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| Case | Query one out of many using descendant cps path | Query one out of many using absolute cps path |
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| Query | //openroadm-device[@device-id="C201-7-1A-14"] | /openroadm-devices/openroadm-device[@device-id="C201-7-1A-19"] |
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Time complexity of | O(N) | O(N) |
| Time complexity of proposed solution | O(N) | O(1) |
| Comments | The use of LIKE 'openroadm-device[%' in the query to match candidates | The use of the absolute path narrows the search space to only direct children of /openroadm-devices - for 3000 devices, we only need to scan 3000 fragments instead of 250k. |
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Note: if we wish to avoid creating additional database fields, using list/container name field would offer the best balance of performance, e.g.
| id | parent_id | anchor_id | xpath | container |
|---|---|---|---|---|
| 1 | NULL | 3 | /bookstore | bookstore |
| 2 | 1 | 3 | /bookstore/categories[@code='1'] | categories |
| 3 | 2 | 3 | /bookstore/categories[@code='1']/books[@title='Matilda'] | books |
| 4 | 2 | 3 | /bookstore/categories[@code='1']/books[@title='The Gruffalo'] | books |
In this case, attributes for any list element path component would need to be looked up (so it would no longer be index-only). My suspicion is that this would have better general performance than using xpath_component alone, but testing is needed to verify.
Work Breakdown for Implementation
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