Join IIUG
 for   
 

Informix News
18 Nov 13 - ZDNet - Top 20 mobile skills in demand... Read
09 Sep 13 - telecompaper - Shaspa and Tatung have shown a new smart home platform at Ifa in Berlin. Powered by the IBM Informix software... Read
06 Sep 13 - IBM data magazine - Mission Accomplished - Miami, Florida will be the backdrop for the 2014 IIUG Informix Conference... Read
01 Feb 13 - IBM Data Magazine - Are your database backups safe? Lester Knutsen (IBM Champion) writes about database back up safety using "archecker"... Read
14 Nov 12 - IBM - IBM's Big Data For Smart Grid Goes Live In Texas... Read
3 Oct 12 - The Financial - IBM and TransWorks Collaborate to Help Louisiana-Pacific Corporation Achieve Supply Chain Efficiency... Read
28 Aug 12 - techCLOUD9 - Splunk kicks up a SaaS Storm... Read
10 Aug 12 - businessCLOUD9 - Is this the other half of Cloud monitoring?... Read
3 Aug 12 - IBM data management - Supercharging the data warehouse while keeping costs down IBM Informix Warehouse Accelerator (IWA) delivers superior performance for in-memory analytics processing... Read
2 Aug 12 - channelbiz - Oninit Group launches Pay Per Pulse cloud-based service... Read
28 May 12 - Bloor - David Norfolk on the recent Informix benchmark "pretty impressive results"... Read
23 May 12 - DBTA - Informix Genero: A Way to Modernize Informix 4GL Applications... Read
9 Apr 12 - Mastering Data Management - Upping the Informix Ante: Advanced Data Tools... Read
22 Mar 12 - developerWorks - Optimizing Informix database access... Read
14 Mar 12 - BernieSpang.com - International Informix User Group set to meet in San Diego... Read
1 Mar 12 - IBM Data Management - IIUG Heads West for 2012 - Get ready for sun and sand in San Diego... Read
1 Mar 12 - IBM Data Management - Running Informix on Solid-State Drives.Speed Up Database Access... Read
26 Feb 12 - BernieSpan.com - Better results, lower cost for a broad set of new IBM clients and partners... Read
24 Feb 12 - developerWorks - Informix Warehouse Accelerator: Continuous Acceleration during Data Refresh... Read
6 Feb 12 - PRLOG - Informix port delivers unlimited database scalability for popular SaaS application ... Read
2 Feb 12 - developerWorks - Loading data with the IBM Informix TimeSeries Plug-in for Data Studio... Read
1 Feb 12 - developerWorks - 100 Tech Tips, #47: Log-in to Fix Central... Read
13 Jan 12 - MC Press online - Informix Dynamic Server Entices New Users with Free Production Edition ... Read
11 Jan 12 - Computerworld - Ecologic Analytics and Landis+Gyr -- Suitors Decide to Tie the Knot... Read
9 Jan 12 - planetIDS.com - DNS impact on Informix / Impacto do DNS no Informix... Read
8 Sep 11 - TMCnet.com - IBM Offers Database Solution to Enable Smart Meter Data Capture... Read
1 Aug 11 - IBM Data Management Magazine - IIUG user view: Happy 10th anniversary to IBM and Informix... Read
8 Jul 11 - Database Trends and Applications - Managing Time Series Data with Informix... Read
31 May 11 - Smart Grid - The meter data management pitfall utilities are overlooking... Read
27 May 11 - IBM Data Management Magazine - IIUG user view: Big data, big time ( Series data, warehouse acceleration, and 4GLs )... Read
16 May 11 - Business Wire - HiT Software Announces DBMoto for Enterprise Integration, Adds Informix. Log-based Change Data Capture... Read
21 Mar 11 - Yahoo! Finance - IBM and Cable&Wireless Worldwide Announce UK Smart Energy Cloud... Read
14 Mar 11 - MarketWatch - Fuzzy Logix and IBM Unveil In-Database Analytics for IBM Informix... Read
11 Mar 11 - InvestorPlace - It's Time to Give IBM Props: How many tech stocks are up 53% since the dot-com boom?... Read
9 Mar 11 - DBTA - Database Administration and the Goal of Diminishing Downtime... Read
2 Feb 11 - DBTAs - Informix 11.7 Flexible Grid Provides a Different Way of Looking at Database Servers... Read
27 Jan 11 - exactsolutions - Exact to Add Informix Support to Database Replay, SQL Monitoring Solutions... Read
25 Jan 11 - PR Newswire - Bank of China in the UK Works With IBM to Become a Smarter, Greener Bank... Read
12 Oct 10 - Database Trends and Applications - Informix 11.7: The Beginning of the Next Decade of IBM Informix... Read
20 Sep 10 - planetIDS.com - ITG analyst paper: Cost/Benefit case for IBM Informix as compared to Microsoft SQL Server... Read
20 Jul 10 - IBM Announcements - IBM Informix Choice Edition V11.50 helps deploy low-cost scalable and reliable solutions for Apple Macintosh and Microsoft Windows... Read
20 Jul 10 - IBM Announcements - Software withdrawal: Elite Support for Informix Ultimate-C Edition... Read
24 May 10 - eWeek Europe - IBM Supplies Database Tech For EU Smart Grid... Read
23 May 10 - SiliconIndia - IBM's smart metering system allows wise use of energy... Read
21 May 10 - CNET - IBM to help people monitor energy use... Read
20 May 10 - ebiz - IBM Teams With Hildebrand To Bring Smart Metering To Homes Across Britain... Read
19 May 10 - The New Blog Times - Misurare il consumo energetico: DEHEMS è pronto... Read
19 May 10 - ZDNet - IBM software in your home? Pact enables five-city smart meter pilot in Europe... Read
17 March 10 - ZDNet (blog) David Morgenstern - TCO: New research finds Macs in the enterprise easier, cheaper to manage than... Read
17 March 2010 - Virtualization Review - ...key components of Big Blue's platform to the commercial cloud such as its WebSphere suite of application ser vers and its DB2 and Informix databases... Read
10 February 2010 - The Wall Street Journal - International Business Machines is expanding an initiative to win over students and professors on its products. How do they lure the college crowd?... Read


End of Support Dates

IIUG on Facebook IIUG on Twitter

[ View Thread ] [ Post Response ] [ Return to Index ] [ Read Prev Msg ] [ Read Next Msg ]

IDS Forum

Re: query sqlexplain interpretation

Posted By: Fernando Nunes
Date: Wednesday, 5 November 2014, at 12:29 p.m.

In Response To: query sqlexplain interpretation (Juan Francisco González Navarro)

It's a bit harder for us to explain why it takes that time vs for you to
say with why you think it shouldn't...
We can see from the query plan that the starting point brings a lot of
records... 1.4M... It's possible that if it started from another table it
would bring less... is that your point?
Or do you think it should work faster even considering the number of rows
that match the conditions and the joins?

We could start by obtaining counts of the several tables involved using the
conditions (consider that if you're doing tabA.col1 = tabB.col1 AND
tabB.col1 BETWEEN X and Y we would need the counts for tabA and tabB).
That could give us a clue where to start the query...

We can see that the 1.4 M rows are "transported" acrross the first join but
it is drastically dropped to 40 rows on the last one... so it could be
better to do thequery the other way round... and easy way to test this
could be writing the tables in different order and use the hint ORDERED...

Besides that and as Obnoxio would answer: Have you tried UPDATE STATISTICS?
:)

On Wed, Nov 5, 2014 at 3:45 PM, Juan Francisco González Navarro <
jfrancisco.navarro@gmail.com> wrote:

> Hello:
>
> CAn someone helps me to understand why this query takes 35 seconds?
>
> Thank you.
>
> QUERY: (OPTIMIZATION TIMESTAMP: 11-05-2014 10:32:41)
> ------
> select
>
>
> c.items,b.muestra,b.prueba,b.valor,b.comentario,a.fecha,a.sid,a.pid,a.demo4,a.demo9
> from adatos a,avalor b, pruebas c where a.sid=b.sid and a.fecha=b.fecha and
> a.baja=b.baja and a.baja=c.baja and a.baja='3000-01-01 00:00:00' and
> b.status in ('V','v','I','i') and b.prueba=c.codigo and c.clase='1' and
> a.fecha between '20140530' and '20140930' and pid='1055052'
>
> Estimated Cost: 5
> Estimated # of Rows Returned: 1
>
> 1) informix.b: INDEX PATH
>
> Filters: informix.b.status IN ('V' , 'v' , 'I' , 'i' )
>
> (1) Index Name: root. 104_24
>
> Index Keys: fecha sid baja muestra prueba (Key-First) (Serial,
> fragments: ALL)
>
> Lower Index Filter: informix.b.fecha >= 20140530
>
> Upper Index Filter: informix.b.fecha <= 20140930
>
> Index Key Filters: (informix.b.baja = datetime(3000-01-01
> 00:00:00) year to second )
>
> 2) informix.c: INDEX PATH
>
> Filters: informix.c.clase = '1'
>
> (1) Index Name: informix. 298_990
>
> Index Keys: codigo baja (Serial, fragments: ALL)
>
> Lower Index Filter: (informix.b.prueba = informix.c.codigo AND
> informix.b.baja = informix.c.baja )
> NESTED LOOP JOIN
>
> 3) informix.a: INDEX PATH
>
> Filters: informix.a.pid = '1055052'
>
> (1) Index Name: root. 183_710
>
> Index Keys: fecha sid baja (Serial, fragments: ALL)
>
> Lower Index Filter: ((informix.a.baja = informix.b.baja AND
> informix.a.sid = informix.b.sid ) AND informix.a.fecha = informix.b.fecha )
> NESTED LOOP JOIN
>
> Query statistics:
> -----------------
>
> Table map :
> ----------------------------
> Internal name Table name
> ----------------------------
> t1 b
> t2 c
> t3 a
>
> type table rows_prod est_rows rows_scan time est_cost
> -------------------------------------------------------------------
> scan t1 1422778 1 1640606 00:13.55 1
>
> type table rows_prod est_rows rows_scan time est_cost
> -------------------------------------------------------------------
> scan t2 1422337 1 1422337 00:22.01 0
>
> type rows_prod est_rows time est_cost
> -------------------------------------------------
> nljoin 1422337 1 00:36.10 3
>
> type table rows_prod est_rows rows_scan time est_cost
> -------------------------------------------------------------------
> scan t3 40 1 1422337 00:20.91 0
>
> type rows_prod est_rows time est_cost
> -------------------------------------------------
> nljoin 40 1 00:57.47 5
>
> --001a1140e2c86c5f7005071e7926
>
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

--
Fernando Nunes
Portugal

http://informix-technology.blogspot.com
My email works... but I don't check it frequently...

--001a11c2ffb6d9353b05071feab9

Messages In This Thread

[ View Thread ] [ Post Response ] [ Return to Index ] [ Read Prev Msg ] [ Read Next Msg ]

IDS Forum is maintained by Administrator with WebBBS 5.12.