Defines the allowed range of log(size) for each level. A level is computed by taking the max segment log size, minuse LEVEL_LOG_SPAN, and finding all segments falling within that range.
Checks if any merges are now necessary and returns a {@link MergePolicy.MergeSpecification} if so. A merge is necessary when there are more than {@link #setMergeFactor} segments at a given level. When multiple levels have too many segments, this method will return multiple merges, allowing the {@link MergeScheduler} to use concurrency.
Determines the largest segment (measured by document count) that may be merged with other segments. Small values (e.g., less than 10,000) are best for interactive indexing, as this limits the length of pauses while indexing to a few seconds. Larger values are best for batched indexing and speedier searches.
The default value is {@link Integer#MAX_VALUE}.
The default merge policy ({@link LogByteSizeMergePolicy}) also allows you to set this limit by net size (in MB) of the segment, using {@link LogByteSizeMergePolicy#setMaxMergeMB}.