Option --optimize-interval is confusive

[Felixoid]

It tells, that The active partitions won't be optimized more than once per this interval, seconds, but:

• The active partition won't be merged unless it was modified during the period
• It's not seconds, but the duration. The same for loop-interval
• There's a mistake in query https://github.com/innogames/graphite-ch-optimizer/blob/master/graphite-ch-optimizer.go#L65. It doesn't make sense to compare @Interval option with maximum age for the current retention. The line should be deleted, then all parts > 1 will proceed.

[lexx-bright]

@Felixoid, to comply with the statement

-- modified_at < (now() - @Interval): we want to merge active partitions only once per interval, -- so do not touch partitions with current active inserts

shouldn't p.modification_time be maxed?

[Felixoid]

If it would be max, we won't touch partitions with rare inserts. The idea is having them merged eventually too, but at most once per interval.