If you're a ServiceNow Administrator or Developer, you need to ensure queries to your tables are performant, and for that you need table indexes. This video is the second and last part of a series providing an overview of indexes. Part 1 introduced indexes and included a simple demonstration of how they can dramatically improve query times. In Part 2, we take a closer look at the Slow Query log, Explain Plans, and composite (multi-column) indexes.
Links to further learning:
• Indexes – Quick Guide I
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• What index should it be? - OR - Slow Queries explained (ServiceNow Community)
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• Improve performance: database indexes and slow queries (ServiceNow Community)
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• Explain plan (MariaDB Documentation)
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• Composite indexes (MariaDB Documentation)
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Timecodes
0:00 Intro & reasons you need indexes
1:35 Slow Queries log and high-impact queries
5:06 Explain Plans
6:35 Composite indexes
7:28 Test 1 – Query two fields, two equality operators
8:00 Test 2 – Query three fields, three equality operators
8:37 Test 3 – Query one field, one equality operators, no leftmost prefix
9:37 Test 4 – Query two fields, two equality operators, different order
10:10 Test 5 – Query two fields, one range, one equality operator
11:43 Pro-tip – Get an explain plan for any (not just slow) queries
13:59 Explain plan for composite indexes
15:14 Conclusion
