Tom Bolton
tom.bolton at donnslaw.co.uk
Tue Jan 25 09:48:29 CST 2005
Hi Mark As outlined in Roz's original post (I'm the developer on her team building this Informix/Access monster) there aren't really any other methods than either using temp tables in your FE (as Jim helpfully suggested earlier today, and as you're doing by the sounds of it) or the method I'm using. No disrespect to Jim's ideas (check his link out, lots of useful info) but it suits my purposes better to use ADO to build tables on the Informix box, swap the data I need into them, and pull it back to the FE using pass-through queries. Be aware though, Informix temp. tables only persist as long as an Informix session, i.e. as long as you have an ODBC connection open - otherwise you have to explicitly build the tables in order to persist them between sessions. For some reason best known to someone, there's no SELECT INTO as with every other database server on the planet. HTH, if you need any more info I have it by the truckload ;-) Tom -----Original Message----- From: Mark A Matte [mailto:markamatte at hotmail.com] Sent: 25 January 2005 14:49 To: accessd at databaseadvisors.com Subject: RE: [AccessD] Data from Informix to Access - dirty reads? Hello All, Every week I do pulls from Informix to A97 using ODBC. 1 of my pulls now is around 1 million records. I use temp tables and append queries. This can take a few hours. Some of the replies in this thread imply there is a much 'better/faster' way. Without changing versions of Access...is there a way to 'tweak'/'speed up' this data pull? Thanks, Mark >From: Roz Clarke <roz.clarke at donnslaw.co.uk> >Reply-To: Access Developers discussion and problem >solving<accessd at databaseadvisors.com> >To: "'Access Developers discussion and problem >solving'"<accessd at databaseadvisors.com> >Subject: RE: [AccessD] Data from Informix to Access - dirty reads? >Date: Tue, 25 Jan 2005 09:52:19 -0000 > >Informix doesn't support XML afaik >< > >We did think about this as a way around connection issues for SQL Server >when we thought that we would have our main db replicating to SQL Server >rather than Informix - our recordsets are going to be up to about 50k rows >I >think. I don't know how XML would perform with that volume of data but it's >academic for now. > >Roz > >-----Original Message----- >From: John W. Colby [mailto:jwcolby at colbyconsulting.com] >Sent: 24 January 2005 20:58 >To: 'Access Developers discussion and problem solving' >Subject: RE: [AccessD] Data from Informix to Access - dirty reads? > > >How much data? Can it export it to an XML file in a location where your fe >can use it? XML has a high overhead but can be useful in cases like this. > >John W. Colby >www.ColbyConsulting.com > >Contribute your unused CPU cycles to a good cause: >http://folding.stanford.edu/ > >-----Original Message----- >From: accessd-bounces at databaseadvisors.com >[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Roz Clarke >Sent: Monday, January 24, 2005 10:23 AM >To: 'Access Developers discussion and problem solving' >Subject: [AccessD] Data from Informix to Access - dirty reads? > > >Hi all > > >We have a bit of a problem with getting data out of our Informix server >since we recently turned on transaction logging for replication. When >extracting data with an Access XP MDE using pass-through queries, Access >locks entire tables in the Informix database, which causes transaction >errors and makes the Informix database scarily unstable. > >Our Informix suppliers told us that the way to avoid these locking issues >was to set the connection to 'dirty read' before running the SQL. However, >Access cannot execute 2 statements in a pass-through query and it does not >hold the connection open between the execution of 1 statement and the next. >Thus when the query is processed the 'dirty read' setting is no longer in >effect. > >We have been racking our brains trying to come up with a workaround. Some >further options that we have considered are: > >* Stick the data in a temp table in Informix. This is no good because >the temp table is destroyed automatically when the connection is closed and >there's no way to make it persist long enough to bind it to a report. >* Use a view in Informix. This is no good because views in Informix >cannot be set read-only. >* Create a permanent table in Informix and destroy it when finished >with it. This is far from ideal because Informix does not support SELECT >INTO and therefore a table would have to be explicitly constructed with >names columns etc. We really need the system to be flexible so that the >queries can be easily changed. >* Use an ADO recordset. This is a PITA because you cannot bind a >report to a recordset in an MDE and we cannot build the report on the fly - >we are a Terminal Services site so we will have up to 20 users in one FE. >* Create a table in Access and destroy it when finished with it. Can't >think of a better way to induce bloating... > >Has anyone faced this kind of problem before? Any bright ideas? Our >foreheads are starting to bleed... > >TIA > >Roz (and Tom) > > >-- >AccessD mailing list >AccessD at databaseadvisors.com >http://databaseadvisors.com/mailman/listinfo/accessd >Website: http://www.databaseadvisors.com > >The contents of this message and any attachments are the property of Donns >Solicitors >and are intended for the confidential use of the named recipient only. >They may be legally > privileged and should not be communicated to, or relied upon, by any >other party without >our written consent. If you are not the addressee, please notify us >immediately so that we >can make arrangements for its return. You should not show this e-mail to >any person or > take copies as you may be committing a criminal or civil offence for >which you may be > liable. 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They may be legally privileged and should not be communicated to, or relied upon, by any other party without our written consent. If you are not the addressee, please notify us immediately so that we can make arrangements for its return. You should not show this e-mail to any person or take copies as you may be committing a criminal or civil offence for which you may be liable. The statement and opinions expressed in this e-mail message are those of the writer, and do not necessarily represent that of Donns Solicitors. Although any files attached to this e-mail will have been checked with virus protection software prior to transmission, you should carry out your own virus check before opening any attachment. Donns Solicitors does not accept any liability for any damage or loss which may be caused by software viruses...