creation and will further break third party tools.

Friday, May 31, 2019

IIUG World 2019 is coming!

The 2019 IIUG World conference registration site is open!

Register now for the Early Bird discount and save! (Don't forget to get your IIUG Member ID number so you can also get the members' discount!)

https://www.iiug.org/conf/2019/iiug/register.php

Also it is not too late to submit user session proposals to the conference board!

Tuesday, February 26, 2019

Informix to the Rescue!

It was 1990. I was brought into a major New York mutual fund and private wealth management firm (call it NB) along with another consultant to review their systems and help them plan for the future. At the time their systems were all written in FORTRAN running on Prime Systems' hardware using a non-SQL relational database system that only ran on Prime. Prime Systems had just announced that they would no longer be manufacturing hardware and would only continue supporting existing computer systems for a few years. Because of this NB needed to find new hardware, a new database system, and port all of their applications to this new environment. We were to help with the product evaluation and recommendation and estimate the porting effort at the end of which one or both of us might be hired full time.

Along the way we evaluated Sun, HP, and DEC hardware (NB was adamant that they were not interested in IBM systems). We mostly looked at various UNIX variants (System V, BSD, and OSF-1), although DEC kept saying things like "Yes, yes we have Alpha based systems running OSF and System V. You really should be looking at VAX/VMS systems!" But NB was convinced that proprietary OS's were the past, they'd just been bitten by Prime/Primos, and wanted to go with a UNIX variant. We had meetings with Oracle, Sybase, Informix, Unify, Progress, and Ingres including some demos and discussions with developers and support engineers about features and internals.

Anyway, we carefully gathered specifications, counted lines of code and numbers of modules, evaluated plans for new projects in the pipeline that had been halted after Prime's announcement, met with hardware and database vendors and after maybe six months or so we made our recommendations. Here they are with a concise brief of our reasons:

  • Hardware - Sun server blades
    HP and DEC each had multiple OS's and hardware platforms. On the OS side, UNIX wasn't the main product for either company. We were concerned about their commitment to UNIX in the future and Sun was 100% UNIX and was gaining ground in the industry.
  • OS - UNIX System V - Solaris
    See hardware...
  • Database - Informix OnLine v4.01
    NB didn't like the locking model on some of the databases. Oracle didn't have any development tools beyond a very simplistic form manager and an ESQL implementation that was incomplete against the developing standard. Also Oracle's SQL dialect did not conform well to the SQL-89 standard. Informix OnLine had row level locking, stored procedures, triggers, referential integrity, and was the first RDBMS that could be archived successfully while fully online (hence the name) processing transactions. Informix had started as a development tool company that happened to have a great database, so there was a very complete ESQL/C implementation as well as a 4th Generation Language (4GL) and high level menu, forms, and reporting tools for building quick applications when responsiveness to business requirements was needed. Sybase was similar in design to Informix, but, at the time, it did not have an ESQL/C implementation at all, only its Open Client (OC) library. While several years later OC became the ODBC v1 interface library standard, at the time it was purely proprietary to Sybase.
  • Development environment - ESQL/C (for its portability across SQL databases)
They said "Thank you." for our recommendation report, hired both of us full time, and then went ahead and bought:
  • Hardware - DEC Alpha - because DEC's stock was performing better in the market than Sun's (NB was, after all, a financial organization).
  • OS - OSF-1 - because both DEC and IBM were driving the development - "How can it not be big!"
  • Database - Sybase - because all of Wall Street was using Sybase, so NB should also! Oh, and Sybase promised to deliver an working ESQL/C in 90 days.
Anyway, long story long, we spend four months getting things up and running on the new systems and ported the first application, NB's client billings and invoice generation. First problem we ran into was how to represent portfolio values. Some financial instruments were priced in Japanese Yen, Italian Lire, and Hungarian Lira. Any client that owned many shares of any of these securities would have either a native currency value with more whole unit digits or a US currency balance with more fractional digits than a Sybase DECIMAL type could hold (15 total digits fixed as 12 to the left of the decimal and three to the right). The head of development and I attended a Sybase Financial Users Group meeting and asked them "What are you doing about this? Do any of you have, or know about, an Open Server module that can handle larger numbers?" (Open Server was a library of functions one could use to add functionality to Sybase - a unique feature at the time.) The answer was basically that "there are no such Open Server modules" because no one was willing to use the Sybase Open Server libraries to basically build a customized server (SOS modules were linked into the base server). "Then how are you handling the larger numbers for big customers with Yen and Lira securities?" we asked. The answer was "We don't have any such, and we're hoping we never do." NB did. (For what it's worth, Informix's DECIMAL type supported up to 32 decimal digits of precision, either floating point or configurable fixed point.) Strike one!

