Personal tools

Database structure

From PhotoVoltaic Logger new generation

Revision as of 16:33, 2 March 2014 by KKoPV (talk | contribs) (pvlng_reading_num / pvlng_reading_str)
Jump to: navigation, search

Abstract

pvlng_type

DBTableType.png

pvlng_channel

DBTableChannel.png

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.

DBTableTree.png

pvlng_reading_num / pvlng_reading_str

DBTableReadingNum.png DBTableReadingStr.png

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.