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Posted by --CELKO-- on 12/03/06 18:06
>> 1. I use an ETL tool, it creates the DDL, I just copied and pasted. <<
There are some open source "pretty printers" for SQL, which would be
good to have around the shop. So many of the packages generate code
for a compiler to use and not for a human being to read.
>> 3. This is a data warehouse, not an operational system. <<
Can you get a DW package, which would handle this stuff much better
than an SQL aimed at OLTP? Or will the boss scream about the budget?
DW is a really diffrent game and that explains some of your code
decisions.
>>. the business keys for the table im trying to update is ADMREP_ID, SESSION_ID and
SESSION_DAY. I concatinate them into a single field [sic] so I have a
unique key. <<
Here we are back to the conceptual problems. Columns are not fields,
nothing like them at all. The concatenation is a bad idea and you
should use a three-column key instead.
>> 6. Yes, it is a Y/N field. Tables that are slowly changing dimensions have start_date, end_date, update_date and curr_ind. Y is the current record [sic] as it is in the operational system. <<
You can get that fact from the dates, can't you? There should be no
need for flags in a DW. Also, that implies that the DW is getting live
feeds from operations. Is that true?
>> 7. This is an area that I would like to have more control within the ETL tool. it looks at the data and determines what type to create. Of course I could create the tables ahead of time, and not let the tool create them for me. <<
That sounds like the answer. The cost of casting, the chance for
errors, etc. is just too much. Can the ETL tool load the tables
without having to immediately re-index them as it goes?
>> Thanks for the constructive suggestions Celko. I've learned a lot on how I might change the UPdate to run faster...no wait a minute, you just finished berating me and came just sort of calling me stupid... Never mind. <<
LOL!!
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