Then we started to really code the application and found that the ESQL/C that Sybase delivered was a) not ready for prime time (apps built with it kept crashing) and b) was brain dead, and missing several features of the language that we needed like named cursors and multiple cursors in a single application. Sybase wanted 12 months to get those features implemented for us. Strike two.

Strike three was performance. Our initial tests were that our brand spanking new DEC Alpha, cutting edge systems, running Sybase, would take up to 4 days to process the data and generate the invoices that the several years old, out-of-date technology of the Prime systems could get done in around one day. Strike 3. 

We called Informix, loaded up Informix Online v5.02 and ESQL/C, exported and imported the database (again), recompiled the code improving it using the features we couldn't get from the Sybase ESQL/C, and wham! We were done with Billing and invoicing in another month or so and getting the invoice runs done on a Sunday afternoon (OK after they finally went out and bought the faster and higher volume printers we had recommended because we were now generating reports faster than the operators could change the paper in the printers they originally purchased - forgot that part). Later other interactive systems were written in Informix 4GL and even a couple using Informix's Forms, Menus, and Reports modules. Go Informix!

Let me know if you want to hear more stories like this.



Monday, February 25, 2019

New series

Followers:

I am about to begin a series of posts that will hopefully be a monthly thing. The basis of the series is stories about how Informix performs against other options in the real world. Some will be older stories (I will probably start there). Others will be more recent. I encourage anyone who wants to send me stories they can relate or a pointer to someone who can relate the story to me privately and I will post these with appropriate sourcing or anonymity as requested.

I am traveling today, so I will start later this week with a story from my own experience from ancient history relating an incident where Informix and Sybase went head-to-head.

Some of the series will be short anecdotes, others more full blown out tales. I hope you enjoy.

Tuesday, October 23, 2018

IIUG World 2018

https://lnkd.in/d6siP7Y I will be presenting two sessions at the 2018 IIUG World Conference in Arlington, Virginia outside Washington DC next week. The first session is "Hello! Your data is calling!" where I will be presenting about the new "Smart Triggers" feature of Informix which allows users to create applications that passively receive notification when data in a registered table is modified. The second session is "Uninterruptable transactions with Informix!" in which I will demonstrate the Informix Transaction Survival feature that will allow active transactions to survive the crash of the primary server in a high availability or remote secondary cluster environment.

Tuesday, April 17, 2018

Looks like Oracle is worried about Informix again!

OMG, it looks like Oracle is beginning to worry about Informix! Why would I say that? Isn't Oracle "The world's most popular database!"? Why should they worry?

I dunno, but in February Oracle announced v18c (actually v12.2 but read on). This latest release of Oracle implements tons of features that have been in Informix for up to 28 years! The need to compete with Informix on features again seems to have surfaced!

Not to tout Oracle, but to point out how forward thinking the Informix development team is, witness:

  • Annual major releases with quarterly updates. To celebrate they have renamed v12.2 to be v18c after the year of its release. One assumes that the Q1 release next year will be v19c.
  • Ability to attach a table to another table as a partition - was that Informix 7.31?
  • All identifiers have been increased from 30 bytes to 128 bytes - Informix v7.30 circa 1998
  • Multitenancy
  • JSON support including dot notation in queries
    • Functions for converting table data to JSON
    • JSON operators in SQL queries
    • New API to allow JSON aware languages to query Oracle JSON documents
    • Ability to update fields within JSON documents
  • RAC based Database Sharding - well sort of. A shared RAC database can have its data segregated so that nodes only operate on a subset of the data. But it is still a monolithic store.
  • NonRAC based Database Sharding - well sort of. Applications must be shard aware. Inserts, updates, and deletes are directed to the appropriate shard in the API layer, not within the database server shard cluster.
  • "Connection Manager" enhanced to manage load balancing between multiple servers. Originally this was closer to Informix Connection Multiplexer feature.
  • Application Continuity - This is similar to Informix's Transaction Survival allowing transactions to complete when a server fails.
  • Session private temporary tables - Informix v4.01 the initial release of Informix Online circa 1990?
  • New Oracle autonomic features to allow for unmanaged cloud databases.