DF14: Faster SOQL? Yes, Please

By John Tan (@johntansfdc) and Chris Peterson (@ca_peterson) at Dreamforce '14

This presentation was recorded and can be watched at http://dreamforce.vidyard.com/watch/4MfH1Hne0EV76ChTjSWfbQ

Transcript

1. Faster SOQL? Yes, please! John Tan Architect Evangelist, salesforce.com @johntansfdc Chris Peterson Force.com MVP Senior Developer, FinancialForce.com @ca_peterson
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3. Your company uses Salesforce/ Force.com …
4. You are a developer or architect …
5. You want to ensure your queries perform …
6. Debug Logs
7. Agenda 1.  Selective Filters 2.  Query Plan Tool Demos
8. Query Plan Tool in Developer Console
9. John Tan Architect Evangelist, salesforce.com
10. Developers Community http://bit.ly/Arch_Core_Resources
11. Cheat sheet http://bit.ly/Query_Cheat_Sheet
12. Chris Peterson Force.com MVP Senior Developer, FinancialForce.com
13. Query Plan API http://bit.ly/Query_Plan_API
14. Selective filters
15. What is the Force.com query optimizer? Generates the most efficient query based on: •  Statistics •  Indexes / Skinny Tables •  Sharing
16. Basic Algorithm •  Pre-query engine •  Chooses the most selective filter from the WHERE clause •  Determine the best leading table/index to drive the query Query optimizer will make the best choice best on the filters in your query.
17. Best Practice: One+ Selective Filter Per SOQL statement
18. Selective Filters: Four Components 1.  Filters - add filters to reduce data 2.  Operators - avoid 2 inefficient filter operators 3.  Thresholds – ensure filter meets selectivity threshold 4.  Index Creation - index the filter field
19. Fields that often make good filters •  Date fields •  Picklists •  Fields with wide and even distribution of values
20. Non-Deterministic Formula Fields Aren’t Good Filters •  Can’t index •  For example: –  References related object –  CASE(MyUser__r.UserType__c,1,”Gold”,”Silver”) –  Create separate field and use trigger to populate Force.com SOQL Best Practices: Nulls and Formula Fields
21. Avoid negative operators Query for reciprocal values instead ✖ Status != 'closed' ✔ Status IN ('open', 'in progress')
22. Avoid filters with a leading % wildcard CONTAINS or LIKE ‘%searchstring%’ ✖ CONTAINS ('district') / LIKE '%district%' ✔ STARTS WITH ('district') / LIKE 'district%'
23. Standard Index Selectivity Threshold A standard index is selective when it returns: •  < 30% of the first 1 million records •  < 15% of returned records after the first 1 million records •  No more than 1 million total records
24. Standard Index Selectivity Threshold For 750,000 Account records •  < 30% of the first 1 million records •  750,000 x .30 = 225,000
25. Standard Index Selectivity Threshold For 3,500,000 Account records •  < 30% of the first 1 million records •  < 15% of returned records after the first 1 million records •  (1,000,000 x .30) + (2,500,000 x .15) = 675,000
26. Standard Index Selectivity Threshold Over 5,600,000 Account records •  No more than 1 million records •  1,000,000
27. Custom Index Selectivity Threshold A custom index is selective when it returns: •  < 10% of the first million records •  < 5% of returned records after the first million records •  No more than 333,333 records
28. Standard Fields With Indexes •  Id •  Name •  OwnerId •  CreatedDate •  SystemModstamp •  RecordType •  Master-detail fields •  Lookup fields
29. Custom Indexes •  Discover common filter conditions •  Determine selective fields in those conditions •  Request custom indexes
30. A filter condition is selective when … … it uses an optimizable operator … it meets the selectivity threshold … selective fields have indexes
31. Demos
32. Query Plan Tool in Developer Console
33. Optimizations
34. AND conditions WHERE FirstName__c = 'Jane' AND LastName__c = 'Doe' AND City__c = 'San Francisco' Step 1 – Allow each index to still be considered if they return < 2X selectivity threshold Step 2 – INTERSECTION of all indexes must meet *selectivity threshold Step 3 – Use composite index join to drive query *If all indexes are standard indexes, use standard index selectivity threshold. Otherwise, use the custom index selectivity threshold
35. AND conditions Composite index join – MyUser object 100,000 total records
36. AND conditions Composite index join – MyUser object 100,000 total records
37. 2-column index For this simple example, it makes more sense to have Customer Support create a 2-column index.
38. OR conditions WHERE FirstName__c = 'Jane' OR LastName__c = 'Doe' OR City__c = 'San Francisco'! Step 1 – Each field must be indexed and meet selectivity threshold Step 2 – UNION of all the indexes must meet *selectivity threshold Step 3 – Use union to drive query *If all indexes are standard indexes, use standard index selectivity threshold. Otherwise, use the custom index selectivity threshold
39. OR conditions Union - MyUser object 100,000 total records
40. Sort Optimization ORDER BY CreatedDate LIMIT 100 Step 1 – ORDER BY on date or number field Step 2 – Bound results with LIMIT clause * May have to add CreatedDate <> null explicitly to WHERE clause
41. Summary
42. Summary •  Query optimizer generates the most efficient query possible •  1+ selective filters per SOQL statement •  Test with > 10K records
43. Links
44. Links •  Architect Core Resources – http://bit.ly/Arch_Core_Resources •  Query cheat sheet – http://bit.ly/Query_Cheat_Sheet •  Query Plan API wiki - http://bit.ly/Query_Plan_API •  Sort Optimization blog - http://bit.ly/Sort_Optimization
46. Q & A