Difference between revisions of "Database structure"
From PhotoVoltaic Logger new generation
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== pvlng_reading_num / pvlng_reading_str == | == pvlng_reading_num / pvlng_reading_str == | ||
| − | [[File:DBTableReadingNum.png]][[File:DBTableReadingStr.png]] | + | [[File:DBTableReadingNum.png]] [[File:DBTableReadingStr.png]] |
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| + | The timestamps are '''not''' stored as "normal" timestamp type, but as '''unsigned integer'''. | ||
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| + | It was tested and have significant more performance for consolidated data readouts. | ||
Revision as of 15:33, 2 March 2014
Contents
Abstract
pvlng_type
pvlng_channel
pvlng_tree
The channel tree is organized in a nested set structure.
The nested set model is a particular technique for representing nested sets (also known as trees or hierarchies) in relational databases. -- Wikipedia:Nested set model
More theory about nested sets.
pvlng_reading_num / pvlng_reading_str
The timestamps are not stored as "normal" timestamp type, but as unsigned integer.
It was tested and have significant more performance for consolidated data readouts.
