com.bigdata.mdi.package.html Maven / Gradle / Ivy
Metadata Index (MDI) and Range Partitioned Indices
This package provides a metadata index and range partitioned indices
managed by that metadata index. Each index partition is a fused view
of one or more resources. Those resources include a mutable BTree
hosted on a Journal and read-only index segments. Reads are against
the fused view. Writes are against the mutable BTree.
Periodically the mutable BTree, or the journal on which it resides,
will fill up and a merge task will generate a read-only index segment.
When a full merge (aka compacting merge) is applied, the result is a
single index segment containing all data for the index
partition. Depending on the history policy, some historical data
versions and delete markers may be purged from the view meaning that
some historical commit states will no longer be readable.
Index partitions are created by a split operation and merged
by a join operation. These operations create new index
partitions having different separator keys. Split and join operations
are not effective until the metadata index has been updated.