As a result, understanding how a query works in Microsoft SQL Server is a highly valuable skill.
Most real-time systems use SQL to manage the incredible amount of data they work with on a daily basis. SQL has been anointed the world’s third most powerful Data Science, Machine Learning software programming language. Salesforce do not process the records in the same order.In this article, we’ll walk-through the concept of the SQL Order by clause and understand how the SQL engine works with the ordering result in a query. So, when you pass the records to theĮxecute in an order, and when it is divided into multiple batches, When we slice the records into batches, the order in which it is "Batches of records are not guaranteed to execute in the order they I'd have to do a bit more experimenting to determine exactly what they're doing on the back-end. However, the response from sfdc is (as I read it) that you won't necessarily receive batches in the exact order in which they appear in the complete result set. Then I could just iterate over the Contacts and rank them. My thought was to start the batch process by querying the 30k records, using the ORDER BY clause to sort them. Restating the issue: Suppose I have 30,000 Contacts and I want to rank them by a certain field in a batch process. I opened a Case with SFDC Support and I learned what the problem is. It's as if the query takes the first 10,000 Contacts it finds, sorts them, and provides them for processing, and then takes the other 2,000, sorts them, and provides them for processing.Ĭan you provide some insight here? Is it not valid to sort an entire recordset in a batch query? Or is there a way to do it? Said another way, you would think that the final item in the list of 10,000 would be larger than the first item in the list of 2,000, but this is not the case.
BUT, if I put the two lists together, the list of 12,000 is not sorted correctly. And that the other 2,000 records are sorted correctly and processed in the correct order. Instead, I show that 10,000 (exactly) records are sorted correctly and processed in the correct order. It appears that the 12,000 Contacts aren't queried as a single group. I've done a lot of logging/debugging to determine what is going wrong. However when reviewing the results, there were incorrect rankings. My process ranks these records based on the sort order (record with the highest value in the sorted number field gets a rank of 1, record with the second highest value gets a rank of 2, etc etc). I have a Batch Apex process that queries about 12,000 Contacts - sorted (descending) by a number field.
0 kommentar(er)
