This is chart from the cheapest E95 station in Dārzciema iela 127. This one automatically takes data from my database where data is checked and updated every 4 hours.
1)Updating database - the new records are added to database only if they are different from previous, last data. Such approach allows to save database space.
2)But in the same time the data reconstructing is needed when the data is taken out of database. For example, if I have no value changes between five days, I would not interpolate the values between records, but in all these days between I make the value as it was in the day before this no-value gap.
Link to the source code.