physical operator for CSB index completed.
Logical CSB index build iterator completed.
Copy before changing the CSBNode class into non-template
Add index manager to maintain the whole set of CSB+ tree indexes.
Includeing the initialize in Environment
Add index name and id to IndexManager.
Supporting CSB+ index range query.
Revise the bug in calculating the block offset when build the index.
Add physical iterator "index_scan"
add getOperatorType to all LogicalOperator. Copy before changing the
indexScan schema and add LogicalIndexScan operator.
Changing the index_query_result structure from vector to map. Override
rangeQuery function to support (), (], [), [] query.