Drew Wutka
DWUTKA at Marlow.com
Thu Jan 14 18:41:29 CST 2010
Ugh.... Drew -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Rocky Smolin Sent: Thursday, January 14, 2010 6:16 PM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Fastest Way Yeah, the doctor says the first four fields could be identical with different results. R -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Drew Wutka Sent: Thursday, January 14, 2010 3:58 PM To: Access Developers discussion and problem solving Subject: Re: [AccessD] Fastest Way Interesting problem here. The quirk is going to be that last field. Can you really have two records with the first four fields (including a date and time) with different 'Test Result Text'. I would think you would end up with a different value in the date and/or time fields for new test results. So, ASSUMING that the Test Result is irrelevant to the uniqueness of a record, I would recommend loading a collection with the first four fields as the 'key' to each item in the collection. I would create a separate table with these 'keys' (for faster loading). Put the fields together with a delimiter like :. This would create a one line string with a unique identifier for each record. For example, if the first record is 1, 1 , 1-29-2004,1214, you're ID field would be 1:1:01292004:1214. Adding that to a collection would put all of the currently imported records into memory in a handy little tiny string, that you can query with an 'error if it doesn't exist' function, creating a pretty instantaneous check if a record has been imported. However, if that fifth field can be different with the first four fields the same, this would probably be a bad approach because that field could jump the amount of memory being used quite a bit! Drew -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Rocky Smolin Sent: Thursday, January 14, 2010 9:01 AM To: 'Access Developers discussion and problem solving' Subject: [AccessD] Fastest Way Dear List: I have a medical database into which lab tests are imported from a spreadsheet (exported from a mainframe medical records database at a big hospital). Front and back ends are Access 2003. The table tblPatientTest has (in addition to the autonumber PK) 5 fields: Patient ID (FK) Test ID (FK) Test Date as Date/Time (indexed duplicates OK) Test Time as long integer - value between 0000 and 2399 (indexed duplicates OK) Test Result - Text (indexed duplicates OK) I'm using DAO to add the records to the table. Imports will happen monthly and the number of records will be on the order of 10,000-100,000 with mean probably around 20k-40k. As the tests are imported I want to check the table to see if the test record is already present by finding a record which matches all 5 fields to prevent duplicate test records from being entered. Since the import will take place monthly, import time is not super critical but before importing the user will run an Error Report which does all the error checking that the import does without actually doing the import. The user then resolves the errors and when the Error report is clean, will run the import. So the error report may have to be run more than once to clean the data. It is possible that the user will try to import a spreadsheet that has already been imported. So it's important to screen for duplicates. So I want to find the fastest method of checking for duplicate. The obvious thing is rs.FindFirst on all five fields, but I'm thinking that may take a really long time. Another possibility would be to create a temporary table in the front end or external mdb, and create indexed records by concatenating all five fields and checking for dups on that table. Probably faster than the first method but creating the table could take a lot of time when the Patient Test table has a few hundred thousand records in it. Or I could add the field of concatenated fields to the table itself as the records are added, indexed and maintain that. Or some other method that I haven't thought of or don't know about. Any advice welcome. MTIA Rocky Smolin Beach Access Software 858-259-4334 www.e-z-mrp.com <http://www.e-z-mrp.com/> www.bchacc.com <http://www.bchacc.com/> The information contained in this transmission is intended only for the person or entity to which it is addressed and may contain II-VI Proprietary and/or II-VI Business Sensitive material. If you are not the intended recipient, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. You are notified that any review, retransmission, copying, disclosure, dissemination, or other use of, or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com The information contained in this transmission is intended only for the person or entity to which it is addressed and may contain II-VI Proprietary and/or II-VI Business Sensitive material. If you are not the intended recipient, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. You are notified that any review, retransmission, copying, disclosure, dissemination, or other use of, or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited.