Re: IDS to DB2 conversion

Well, I checked out the presentation, and it does give me pause. Thanks! Tim "Serge Rielau" <srielau@ca.eye-be-em.com> wrote in message news:bvo9gn$rv5$1@hanover.torolab.ibm.com... > And check out Bob Carts' seesion in WAIUG: > http://www.iiug.org/waiug/present/meeting200401/index.html > > Cheers > Serge > > -- > Serge Rielau > DB2 SQL Compiler Development > IBM Toronto Lab

Tim Schaefer wrote: > Well, I checked out the presentation, and it does give me pause. Why? > "Serge Rielau" <srielau@ca.eye-be-em.com> wrote in message > news:bvo9gn$rv5$1@hanover.torolab.ibm.com... >> And check out Bob Carts' seesion in WAIUG: >> http://www.iiug.org/waiug/present/meeting200401/index.html -- "C'est pas parce qu'on n'a rien ' dire qu'il faut fermer sa gueule" - Coluche

Don't you ever sleep geezuz. :-) So far a couple of things that the ppt showed that DB2 is clearly behind in a few things. But I'm not just reading that ppt from an Informix perspective, but also how it stacks up to SQL-Server, and here's where the wheels start to come off on a couple of missing features in DB2. It's not terrible stuff, but glaring enough. I'm a bit concerned about log management in DB2 for example, already a real annoyance in SQL-Server, you can't turn it off, but apparently in DB2 you can when using the "high-speed" loader. I guess DB2 will end up being more like SQL-Server/Sybase than Informix. Protected logs. Bummer on log management. Was hoping to be able to control logs like Informix. I find it interesting that you can't alter a table or columns, in DB2, is that really true? That's kinda primitive isn't it? No virtual table interface either. Hmmmm. Too bad. Just a few things I find annoying, but in context, Informix is not an option for us, we have to choose anything but. Tim "Obnoxio The Clown" <obnoxio@hotmail.com> wrote in message news:bvpdte$vauff$3@ID-64669.news.uni-berlin.de... > Tim Schaefer wrote: > > > Well, I checked out the presentation, and it does give me pause. > > Why? > > > "Serge Rielau" <srielau@ca.eye-be-em.com> wrote in message > > news:bvo9gn$rv5$1@hanover.torolab.ibm.com... > >> And check out Bob Carts' seesion in WAIUG: > >> http://www.iiug.org/waiug/present/meeting200401/index.html > > -- > "C'est pas parce qu'on n'a rien ' dire qu'il faut fermer sa gueule" > - Coluche

Tim Schaefer wrote: > Don't you ever sleep geezuz. Not enough, no. > I find it interesting that you can't alter a table or columns, > in DB2, is that really true? That's kinda primitive isn't it? You can't drop a column, is all. You can add columns and change the data type, AFAIK. Ironically enough, RedBrick is also pretty crap at dropping columns -- you can do it, but it will randomly shag your table. :o) -- "C'est pas parce qu'on n'a rien ''' dire qu'il faut fermer sa gueule" - Coluche

Tim Schaefer wrote: > Just a few things I find annoying, but in context, Informix is not > an option for us, we have to choose anything but. One of the more interesting things I found was the implicit observation on performance: "adequate" with indexes. I wonder how much of a drop can still be considered "adequate"...? -- "C'est pas parce qu'on n'a rien ''' dire qu'il faut fermer sa gueule" - Coluche

Schema evolution is coming. DB2 Stinger brings minor stuff like DROP/ADD IDENTITY and generated as well as ALTER DEFAULT. The more serious stuff will follow later. Temp tables can be NOT LOGGED with defined behaviour on what happens on COMMIT/ROLLBACK. I saw in the presentation that UPDATE FROM was pointed out. DB2 supports MERGE with is SQL standard and a superset of UPDATE FROM. DB2 Stinger will also bring an onstat like tool (no it won't be called onstat of course) What is a virtual table interface? DB2 supports table functions and wrappers. Table functions are read-only though. A nickname on a wrapper supports full DML. Sometimes the same function is just implemented in another way.... Cheers Serge -- Serge Rielau DB2 SQL Compiler Development IBM Toronto Lab

Serge Rielau wrote: > Schema evolution is coming. That's wonderful. What does it mean, though? > DB2 Stinger will also bring an onstat like tool (no it won't be called > onstat of course) db2stat? > What is a virtual table interface? It is a mechanism that allows you to write an interface for _any_ data source and access it via IDS as though it was a table. A similar mechanism exists for creating indexes on such data sources. A bit like federation, except it allows you to access and index *any* data source, the sort of thing that could only go into a BLOB. > DB2 supports table functions and wrappers. Table functions are read-only > though. A nickname on a wrapper supports full DML. Once again, what does this mean? -- "C'est pas parce qu'on n'a rien ''' dire qu'il faut fermer sa gueule" - Coluche

Another word for schema would be layout. Talking of schema evolution commonly means talking about changes to the layout of the tables (such as columns, datatypes etc). Online schema evolution would then be changing the layout of the tables without affecting accessibility. onstat => db2pd What you do with a virtual table interface DB2 does with Wrappers then. There are predefined wrappers, but you can also roll your own. Wrappers can wrap relational as well as non relational data such as Blast. I found this presentation on the web. May be helpful: http://www.lightyr.com/presentations/DB2Info_Integrator_SFDB2UserGrp10-14-03.pdf The basic idea is three staged: A "server" defintion hooks you up with the source system A "wrapper" definition defined the interface to a specific kind of object on the server A "nickname" instantiates a remote object from the server as a local table using the wrapper. Cheers Serge -- Serge Rielau DB2 SQL Compiler Development IBM Toronto Lab